检索结果-南通市图书馆

图书情报工作 2001年第11期45卷 72-74,29页

作者：曹臻西北农林科技大学图书馆陕西杨陵712100

分析我国区域文献资源保障与服务系统的现状及存在的问题,提出以省市一级为基本构成,逐步建立区域文献资源保障与服务系统的设想,并对其管理机制进行探讨。

关键词：区域图书馆事业文献资源保障系统管理机制文献资源服务系统

Pyrolysis Characteristics and Thermal Kinetics of Degradable Films

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Pedosphere 2007年第5期17卷 654-659页

作者： WANG Xing LU Jia-Long ZHANG Yi-Ping College of Resources and Environment Northwest Agriculture and Forestry University Yangling 712100 （China） Shaanxi Provincial Bureau of Soil and Water Conservation Xi＇an 710004 （China）

Developing degradable films is an important means for resolving the problem of film pollution; however, in recent years, there have been only few studies related to the thermal analysis of degradable plastic films. This research detailed the composition and pyrolysis of one kind of ordinary and three kinds of degradable plastic films using the differential thermal analysis （DTA） technique. The results showed that degradable films and ordinary film had similar DTA curves, which reflected their similar compositions; however, small differences were measured, which were due to the added constituents of the degradable films. The pyrolysis reaction orders of each film were about 0.93. The pyrolysis activation energies and pre-exponential factors followed the order of ordinary film 〉 photodegradable film 〉 photodegradable calcium carbonate film 〉 biodegradable film. The results of this research laid the foundation for new theories for harnessing soil pollution caused by plastic films.

关键词： degradable film differential thermal analysis pyrolysis thermal kinetics

Origin of Gymnocypris przewalskii and phylogenetic history of Gymnocypris eckloni (Teleostei: Cyprinidae)

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Progress in Natural science:Materials International 2007年第05期17卷 520-528页

作者： Zhao Kai, Duan Ziyuan, Yang Gongshe, Peng Zuogang, He Shunping and Chen Yiyu (Institute of Hydrobiology, Chinese Academy of sciences, Wuhan 430072. China Laboratory of Animal Fat Deposition and Muscle Development, northwest sci-tech {2. of agriculture and forestry, yangling 712.00, China agriculture and Animal Husbandry College, Qinghai {2., Xining 810003, China Institute of Genetics and Developmental Biology, Chinese Academy of sciences, Beijing 100101, China) [a]Institute of Hydrobiology Chinese Academy of Sciences Wuhan China [b]Laboratory of Animal Fat Deposition and Muscle Development Northwest Sci-Tech University of Agriculture and Forestry Yangling China [c]agriculture and Animal Husbandry College Qinghai University Xining China [d]Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China

The origins and phylogenetic patterns were assessed for G. przewalskii and G. eckloni by analyzing the complete mtDNA cytochrome b gene sequence (1140bp). Phylogenetic analyses further supported that there were three mtDNA lineages (A-C) identified in G. przewalskii and G. eckloni, demonstrating that outer rakers of the first gill have little significance in the phylogeny of the Gymnocypris fishes. The network established showed that G . eckloni of the Yellow River specific haplotype Al was a founder and it radiated all haplotypes of G. przewalskii which suggested G . przewalskii might only originate from one of two maternals of G . eckloni from the Yellow River. Fs test and mismatch analysis showed at least two expansion events in the population of G. przewalskii about 0.2.34 Ma and 0.0658 Ma, while G. eckloni from Qaidam Basin could have experienced severe bottleneck effect about 0.0693 Ma. The population expansion was detected in subclades Al and A2. with the most recent common ancestor (TMRCA) about 0. 2.08±0.01 Ma and 0.1319±0. 015 Ma, respectively, which were within the geological age range of "Gonghe Movement" event that caused the separation of Lake Qinghai from the upper Yellow River. These results suggested the effect of the fish diversification by rapid uplift of the Qing-hai-Tibetan Plateau in the Late Pleistocene.

关键词： G. przewalskii G. eckloni origin Cyt b phylogeography.

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现代图书馆信息传递过程中的损失研究

图书情报工作 2002年第10期46卷 66-70页

作者：白君礼西北农林科技大学图书馆陕西杨凌712100

对传统图书馆、数字图书馆信息传递过程进行定性、定量分析研究,分析信息在传递过程中损失的原因,提出减少信息损失的一些方法和对策。

关键词：现代图书馆信息传递信息损失原因用户素质教育信息通道信息服务人员

K~+channels inhibited by hydrogen peroxide mediate abscisic acid signaling in Vicia guard cells

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Cell Research 2001年第3期11卷 195-202页

作者： ZHANG XIAO, YU CHEN MIAO, GUO YONG AN, YUN ZHOU, ZHOU PING SHANGGUAN,JUN FENG GAO, CHUN PENG SONG College of life sciences, Norihwest sci-{2. university of {2. and forestry, yangling 712.00, China Department of Biology, Henan university, Kaifeng College of life sciences Northwest Sci-Tech University of Agriculture and Forestry Yangling 712100 China. Department of Biology Henan University Kaifeng 475001 China. National Laboratory of Soil Erosion and Dryland Farming the Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling 712100 China.

A number of studies show that environmental stress conditions increase abscisic acid (ABA) and hydrogen peroxide (H2.2. levels in plant cells. Despite this central role of ABA in altering stomatal aperture by regulating guard cell ion transport, little is known concerning the relationship between ABA and H2.2.in signal transduction leading to stomatal movement. Epidermal strip bioassay illustrated that ABA- inhibited stomatal opening and ABA-induced stomatal closure were abolished partly by externally added catalase (CAT) or diphenylene iodonium (DPl), which are a H2.2.scavenger and a NADPH oxidase inhibitor respectively. In contrast, internally added CAT or DPI nearly completely or partly reversed ABA-induced closure in half-stoma. Consistent with these results, whole-cell patch-clamp analysis showed that intracellular application of CAT or DPI partly abolished ABA-inhibited inward K+ current across the plasma membrane of guard cells. H2.2.mimicked ABA to inhibit inward K+ current, an effect which was reversed by the addition of ascorbic acid (Vc) in patch clamping micropipettes. These results suggested that H2.2.mediated ABA-induced stomatal movement by targeting inward K+ channels at plasma membrane.

关键词： Hydrogen peroxide abscisic acid K+ channels patch clamp vicia guard cell.

ADVANCES IN WHEAT RUST RESEARCHES IN CHINA

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ADVANCES IN WHEAT RUST RESEARCHES IN CHINA

Quantitative analysis of soil pores under natural vegetation successions on the Loess Plateau

The ⅩⅤth International Plant Protection Congress

作者： LI Zhen-qi northwest sci-{2.. {2. of agriculture and forestry yangling 712.00 China

来源： cnki会议评论

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science China Earth sciences 2010年第4期53卷 617-625页

作者： ZHAO ShiWei1,ZHAO YongGang1,2.& WU JinShui3 1 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,northwest agriculture & {2. university,yangling 712.00,China 2.Graduate university of Chinese Academy of sciences,Beijing 100049,China 3 Institute of Subtropical agriculture,Chinese Academy of sciences,Changsha 41012.,China 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Northwest Agriculture & Forestry University Yangling 712100 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Institute of Subtropical Agriculture Chinese Academy of Sciences Changsha 410125 China

Soil pore is a key attribute of the soil structure that affects soil reservoir under natural vegetation recovery on the Loess *** study is to quantitatively analyze soil pore parameters,measured with Computed Tomography(CT) at 15-57 mm depths under five different vegetation succession stages using a concept of substituting "space" for "time" in the Ziwuling Forest Region of the Loess *** results showed that the soil pore parameters,such as pore number,porosity,circularity,and fractal dimension,increased significantly under the natural vegetation successions and varied with the pattern climax community stage>pioneering arbor community stage>scrub community stage>herbaceous community stage>abandoned farmland stage,indicating that natural vegetation recovery could remarkably improve soil pore *** the vegetation succession,this positive effect will be strengthened gradually,which means that the soil pore parameters may appear to be best at the climax community *** organic matter content increased linearly with the soil pore parameters(P<0.001).Increased organic matter accumulation was one of the major reasons for the changes in soil pore characteristics in natural vegetation succession.

关键词： Computed Tomography Loess Plateau natural vegetation succession soil pore soil organic matter

Effect of molecular weight of dissolved organic matter on toxicity and bioavailability of copper to lettuce

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Journal of Environmental sciences 2010年第12期22卷 1960-1965页

作者： Xudong Wang,Xianni Chen,Shuai Liu,Xizu Ge College of Resource and Environment,northwest agriculture and {2. university,Shaanxi 712.00,China [a] College of Resource Environment Northwest Agriculture forestry university Shaanxi 712100 China

To clarify the effects of molecular weight of dissolved organic matter （DOM） on the toxicity and bioavailability of copper （Cu） to plants, DOM extracted from chicken manure was ultra-filtered into four fractions according to their molecular weights by means of sequential-stage ultrafiltration technique. Lettuce seeds were germinated by being exposed to the solutions containing Cu^2. with or without different fractions of DOM. The concentration of copper in roots, leaves, sprouts and the length of roots were investigated. The results showed that not all fractions of DOM could improve copper availability or toxicity. The fraction of DOM with larger molecular weight more than 1 kDa had higher complexation stability with Cu^2. and caused lower concentration of free Cu^2. ion in the solution of copper plus the fraction, resulting in lower availability and toxicity of copper to lettuce, but the fraction with molecular weight less than 1 kDa had the opposite function. Therefore, the molecular weight of 1 kDa may be the division point to determine DOM to increase or decrease copper availability and toxicity.

关键词： fraction of dissolved organic matter complexation stability coooer availability

SEVERAL sciENTIFIC PROBLEMS ON ECOLOGICAL SAFETY AND AGRICULTURAL SUSTAINABLE DEVELOPMENT IN WEST CHINA

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Natural Disaster Reduction in China 2002年第2期 25-29页

作者： Yang Zhengli 1, Yang Gaihe 1 and Zhang Dapeng 2.(1.northwest sci {2. {2. of agriculture and forestry, yangling 712.00, Shaanxi, China 2.Station of Soil and Manure, Department of agriculture, Shaanxi, 710000, China)

The article addresses several scientific issues regarding the ecological safety and agricultural sustainable development in the west of China from the perspectives of system ecology and system eco economics, including the relationship between agricultural development and ecological construction, development based ecological balance, the relationship between ecological agriculture and agricultural modernization, and ecological rehabilitation.

关键词： ecological safety agricultural sustainable development ecological rehabilitation west China

DARBOUX TRANSFORMATION OF A NONLINEAR EVOLUTION EQUATION AND ITS EXPLICIT SOLUTIONS

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Acta Mathematica scientia 2011年第4期31卷 1457-1464页

作者：李文敏韩有攀周高军 College of sciences the Northwest Sci-Tech University of Agriculture and Forestry College of sciences Xi'an Jiaotong University Department of Mathematics Henan College of Education

In this paper, we study a differential-difference equation associated with discrete 3 × 3 matrix spectral problem. Based on gauge transformation of the spectral problm, Darboux transformation of the differential-difference equation is given. In order to solve the differential-difference equation, a systematic algebraic algorithm is given. As an application, explicit soliton solutions of the differential-difference equation are given.

关键词： Darboux transformation solitons explicit solution Lax-pair differentialdifference equation