检索结果-南通市图书馆

有机化学 2003年第Z1期23卷 411-412页

作者： SONG Hua-Can WEN Huan LIANG Dong SUN Yi-Feng School of Chemistry and Chemical Engineering Zhongshan University Guangzhou 510275 School of Chemistry and Chemical Engineering Zhongshan University Guangzhou 510275 School of Chemistry and Chemical Engineering Zhongshan University Guangzhou 510275 School of Chemistry and Chemical Engineering Zhongshan University Guangzhou 510275

　　It has attracted a lot of attentions to synthesize and investigate the behaviors of organic second-order nonlinear optical (NLO) materials. [1,2] We have ever reported that acridine derivatives ,[3] 4-substituted-benzylideneoxazol-5(4H)-one[4] and 4,4′-di-styryl-biphenyl derivatives[5] possess good second-order NLO properties. Coumarin derivatives are good organic optical materials and azobenzene derivatives possess a higher second-order nonlinear polarization values, however, there are few reports about the study on the synthetic method, optical behavior, especially,second-order NLO properties of 3-substitued-6-(substituted-phenylazo) coumarin derivatives. Therefore, a series of the following compounds were prepared in order to investigate their NLO behavior.……

关键词： optical materials nonlinear optical synthetic method in order

Fortification Challenges and Needs

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

Biomedical and Environmental Sciences 2001年第1期14卷 98-103页

作者： RODOLFO F. FLORENTINO President Philippine Association of Nutrition Philippines

Experience in many parts of the developing world has shown that food fortification offers a cost_effective and sustainable solution to the problem of micronutrient malnutrition. Building on the advances in science and technology and backed by studies on the economic benefits of fortification programs, governments and industry are beginning to respond positively to the call of nutrition advocates to adopt fortification as a long_term strategy. On the other hand, formidable challenges still remain in many countries in Asia, constraining the widespread adoption of this strategy. The science and technology community needs to provide adequate scientific and technological information as basis for planning and decision making. The government faces the challenge of providing the enabling environment for all stakeholders to cooperate in the fortification effort. Industry faces the challenge of adapting its production system to the requirements of fortification in order that they can contribute to social objectives while pursuing their economic objectives. The international and bilateral aid agencies need to seek tried and innovative ways to support the multiple players of food fortification, as these players in turn face the challenges that confront them.

关键词： science and technology production system economic benefits decision making in order

Risk Management——An Industry Approach

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2001年第1期14卷 21-29页

作者： ANTHONY C. HUGGETT Regional Quality Assurance Laboratory

An effective risk management system covering the whole process of food production from “farm to fork” is required by the food industry in order to assure that the food provided to consumers is safe. Food safety and quality assurance begins with the design and development of food products starting with product conceptualisation and continuing with the selection, purchasing, and evaluation of raw materials and with the specifications for processing, packaging and distribution. Within a larger quality management framework a number of tools have been developed by the food industry, which when used in an integrated fashion facilitate the management of food safety. These include good manufacturing practice (GMP), good hygiene practice (GHP) and HACCP (hazard analysis critical control point) as well as quality systems which allow the verification that all factors affecting the safety of a product are under control. Finally, regulations and systems can only function if they are applied. Everyone, from the farmer, the line operator in the manufacturing plant, to the person handling the food in distribution and sales, needs to be aware of his influence with regards safety. The effectiveness of safety awareness programs specific to each area is key to an industry approach to risk management.

关键词： risk management system food industry food safety critical control point quality management quality assurance quality systems raw materials food products in order used in

Discussion on the feature of strong earthquake: orderly distribution in time, space and intensity before the Western Kunlun Mountain Pass M=8.1 earthquake

在线全文

学校读者我要写书评

暂无评论

Acta Seismologica Sinica(English Edition) 2003年第6期16卷 598-605页

作者：张晓东张永仙吕梅梅余素荣 Center for Analysis and Prediction China Seismological Bureau Beijing 100036 China

In the paper, the feature of strong earthquake orderly distribution in time, space and intensity before the Western Kunlun Mountain Pass M=8.1 earthquake is preliminarily studied. The modulation and triggering factors such as the earth rotation, earth tides are analyzed. The results show that: the giant earthquakes with the magnitude more than 8 occurred about every 24 years and the earthquakes with the magnitude more than 7 about every 7 years in Chinese mainland. The Western Kunlun Mountain M=8.1 earthquake exactly occurred at the expected time; The spatial distance show approximately the same distances between each two swarms. The earth rotation, earth tide, sun tide and sun magnetic field have played a role of modulation and triggering in the intensity. At last, the condi-tions for earthquake generation and occurrence are also discussed.

关键词： giant earthquake time, space and intensity in order feature

Definition and Measurement of Child Malnutrition

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2001年第4期14卷 283-291页

作者： GEKE－You CHANGSU－YING 等 InstituteofNutritionandFoodHygiene ChineseAcademyofpreventiveMedicineBeijing100050China

Child Malnutrition has been defined or described in many ways. To summarize the common points, child malnutrition may be defined as a pathological state resulting from inadequate nutrition, including undernutrition (protein- energy malnutrition) due to insufficient intake of energy and other nutrients; overnutrition (overweight and obesity) due to excessive consumption of energy and other nutrients; deficiency diseases due to insufficient intake of one or more specific nutrients such as vitamins or minerals. In the assessment of child malnutrition, a large number of measures are available. Among these measuring methods, Z-score, growth charts, weight-for-length index (WLI), height standard weight, body mass index, skin fold thickness and clinical grading diagnosis standard for child malnutrition are selected for discussion. The same set of anthropometry data of a group of preschool children was analyzed by using different methods. The results showed that it was very difficult to determine the nutritional state of children using a single index. For a given group of children, Z-score method is recommended to observe their height, weight and weight for height at the same time in order to have a comprehensive understanding.

关键词： preschool children measuring methods in order

Cooling Rates of PREP Ti48Al Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2001年第1期17卷 91-92页

作者： Xuezhu MA Jun SHEN Xiumei QI Jun JIA School of Materials Science&Engineering Harbin institute of TechnologyHarbin 150001China

Determining the cooling rate of a rapidly-solidified (RS) technique subjectively is a prerequisite of knowing the RS technique, and it is difficult. Model of heat transfer is constructed in this paper in order to calculate cooling rates of rapidly-solidified Ti48AI alloy. Rapid solidification technique utilized is the plasma rotating electrode process (PREP hereafter). The results show that: the cooling rate of PREP is at the scope of 102-103 K/s.

关键词： cooling rate electrode process heat transfer RS technique in order

SYSTEMS BIOLOGY BRINGS LIFE SCIENCES CLOSER—REPORT ON THE CHINA-UK SYSTEMS BIOLOGY WORKSHOP 2005

在线全文

学校读者我要写书评

暂无评论

Genomics, Proteomics & Bioinformatics 2005年第3期3卷 194-196页

作者： Ming Chen Bioinformatics Group College of Life Sciences Zhejiang University Hangzhou 310029 China

The China-UK Systems held during June 20-21 Biology Workshop 2005 was in the National Science Park of Zhejiang University, Hangzhou, China. It was organized by the Institute of Bioinformatics, Zhejiang University, and was initiated by Prof. Dr. Jun Zhu （Zhejiang University） and Prof. Dr. John Findlay （University of Leeds, UK）. The workshop was part of the program called UK-China Partners in Science, a one-year campaign that was initiated by the British government to explore more collaborations between UK and China on science and technology. It was attended also by a representative of this program, Mr. Frank Yuan, senior science ＆ innovation officer. The idea of the workshop was to bring together experts with specialists in systems biology in order to promote the ＂natural partnership＂ between scientists from the two countries. The most important items of systcms biology considered at the workshop were：（1） New technologies and advances in systems biology; （2） Research developments in genomics and proteomics; （3） New methodologies and software in computational biology; （4） Research collaboration on systems biology between China and UK.

关键词： Systems Biology science and technology computational biology in order

Effects of nerve growth factor on the expression of caspase-12 of nerve cells in cerebral ischemia/reperfusion area

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2006年第4期1卷 293-296页

作者： Jiping Yang Huaijun Liu Ying Li Yan Liu Haiqing Yang Department of Medical Imaging Second Hospital Hebei Medical University Shijiazhuang 050000 Hebei Province China Department of Internal Medicine Second Hospital Hebei Medical University Shijiazhuang 050000 Hebei Province China

BACKGROUND： Researches suggest that cascade reaction of cysteine protease mediated by caspase-12 can cause apoptosis after cerebral ischemia/reperfusion injury; however, nerve growth factor （NGF） can reduce apoptosis through inhibiting activation of that reaction. OBJECTIVE： To observe the effect of NGF on the expression of caspase-12 in brain tissue of rabbits with cerebral ischemia/reperfusion injury, and elucidate the protective mechanism of NGF on neural apoptosis induced by cerebral ischemia/reperfusion injury. DESIGN： Randomized controlled animal study SETTING： Department of Image, Second Hospital, Hebei Medical University .MATERIALS ： A total of 26 healthy New Zealand rabbits, of clean grade, aged 4.5-5 months, weighing （2.6±0.2） kg, were selected in this study. Reagents： NGF （Xiamen Beida Zhilu Biotechnology Co., Ltd.）; caspase-12 （Santa Cruz Biotechnology Company, USA, clone number： SC-12395）; caspase-3 （Santa Cruz Biotechnology Company, USA, clone number： SC-7272）; biotin-antibody Ⅱ and ABC compound （Wuhan Boster Company）; in situ end-labeling （ISEL, Beijing Zhongshan Company）. METHODS： The experiment was carried out in the Laboratories of Nerve Molecule Image Science and Neurology of the Second Hospital of Hebei Medical University from May to August 2005. （1） All animals were randomly divided into three groups. Ischemia/reperfusion （I/R） group （n=10）： Left middle cerebral artery （MCA） was blocked for 2 hours and then blooded for 2 hours in order to establish focal cerebral ischemi- a/reperfusion models. Sham operation group （n=6）： Cork was inserted with 3 cm in depth, and then pulled to common carotid artery. Other procedures were as the same as those in ischemia/reperfusion group. Treatment group （n=-10）： After modeling, 400 AU （16 μg/L） NGF was inserted into cerebral infarction focus immediately. （2） Brain tissue was taken out from left ischemia/reperfusion area at 3 days after operation in sham operation group and at 3 days after reperfusion in other two groups, In addition, contents of ca

关键词： focal cerebral ischemia nerve cells cascade reaction middle cerebral artery common carotid artery cerebral infarction cysteine protease flow cytometry growth factor animal study New Zealand in order

A New Biflavone from Selaginella pulvinata Maxim

在线全文

学校读者我要写书评

暂无评论

有机化学 2003年第Z1期23卷 395-396页

作者： XU Kang-Ping XU Zhi DENG Yin-Hua LI Fu-Shuang ZHOU Ying-Jun HU Gao-Yun TAN Gui-Shan Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078 Department of Medicinal Chemistry School of Pharmaceutical Sciences Central South University Changsha 410078

　　Selaginella pulvinata Maxim. distributes all over the country of China and is used for the treatment for haemor rhage. [1] We studied on the chemical constituents of S. pulvinata in order to find the active compounds. Dried stems and leaves of S. pulvinata (6.5 kg) were extracted with 70% ethanol twice. The extract was evaporated under vacuum and than suspended in water, extracted with petroleum and EtOAc sequentially. The EtOAc extract was chromatographed on silica gel, eluted with CHCl3-MeOH. As a result, a novel biflavone, named pulvinatabiflavone, was obtained from fractions 75 ～ 78. Its structure was determined on the basis of spectroscopic analysis as 5,5″, 4′″ trihydroxy-7,7″-dimethoxy-[4′-O-6″]-biflavone (compound 1).……

关键词： spectroscopic analysis chemical constituents silica gel in order

The Textured Growth Characteristics of Diamond Films on CoSi2 (001)

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

材料科学与工程学报 2000年第Z2期20卷 653-656页

作者： C.Z.Gu Fraunhofer-Instiut f(u)r Schicht- und Oberfl(a)chentecbnik Bienroder Weg 54E 38108 Braunschweig Germany

Epitaxial CoSi2 (001) layers, deposited on Si (001) substrate by molecular beam allotaxy (MBA), were used as substrate for diamond deposition in order to realise new applications. The results indicate that, in a microwave plasma chamber, diamond can be nucleated with a higher density on CoSi2 at lower temperatures using a bias enhanced method. High quality, [001]-textured diamond films can be synthesized on CoSi2 (001) using the [001] textured growth conditions. So far an epitaxial growth of diamond on CoSi2 cannot be observed. Statistically, a rotating angle distribution of diamond grains around the [001] axis in an [001]-textured film shows, however, preferred in-plane orientations of 13°, 22°, 45° and 77° relative to the CoSi2 [011]axis. The structural and chemical analyses show that no Co and Si element diffusion from the CoSi2 substrate into the diamond film can be detected.

关键词： Diamond Films epitaxial growth plasma chamber diamond films in order