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Alteration of functional connectivity in patients with Alzheimer’s disease revealed by resting-state functional magnetic resonance imaging 预览
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作者 Jie Zhao Yu-Hang Du +2 位作者 Xue-Tong Ding Xue-Hu Wang Guo-Zun Men 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第2期285-292,共8页
The main symptom of patients with Alzheimer’s disease is cognitive dysfunction. Alzheimer’s disease is mainly diagnosed based on changes in brain structure. Functional connectivity reflects the synchrony of function... The main symptom of patients with Alzheimer’s disease is cognitive dysfunction. Alzheimer’s disease is mainly diagnosed based on changes in brain structure. Functional connectivity reflects the synchrony of functional activities between non-adjacent brain regions, and changes in functional connectivity appear earlier than those in brain structure. In this study, we detected resting-state functional connectivity changes in patients with Alzheimer’s disease to provide reference evidence for disease prediction. Functional magnetic resonance imaging data from patients with Alzheimer’s disease were used to show whether particular white and gray matter areas had certain functional connectivity patterns and if these patterns changed with disease severity. In nine white and corresponding gray matter regions, correlations of normal cognition, early mild cognitive impairment, and late mild cognitive impairment with blood oxygen level-dependent signal time series were detected. Average correlation coefficient analysis indicated functional connectivity patterns between white and gray matter in the resting state of patients with Alzheimer’s disease. Functional connectivity pattern variation correlated with disease severity, with some regions having relatively strong or weak correlations. We found that the correlation coefficients of five regions were 0.3–0.5 in patients with normal cognition and 0–0.2 in those developing Alzheimer’s disease. Moreover, in the other four regions, the range increased to 0.45–0.7 with increasing cognitive impairment. In some white and gray matter areas, there were specific connectivity patterns. Changes in regional white and gray matter connectivity patterns may be used to predict Alzheimer’s disease;however, detailed information on specific connectivity patterns is needed. All study data were obtained from the Alzheimer’s Disease Neuroimaging Initiative Library of the Image and Data Archive Database. 展开更多
关键词 Alzheimer's disease blood oxygen level-dependent signal correlation coefficient FUNCTIONAL connectivity pattern FUNCTIONAL magnetic resonance imaging GRAY MATTER RESTING state white MATTER
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Differential neuronal reprogramming induced by NeuroD1 from astrocytes in grey matter versus white matter 预览
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作者 Min-Hui Liu Wen Li +3 位作者 Jia-Jun Zheng Yu-Ge Xu Qing He Gong Chen 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第2期342-351,共10页
A new technology called in vivo glia-to-neuron conversion has emerged in recent years as a promising next generation therapy for neural regeneration and repair. This is achieved through reprogramming endogenous glial ... A new technology called in vivo glia-to-neuron conversion has emerged in recent years as a promising next generation therapy for neural regeneration and repair. This is achieved through reprogramming endogenous glial cells into neurons in the central nervous system through ectopically expressing neural transcriptional factors in glial cells. Previous studies have been focusing on glial cells in the grey matter such as the cortex and striatum, but whether glial cells in the white matter can be reprogrammed or not is unknown. To address this fundamental question, we express NeuroD1 in the astrocytes of both grey matter(cortex and striatum) and white matter(corpus callosum) to investigate the conversion efficiency, neuronal subtypes, and electrophysiological features of the converted neurons. We discover that NeuroD1 can efficiently reprogram the astrocytes in the grey matter into functional neurons, but the astrocytes in the white matter are much resistant to neuronal reprogramming. The converted neurons from cortical and striatal astrocytes are composed of both glutamatergic and GABAergic neurons, capable of firing action potentials and having spontaneous synaptic activities. In contrast, the few astrocyte-converted neurons in the white matter are rather immature with rare synaptic events. These results provide novel insights into the differential reprogramming capability between the astrocytes in the grey matter versus the white matter, and highlight the impact of regional astrocytes as well as microenvironment on the outcome of glia-toneuron conversion. Since human brain has large volume of white matter, this study will provide important guidance for future development of in vivo glia-to-neuron conversion technology into potential clinical therapies. Experimental protocols in this study were approved by the Laboratory Animal Ethics Committee of Jinan University(approval No. IACUC-20180321-03) on March 21, 2018. 展开更多
关键词 ASTROCYTE CONVERSION efficiency corpus callosum cortex grey MATTER in vivo cell CONVERSION NeuroD1 neuron REPROGRAMMING STRIATUM white MATTER
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Trophic factors are essential for the survival of grafted oligodendrocyte progenitors and for neuroprotection after perinatal excitotoxicity 预览
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作者 Megumi Hirose-Ikeda Brian Chu +5 位作者 Paul Zhao Omar Akil Elida Escalante Laurent Vergnes Carlos Cepeda Araceli Espinosa-Jeffrey 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第3期557-568,共12页
The consequences of neonatal white matter injury are devastating and represent a major societal problem as currently there is no cure.Prematurity,low weight birth and maternal pre-natal infection are the most frequent... The consequences of neonatal white matter injury are devastating and represent a major societal problem as currently there is no cure.Prematurity,low weight birth and maternal pre-natal infection are the most frequent causes of acquired myelin deficiency in the human neonate leading to cerebral palsy and cognitive impairment.In the developing brain,oligodendrocyte(OL)maturation occurs perinatally,and immature OLs are particularly vulnerable.Cell replacement therapy is often considered a viable option to replace progenitors that die due to glutamate excitotoxicity.We previously reported directed specification and mobilization of endogenous committed and uncommitted neural progenitors by the combination of transferrin and insulin growth factor 1(TSC1).Here,considering cell replacement and integration as therapeutic goals,we examined if OL progenitors(OLPs)grafted into the brain parenchyma of mice that were subjected to an excitotoxic insult could rescue white matter injury.For that purpose,we used a well-established model of glutamate excitotoxic injury.Four-day-old mice received a single intraparenchymal injection of the glutamate receptor agonist N-methyl-D-aspartate alone or in conjunction with TSC1 in the presence or absence of OLPs grafted into the brain parenchyma.Energetics and expression of stress proteins and OL developmental specific markers were examined.A comparison of the proteomic profile per treatment was also ascertained.We found that OLPs did not survive in the excitotoxic environment when grafted alone.In contrast,when combined with TSC1,survival and integration of grafted OLPs was observed.Further,energy metabolism in OLPs was significantly increased by N-methyl-D-aspartate and modulated by TSC1.The proteomic profile after the various treatments showed elevated ubiquitination and stress/heat shock protein 90 in response to N-methyl-D-aspartate.These changes were reversed in the presence of TSC1 and ubiquitination was decreased.The results obtained in this pre-clinical study indicate that the use 展开更多
关键词 MYELIN regeneration MYELINATION OLIGODENDROCYTES periventricular leukomalacia premature birth proteomics TROPHIC factors white matter injury
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Investigating the coagulation of non-proteinaceous algal organic matter: Optimizing coagulation performance and identification of removal mechanisms
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作者 Jana Naceradska Katerina Novotna +2 位作者 Lenka Cermakova Tomas Cajthaml Martin Pivokonsky 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第5期25-34,共10页
The removal of algal organic matter(AOM) is a growing concern for the water treatment industry worldwide. The current study investigates coagulation of non-proteinaceous AOM(AOM after protein separation), which has be... The removal of algal organic matter(AOM) is a growing concern for the water treatment industry worldwide. The current study investigates coagulation of non-proteinaceous AOM(AOM after protein separation), which has been minimally explored compared with proteinaceous fractions. Jar tests with either aluminum sulphate(alum) or polyaluminium chloride(PACl) were performed at doses of 0.2–3.0 mg Al per 1 mg of dissolved organic carbon in the p H range 3.0–10.5. Additionally, non-proteinaceous matter was characterized in terms of charge, molecular weight and carbohydrate content to assess the treatability of its different fractions. Results showed that only up to 25% of non-proteinaceous AOM can be removed by coagulation under optimized conditions. The optimal coagulation p H(6.6–8.0 for alum and 7.5–9.0 for PACl) and low surface charge of the removed fraction indicated that the prevailing coagulation mechanism was adsorption of non-proteinaceous matter onto aluminum hydroxide precipitates. The lowest residual Al concentrations were achieved in very narrow p H ranges, especially in the case of PACl. High-molecular weight saccharidelike organics were amenable to coagulation compared to low-molecular weight(< 3 k Da)substances. Their high content in non-proteinaceous matter(about 67%) was the reason for its low removal. Comparison with our previous studies implies that proteinaceous and nonproteinaceous matter is coagulated under different conditions due to the employment of diverse coagulation mechanisms. The study suggests that further research should focus on the removal of low-molecular weight AOM, reluctant to coagulate, with other treatment processes to minimize its detrimental effect on water safety. 展开更多
关键词 ALGAL organic MATTER CHLORELLA vulgaris Coagulation FLOCCULATION Non-proteinaceous MATTER Water treatment
The next-generation sphingosine-1 receptor modulator BAF312(siponimod) improves cortical network functionality in focal autoimmune encephalomyelitis 预览
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作者 Petra Hundehege Manuela Cerina +13 位作者 Susann Eichler Christian Thomas Alexander M. Herrmann Kerstin Goel Thomas Müntefering Juncal Fernandez-Orth Stefanie Bock Venu Narayanan Thomas Budde Erwin-Josef Speckmann Heinz Wiendl Anna Schubart Tobias Ruck Sven G. Meuth 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第11期1950-1960,共11页
Autoimmune diseases of the central nervous system(CNS) like multiple sclerosis(MS) are characterized by inflammation and demyelinated lesions in white and grey matter regions. While inflammation is present at all stag... Autoimmune diseases of the central nervous system(CNS) like multiple sclerosis(MS) are characterized by inflammation and demyelinated lesions in white and grey matter regions. While inflammation is present at all stages of MS, it is more pronounced in the relapsing forms of the disease, whereas progressive MS(PMS) shows significant neuroaxonal damage and grey and white matter atrophy. Hence, disease-modifying treatments beneficial in patients with relapsing MS have limited success in PMS. BAF312(siponimod) is a novel sphingosine-1-phosphate receptor modulator shown to delay progression in PMS. Besides reducing inflammation by sequestering lymphocytes in lymphoid tissues, BAF312 crosses the blood-brain barrier and binds its receptors on neurons, astrocytes and oligodendrocytes. To evaluate potential direct neuroprotective effects, BAF312 was systemically or locally administered in the CNS of experimental autoimmune encephalomyelitis mice with distinct grey-and white-matter lesions(focal experimental autoimmune encephalomyelitis using an osmotic mini-pump). Ex-vivo flow cytometry revealed that systemic but not local BAF312 administration lowered immune cell infiltration in animals with both grey and white matter lesions. Ex-vivo voltage-sensitive dye imaging of acute brain slices revealed an altered spatio-temporal pattern of activation in the lesioned cortex compared to controls in response to electrical stimulation of incoming white-matter fiber tracts. Here, BAF312 administration showed partial restore of cortical neuronal circuit function. The data suggest that BAF312 exerts a neuroprotective effect after crossing the blood-brain barrier independently of peripheral effects on immune cells. Experiments were carried out in accordance with German and EU animal protection law and approved by local authorities(Landesamt für Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen;87-51.04.2010.A331) on December 28, 2010. 展开更多
关键词 multiple SCLEROSIS FOCAL experimental autoimmune ENCEPHALOMYELITIS CORTICAL grey MATTER white MATTER BAF312 neuroaxonal damage neuroprotection
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Informational Model of Consciousness: From Philosophic Concepts to an Information Science of Consciousness 预览
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作者 Florin Gaiseanu 《哲学研究:英文版》 2019年第4期181-196,共16页
On the long and well-worn road of many, but justifiable attempts of human to discover his origin, his trajectory as a species, and a suitable understanding consciousness, his system allowing the connection to the envi... On the long and well-worn road of many, but justifiable attempts of human to discover his origin, his trajectory as a species, and a suitable understanding consciousness, his system allowing the connection to the environment and to his own organism, the concepts and models of philosophy enunciated or experienced by millennia, meet today with modern science concepts of physics and of science of information. Based on recent discoveries of quantum physics and astrophysics, revealing a new understanding of our environment and starting from some philosophical concepts on information of matter and of living structures, this work discusses the dynamics of information within the frame of the Informational Model of Consciousness as an informational system of the human body, connected both to the environment and to the body itself, to control the adaptation for survival. It is shown that consciousness is actually an informational projection in the mind of seven informational subsystems, three of which forming the operative system of consciousness for the short-term adaptation, and other three forming the programmed operating system, dedicated to the maintenance of body and to the long-term survival of species, showing various inputs and outputs of information. The seventh subsystem is the information pole, connecting the organism with the external information, especially related to the extra-sensorial properties of the mind, the human body appearing as a bipolar info-matter structure, managed by the brain. The received information is progressively integrated into the informational system of the organism, which absorbs and emanates information as a reactive system for adaptation, able to operate both with matter-related (codified) and non-matter related (virtual) information. As both connections with external and internal environment (body itself) can be described in terms of information, this model opens the gate to investigate consciousness by means of the tools of the information science, offering also answers to the phi 展开更多
关键词 CONSCIOUSNESS informational model of CONSCIOUSNESS dynamics of INFORMATION MATTER integration of INFORMATION INFORMATION science PHILOSOPHICAL concepts matter-related INFORMATION information-assisted LIVING
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Simplified dark matter models with loop effects in direct detection and the constraints from indirect detection and collider search
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作者 李佟 吴培文 《中国物理C:英文版》 SCIE CAS CSCD 2019年第11期21-29,共9页
We reexamine the simplified dark matter(DM) models with fermionic DM particle and spin-0 mediator.The DM-nucleon scattering cross sections in these models are low-momentum suppressed at tree-level,but receive sizable ... We reexamine the simplified dark matter(DM) models with fermionic DM particle and spin-0 mediator.The DM-nucleon scattering cross sections in these models are low-momentum suppressed at tree-level,but receive sizable loop-induced spin-independent contribution.We perform one-loop calculations for scalar-type and twist-2 DM-quark operators,and complete two-loop calculations for scalar-type DM-gluon operator.Analyzing the looplevel contribution from new operators,we find that future direct detection experiments could be sensitive to a fraction of the parameter space.The indirect detection and collider search also provide complementary constraints on these models. 展开更多
关键词 direct dark matter detection loop effect simplified dark matter models
Characterization of dissolved organic matter and membrane fouling in coagulation-ultrafiltration process treating micro-polluted surface water
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作者 Fan Bu Baoyu Gao +2 位作者 Qinyan Yue Xue Shen Wenyu Wang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第1期318-324,共7页
Coagulation-ultrafiltration (C-UF)is widely used for surface water treatment.With the removal of pollutants,the characteristics of organic matter change and affect the final treatment efficiency and the development of... Coagulation-ultrafiltration (C-UF)is widely used for surface water treatment.With the removal of pollutants,the characteristics of organic matter change and affect the final treatment efficiency and the development of membrane fouling.In this study,we built a dynamic C-UF set-up to carry out the treatment of micro-polluted surface water,to investigate the characteristics of dissolved organic matter from different units.The influences of poly aluminum chloride and poly dimethyldiallylammonium chloride (PDMDAAC)on removal efficiency and membrane fouling were also investigated.Results showed that the dosage of PDMDAAC evidently increased the UV254 and dissolved organic carbon removal efficiencies, and thereby alleviated membrane fouling in the C-UF process.Most hydrophobic bases (HOB) and hydrophobic neutral fractions could be removed by coagulation.Similarly,UF was good at removing HoB compared to hydrophilic substances (HIS)and hydrophobic acid (HoA) fractions.HiS and HoA fractions with low molecule weight accumulated on the surface of the membrane,causing the increase of transmembrane pressure (TMP).Membrane fouling was mainly caused by a removable cake layer,and mechanical cleaning was an efficient way to decrease the TMP. 展开更多
关键词 COAGULATION ULTRAFILTRATION Dissolved organic MATTER Membrane FOULING
In-medium NN→NΔ cross section and its dependence on effective Lagrange parameters in isospin-asymmetric nuclear matter
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作者 崔莹 张英逊 李祝霞 《中国物理C:英文版》 SCIE CAS CSCD 2019年第2期115-124,共10页
The in-medium NN→N△ cross sections and its differential cross sections in isospin asymmetric nuclear medium are investigated in the framework of the one-boson exchange model by including isovector mesons, i.e., δan... The in-medium NN→N△ cross sections and its differential cross sections in isospin asymmetric nuclear medium are investigated in the framework of the one-boson exchange model by including isovector mesons, i.e., δand p mesons. Our results show that the in-medium NN→N△ cross sections are suppressed when the density increases, and the differential cross sections become isotropic with an increase in the density around the △ threshold energy. The isospin splitting on the medium correction factor, R =σNN→N△*/σNN→N△free is observed for different channels of NN→N△, especially around the threshold energy for all the effective Lagrangian parameters. By analyzing the selected effective Lagrangian parameters, our results show that the larger effective mass is, the weaker medium correction R is. 展开更多
关键词 in-medium NN→NΔcross SECTION isospin-asymmetric nuclear matter Lagrangian PARAMETERS differential CROSS SECTION
Nearby dark matter subhalo that accounts for the DAMPE excess
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作者 赵熠 毕效军 +1 位作者 林苏杰 殷鹏飞 《中国物理C:英文版》 SCIE CAS CSCD 2019年第8期124-129,共6页
The precise spectrum of electrons and positrons at high energies plays an important role in understanding their origin. DArk Matter Particle Explorer has reported their first measurement of the e^+e^- spectrum from 25... The precise spectrum of electrons and positrons at high energies plays an important role in understanding their origin. DArk Matter Particle Explorer has reported their first measurement of the e^+e^- spectrum from 25 GeV to 4.6 TeV. This spectrum reveals a tentative peak at ~1.4 TeV, which requires a nearby source of e^+e^-. In this work, we study the properties of a large nearby dark matter subhalo that accouns for this spectral peak, such as its mass and distance from Earth, for different concentration models. We compare spectra of the sources in 3FGL with that from DM annihilation in the subhalo, and find ten candidates that have comparable gamma-ray spectra. However, according to the N-body simulation, the probability that such a large subhalo is close enough to Earth is less than 0.1%. 展开更多
关键词 DARK MATTER DAMPE
Observational constraints on running vacuum model
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作者 张进军 Chung-Chi Lee 耿朝强 《中国物理C:英文版》 SCIE CAS CSCD 2019年第2期132-137,共6页
We investigate the power spectra of the CMB temperature and matter density in the running vacuum model(RVM) with the time-dependent cosmological constant of A=3 vH2+ Λ0, where H is the Hubble parameter. In this model... We investigate the power spectra of the CMB temperature and matter density in the running vacuum model(RVM) with the time-dependent cosmological constant of A=3 vH2+ Λ0, where H is the Hubble parameter. In this model, dark energy decreases in time and decays to both matter and radiation. By using the Markov chain Monte Carlo method, we constrain the model parameter v as well as the cosmological observables. Explicitly, we obtain v ≤1.54× 10-4(68% confidence level) in the RVM with the best-fit χRVM2 =13968.8, which is slightly smaller thanχΛCDM2= 13969.8 in the ΛCDM model of v = 0. 展开更多
关键词 matter power SPECTRUM running VACUUM MODEL CMB temperature SPECTRUM COSMOLOGICAL CONSTANT
Vertical Distribution of Soil Pyrogenic Matter: A Review
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作者 Eleanor HOBLEY 《土壤圈:英文版》 SCIE CAS CSCD 2019年第2期137-149,共13页
Alteration of terrestrial biomass during fire produces pyrogenic matter, a large quantity of which is deposited on and may enter soils. The amount of annual burning around the globe implies greater production and stor... Alteration of terrestrial biomass during fire produces pyrogenic matter, a large quantity of which is deposited on and may enter soils. The amount of annual burning around the globe implies greater production and storage of carbon in soil pyrogenic organic matter(pyrOM) than is regularly found in investigations of soil pyrogenic matter. A portion of this unaccounted for pyrogenic material may be translocated to subsurface soil depths, which is frequently excluded from soil investigations, and the presence of subsoil charcoal helps to partially fill this pyrOM gap. In this paper, I discuss the mechanisms for vertical redistribution of pyrogenic matter in soils and develop conceptual models to describe the depth, particle size, and age distribution of pyrogenic matter resulting from different translocation mechanisms. Based on the relationships between pyrogenic matter turnover and translocation, the suitability of pyrogenic matter in soils as an indicator for soil processes is discussed. Deciphering the relationships between pyrogenic matter depth, particle size, and age distribution yields valuable insights into the dynamics of soil forming processes as well as soil pyrogenic matter turnover,which should therefore, be a focus of future studies. 展开更多
关键词 age BLACK carbon charcoal MOBILITY organic MATTER particle size SUBSOIL TRANSLOCATION
Nuclear matter and neutron star properties with the extendedNambu-Jona-Lasinio model
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作者 陈晏军 《中国物理C:英文版》 SCIE CAS CSCD 2019年第3期82-90,共9页
An extended Nambu-Jona-Lasinio(eNJL) model with nucleons as the degrees of freedom is used to investigate properties of nuclear matter and neutron stars(NSs),including the binding energy and symmetry energy of the nuc... An extended Nambu-Jona-Lasinio(eNJL) model with nucleons as the degrees of freedom is used to investigate properties of nuclear matter and neutron stars(NSs),including the binding energy and symmetry energy of the nuclear matter, the core-crust transition density, and mass-radius relation of NSs. The fourth-order symmetry energy at saturation density is also investigated. When the bulk properties of nuclear matter at saturation density are used to determine the model parameters, the double solutions of parameters are obtained for a given nuclear incompressibility. It is shown that the isovector-vector interaction has a significant influence on the nuclear matter and NS properties, and the sign of isovector-vector coupling constant is critical in the determination of the trend of the symmetry energy and equation of state. The effects of the other model parameters and symmetry energy slope at saturation density are discussed. 展开更多
关键词 NEUTRON STARS nuclear matter EXTENDED Nambu-Jona-Lasinio model SYMMETRY energy
Phase Transition and Critical Phenomenon Occurring in Granular Matter
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作者 冯耀东 苏涛 +1 位作者 史庆藩 孙刚 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第9期32-35,共4页
We investigate the granular flow states in a channel with bottleneck by molecular dynamics simulations.Our study is restricted only on a selected key area rather than on the whole system to focus on the flow propertie... We investigate the granular flow states in a channel with bottleneck by molecular dynamics simulations.Our study is restricted only on a selected key area rather than on the whole system to focus on the flow properties of a single granular state.A random force field is introduced to control the granular temperature.It is also pointed out that the flow rate in the granular flow can be correlated with the pressure,which leads us to carry out a comprehensive study similar to the classical study for general liquid-gas phase transition.Our results show that the dilute flow state and the dense flow state of the granules are similar to the gas state and the liquid state of general substances,respectively,and the properties of phase transition and critical phenomenon are also similar to those occurring in general substances. 展开更多
关键词 simulation PHASE TRANSITION and CRITICAL Phenomenon Occurring in GRANULAR MATTER
The Relationship Between Plant Community Characteristics and Soil Organic Matter Content of Sedentary Grazing Pastures in a Typical Steppe 预览
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作者 SARULA SAIXIYALATU +1 位作者 CHUN Feng ZHANG Weiqing 《景观研究:英文版》 2019年第1期57-60,64共5页
In order to discuss the relationship between the characteristics of plant communities and the content of topsoil organic matter under the condition of two-season sedentary grazing,authors of this paper selected a Stip... In order to discuss the relationship between the characteristics of plant communities and the content of topsoil organic matter under the condition of two-season sedentary grazing,authors of this paper selected a Stipa krylovii steppe for research and studied the plant community characteristics and the topsoil organic matter content.The results showed that in the sedentary grazing area,the perennial plant species decreased,the annual plant species increased,and the topsoil organic matter content decreased.There were a negative correlation between plant biomass and topsoil organic matter content,and a positive correlation between total coverage and topsoil organic matter content.The change of plant community characteristics in the sedentary grazing area was related to the implementation of the system of transferring the pasture use rights to the herdsmen and controlled grazing. 展开更多
关键词 STIPA krylovii STEPPE Plant community characteristics Soil organic matter content SEDENTARY GRAZING
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Potential factors and mechanism of particulate matters explosive increase induced by free radicals oxidation
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作者 Guoying Wang Shiming Jia +11 位作者 Xiuli Niu Haoqi Tian Yanrong Liu Zhong Xie Chao Liu Yucan Dong Ying Su Jianglei Yu Gaofeng Shi Xuefu Chen Lan Li Peng Zhang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第7期205-213,共9页
Atmospheric particulate pollution in China has attracted much public attention.Occasionally, the particle number concentration increases sharply in a short time period,which is defined as a 'particulate matter exp... Atmospheric particulate pollution in China has attracted much public attention.Occasionally, the particle number concentration increases sharply in a short time period,which is defined as a 'particulate matter explosive increase'. Heavy particulate matter pollution not only reduces visibility but also has an adverse effect on human health. Hence,there is an urgent need to discover the causes of particulate matter explosive increase.During this campaign, the particle number concentration and free radicals were measured at a tall building on the campus of Lanzhou University of Technology. Additionally, we examined a series of chemicals to reproduce the observed particulate matter explosive increase in a smog chamber to determine its potential factors. Then, we analyzed the mechanism of particulate matter explosive increase in the presence of free radicals. We found that, among the potential inorganic and organic sources analyzed, a mixture of organic and SO2 in the research region had a major effect on particulate matter explosive increase. Moreover, free radical oxidation has a large effect, especially in the formation of organic particulates. 展开更多
关键词 PARTICULATE MATTER pollution Particle number concentration EXPLOSIVE INCREASE Free RADICAL OXIDATION
Dark matter and LHC phenomenology of a scale-invariant scotogenic model
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作者 郭超 郭书源 廖益 《中国物理C:英文版》 SCIE CAS CSCD 2019年第10期14-23,共10页
We study the phenomenology of a model that addresses the neutrino mass, dark matter, and generation of the electroweak scale in a single framework. Electroweak symmetry breaking is realized via the Coleman-Weinberg me... We study the phenomenology of a model that addresses the neutrino mass, dark matter, and generation of the electroweak scale in a single framework. Electroweak symmetry breaking is realized via the Coleman-Weinberg mechanism in a classically scale invariant theory, while the neutrino mass is generated radiatively through interactions with dark matter in a typically scotogenic manner. The model introduces a scalar triplet and singlet and a vector-like fermion doublet that carry an odd parity of Z2, and an even parity scalar singlet that helps preserve classical scale invariance. We sample over the parameter space by taking into account various experimental constraints from the dark matter relic density and direct detection, direct scalar searches, neutrino mass, and charged lepton flavor violating decays. We then examine by detailed simulations possible signatures at the LHC to find some benchmark points of the free parameters. We find that the future high-luminosity LHC will have a significant potential in detecting new physics signals in the dilepton channel. 展开更多
关键词 COLLIDER PHENOMENOLOGY NEUTRINO mass generation dark matter particle classical SCALE INVARIANCE
Photodegradation of 2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P) in coastal seawaters: Important role of DOM
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作者 Xi Chen Jieqiong Wang +3 位作者 Jingwen Chen Chengzhi Zhou Feifei Cui Guoxin Sun 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第11期129-137,共9页
Benzotriazole UV stabilizers (BT-UVs) have attracted concems due to their ubiquitous occurrence in the aquatic environment,and their bioaccumulative and toxic properties.However,little is known about their aquatic env... Benzotriazole UV stabilizers (BT-UVs) have attracted concems due to their ubiquitous occurrence in the aquatic environment,and their bioaccumulative and toxic properties.However,little is known about their aquatic environmental degradation behavior.In this study,photodegradation of a representative of BT-UVs,2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P),was investigated under simulated sunlight irradiation.Results show that UV-P photodegrades slower under neutral conditions (neutral form) than under acidic or alkaline conditions (cationic and anionic forms).Indirect photodegradation is a dominant elimination pathway of UV-P in coastal seawaters.Dissolved organic matter (DOM) from seawaters accelerate the photodegradation rates mainly through excited triplet DOM (3DOM*),and the roles of singlet oxygen and hydroxyl radical are negligible in the matrixes.DOM from seawaters impacted by mariculture exhibits higher steady-state concentration of 3DOM*([3DOM*]) relative to those from pristine seawaters,leading to higher photosensitizing effects on the photodegradation.Halide ions inhibit the DOM-sensitized photodegradation of UV-P by decreasing [3DOM*].Photodegradation half-lives of UV-P are estimated to range from 24.38 to 49.66 hr in field water bodies of the Yellow River estuary.These results are of importance for assessing environmental fate and risk UV-P in coastal water bodies. 展开更多
关键词 BENZOTRIAZOLE UV STABILIZERS PHOTODEGRADATION Dissolved organic matter COASTAL seawaters
Bacterial community succession in response to dissolved organic matter released from live jellyfish 预览
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作者 HAO Wenjin WICHELS Antje +2 位作者 FUCHS Bernhardt TANG Xuexi GERDTS Gunnar 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第4期1229-1244,共16页
Jellyfish blooms have increased worldwide, and the outbreaks of jellyfish population not only affect the food web structures via voracious predation but also play an important role in the dynamics of nutrients and oxy... Jellyfish blooms have increased worldwide, and the outbreaks of jellyfish population not only affect the food web structures via voracious predation but also play an important role in the dynamics of nutrients and oxygen in planktonic food webs. However, it remains unclear whether specific carbon compounds released through jellyfish metabolic processes have the potential to shape bacterial community composition. Therefore, in this study, we aimed to investigate the compositional succession of the bacterioplankton community in response to the dissolved organic matter (DOM) released by the live Scyphomedusae Cyanea lamarckii and Chrysaora hysoscella collected from Helgoland Roads of the North Sea. The bacterial community was significantly stimulated by the DOM released form live jellyfish and different dominant phylotypes were observed for these two Scyphomedusae species. Furthermore, the bacterial community structures in the different DOM sources, jellyfish-incubated media, Kabeltonne seawater, and artificial seawater (DOM-free) were significantly different, as revealed by automated ribosomal intergenic spacer analysis fingerprints. Catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) revealed a rapid species-specific shift in bacterial community composition. Gammaproteobacteria dominated the community instead of the Bacteroidetes community for C. lamarckii, whereas Gammaproteobacteria and Bacteroidetes dominated the community for C. hysoscella. The significant differences in the bacterial community composition and succession indicate that the components of the DOM released by jellyfish might differ with jellyfish species. 展开更多
关键词 BACTERIAL COMMUNITY structure BACTERIAL COMMUNITY composition dissolved organic matter JELLYFISH automated rRNA INTERGENIC spacer analysis (ARISA) catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH)
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Comparative Analysis on Two Kinds of Measurement Methods of Particulate Matters in Waste Gas of Low Velocity 预览
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作者 Li Weijun Ji Guangjun +2 位作者 Yang Xianglin Zhang Xingyao Jing Yifeng 《气象与环境研究:英文版》 CAS 2019年第5期70-73,共4页
In the current waste gas sampling of fixed source,it is required that deviation of tracking rate of constant velocity sampling should not be more than 10%.When flow rate of the waste gas is less than 5 m/s,the trackin... In the current waste gas sampling of fixed source,it is required that deviation of tracking rate of constant velocity sampling should not be more than 10%.When flow rate of the waste gas is less than 5 m/s,the tracking rate can not meet this requirement.The sampling of fixed velocity can meet the requirement of particulate matter sampling on gas collection volume at low velocity.Through the comparison of two different methods for the determination of particulate matter in waste gas under the low flow velocity of flue gas,it was found that there were some differences between the fixed velocity measurement and the constant velocity measurement.The results showed that measurement result of the fixed velocity was higher than that of constant velocity measurement under low velocity.At the same time,the deviation of fixed velocity measurement was not obvious under different low velocity. 展开更多
关键词 LOW flow VELOCITY PARTICULATE MATTER Measurement COMPARATIVE analysis
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