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Anemia in patients with high-risk acute coronary syndromes admitted to Intensive Cardiac Care Units 预览
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作者 Victoria Lorente Jaime Aboal +17 位作者 Cosme Garcia Jordi Sans-Rosello Antonia Sambola Rut Andrea Carlos Tomas Gil Bonet David Vinas Nabil el Ouaddi Santiago Montero Javier Cantalapiedra Margarida Pujol Isabel Hernandez Maria Perez-Rodriguez Isaac Llao Jose C Sanchez-Salado Miquel Gual Albert Ariza-Sole 《老年心脏病学杂志:英文版》 SCIE CAS CSCD 2020年第1期35-42,共8页
Background Little information exists about the role of anemia in patients with acute coronary syndromes(ACS)admitted to Intensive Cardiac Care Units(ICCU).The aim of this study was to assess the prevalence of anemia a... Background Little information exists about the role of anemia in patients with acute coronary syndromes(ACS)admitted to Intensive Cardiac Care Units(ICCU).The aim of this study was to assess the prevalence of anemia and its impact on management and outcomes in this clinical setting.Methods All consecutive patients admitted to eight different ICCUs with diagnosis of non-ST segment elevation ACS(NSTEACS)were prospectively included.Anemia was defined as hemoglobin<130 g/L in men and<120 g/L in women.The association between anemia and mortality or readmission at six months was assessed by the Cox regression method.Results A total of 629 patients were included.Mean age was 66.6 years.A total of 197 patients(31.3%)had anemia.Coronary angiography was performed in most patients(96.2%).Patients with anemia were significantly older,with a higher prevalence of comorbidities,poorer left ventricle ejection fraction and higher GRACE score values.Patients with anemia underwent less often coronary angiography,but underwent more often intraaortic counterpulsation,non-invasive mechanical ventilation and renal replacement therapies.Both ICCU and hospital stay were significantly longer in patients with anemia.Both the incidence of mortality(HR=3.36,95%CI:1.43–7.85,P=0.001)and the incidence of mortality/readmission were significantly higher in patients with anemia(HR=2.80,95%CI:2.03–3.86,P=0.001).After adjusting for confounders,the association between anemia and mortality/readmission remained significant(P=0.031).Conclusions Almost one of three NSTEACS patients admitted to ICCU had anemia.Most patients underwent coronary angiography.Anemia was independently associated to poorer outcomes at 6 months. 展开更多
关键词 Acute CORONARY SYNDROMES ANEMIA INTENSIVE CARDIAC care units Prognosis
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Diversity of oligotrich ciliates(Ciliophora,Spirotrichea)in the northern coast of South China Sea as revealed in LSU rDNA sequences 预览
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作者 LU Kaihui LIU Weiwei +4 位作者 Alan WARREN XU Yusen ZHU Changyu ZHAO Yan YI Zhenzhen 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2020年第1期156-167,I0001-I0011共23页
Although the taxonomy of oligotrich ciliates has been widely investigated,yet the species diversity remains poorly known.We newly designed a pair of oligotrich-specific LSU rDNA primers covering the 600-bp D1/D2 regio... Although the taxonomy of oligotrich ciliates has been widely investigated,yet the species diversity remains poorly known.We newly designed a pair of oligotrich-specific LSU rDNA primers covering the 600-bp D1/D2 region,and it was effective for detecting oligotrich species.Using the primers,we constructed the cloning libraries to investigate the species diversity of oligotrichs in the northern coastal waters of the South China Sea.In total,165 oligotrich sequences were obtained from five widely separated sampling sites.Sixty operational taxonomic units(OTUs)were obtained at 99%similarity threshold,and low-abundance OTUs with no more than two sequences contributed most of these(about 78%).Our findings are consistent with previous morphological studies,Strombidium was found the most abundant and widely distributed genus in this area.In addition,the BLAST search in the NCBI database resulted in 95%OTUs matching with named oligotrich species in similarity below 99%.Therefore,oligotrich morphospecies diversity has been underestimated as low-abundance species,and the LSU rDNA oligotrich sequence database needs to be better promoted. 展开更多
关键词 DIVERSITY low-abundance species oligotrich CILIATES operational TAXONOMIC units (OTUs)
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Ophiolites of the Central Asian Orogenic Belt:Geochemical and petrological characterization and tectonic settings 预览
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作者 Harald Furnes Inna Safonova 《地学前缘:英文版》 CAS CSCD 2019年第4期1255-1284,共30页
We present a compilation of published data(field,petrography,ages and geochemistry)from 73 ophiolitic complexes of the Central Asian Orogenic Belt.The ophiolitic complexes,ranging in age from Neoproterozoic to Triassi... We present a compilation of published data(field,petrography,ages and geochemistry)from 73 ophiolitic complexes of the Central Asian Orogenic Belt.The ophiolitic complexes,ranging in age from Neoproterozoic to Triassic.have been geochemically classified as subduction-related and subductionunrelated categories applying recent,well-established discrimination diagrams.The subductionunrelated category is further subdivided into Mid-Ocean Ridge type(MOR),a common rift-drift stage and Plume type,and the subduction-related category is subdivided into Backarc(BA),Forearc(FA).Backarc to Forearc(BA-FA)and Volcanic Arc(VA)types.The four subduction-related types define highly different geochemical features,with the BA and FA types defining end members showing subduction influence of 10%-100%and 90%-100%subduction influence,respectively,and the two other types(BAFA and VA)define values between the two end members.The subduction-related category comprises79%of the examined ophiolites,of which the BA type ophiolites is by far the dominant group,followed by the BA-FA type,and with FA and VA types as subordinate groups.The Neoproterozoic and Ordovician complexes exhibit the highest,whereas those of Silurian age exhibit the lowest subduction-influence.Of the remaining 21%subduction-unrelated ophiolites,the MOR type dominates.Both the subductionrelated and subduction-unrelated types,in particular the latter,are commonly associated with alkaline basalts taken to represent ocean island magmatism.Harzburgite,dunite,gabbro and basalt are the common lithologies in all ophiolite types,whereas the BA-FA,FA and VA types generally contain intermediate to felsic rocks,and in the FA type boninites occur.The subduction-related ophiolites types generally show low metamorphic grade,whereas greenschist.amphibolite and blueschist grades occur in the subduction-unrelated and BA types.The highly different subduction contribution(from 0 to 100%in the MOR and FA,respectively),attest to variable dips of the subducting slab,as well as variable flux of s 展开更多
关键词 GEOCHEMICAL classification Subduction-unrelated UNITS Subduction-related UNITS SUBDUCTION fingerprint Intra-plate MAGMAS Arc erosion
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Tables of Pure Quintic Fields 预览
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作者 Daniel C. Mayer 《理论数学进展(英文)》 2019年第4期347-403,共57页
By making use of our generalization of Barrucand and Cohn’s theory of principal factorizations in pure cubic fields and their Galois closures with 3 possible types to pure quintic fields and their pure metacyclic nor... By making use of our generalization of Barrucand and Cohn’s theory of principal factorizations in pure cubic fields and their Galois closures with 3 possible types to pure quintic fields and their pure metacyclic normal fields with 13 possible types, we compile an extensive database with arithmetical invariants of the 900 pairwise non-isomorphic fields N having normalized radicands in the range 2≤D3. Our classification is based on the Galois cohomology of the unit group UN, viewed as a module over the automorphism group Gal(N/K) of N over the cyclotomic field K=Q(ξ5), by employing theorems of Hasse and Iwasawa on the Herbrand quotient of the unit norm index (Uk:NN/K(UN)) by the number #(PN/K/PK) of primitive ambiguous principal ideals, which can be interpreted as principal factors of the different DN/K. The precise structure of the F5-vector space of differential principal factors is expressed in terms of norm kernels and central orthogonal idempotents. A connection with integral representation theory is established via class number relations by Parry and Walter involving the index of subfield units (UN:U0).?The statistical distribution of the 13 principal factorization types and their refined splitting into similarity classes with representative prototypes is discussed thoroughly. 展开更多
关键词 PURE Quintic FIELDS PURE Metacyclic FIELDS Units GALOIS COHOMOLOGY Differential Principal FACTORIZATION Types SIMILARITY Classes Prototypes Class Group Structure
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The Basic Units of Living Things:A Cell
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作者 周越 《数理天地:高中版》 2019年第7期48-49,共2页
What is a cell?Definition,A cell is the basic unit of all living things.It is the unit of life.Some living things consistof only one cell.They are called unicellular(one-celled).Other living things consist of more tha... What is a cell?Definition,A cell is the basic unit of all living things.It is the unit of life.Some living things consistof only one cell.They are called unicellular(one-celled).Other living things consist of more thanone cell.They are called multicellular(many-celled).All plants and animals are multicellular.God provided his creation with a great variety of cells.Yet,as you will learn,all cells have somethings in common.Basic parts of a cell. 展开更多
关键词 Basic UNITS LIVING THINGS
大型机组热态快速启停技术研究 预览
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作者 靖长财 《神华科技》 2019年第3期53-54,69共3页
针对机组快速启停调峰问题,本文进行了系统性分析,提出了需要改进的技术方案,并且对关键技术问题进行分析,通过技术论证、技术改造后可以实现机组快速启停,但是对机组设备可靠性和灵活性提出了适应性的要求。因此实现此方式需要增加技... 针对机组快速启停调峰问题,本文进行了系统性分析,提出了需要改进的技术方案,并且对关键技术问题进行分析,通过技术论证、技术改造后可以实现机组快速启停,但是对机组设备可靠性和灵活性提出了适应性的要求。因此实现此方式需要增加技术改造投入,并且对设备维护和运行操作提出了更高的要求,这样才能实现热态快速启停调峰。 展开更多
关键词 机组 热态 启停 技术措施
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Rules for Amalgamating the Reliability of Elements of Powertrain Systems at Maintenance 预览
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作者 S.V.Belodedenko V.I.Hanush О.M.Hrechanyi 《机械工程与自动化:英文版》 2019年第1期24-32,共9页
The amalgamation procedure is actual when using structural methods of reliability.This may apply as the case of the action of a complex of damaging processes on a structural element and the case of the action of a cer... The amalgamation procedure is actual when using structural methods of reliability.This may apply as the case of the action of a complex of damaging processes on a structural element and the case of the action of a certain damaging process on a system of elements.Classical methods of reliability are poorly adapted for powertrain mechanical systems with a series structural scheme of elements subjected to the gradual influence of several degradation processes.The problem of amalgamation of individual indicators is exacerbated at the stage of operation when diagnosing the technical state of the mechanical system.The application of the classical rule of amalgamation by multiplying the probabilities of survival leads to the effect of over-maintenance.New rules of amalgamation have been developed,which deprive the assessment of the reliability of excessive conservatism.The complex index of the technical condition is offered—the resource safety index(RSI).Its use determines the remaining lifetime.The algorithm for searching the RSI contains an assessment of the criticality of the failure.The search of RSI under the influence of the complex of damaging processes on the element of the powertrain system is demonstrated.The efficiency of the RSI method is shown by the example of the reliability assessment of aircraft bolts.Application of the RSI method increases the guaranteed lifetime by 4-10 times compared with traditional methods. 展开更多
关键词 RELIABILITY indices POWERTRAIN units maintenance RESOURCE LIFETIME RISK
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Redefining the Kilogram 预览
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作者 Chris Palmer 《工程(英文)》 2019年第3期361-362,共2页
In November 2018, scientists from 60 countries voted unanimously to redefine the kilogram and three other standard units of measure: the ampere, for electrical current;the kelvin, for temperature;and the mole, which d... In November 2018, scientists from 60 countries voted unanimously to redefine the kilogram and three other standard units of measure: the ampere, for electrical current;the kelvin, for temperature;and the mole, which describes the amount of a chemical substance [1]. 展开更多
关键词 STANDARD UNITS of MEASURE KILOGRAM
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Infection management strategy based on prevention and control of nosocomial infections in intensive care units
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作者 Long-Xiang Su Xiao-Ting Wang +2 位作者 Pan Pan Wen-Zhao Chai Da-Wei Liu 《中华医学杂志:英文版》 SCIE CAS CSCD 2019年第1期115-119,共5页
Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection,which is clinical problem often faced by intensive care units (ICU) doctors.Without positive treatment,the in... Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection,which is clinical problem often faced by intensive care units (ICU) doctors.Without positive treatment,the incidence and mortality of sepsis are high.^[1]As hospital infection control plays an essential role in treating the nosocomial infections in the ICU,and according to the clinical presentation of critically ill patients,the biological characteristics of pathogenic microorganisms and the ICU environment,this article put forward a strategy for the nosocomial infections in the ICU. 展开更多
关键词 NOSOCOMIAL INFECTIONS INTENSIVE CARE units PREVENTION control
Conservation genetics of a resident population of Greylag Goose (Anser anser) at the southernmost limit of the species' distribution in Europe 预览
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作者 Anastasios Bounas Giorgos Catsadorakis +3 位作者 Annita Logotheti Berend Voslamber Antonios Magoulas Dimitris Tsaparis 《鸟类学研究:英文版》 CSCD 2019年第1期53-62,共10页
Background:Conservation of small and isolated populations can be challenging since they are prone to loss of genetic diversity due to random genetic drift and inbreeding.Therefore,information from the assessment of ge... Background:Conservation of small and isolated populations can be challenging since they are prone to loss of genetic diversity due to random genetic drift and inbreeding.Therefore,information from the assessment of genetic diversity and structure are needed for conservation programs to determine the appropriate management strategy for the populations.We investigated the levels of genetic variability in a resident Greylag Goose (Anser anser) population,the southernmost breeding population of the species in Europe and the sole viable population of any goose species in Greece.Methods:A fragment of mtDNA Control Region and a panel of 11 microsatellite markers were used to search for any signs of genetic impoverishment and population substructure and to reveal the underlying processes through the identification of possible past demographic events.Results:The population was found to be monomorphic in the amplified fragment of the mitochondrial Control Region,with all individuals sharing a single private haplotype.Analyses showed a lack of any population substructure indicating a panmictic population.Although the population seems to have experienced a strong and recent genetic bottleneck and exhibits a small effective population size,we did not find evidence of either extremely low levels of genetic diversity or inbreeding depression.Conclusions:The recent demographic decline we detected and the combined influence of residency and anthropogenic factors have probably shaped the current genetic status.Our study population does not need emergency conservation actions but should be regarded as a discrete management unit.Future management strategies should focus on population and genetic monitoring and preventing further abundance declines that would increase the risk of genetic impoverishment. 展开更多
关键词 Conservation Genetic VARIABILITY INBREEDING Isolation Management units Microsatellites mtDNA Nonmigratory population
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Discovery of Hesigewula Sag on the western margin of Da Hinggan Mountains in China and its significance in petroleum geology 预览
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作者 Shi-zhen Li Wei-bin Liu +4 位作者 Dan-dan Wang Wen-hao Zhang Yan-hua Lin Shu Tao Yao-hui Xu 《中国地质(英文)》 2019年第4期439-457,共19页
With Songliao Basin in northeast China entering the middle-late stage of the exploration and development of oil and gas resources,it is urgent to open up new areas for oil and gas exploration on the periphery of the b... With Songliao Basin in northeast China entering the middle-late stage of the exploration and development of oil and gas resources,it is urgent to open up new areas for oil and gas exploration on the periphery of the basin.Five sedimentary sags have been discovered in the western margin of the Da Hinggan Mountains through high-precision gravity,magnetic,and electrical prospecting engineering.According to the conditions of the 5 sags such as buried depth,area,and the scale of source rock,Hesigewula Sag was preferentially selected to deploy two-dimensional seismic prospecting and drilling.As a result,the stratigraphic distribution and structure of Hesigewula Sag were preliminarily ascertained,the main sedimentary facies developed in Aershan Formation-Tengger Formation of the Lower Cretaceous was summarized,and the assessment parameters of source rock of Hesigewula Sag were obtained.According to the research results,the Hesigewula Sag can be divided into 3 second-order tectonic units including the western bulge,the central sag,and the eastern bulge respectively,and the sag was formed mainly subject to the west fractures.Three sedimentary facies including fan delta facies,braided river delta facies,and lacustrine facies have been identified in the Aershan Formation-Tengger Formation of the sag.The source rock in the first member and second member of Tengger Formation in the sag features high abundance of organic matter,meeting the standards of good source rocks.The kerogen of the source rock is mainly of type Ⅱ1-Ⅱ2.The organic matter in the source rock is characterized by low maturity and it entered the evolution stage of low maturity from the second member of Tengger Formation.Furthermore,Hesigewula Sag bears a strong similarity to other petroliferous sags in Erlian Basin in structure,sedimentation,source rock,and other characteristics.Therefore,it can be preliminarily determined that Hesigewula Sag boasts great potential for oil and gas resources. 展开更多
关键词 Tectonic units Tectonic evolution Sedimentary facies Characteristics of source rock Oil and gas exploration engineering Hesigewula Sag Erlian Basin Inner Mongolia China
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Clinical characteristics and management of patients with fat embolism syndrome in level I Apex Trauma Centre
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作者 Richa Aggarwal Arnab Banerjee +2 位作者 Kapil dev Soni Atin Kumar Anjan Trikha 《中华创伤杂志:英文版》 CAS CSCD 2019年第3期172-176,共5页
Purpose: Fat embolism syndrome (FES) is systemic manifestation of fat emboli in the circulation seen mostly after long bone fractures. FES is considered a lethal complication of trauma. There are various case reports ... Purpose: Fat embolism syndrome (FES) is systemic manifestation of fat emboli in the circulation seen mostly after long bone fractures. FES is considered a lethal complication of trauma. There are various case reports and series describing FES. Here we describe the clinical characteristics, management in ICU and outcome of these patients in level I trauma center in a span of 6 months. Methods: In this prospective study, analysis of all the patients with FES admitted in our polytrauma intensive care unit (ICU) of level I trauma center over a period of 6 months (from August 2017 to January 2018) was done. Demographic data, clinical features, management in ICU and outcome were analyzed. Results: We admitted 10 cases of FES. The mean age of patients was 31.2 years. The mean duration from time of injury to onset of symptoms was 56 h. All patients presented with hypoxemia and petechiae but central nervous system symptoms were present in 70% of patients. The mean duration of mechanical ventilation was 11.7 days and the mean length of ICU stay was 14.7 days. There was excellent recovery among patients with no neurological deficit. Conclusion: FES is considered a lethal complication of trauma but timely management can result in favorable outcome. FES can occur even after fixation of the fracture. Hypoxia is the most common and earliest feature of FES followed by CNS manifestations. Any patient presenting with such symptoms should raise the suspicion of FES and mandate early ICU referral. 展开更多
关键词 Fat EMBOLISM TRAUMA CENTERS INTENSIVE care units Patient outcome assessment
Gut Microbiota Reconstruction Following Host Infection with Bloodstage Plasmodium berghei ANKA Strain in a Murine Model 预览
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作者 Zhi-gang FAN Xiao LI +3 位作者 Hai-yi FU Li-min ZHOU Fei-li GONG Min FANG 《当代医学科学(英文)》 SCIE CAS 2019年第6期883-889,共7页
Malaria remains a global health problem.The relationship between Plasmodium spp.and the gut microbiota as well as the impact of Plasmodium spp.on the gut microbiota in vertebrate hosts is unclear.The aim of the curren... Malaria remains a global health problem.The relationship between Plasmodium spp.and the gut microbiota as well as the impact of Plasmodium spp.on the gut microbiota in vertebrate hosts is unclear.The aim of the current study was to evaluate the effect of blood-stage Plasmodium parasites on the gut microbiota of mice.The gut microbiota was analyzed by 16S rRNA sequencing and bioinformatic analyses at three stages.The gut microbiota changed during the three phases:the healthy stage,the infection stage,and the cure stage(on the 9th day after malarial elimination).Moreover,the gut microbiota of these infected animals did not recover after malaria infection.There were 254 operational taxonomic units(OTUs)across all three stages,and there were unique strains or OTUs at each stage of the experiment.The percentages of community abundance of 8 OTUs changed significantly(P<0.05).The dominant OTU in both the healthy mice and the mice with malaria was OTU265,while that in the cured mice was OTU234.In addition,the changes in OTU147 were the most noteworthy.Its percentage of community abundance varied greatly,with higher values during malaria than before malaria infection and after malaria elimination.These results indicated that the external environment influenced the gut microbiota after host C57BL/6 mice were infected with blood-stage P.berghei ANKA and that the same was true during and after elimination of blood-stage P.berghei ANKA.In addition,we could not isolate OTU147 for further study.This study identified gut microbiota components that were reconstructed after infection by and elimination of blood-stage P.berghei ANKA in host C57BL/6 mice,and this process was affected by P.berghei ANKA and the external environment of the host. 展开更多
关键词 MALARIA gut microbiota operational taxonomic units Plasmodium berghei C57BL/6 mice reconstruction of the microbiota
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Utilization of Azobenzene Units to Control Zinc-mediated Ring Opening Polymerization of Cyclic Esters
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作者 SUN Junqi 《高等学校化学研究:英文版》 SCIE CAS CSCD 2019年第5期747-748,共2页
Salicylaldimine Zn(Ⅱ) complexes bearing azobenzene moieties were prepared to catalyze ring opening polymerization of various cyclic esters. The different reactivities of the trans and cis isomers of the zinc complexe... Salicylaldimine Zn(Ⅱ) complexes bearing azobenzene moieties were prepared to catalyze ring opening polymerization of various cyclic esters. The different reactivities of the trans and cis isomers of the zinc complexes provide a facile strategy to control polymerization processes as well as the compositions of the resultant polymers. 展开更多
关键词 AZOBENZENE UNITS CONTROL Zinc-mediated Cyclic ESTERS
Analysis of the Perception of Users of Pre-hospital Architecture in Light Steel Frame:A Case Study in Minas Gerais,Brazil 预览
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作者 Mirvane Vasconcelos S. Melo Henor Arthur Souza 《土木工程与建筑:英文版》 2019年第4期251-258,共8页
The quality of many physical spaces can be achieved from the use of a flexible architecture.Understanding whether such a building has acceptable comfort conditions,adequate division of its internal spaces,efficiency o... The quality of many physical spaces can be achieved from the use of a flexible architecture.Understanding whether such a building has acceptable comfort conditions,adequate division of its internal spaces,efficiency of functionality,can be possible by consulting its own users/employees,analyzing and considering one of the basic concepts for architectural spatial design:people and environments are inseparable and cannot be thought out separately.Therefore,the purpose of this case study is to analyze the perception of users and managers of three USP(Unidades de Saúde Públicas)(Public Health Units),built in the LSF(Light Steel Framing)system,in relation to the built environment and thus contribute to a reflection on health care architecture based on identified gaps.These Public Health Units in LSF are located in 3(three)different cities in the interior of the state of Minas Gerais,in the southeastern region of Brazil.To this end,the development of the work is carried out through on-site interviews with users and managers.The answers of the questionnaires are analyzed with the help of the software SPSS(Statistical Package for the Social Sciences),version 19.0.The results show that the buildings present project inadequacies related to the performance of self-supporting closures,extensive to the presence of cracks and infiltrations and to some aspects related to environmental comfort.However,the hospital architecture produced with the LSF can allow flexibility,modifications and probably possible solutions to these issues. 展开更多
关键词 Hospital ARCHITECTURE Public Health Units LSF FLEXIBILITY of SPACES
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现浇空间异形曲面屋面施工技术 预览
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作者 金彦钊 艾克拜尔·阿不来提 +4 位作者 潘亚泽 陈选飞 薛彪 王兴 杨旭东 《施工技术》 CAS 2019年第22期105-108,共4页
科威特大学城ACSF项目603地块示范学校(Model School)项目屋面为现浇不规则曲率空间曲面,常规模板体系难以满足曲面定位拟合及承载力要求。针对以上施工难点,采用单元体模板拼装,将曲屋面划分单元格,以平面模板加定制背楞框架组成单元体... 科威特大学城ACSF项目603地块示范学校(Model School)项目屋面为现浇不规则曲率空间曲面,常规模板体系难以满足曲面定位拟合及承载力要求。针对以上施工难点,采用单元体模板拼装,将曲屋面划分单元格,以平面模板加定制背楞框架组成单元体,然后按节点高度拼接成曲面。根据屋面坡度分缓屋面和陡屋面设计单元体类型。研究结果及实践表明,该施工方法可操作性强,既承载力又极大程度契合曲面曲率变化。 展开更多
关键词 屋面 异形曲面 单元体 拼装 施工技术
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Polarization multiplexing based duplex radio-over-fiber link for millimeter wave signal transmission to a ring of multiple radio access units
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作者 Tayyab MEHMOOD Hina QAYYUM Salman GHAFOOR 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第2期300-306,共7页
A radio-over-fiber(RoF) distributed antenna system(DAS) architecture is proposed, where millimeter wave(mm-wave) signals are transmitted to four different radio access units(RAUs) arranged in a ring topology.The propo... A radio-over-fiber(RoF) distributed antenna system(DAS) architecture is proposed, where millimeter wave(mm-wave) signals are transmitted to four different radio access units(RAUs) arranged in a ring topology.The proposed architecture transmits duplex data of 128 Mb/s to each RAU in both downlink(DL) and uplink(UL)directions. The radio frequency(RF) signals are transmitted by polarization multiplexing a multi-wavelength source.Millimeter-wave signals at a frequency of 25 GHz are generated at each RAU using remote heterodyne detection.The proposed architecture provides increased coverage while maintaining good bit error rate(BER) results. 展开更多
关键词 RADIO over fiber MILLIMETER wave RADIO access UNITS
A descriptor of “material genes”: Effective atomic size in structural unit of ionic crystals
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作者 CHEN Dong LI ShunNing +7 位作者 JIE JianShu LI SiBai ZHENG ShiSheng WENG MouYi YU ChangCheng LI ShuCheng CHEN DaJun PAN Feng 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第5期849-855,共7页
The atomic size of each element, described by the ionic radius, is one category of 'material genes' and can facilitate our understanding of atomic arrangements in compounds. Most of the ionic radii currently u... The atomic size of each element, described by the ionic radius, is one category of 'material genes' and can facilitate our understanding of atomic arrangements in compounds. Most of the ionic radii currently used to measure the sizes of cations and anions in ionic crystals are derived from hard-sphere model based on the coordination numbers, or the soft-sphere model incorporating the effect of ionic polarization. Herein we take a first step towards a novel 'effective atomic size'(EAS) model,which takes into consideration the impact of the types and number of neighboring atoms on the relationship between ionic radii and interatomic distances. Taking the binary compounds between Group IA/IIA and VIA/VIIA elements gathered from the latest databases as an example, we show that the proposed EAS model can yield excellent agreement between the predicted and the DFT-calculated interatomic distances, with deviation of less than 0.1 ?. A set of EAS radii for ionic crystals has been compiled and the role of coordination numbers, geometric symmetry and distortion of structural units has been examined. Thanks to its superior predictability, the EAS model can serve as a foundation to analyze the structure of newly-discovered compounds and to accelerate materials screening processes in the future works. 展开更多
关键词 ionic RADII interatomic distance EFFECTIVE ATOMIC SIZE coordination environment STRUCTURAL units
标准编制中量与单位常见问题及处理 预览
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作者 吴明亮 崔晓军 +1 位作者 王一飞 薛建军 《中国质量与标准导报》 2019年第2期41-48,共8页
依据GB/T 1.1—2009《标准化工作导则 第1部分:标准的结构和编写》给出的规则,结合GB 3100《国际单位制及其应用》、GB 3101《有关量、单位和符号的一般原则》等标准要求,给出了在标准编制中量与单位的常见问题,提出了笔者对这些问题的... 依据GB/T 1.1—2009《标准化工作导则 第1部分:标准的结构和编写》给出的规则,结合GB 3100《国际单位制及其应用》、GB 3101《有关量、单位和符号的一般原则》等标准要求,给出了在标准编制中量与单位的常见问题,提出了笔者对这些问题的处理办法。 展开更多
关键词 标准编制 单位
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Optimum development options and strategies for water injection development of carbonate reservoirs in the Middle East 预览
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作者 SONG Xinmin LI Yong 《石油勘探与开发:英文版》 2018年第4期723-734,共12页
Through the research on several carbonate reservoirs developed in the Middle East, the basic characteristics of different types of carbonate reservoirs are determined, and a set of high-efficiency water injection deve... Through the research on several carbonate reservoirs developed in the Middle East, the basic characteristics of different types of carbonate reservoirs are determined, and a set of high-efficiency water injection development options and strategies are presented. Hidden baffles and barriers exist in carbonate reservoirs in the Middle East, so the reservoirs could be divided into different separated development units based on the baffles and barriers characteristics. Flexible and diverse profile control techniques such as high angle wells and simple and applicative zonal water injection have been introduced to improve the control and development degree of reservoirs. Three principal water injection development methods suitable for different carbonate reservoirs in the Middle East are proposed, including the combination of crestal gas injection and peripheral water injection, bottom interval injection and top interval production(buoyancy underpinning), and 'weak point and strong plane' area well pattern. Based on the characteristics of very low shale content, fast and far pressure transmission in the Middle East carbonate reservoirs, a large well-spacing flood pattern is recommended, and reasonable development strategies have been made such as moderate water injection rate and maintaining reasonable production pressure drawdown and voidage replacement ratio, so as to maximize the recovery of reservoirs in the none or low water cut period. 展开更多
关键词 CARBONATE RESERVOIRS the Middle East water injection DEVELOPMENT OPTIONS DEVELOPMENT strategy barrier and BAFFLE SEPARATED DEVELOPMENT units
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