检索结果-南通市图书馆

A chemical etching route to controllable fabrication of TiO2 hollow nanospheres for enhancing their photocatalytic activity

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2013年第2期7卷 192-201页

作者： Weixin ZHANG Jie xing Zeheng yang mei KONG Hongxu YAO School of Chemical Engineering Hefei University of Technology Anhui 230009 China Anhui Key Laboratory of Controllable Chemical Reaction & Material Chemical Engineering Anhui 230009 China

The TiO2 hollow nanospheres with diameters of about 230 nm were prepared by a simple and controllable route based on hydrolysis of Ti（OBu）4 on the surfaces of the Cu20 solid nanospheres followed by inward etching of the Cu20 nanospheres. The as-prepared samples were characterized by X-ray diffraction, transmis- sion electron microscopy and scanning electron micro- scopy. The further post-heat treatment led to the high crystallization of the TiO2 hollow nanospheres. The photocatalytic performances of these samples were evaluated for the photodegradation of rhodamine B （RhB） under UV-light irradiation. The as-prepared TiO2 hollow nanospheres showed higher photocatalytic activity than the CuO and the CuO/TiO2 hollow nanospheres. Effects of temperature and time for post-heat treatment of TiO2 as well as initial RhB concentrations on the RhB photodegradation have also been studied. The results show that the TiO2 hollow nanospheres have the good reusability as photocatalysts and are promising in waste water treatment.

关键词： TiO2 hollow nanospheres rhodamine B,photocatalytic activity

汉防己甲素对肾病综合征大鼠肾皮质Ⅳ型胶原基因表达的影响

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

上海中医药大学学报 2001年第3期15卷 49-50页

作者：董兴刚安增梅杨海春上海市第二人民医院肾内科上海200011

为探讨中药汉防己甲素对肾病综合征的影响 ,采用单侧肾切除加两次注射阿霉素制造肾病综合征大鼠模型 ,观察分别经汉防己甲素和络活喜治疗后肾皮质Ⅳ型胶原基因表达。结果 :两药均能使模型鼠肾皮质Ⅳ型胶原mRNA表达明显下调。提示汉防己... 详细信息

为探讨中药汉防己甲素对肾病综合征的影响 ,采用单侧肾切除加两次注射阿霉素制造肾病综合征大鼠模型 ,观察分别经汉防己甲素和络活喜治疗后肾皮质Ⅳ型胶原基因表达。结果 :两药均能使模型鼠肾皮质Ⅳ型胶原mRNA表达明显下调。提示汉防己甲素可预防和延缓肾病综合征。

关键词：汉防已甲素肾病综合征 Ⅳ型胶原基因表达

金属掺杂Ce-M(M=Fe、Ni和Cu)催化剂的CO低温氧化性能研究

在线全文

学校读者我要写书评

暂无评论

燃料化学学报 2017年第6期45卷 707-713页

作者：李树娜石奇李小军方振华孙平周跃花张杏梅杨晓慧西安文理学院化学工程学院陕西省表面工程与再制造重点实验室陕西西安710065

采用水热合成法制备了一系列不同金属掺杂的Ce-M(M=Fe、Ni和Cu)复合氧化物,运用低温N_2吸附-脱附、XRD、H2-TPR、拉曼光谱和XPS等表征技术对Ce-M复合氧化物的结构与其CO低温氧化反应性能之间的关系进行了关联。结果表明,将Fe、Ni和Cu掺... 详细信息

采用水热合成法制备了一系列不同金属掺杂的Ce-M(M=Fe、Ni和Cu)复合氧化物,运用低温N_2吸附-脱附、XRD、H2-TPR、拉曼光谱和XPS等表征技术对Ce-M复合氧化物的结构与其CO低温氧化反应性能之间的关系进行了关联。结果表明,将Fe、Ni和Cu掺入CeO_2明显提高了其氧空位的含量,提升了晶格氧的流动性,从而使Ce-M催化剂的还原能力和催化活性高于纯CeO_2。其中,CeCu催化剂氧空位最多、还原能力最好,催化活性最高,130℃下即可将CO完全氧化;其次是CeNi催化剂,180℃时实现CO完全氧化;与之相比,CeFe催化剂的活性最差,200℃时的CO转化率仅为92%。

关键词：掺杂CeO2 Fe2O3 NiO2 CuO 氧空位 CO低温氧化

在线全文

学校读者我要写书评

暂无评论

潜阳降压胶囊的鉴别及含量测定研究

时珍国医国药 2003年第9期14卷 543-544页

作者：刘兴文梅娇杨晓东重庆市北碚区中医医院 400700

目的 :探讨潜阳降压胶囊的质控标准。方法 :用沉淀显色法鉴别方中钩藤碱及钙盐 ;用薄层色谱法鉴别白芍及玄参 ;用容量法测定钩藤碱的含量。结果 :方法简便 ,重现性好 ,质量可控。结论

关键词：潜阳降压胶囊鉴别含量测定钩藤碱芍药苷

Bunch-length measurement at a bunch-by-bunch rate based on time–frequency-domain joint analysis techniques and its application

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第4期35卷 165-175页

作者： Hong-Shuang Wang xing yang Yong-Bin Leng Yi-mei Zhou Ji-Gang Wang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

This paper presents a new technique for measuring the bunch length of a high-energy electron beam at a bunch-by-bunch rate in storage *** technique uses the time–frequency-domain joint analysis of the bunch signal to obtain bunch-by-bunch and turn-by-turn longitudinal parameters,such as bunch length and synchronous *** bunch signal is obtained using a button electrode with a bandwidth of several *** data acquisition device was a high-speed digital oscilloscope with a sampling rate of more than 10 GS/s,and the single-shot sampling data buffer covered thousands of *** bunch-length and synchronous phase information were extracted via offline calculations using Python *** calibration coefficient of the system was determined using a commercial streak ***,this technique was tested on two different storage rings and successfully captured various longitudinal transient processes during the harmonic cavity debugging process at the Shanghai Synchrotron Radiation Facility(SSRF),and longitudinal instabilities were observed during the single-bunch accumulation process at Hefei Light Source(HLS).For Gaussian-distribution bunches,the uncertainty of the bunch phase obtained using this technique was better than 0.2 ps,and the bunch-length uncertainty was better than 1 *** dynamic range exceeded 10 *** technology is a powerful and versatile beam diagnostic tool that can be conveniently deployed in high-energy electron storage rings.

关键词： Bunch-by-bunch diagnostic Bunch-length measurement Synchronous phase measurement Joint time–frequency-domain analysis Longitudinal instability

One new record species,Ithocritus ruber(Hope,1839) from China(Coleoptera:Cerambycidae:Lamiinae:Petrognathini)

在线全文

学校读者我要写书评

暂无评论

动物分类学报 2014年第2期39卷 309-312页

作者： mei-Ying Lin xing-Ke yang Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of Sciences

Ithocritus tuber （Hope, 1839） is recorded from Yunnan, China for the first time. Supplementary description of the female genitalia is made. Photographs of habitus and genitalia of female, a key to the 3 genera 4 spe... 详细信息

关键词： Ithocritus tuber (Hope 1839) new record female key China.

Time Trends of Cancer Incidence in Urban Beijing,1998-2007

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2011年第1期23卷 15-20页

作者： Ning Wang Wei-xing Zhu Xiu-mei xing Lei yang Ping-ping Li Wei-cheng You Key laboratory of Carcinogenesis and Translational Research （Ministry of Education） Beijing Cancer Registry Beijing 100142 China Key laboratory of Carcinogenesis and Translational Research （Ministry of Education） Department of Cancer Epidemiology Peking University School of Oncology Beijing Cancer Hospital ＆ Institute Beijing 100142 China

Objective：To report the time trends of cancer incidence in urban Beijing from 1998 to ***：All data were obtained from Beijing Cancer Registry from 1998-2007 in urban *** trends of incidence rate of cancer were assessed by annual percentage change（APC） of age-standardized incidence rate（ASR） of world standard population during this 10-year ***：For all 156851 cancer cases combined,the incidence rate rose in both males and females,with an APC of 2.23% and 3.74%,*** incidence rate of upper gastrointestinal cancers declined significantly,with an APC of-2.83% in esophageal cancer and-1.37% in male gastric cancer,while lower gastrointestinal cancer,such as colorectal cancer,increased with an APC of 4.08%.The rates of kidney and bladder cancer increased with an APC of 7.93% and 5.57%,*** women,the APC continued to rise in breast cancer（4.98%）,ovary cancer（6.16%）,cervix uteri cancer（11.74%）,corpus uteri cancer（6.96%） and thyroid gland cancer（13.39%）.The rate of prostate cancer among men increased with an APC of 8.58%;the rate of lymphoma and leukemia increased with APC of 5.48% and 5.44%,***：Because of population aging and urban modernization,the cancer burden in Beijing has become more and more severe and similar to the western developed countries.

关键词： Oncology Epidemiology Incidence Trend

Extrinsic and intrinsic factors controlling spermatogonial stem cell self-renewal and differentiation

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2015年第3期17卷 347-354页

作者： xing-xing mei Jian Wang Ji Wu Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) Bio-X Institutes Shanghai Jiao Tong University Shanghai 200240 China Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education Ningxia Medical University Yinchuan 750004 China Shanghai Key Laboratory of Reproductive Medicine Shanghai 200025 China

Spermatogonial stem cells （SSCs）, the stem cells responsible for male fertility, are one of a small number of cells with the abilities of both self-renewal and generation of large numbers of haploid cells. Technology improvements, most importantly, transplantation assays and in vitro culture systems have greatly expanded our understanding of SSC self-renewal and differentiation. Many important molecules crucial for the balance between self-renewal and differentiation have been recently identified although the exact mechanism（s） remain largely undefined. In this review, we give a brief introduction to SSCs, and then focus on extrinsic and intrinsic factors controlling SSCs self-renewal and differentiation.

关键词： differentiation self-renewal signal spermatogonial stem cells

Thermodynamics of Ion Pair of Magnesium Sulfate in Mixed Solvent

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

Chemical Research in Chinese Universities 2006年第3期22卷 403-405页

作者： yang Jia-zhen CHANG Xiao-hong LU xing-mei Department of Chemistry Liaoning University Shenyang 110036 P. R. China Department of Chemistry Shenyang Normal University Shenyang 110034 P.R. China

Introduction Magnesium sulfate is an archetypal 2-2 salt that plays a central role in defining the characteristics of higher valent electrolyte solutions and its solution has been widely used to test various theories of strong electrolyte behavior and to develop models of ion association in solution. Up to now, the ion pairs of magnesium sulfate in an aqueous solution have been widely investigated by using different experimental techniques, such as conductometry , cryoscopy potentiometry solubility and Raman spectrometry. However, to our knowledge, no measurement of the standard association constant of the ion pairs, [ MgSO4 ]^0 in a glucosewater mixed solvent is available.

关键词： Association constant Mixed solvent MgSO4 Ion pair