检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

压电参数的光反馈干涉测量方法

计量学报 2008年第4期29卷 349-352,386页

作者：叶会英禹延光郑州大学信息工程学院河南郑州450052

研究了光反馈自混合干涉现象,建立了干涉法测量形变的原理,从而提出了一种基于光反馈干涉效应测量压电应变常数的方法。设计了梯度迭代算法,由实验数据提取被测压电器件的应变量。用一种已知参数的压电器件对此方法进行了验证,测试结果... 详细信息

研究了光反馈自混合干涉现象,建立了干涉法测量形变的原理,从而提出了一种基于光反馈干涉效应测量压电应变常数的方法。设计了梯度迭代算法,由实验数据提取被测压电器件的应变量。用一种已知参数的压电器件对此方法进行了验证,测试结果与参照值误差不超过5%。光反馈干涉测试系统所需光学元器件少、结构紧凑,既能用于实验室也能用于工厂车间。

关键词：计量学压电参数测量光反馈式自混合干涉测量拟合算法

Aging behavior and precipitate characterization of Zn-rich Al-Zn-Mg-Cu alloys with various Mg and Cu contents

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2021年第8期28卷 1064-1073页

作者： Hai-chao Li Ming Li Dong-ye yang Fu-yang Cao yan-dong Jia Zhi-shui Yu Jian Zhao Tong Liu Hong Zhan Qiang Chen Jian-fei sun School of Materials Engineering Shanghai University of Engineering ScienceShanghai 201620China Sichuan Kelun Pharmaceutical Research Institute Chengdu 611138SichuanChina School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghai 200444China School of Mechanical and Automotive Engineering Anhui Polytechnic UniversityWuhu 241000AnhuiChina Southwest Technology and Engineering Research Institute Chongqing 400039China

Four Zn-rich Al-Zn-Mg-Cu alloys with different Mg and Cu contents were fabricated by spray *** effects of Mg and Cu contents on the aging behaviors of the whole precipitation process of the alloys were systematically *** results show that the primary precipitates in the under-aged and peak-aged alloys are GPⅡ and η'phases;no GPⅠ zones were *** aging,the dissolution driving force of the precipitates increases with increasing Mg content;therefore,the volume fraction of precipitates in the grain interior and the area fraction of precipitates at the grain boundary increase obviously,which contributes to a considerable improvement in yield strength and decrease in plasticity of the high Mg content *** content has no apparent effect on the size and volume fraction of ***,a higher Cu content can effectively prevent coarsening and transformation of precipitates,which is beneficial to maintain the peak aging state of the *** research provides a basis for the composition optimization of the rapid-solidified highly alloying Al-Zn-Mg-Cu alloys.

关键词： Al-Zn-Mg-Cu alloy Zn-rich alloy Aging behavior Precipitate characterization Property

Effects of Plant Oil Mixture on Production Performance,Carcass and Beef Quality in Beef Cattle

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Husbandry and Feed Science 2011年第6期3卷 12-16页

作者： XIA guang-jun yan Chang-guo LIU Cheng-ming Agricultural College Yanbian University Yanji 133000 China Hunchun Tianyi Livestock Husbandry Co. Ltd. Hunchun 133300 China

[Objective] To study the effects of plant oil mixture on production performance, carcass and beef quality in beef cattle. [Method] Single-factor randomized blocks design was used. Sixteen healthy yanbian yellow bulls having close body weight were selected and randomly divided into four groups, four cattle per group. Been oil, safflower oil and sunflower oil were mixed respectively at a volume ratio of 11：5：4. The oil blend was added to the daily diets of beef cattle respectively at a proportion of 4%, 5% and 6%. The effects of the plant oil mixture on production performance, carcass and beef quality were investigated. [ Result.] Compared with the control cattle, the experimental cattle had significantly lower feed intake （P 〈 0.05）, non-significantly higher efficiency of feed utilization, and significantly lower digestibility of crude fiber and calcium （P 〈 0.05）. With the increasing level of plant oil, the digestibility of dry matter showed a decreasing trend. The digestibility of dry matter was significantly lower in the cattle fed on the plant oil mixture at a level of 6% than in the control （ P 〈 0.05）. The plant oil mixture had no effect on the digestibility of crude protein, ether extract, crude ash, nitrogen-free extract and phosphorus. With the increasing level of plant oil, the serum content of high-density lipoprotein showed an increasing trend. The serum content of high-density lipoprotein was significantly higher in the cattle fed on the plant oil mixture at a level of 6% than in the control （ P 〈 0.05）. With the increasing level of plant oil, the content of total cholesterol showed an increasing trend, whereas the content of low-density lipoprotein showed a decreasing trend. Moreover, other indicators did not change significantly. The experimental cattle had larger eye muscle area and better beef quality than the control group. The content of crude protein and ether extract in beef increased with the increasing level of plant oil. [ Conclusion] The plan

关键词： Plant oil Beef cattle Production performance Carcass Beef quality

Boosting chiral carboxylic acid hydrogenation by tuning metal-MO_(x)-support interaction in Pt-ReO_(x)/TiO_(2) catalysts

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Catalysis 2022年第8期43卷 2034-2044页

作者： guang Gao Zelun Zhao Jia Wang Yongjie Xi Peng sun Fuwei Li State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000GansuChina

Engineering the surface microenvironment by tuning the binary interactions between a supported metal with a secondary metal oxide(MO_(x))or support has been a common method for improving the catalytic performance of supported metal ***,few studies have investigated the ternary interactions among the metal,MO_(x),and ***,we report for the first time the formation of metal-MO_(x)-support interaction(MMSI)in reducible TiO_(2)-supported PtReO_(x) catalysts,affording 87% yield and 100% ee in the tandem hydrogenation of an aqueous chiral cyclohexane-1,2-dicarboxylic acid into the corresponding diol;the catalytic activity is eight times higher than that obtained with non-reducible support counterparts in the same reaction via traditional batch synthesis with multiple steps and unfriendly *** experimental and computational studies suggest that the TiO_(2) crystalline phase-dependent density of the oxygen vacancies induces different Pt-ReO_(x)-TiO_(2) interactions,which dominate the electron transfer therein and tune the adsorption strength of the carbonyl moiety of the substrate/intermediate,thus promoting the hydrogenation activity and *** addition,the strong MMSI endows the optimal rutile TiO_(2) supported PtReO_(x) catalyst with an outstanding lifetime of 400 h in a fixed-bed reactor under acidic aqueous conditions and ensures efficient applications in the selective hydrogenation of aliphatic dicarboxylic acids and functional carboxylic *** work provides a promising strategy for the development of efficient and stable supported catalysts for the selective hydrogenation of diverse C-O and C=O bonds.

关键词： Metal-MO_(x)-support interaction Synergistic catalysis Carboxylic acid Hydrogenation Alcohols with chiral group

The association between the baseline bone resorption marker CTX and incident dysglycemia after 4 years

在线全文

学校读者我要写书评

暂无评论

Bone Research 2017年第3期5卷 235-241页

作者： Ting-ting Liu Dong-mei Liu yan Xuan Lin Zhao Li-hao sun Dian-dian Zhao Xiao-feng Wang yang He Xing-Zhi Guo Rui Du Ji-qiu Wang Jian-min Liu Hong-yan Zhao Bei Tao Department of Endocrine and Metabolic Diseases Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai Institute of Endocrine and Metabolic Diseases Shanghai Clinical Center for Endocrine and Metabolic Diseases Department of Geriatrics Ruijin Hospital North Shanghai Jiao Tong University School of Medicine Department of Endocrine and Metabolic Diseases Zhong Shan Hospital Fudan University

Bone is an endocrine organ involved in modulating glucose homeostasis. The role of the bone formation marker osteocalcin （OCN） in predicting diabetes was reported, but with conflicting results. No study has explored the association between baseline bone resorption activity and incident diabetes or prediabetes during follow-up. Our objective was to examine the relationship between the baseline bone resorption marker crosslinked C-telopeptide of type I collagen （CTX） and glycemic dysregulation after 4 years. This longitudinal study was conducted in a university teaching hospital. A total of 195 normal glucose tolerant （NGT） women at baseline were invited for follow-up. The incidence of diabetes and prediabetes （collectively defined as dysglycemia） was recorded. A total of 128 individuals completed the 4-year study. The overall conversion rate from NGT to dysglycemia was 31.3%. The incidence of dysglycemia was lowest in the middle tertile [16.3% （95% confidence interval （CI）, 6.8%-30.70/0）] compared with the lower [31.0% （95% CI, 17.2%-46.1%）] and upper [46.5% （95% CI, 31.2%-62.6%）] tertiles of CTX, with a significant difference seen between the middle and upper tertiles （P = 0.002 5）. After adjusting for multiple confounding variables, the upper tertile of baseline CTX was associated with an increased risk of incident dysglycemia, with an odds ratio of 7.09 （95% CI, 1.73-28.99） when the middle tertile was the reference. Osteoclasts actively regulate glucose homeostasis in a biphasic model that moderately enhanced bone resorption marker CTX at baseline provides protective effects against the deterioration of glucose metabolism, whereas an overactive osteoclastic function contributes to an increased risk of subsequent dysglycemia.

关键词： CTX The association between the baseline bone resorption marker CTX and incident dysglycemia after 4 years

在线全文

学校读者我要写书评

暂无评论

城市蓝绿空间冷却效应的研究进展

西部林业科学 2023年第2期52卷 158-167,174页

作者：孙源爽刘光燕屈海燕沈阳建筑大学建筑与规划学院辽宁沈阳110168

本文基于419篇Web of ScienceTM和176篇中国知网数据库的相关文献,借助CiteSpace可视化图谱分析工具,对城市冷却效应领域的研究现状以及热点趋势进行定量和辅助定性分析。同时梳理热岛效应的3种研究方法,并探讨城市绿色、蓝色、蓝绿协... 详细信息

本文基于419篇Web of ScienceTM和176篇中国知网数据库的相关文献,借助CiteSpace可视化图谱分析工具,对城市冷却效应领域的研究现状以及热点趋势进行定量和辅助定性分析。同时梳理热岛效应的3种研究方法,并探讨城市绿色、蓝色、蓝绿协同空间的冷却效应机制,以及城市蓝绿空间对周边环境的冷却幅度,以期为营造健康的人居环境提供参考。结果显示:2002—2022年城市热岛领域的发文量呈递增态势,国外研究时间较国内起步较早且数量较多,如何设计城市的景观因子来达到更好的冷却效应是今后的研究趋势。气象监测、遥感卫星技术和计算机数值模拟3种研究方法目前均具有不同优缺点和适应性,应多种研究方法相结合。以往研究内容的探讨多集中在城市蓝色、绿色、蓝绿协同以及城市蓝绿空间对周围冷却幅度等4个方面,文献计量分析表明由于冷却效应的影响因素众多,故绿色空间冷却效应机制、周边环境影响冷却幅度的研究尚存在矛盾。而蓝色、绿色空间冷却强度还未确定,应深入研究。本文为城市规划者最大化实现冷却效应提供理论依据。

关键词： UHI效应城市公园蓝色空间绿色空间冷却效应蓝绿协同

维普期刊数据库博看期刊

Exotic origin of the Chinese continental shelf: new insights into the tectonic evolution of the western Pacific and eastern China since the Mesozoic

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2015年第18期60卷 1598-1616页

作者： Yaoling Niu Yi Liu Qiqi Xue Fengli Shao Shuo Chen Meng Duan Pengyuan Guo Hongmei Gong yan Hu Zhenxing Hu Juanjuan Kong Jiyong Li Jinju Liu Pu sun Wenli sun Lei Ye Yuanyuan Xiao Yu Zhang Institute of Oceanology Chinese Academy of Sciences Department of Earth Sciences Durham University School of Earth Science and Resources China University of Geosciences Institute of Deep Sea Science and Engineering Chinese Academy of Sciences School of Earth Sciences Lanzhou University

The effect of paleo-Pacific subduction on the geological evolution of the western Pacific and continental China is likely complex. Nevertheless, our analysis of the distribution of Mesozoic granitoids in the eastern continental China in space and time has led us to an interesting conclusion： The basement of the continental shelf beneath East and South China Seas may actually be of exotic origin geologically unrelated to the continental lithosphere of eastern China. By accepting the notion that the Jurassic- Cretaceous granitoids in the region are genetically associated with western Pacific subduction and the concept that subduction may cease to continue only if the trench is being jammed, then the termination of the granitoid magmatism throughout the vast region at -88±2 Ma manifests the likelihood of ＂sudden＂, or shortly beforehand （- 100 Ma）, trench jam of the Mesozoic western Pacific subduction. Trench jam happens if the incoming ＂plate＂ or portion of the plate contains a sizeable mass that is too buoyant to subduct. The best candidate for such a buoyant and unsubductable mass is either an oceanic plateau or a micro-continent. We hypothesize that the basement of the Chinese continental shelf represents such an exotic, buoyant and unsubductable mass, rather than seaward extension of the continental lithosphere of eastern China. The locus of the jammed trench （i.e., the suture） is predictably located on the shelf in the vicinity of, and parallel to, the arc-curved coastal line of the southeast continental China. It is not straightforward to locate the locus in the northern section of the East China Sea shelf because of the more recent （〈20 Ma） tectonic re-organization associated with the opening of the Sea of Japan. We predict that the trench jam at - 100 Ma led to the re-orientation of the Pacific plate motion in the course of NNW direction as inferred from the age-progressive Emperor Seamount Chain of Hawaiian hotspot origin （its oldest unsubdued Meiji and Detroi

关键词： Mesozoic granitoids in eastern ChinaExotic origin of Chinese continental shelf Trenchjam Transform plate boundary Basal hydrationweakening Lithosphere thinning Cratondestruction Mantle hydrous melting Crustalmelting Plate tectonics South China Sea

Efficacy and Safety of Aspirin for Prevention of Hepatocellular Carcinoma:An Updated Meta-analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Clinical and Translational Hepatology 2022年第5期10卷 835-846页

作者： Lun-Jie yan Sheng-Yu Yao Hai-Chao Li guang-Xiao Meng Kai-Xuan Liu Zi-Niu Ding Jian-Guo Hong Zhi-Qiang Chen Zhao-Ru Dong Tao Li Department of General Surgery Qilu HospitalShandong UniversityJinanShandongChina Department of Hepatobiliary Surgery The second Hospital of Shandong UniversityJinanShandongChina

Background and Aims:Previous meta-analyses have shown that aspirin use may reduce the risk of hepatocellular carcinoma(HCC).However,the optimal dose,frequency,and duration of aspirin use or the safety and efficacy of aspirin in target populations for HCC prevention remain *** study aim was to investigate the efficacy and safety of aspirin for prevention of ***:Publications were retrieved by a comprehensive literature research of several *** on a random-effects model,hazard ratios(HRs)and the corresponding 95%confidence intervals(CIs)were used to assess the pooled *** dose-response relationship between aspirin use and HCC risk was assessed with a restricted cubic spline ***:Twenty-two studies were included in the *** use was associated with a reduced risk of HCC(HR=0.64,95%CI:0.56–0.75).The effect was robust across sex and age;however,women and the non-elderly had the greatest benefit from aspirin *** preventive effect was well reproduced in those with *** use and long-term use of aspirin appeared to offer greater *** 100 mg/d was associated with maximum reduction of HCC *** use did slightly increase the risk of bleeding(HR=1.14,95%CI:1.02–1.27).Conclusions:Our meta-analysis confirmed that use of aspirin significantly reduced the incident risk of *** and long-term aspirin use offers a greater *** use was associated with an increased risk of *** recommend 100 mg/d aspirin as a feasible dose for further research on primary prevention of HCC in a broad at-risk population.

关键词： Aspirin Hepatocellular carcinoma Prevention Meta-analysis Doseresponse analysis

RESTplus: an improved toolkit for resting-state functional magnetic resonance imaging data processing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science Bulletin 2019年第14期64卷 953-954页

作者： Xi-Ze Jia Jue Wang Hai-yang sun Han Zhang Wei Liao Ze Wang Chao-Gan yan Xiao-Wei Song Yu-Feng Zang Center for Cognition and Brain Disorders Institutes of Psychological Sciences Hangzhou Normal University Hangzhou 311121 China Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments Hangzhou 377727 China Department of Radiology and Biomedical Research Imaging Center University of North Carolina at Chapel Hill Chapel Hill NC 27517 USA School of Life Science and Technology Center for Information in BioMedicine University of Electronic Science and Technology of China Chengdu 610054 China CAS Key Laboratory of Behavioral Science Institute of Psychology Beijing 100101 China Department of Psychology University of Chinese Academy of Sciences Beijing 100101 China Preclinical Pharmacology Section National Institute on Drug Abuse Baltimore 21224 USA

Resting-state functional magnetic resonance imaging (RS-fMRI)[1,2] provides relatively high spatial and temporal resolution for mapping spontaneous brain activity non-invasively. It has been widely used in cognitive neuroscience and clinical studies. A number of comprehensive software packages have been developed for RS-fMRI data analysis, among which a MATLAB package named REST (RESing-state fMRI data analysis Toolkit, released in October 2008 at http://***)[3] is the earliest one dedicated to RS-fMRI analysis. REST focuses on RS-fMRI postprocessing metrics.

关键词： Resting-state functional magnetic resonance imaging (RS-fMRI) REST MATLAB