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Synthetic chromosome evolves the yeast genome
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作者 Fei Teng Wei Li Qi Zhou 《中国科学:生命科学英文版》 SCIE CAS CSCD 2019年第5期708-709,共2页
Genomic structural variations play a critical role in biological function and phenotypic diversity. Although smallscale variations, such as insertion, deletion, and point mutations, have been extensively investigated,... Genomic structural variations play a critical role in biological function and phenotypic diversity. Although smallscale variations, such as insertion, deletion, and point mutations, have been extensively investigated, studies on largescale structural variations such as segmental duplication,inversion, and chromosome-scale variations remain limited.In the recent decade。 展开更多
关键词 LI SYNTHETIC CHROMOSOME evolves the YEAST GENOME FIGURE
基于新型^18F微反应器的^18F-阿法肽的自动化制备及microPET/CT显像 被引量:1
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作者 张健 周晓宝 +4 位作者 石琴 孙玉云 章英剑 张勇平 王明伟 《中华核医学与分子影像杂志》 CAS 北大核心 2019年第4期196-200,共5页
目的探讨基于新型^18F微反应器的^18F-阿法肽(Alfatide Ⅱ)的自动化制备方法,并行荷瘤裸鼠microPET/CT显像。方法采用自主研制的^18F微反应器和水相[^18F]氟化铝螯合标记法,自动化制备^18F-Alfatide Ⅱ,测量其放化产率,对^18F-Alfatide... 目的探讨基于新型^18F微反应器的^18F-阿法肽(Alfatide Ⅱ)的自动化制备方法,并行荷瘤裸鼠microPET/CT显像。方法采用自主研制的^18F微反应器和水相[^18F]氟化铝螯合标记法,自动化制备^18F-Alfatide Ⅱ,测量其放化产率,对^18F-Alfatide Ⅱ注射液进行质量分析。建立乳腺癌ZR-75-1和鼻咽癌CNE1荷瘤裸鼠模型各3只,分别于注射^18F-Alfatide Ⅱ后0.5、1.0和2.0 h行microPET/CT显像,勾画感兴趣区(ROI),计算肿瘤/肌肉(T/M)比值。结果采用^18F微反应器自动化制备了^18F-Alfatide Ⅱ,总合成时间约40 min,放化产率为(28±6)%(非衰变校正,n=11),放化纯>97%,质量分析指标均符合要求。ZR-75-1和CNE1荷瘤裸鼠^18F-Alfatide Ⅱ microPET/CT显像清晰,肿瘤部位放射性摄取明显,注射后1.0 h T/M比值>4.0。结论成功采用^18F微反应器自动化制备^18F-Alfatide Ⅱ,合成时间短,放化产率高,有助于其在microPET/CT肿瘤显像中的研究。 展开更多
关键词 肽类 精氨酸-甘氨酸-天冬氨酸 氟放射性同位素 化学技术 合成 乳腺肿瘤 鼻咽肿瘤 肿瘤移植 小鼠
Modified version of three-component model-based decomposition for polarimetric SAR data 预览
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作者 ZHANG Shuang YU Xiangchuan WANG Lu 《系统工程与电子技术:英文版》 SCIE EI CSCD 2019年第2期270-277,共8页
A new hybrid Freeman/eigenvalue decomposition based on the orientation angle compensation and the various extended volume models for polarimetric synthetic aperture radar(PolSAR) data are presented. There are three st... A new hybrid Freeman/eigenvalue decomposition based on the orientation angle compensation and the various extended volume models for polarimetric synthetic aperture radar(PolSAR) data are presented. There are three steps in the novel version of the three-component model-based decomposition.Firstly, two special unitary transform matrices are applied on the coherency matrix for deorientation to decrease the correlation between the co-polarized term and the cross-polarized term.Secondly, two new conditions are proposed to distinguish the manmade structures and the nature media after the orientation angle compensation. Finally, in order to adapt to the scattering properties of different media, five different volume scattering models are used to decompose the coherency matrix. These new conditions pre-resolves man-made structures, which is beneficial to the subsequent selection of a more suitable volume scattering model.Fully PolSAR data on San Francisco are used in the experiments to prove the efficiency of the proposed hybrid Freeman/eigenvalue decomposition. 展开更多
关键词 polarimetric synthetic aperture RADAR (PolSAR) RADAR POLARIMETRY hybrid Freeman/eigenvalue DECOMPOSITION scattering model
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AIEgens-lightened Functional Polymers:Synthesis,Properties and Applications
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作者 Shi-Yuan Zhou Hai-Bo Wan +3 位作者 Feng Zhou Pei-Yang Gu Qing-Feng Xu Jian-Mei Lu 《高分子科学:英文版》 SCIE CAS CSCD 2019年第4期302-326,I0005共26页
Recently,polymers with aggregation-induced emission(AIE)effects have attracted significant attention due to their broad applications in luminescence sensors,stimuli responsive materials,electroluminescence devices,etc... Recently,polymers with aggregation-induced emission(AIE)effects have attracted significant attention due to their broad applications in luminescence sensors,stimuli responsive materials,electroluminescence devices,etc.In this review,we summarize recent advances concerning AIE polymers.Four types of AIE polymers including end-functionalized polymers,side-chain polymers,main-chain polymers,and other polymers according to the location of AIEgens,are described.Their synthetic preparation,optical property,AIE effects,and applications are also illustrated in this review. 展开更多
关键词 Aggregation-induced EMISSION FUNCTIONAL POLYMERS SYNTHETIC method Application
How synthetic microfibers end up in food & drinking water 预览
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《中国纺织:英文版》 2019年第5期44-45,共2页
No one sets out to refresh themselves by drinking plastic. But microscopic pollution are in virtually every body of water on Earth. While the debris comes from a number of sources, including food and drink packaging a... No one sets out to refresh themselves by drinking plastic. But microscopic pollution are in virtually every body of water on Earth. While the debris comes from a number of sources, including food and drink packaging and cosmetics, research is pointing to synthetic textile microfibers as a major culprit. Studies show hundreds of thousands of microplastic particles can enter the wa-ter supply just by laundering that polo shirt, midi dress or yoga pants. 展开更多
关键词 SYNTHETIC MICROFIBERS FOOD DRINKING water
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A SAR imaging method based on generalized minimax-concave penalty
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作者 Zhonghao WEI Bingchen ZHANG Yirong WU 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第2期214-216,共3页
Dear editor,Sparse signal processing offers a framework for synthetic aperture radar(SAR)imaging [1,2].As an efficient tool in sparse signal processing,L1 minimization is often used in the reconstruction of SAR images... Dear editor,Sparse signal processing offers a framework for synthetic aperture radar(SAR)imaging [1,2].As an efficient tool in sparse signal processing,L1 minimization is often used in the reconstruction of SAR images.When implemented in SAR imaging [3-5],L1 minimization offers significant improvement in the properties by suppressing the sidelobes and clutter. 展开更多
关键词 SPARSE signal framework for SYNTHETIC SIGNIFICANT improvement
Regulation by competition:a hidden layer of gene regulatory network
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作者 Lei Wei Ye Yuan +6 位作者 Tao Hu Shuailin Li Tianrun Cheng Jinzhi Lei Zhen Xie Michael Q.Zhang Xiaowo Wang 《中国电气与电子工程前沿:英文版》 CSCD 2019年第2期110-121,共12页
Background:Molecular competition brings about trade-offs of shared limited resources among the cellular components,and thus introduces a hidden layer of regulatory mechanism by connecting components even without direc... Background:Molecular competition brings about trade-offs of shared limited resources among the cellular components,and thus introduces a hidden layer of regulatory mechanism by connecting components even without direct physical interactions.Several molecular competition scenarios have been observed recently,but there is still a lack of systematic quantitative understanding to reveal the essence of molecular competition.Methods:Here,by abstracting the analogous competition mechanism behind diverse molecular systems,we built a unified coarse-grained competition motif model to systematically integrate experimental evidences in these processes and analyzed general properties shared behind them from steady-state behavior to dynamic responses.Results:We could predict in what molecular environments competition would reveal threshold behavior or display a negative linear dependence.We quantified how competition can shape regulator-target dose-response curve,modulate dynamic response speed,control target expression noise,and introduce correlated fluctuations between targets.Conclusions:This work uncovered the complexity and generality of molecular competition effect as a hidden layer of gene regulatory network,and therefore provided a unified insight and a theoretical framework to understand and employ competition in both natural and synthetic systems. 展开更多
关键词 systems BIOLOGY COMPUTATIONAL modeling molecular COMPETITION REGULATION SYNTHETIC BIOLOGY network MOTIF
Metal-free C3-alkoxycarbonylation of quinoxalin-2(1H)-ones with carbazates as ecofriendly ester sources
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作者 Long-Yong Xie Sha Peng +6 位作者 Tai-Gang Fan Yan-Fang Liu Meng Sun Li-Lin Jiang Xing-Xing Wang Zhong Cao Wei-Min He 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第4期460-464,共5页
Quinoxaline-3-carboxylates and analogues are prevalent key structural motifs in bioactive natural products and synthetic drugs.However,the practical protocol for preparation of these motifs from simple raw materials u... Quinoxaline-3-carboxylates and analogues are prevalent key structural motifs in bioactive natural products and synthetic drugs.However,the practical protocol for preparation of these motifs from simple raw materials under mild conditions remains rare.In this article,we report a facile protocol for the efficient preparation of various quinoxaline-3-carbonyl compounds(30 examples,63%–92%)through oxidation coupling of quinoxalin-2(1H)-ones with readily available carbazates(or acyl hydrazines)in the presence of K2S2O8 as an oxidant in metal-and base-free conditions.When tert-butyl carbazate was used as the coupling reagent,the decarboxylation product 3-(tert-butyl)-1-methylquinoxalin-2(1H)-one was obtained.The application of this process into a gram-scale synthesis can be easily accomplished.Mechanistic investigations reveal that the functionalization of quinoxalin-2(1H)-ones via a free-radical pathway. 展开更多
关键词 quinoxalin-2(1H)-ones ALKOXYCARBONYLATION carbazates synthetic methods METAL-FREE
Micromagnetic simulations on demagnetization processes in anisotropic Nd2Fe14B magnets
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作者 Lei Li Shengzhi Dong +5 位作者 Rui Han Kuikui Song Dong Li Minggang Zhu Wei Li Wei Sun 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第6期628-632,共5页
Individual grains with diverse dimensional parameters were introduced to investigate the magnetization reversals in anisotropic Nd2 Fe14B magnets. The micromagnetic simulations were carried out via Object Oriented Mic... Individual grains with diverse dimensional parameters were introduced to investigate the magnetization reversals in anisotropic Nd2 Fe14B magnets. The micromagnetic simulations were carried out via Object Oriented MicroMagnetic Framework(OOMMF). With the same bottom area and height, analysis results show that the coercive fields for different bottom shapes are of similar values. Designed as a cubic grain,the coercive field presents descending tendency as grain volume ascends. Under constant grain volume,with aspect ratio increasing, the coercive field decreases in the beginning and increases soon. Based on the demagnetization field vector, the effects of bottom shape, grain volume and aspect ratio on the coercive field can be explained. The nucleation point is chosen to discuss. Its synthetic field and reversal field are calculated by parallelogram law and inverse external field equation, respectively. The synthetic field equal to the reversal field is defined as critical field, which always shows the same tendency as the coercive field for all cases of this study. It can be concluded that critical field is qualified to be a reference index to measure the magnitude of coercive field. 展开更多
关键词 MICROMAGNETIC simulation DEMAGNETIZATION FIELD Coercive FIELD SYNTHETIC FIELD CRITICAL FIELD Rare earths
Mutant p53 in cancer therapy-the barrier or the path
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作者 Xiang Zhou Qian Hao Hua Lu 《分子细胞生物学报:英文版》 SCIE CAS CSCD 2019年第4期293-305,共13页
Since wild-type p53 is central for maintaining genomic stability and preventing oncogenesis, its coding gene TP53 is highly mutated in ~50% of human cancers, and its activity is almost abrogated in the rest of cancers... Since wild-type p53 is central for maintaining genomic stability and preventing oncogenesis, its coding gene TP53 is highly mutated in ~50% of human cancers, and its activity is almost abrogated in the rest of cancers. Approximately 80% of p53 mutations are single point mutations with several hotspot mutations. Besides loss of function and dominant-negative effect on the wild-type p53 activity, the hotspot p53 mutants also acquire new oncogenic functions, so-called ‘gain-of-functions’(GOF). Because the GOF of mutant p53 is highly associated with late-stage malignance and drug resistance, these p53 mutants have become hot targets for developing novel cancer therapies. In this essay, we review some recent progresses in better understanding of the role of mutant p53 GOF in chemoresistance and the underlying mechanisms, and discuss the pros and cons of targeting mutant p53 for the development of anti-cancer therapies. 展开更多
关键词 MUTANT p53 GAIN-OF-FUNCTION cancer therapy CHEMORESISTANCE synthetic LETHALITY
Electrochemical Oxidative Csp^3—H/S—H Cross-Coupling with Hydrogen Evolution for Synthesis of Tetrasubstituted Olefins
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作者 Fangling Lu Zengzhuan Yang +4 位作者 Tao Wang Tianhao Wang Yuying Zhang Yong Yuan Aiwen Lei 《中国化学:英文版》 SCIE CAS CSCD 2019年第6期547-551,I0002共6页
Tetrasubstituted olefins are significant scaffolds as they are prevalent in many biologically active compounds and versatile building blocks for organic synthesis. Herein, we report an electrochemical oxidative Csp^3... Tetrasubstituted olefins are significant scaffolds as they are prevalent in many biologically active compounds and versatile building blocks for organic synthesis. Herein, we report an electrochemical oxidative Csp^3—H/S—H cross-coupling reaction, in which various tetrasubstituted olefins were prepared under base-free, transition metal-free, and oxidants-free reaction conditions. 展开更多
关键词 ELECTROCHEMISTRY C-H activation CROSS-COUPLING RADICAL REACTIONS synthetic methods
A Novel Thermomorphic System for Electrocatalytic Diels-Alder Reactions
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作者 Yasushi Imada Naoki Shida +1 位作者 Yohei Okada Kazuhiro Chiba 《中国化学:英文版》 SCIE CAS CSCD 2019年第6期557-560,共4页
The discovery that lithium bis(trifluoromethane)sulfonamide (LiTFSI)/1-nitropropane (PrNO2) solution functions as a less polar alternative to lithium perchlorate (LiClO4)/nitromethane (MeNO2) solution has led to the d... The discovery that lithium bis(trifluoromethane)sulfonamide (LiTFSI)/1-nitropropane (PrNO2) solution functions as a less polar alternative to lithium perchlorate (LiClO4)/nitromethane (MeNO2) solution has led to the development of a novel thermomorphic system for electrocatalytic Diels-Alder reactions. Methyl cyclohexane (Me-c-Hex) can form a monophasic condition with LiTFSI/PrNO2 solution at room temperature, enabling the use of hydrophobic dienophiles. After the electrochemical reaction, a biphasic condition can be formed at –50°C, where the cycloadducts are selectively recovered from the upper Me-c-Hex phase and the remaining lower LiTFSI/PrNO2 solution can be reused. 展开更多
关键词 thermomorphic SYSTEM electro CATALYTIC DIELS-ALDER reaction ELECTROCHEMISTRY synthetic methods CYCLOADDITION
Transition Periods Between Sea Ice Concentration and Sea Surface Air Temperature in the Arctic Revealed by an Abnormal Running Correlation 预览
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作者 JI Xupeng ZHAO Jinping 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期633-642,共10页
This study used the synthetic running correlation coefficient calculation method to calculate the running correlation coefficients between the daily sea ice concentration(SIC) and sea surface air temperature(SSAT) in ... This study used the synthetic running correlation coefficient calculation method to calculate the running correlation coefficients between the daily sea ice concentration(SIC) and sea surface air temperature(SSAT) in the Beaufort-Chukchi-East Siberian-Laptev Sea(BCEL Sea), Kara Sea and southern Chukchi Sea, with an aim to understand and measure the seasonally occurring changes in the Arctic climate system. The similarities and differences among these three regions were also discussed. There are periods in spring and autumn when the changes in SIC and SSAT are not synchronized, which is a result of the seasonally occurring variation in the climate system. These periods are referred to as transition periods. Spring transition periods can be found in all three regions, and the start and end dates of these periods have advancing trends. The multiyear average duration of the spring transition periods in the BCEL Sea, Kara Sea and southern Chukchi Sea is 74 days, 57 days and 34 days, respectively. In autumn, transition periods exist in only the southern Chukchi Sea, with a multiyear average duration of only 16 days. Moreover, in the Kara Sea, positive correlation events can be found in some years, which are caused by weather time scale processes. 展开更多
关键词 ARCTIC SEA ice CONCENTRATION SEA surface air temperature synthetic running CORRELATION coefficient transition period
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Advanced technology of high-resolution radar: target detection, tracking, imaging, and recognition
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作者 Teng LONG Zhennan LIANG Quanhua LIU 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第4期1-26,共26页
In recent years, the performances of radar resolution, coverage, and detection accuracy have been significantly improved through the use of ultra-wideband, synthetic aperture and digital signal processing technologies... In recent years, the performances of radar resolution, coverage, and detection accuracy have been significantly improved through the use of ultra-wideband, synthetic aperture and digital signal processing technologies. High-resolution radars (HRRs) utilize wideband signals and synthetic apertures to enhance the range and angular resolutions of tracking, respectively. They also generate one-, two-, and even threedimensional high-resolution images containing the feature information of targets, from which the targets can be precisely classified and identified. Advanced signal processing algorithms in HRRs obtain important information such as range-Doppler imaging, phase-derived ranging, and micro-motion features. However, the advantages and applications of HRRs are restricted by factors such as the reduced signal-to-noise ratio (SNR) of multi-scatter point targets, decreased tracking accuracy of multi-scatter point targets, high demands of motion compensation, and low sensitivity of the target attitude. Focusing on these problems, this paper systematically introduces the novel technologies of HRRs and discusses the issues and solutions relevant to detection, tracking, imaging, and recognition. Finally, it reviews the latest progress and representative results of HRR-based research, and suggests the future development of HRRs. 展开更多
关键词 HIGH-RESOLUTION RADAR integrated detection and TRACKING multiple target TRACKING phase-derived velocity inverse synthetic APERTURE radar(ISAR) hierarchical classification CONVOLUTION neural network
Can Synthetic All-Metal Cluster Compound Support Multifold (n and a) Aromaticity and d-Orbital Aromaticity?
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作者 Xue-Rui You Hua-Jin Zhai 《中国化学:英文版》 SCIE CAS CSCD 2019年第2期126-130,I0002共6页
Summary of main observation and conclusion There are active debates on whether the concept of aromaticity should be exte nded bey ond carb on based organic systems. One argument against such extension is that the prop... Summary of main observation and conclusion There are active debates on whether the concept of aromaticity should be exte nded bey ond carb on based organic systems. One argument against such extension is that the proposed new aromatic species are not bottleable. We present herein in-depth chemical bonding analyses of a synthetic, core-shell, intermetalloid [Pd3Sn8Bi6]^4-.cluster. The computational data unravel unprecedented five-fold (π and σ) aromaticity, in cludi ng d-orbital aromaticity. Delocalized electr on clouds in this all-metal system cover the Pd3 core, trigonal pyramid Sn4 caps, peripheral Bi6 ring, and roof-like Sn2Bi2 walls, each following the (4n+2) Huckel rule. The present finding is beyond imagination, providing a compelling example that all-metal aromaticity not only exists in bulk compounds, but also can be in multifold π/σ fashion. 展开更多
关键词 SYNTHETIC ALL-METAL CLUSTER SUPPORT Multifold
树脂材料SureFil SDR行预防性树脂充填的细菌黏附性 预览
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作者 徐群昊 陆钰璞 白宇宏 《中国组织工程研究》 CAS 北大核心 2019年第10期1496-1500,共5页
背景:有研究发现将树脂材料SureFil SDR作为衬洞材料时,较其他流动树脂具有更好的洞壁适应性及独有的自动找平特性,但将其用于预防性树脂充填尚未见报道。目的:比较窝沟封闭剂、Z350XT流体树脂、SureFil SDR树脂材料在粗糙度与细菌黏附... 背景:有研究发现将树脂材料SureFil SDR作为衬洞材料时,较其他流动树脂具有更好的洞壁适应性及独有的自动找平特性,但将其用于预防性树脂充填尚未见报道。目的:比较窝沟封闭剂、Z350XT流体树脂、SureFil SDR树脂材料在粗糙度与细菌黏附上的差异,探讨树脂材料SureFil SDR行预防性树脂充填的可行性。方法:将窝沟封闭剂、Z350XT流体树脂、SureFil SDR树脂材料分别制备成8 mm×2 mm×2 mm的长方体试件,利用MarSurf粗糙度仪测量3种试件的表面粗糙度。将窝沟封闭剂、Z350XT流体树脂、SureFil SDR树脂材料分别制备成8 mm×8 mm×2 mm的圆柱体试件,放入变形链球菌悬液中培养48 h,检测材料表面的细菌黏附量。结果与结论:①3种材料表面的粗糙度:SureFil SDR树脂材料<Z350XT流体树脂<窝沟封闭剂,组间两两比较差异均有显著性意义(P<0.05);②3种材料表面的细菌黏附量:SureFil SDR树脂材料<Z350XT流体树脂<窝沟封闭剂,组间两两比较差异均有显著性意义(P<0.05);③对粗糙度和细菌黏附量之间采用关联性分析,粗糙度和细菌黏附量之间具有高度正相关性,即随着材料粗糙度的减小,细菌黏附量减小(r=0.962,P=0.017 6);④结果表明,相对于窝沟封闭剂和Z350XT流体树脂而言,SureFil SDR是理想的预防性树脂充填封闭材料。 展开更多
关键词 口腔材料 预防性树脂充填 细菌黏附性 流体树脂 树脂充填封闭材料 树脂类 合成 细菌粘附 组织工程
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Mesoporous activated carbon-zeolite composite prepared from waste macadamia nut shell and synthetic faujasite
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作者 Surachai Wongcharee Vasantha Aravinthan Laszlo Erdei 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2019年第1期226-236,共11页
Novel activated carbon-zeolite composite adsorbent was prepared from macadamia shell bio-waste and synthetic zeolite X using hydrothermal treatment.Characterisation studies revealed mainly mesoporous structure with 41... Novel activated carbon-zeolite composite adsorbent was prepared from macadamia shell bio-waste and synthetic zeolite X using hydrothermal treatment.Characterisation studies revealed mainly mesoporous structure with 418 m2·g-1 BET surface area with faujasite clusters on the carbon carrier.Sorption capacity for methylene blue model pollutant increased from 85 to 97 mg·g-1 with the temperature increase from 25 to 45℃,and improved with increasing pH.Nonlinear regression analyses found accurate fit to the pseudo-first-order kinetics model and intra-particle diffusion rate controlling mechanism.Excellent fits to the Jovanovic isotherm model indicated monolayer coverage on chiefly homotattic surfaces with variable potential.The thermodynamic analysis confirmed spontaneous and endothermic physisorption process.The spent adsorbent was regenerated with 20%capacity loss over five reuse cycles.Although the adsorbent was developed for ammonia,heavy metal and organic matter removal from water sources,the results also indicate good performance in cationic dye removal from wastewaters. 展开更多
关键词 Activated carbon Adsorptio n SYNTHETIC FAUJASITE Functional COMPOSITE METHYLENE blue
Recent advances in new trifluoromethoxylation reagents
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作者 Xiaofei Zhang Pingping Tang 《中国科学:化学英文版》 SCIE EI CAS CSCD 2019年第5期525-532,共8页
The trifluoromethoxy(CF3O) group has become a novel moiety in various fields because of its unique features. However, despite the promising applications, the synthesis of CF3O-containing compounds is still a challenge... The trifluoromethoxy(CF3O) group has become a novel moiety in various fields because of its unique features. However, despite the promising applications, the synthesis of CF3O-containing compounds is still a challenge due to indirect synthetical strategies and volatile reagent which is hard to handle. Until very recently, several innovative reagents were developed to facilitate the trifluoromethoxylation reaction and make CF3O-containing compounds more accessible. This review mainly focuses on the recent advances in new trifluoromethoxylation reagents and their usage. 展开更多
关键词 trifluoromethoxy GROUP trifluoromethoxylation REAGENT SYNTHETIC METHODS FLUORINE
Intertidal area classification with generalized extreme value distribution and Markov random field in quad-polarimetric synthetic aperture radar imagery
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作者 Ting-ting JIN Xiao-qiang SHE +1 位作者 Xiao-lan QIU Bin LEI 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第2期253-264,共12页
Classification of intertidal area in synthetic aperture radar(SAR) images is an important yet challenging issue when considering the complicatedly and dramatically changing features of tidal fluctuation. The difficult... Classification of intertidal area in synthetic aperture radar(SAR) images is an important yet challenging issue when considering the complicatedly and dramatically changing features of tidal fluctuation. The difficulty of intertidal area classification is compounded because a high proportion of this area is frequently flooded by water, making statistical modeling methods with spatial contextual information often ineffective. Because polarimetric entropy and anisotropy play significant roles in characterizing intertidal areas, in this paper we propose a novel unsupervised contextual classification algorithm. The key point of the method is to combine the generalized extreme value(GEV) statistical model of the polarization features and the Markov random field(MRF) for contextual smoothing. A goodness-of-fit test is added to determine the significance of the components of the statistical model. The final classification results are obtained by effectively combining the results of polarimetric entropy and anisotropy. Experimental results of the polarimetric data obtained by the Chinese Gaofen-3 SAR satellite demonstrate the feasibility and superiority of the proposed classification algorithm. 展开更多
关键词 INTERTIDAL CLASSIFICATION Polarimetric synthetic APERTURE radar Finite MIXTURE MODEL Markov random field Generalized extreme value MODEL
合成类蛋白酪氨酸磷酸酶1B抑制剂专利现状分析 预览
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作者 沈芳 马永涛 +1 位作者 张雄辉 李瑶 《药学研究》 CAS 2019年第2期115-119,共5页
蛋白酪氨酸磷酸酶1B(PTP1B)是治疗2型糖尿病的潜在的重要靶点,与肥胖、肿瘤也具有密切关系,本文从专利分布和布局的角度出发,选择以蛋白酪氨酸磷酸酶1B抑制剂作为主题,使用关键词对全球专利数据库中的全球发明专利申请进行了检索,得到... 蛋白酪氨酸磷酸酶1B(PTP1B)是治疗2型糖尿病的潜在的重要靶点,与肥胖、肿瘤也具有密切关系,本文从专利分布和布局的角度出发,选择以蛋白酪氨酸磷酸酶1B抑制剂作为主题,使用关键词对全球专利数据库中的全球发明专利申请进行了检索,得到相关的发明专利申请,对上述数据进行人工筛选分类,重点对合成类蛋白酪氨酸磷酸酶1B抑制剂专利态势作了研究分析,以期能够为该领域药物的开发与仿制提供有益的借鉴与参考。 展开更多
关键词 糖尿病 蛋白酪氨酸磷酸酶 蛋白酪氨酸磷酸酶1B 合成 专利
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