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Search Results: 1 - 10 of 34424 matches for " 汪凯闰 "
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食品与药品中维生素C含量的检测方法进展
Research Progress in Development of the Determination Methods of Vitamine C in Food and Pharmaceuticals  [PDF]
朱宏亮, 戴火锋, 汪凯闰, 姚屠鹏, 张蕴, 沈昊宇
Advances in Analytical Chemistry (AAC) , 2013, DOI: 10.12677/AAC.2013.32003
Abstract: 维生素C是人体不可缺少的营养物质之一，人体主要通过新鲜水果、蔬菜或药片来获取或补充维生素C。因此维生素C的含量成为评价食品营养价值和药品质量的重要标准之一。随着对食品安全的日益关心，食品营养中维生素C和医药品的定量分析已经吸引了越来越多的关注。近年来食品与药品中维生素C的检测方法发展较为迅速，主要有滴定分析法、光度法、电化学法、化学发光法、流动注射法、液相色谱法以及原子吸收间接法等。本文对比总结了这些方法的原理、特点以及应用范围，讨论了方法的优缺点，以期为选择合适的检测方法提供一定的参考。

Vitamin C is necessary to the growth and metabolism for human beings. Vitamin C is mainly from fruits, vegetables and medicine, so it is one of the important standards to evaluate the quality of the food nutrition and medicine. With the growing concern of food safety, the quantitative analysis of vitamin C in food nutrition and pharmaceuticals has attracted more and more attention. In recent years, determination techniques of vitamin C in food and pharma- ceuticals have been developed rapidly, including titrimetric method, spectrophotometric method, electrochemical me- thod, chemiluminescence method, flow injection analysis, liquid chromatography and indirect atomic adsorption me- thods, etc. In this work, some principles, characteristic and the recent progress of reported methods have been summarized and compared.

 

资源富集地区经济贫困的成因与对策研究——以山西省为例
王闰平,陈凯
资源科学 , 2006,
Abstract: 煤炭大省山西拥有得天独厚的丰富的自然资源，但是山西经济始终处于一种与其资源禀赋极不相称的落后状态。本文结合国外学者已经取得的研究成果，对煤炭大省山西经济陷入困境的原因进行了深入分析。研究认为在运输系统高度发达、运输成本日益降低的当今世界，资源丰富型国家或地区的资源优势已经逐渐丧失。而许多资源丰富型国家或地区仍然偏重于发展资源生产性行业，往往形成资源产业“一枝独秀”的畸形产业结构，导致制造业衰落，经济价值外逸，人才外流，生态环境恶化，造成巨大经济损失。加之腐败和寻租行为的严重打击，政府又缺乏制度创新的动力，因此最终导致其经济地位的日益下降，这也正是导致煤炭大省山西经济陷入困境的根本原因。最后，本文对山西经济如何走出困境进行了探讨：①积极推动制度创新，通过证券化把自然资源变“活”;②合理调整产业结构，激励制造业及服务业的发展。
Existence of Periodic Solutions for a Type of High Order Neutral Functional Differential Equations
一类高阶中立型泛函微分方程周期解的存在性
汪凯
数学物理学报(A辑) , 2009,
Abstract: By employing the coincidence degree theory, the author studies a kind of higher order neutral functinal differential equation with distributed delay. Some simple conditions which guarantee the existence of periodic solutions to the equation are obtained.
一种基于预估算法的专家式控制
汪庭凯
重庆大学学报 , 1992,
Abstract: 本文将专家系统技术同预估控制方法相结合,得到了一种新的专家式控制方法。该方法采用多模态控制结构,并结合了在线的特征量识别技术,因而在过渡过程中能够较好地发挥人的控制经验和预估控制算法的作用。仿真实验表明,该专家式控制在被控对象变化或出现故障以及负载突变时均具有很强的鲁棒性和较强的适应能力。
凤尾菇菌丝生长过程的预测模型
汪庭凯
重庆大学学报 , 1987,
Abstract: 作者对凤尾菇菌丝生长过程进行了大量的实验研究,根据凤尾菇菌丝在袋栽情况下的特点,建立了凤尾菇菌丝生长过程的预测模型。仿真实验表明,该预测模型能较好地与实测数据吻合。
具有不精确推理能力的信息管理系统
汪庭凯
重庆大学学报 , 1989,
Abstract: 本文将人工智能中的一些基本思想和方法引入信息管理系统,提出了一种能够根据带可信度的知识进行不精确推理的信息管理系统的设计方案。由该方案设计出的系统不仅具有一定的不精确推理能力,同时还具有适应面广、易变更和扩展等特点。本文介绍了这一设计方案及程序实现技巧。
传感器网络节点间距离估计方法
李凯？,汪芸？
软件学报 , 2009,
Abstract: 传感器节点间距离的估计是传感器网络节点定位方法的基础.已有的各种定位以及距离估计方法对传感器网络的部署以及测量特性提出了各种苛刻的要求,而这些要求在实际的应用环境中无法得到满足,因此造成了已有方法难以实现和应用.提出了对传感器网络中节点间路径的弯曲程度进行描述的方法.利用该方法,可以获取对路径弯曲具有较大影响的节点,即拐点,根据这些节点完成对测量距离的修正.在此基础上,根据对不同路径弯曲程度相似性的比较,可以完成对传感器网络中各个节点到达信标节点测量距离的修正.仿真结果表明,特别是在节点分布不均匀的情况下,该方法优于pdm和dv-distance方法.
工人阶级的形成:一个争议话题
汪仕凯
社会学研究 , 2013,
Abstract: 阶级形成是分析工人阶级的重要概念。本文通过文献梳理试图从阶级意识、阶级反抗的理由、阶级形成的场域、阶级形成的关键条件、阶级形成的模式等五个方面来展现阶级形成所包含的内容。在阶级意识层面,理论界存在自我生长和外在灌输两种意见；在反抗的理由层面,理论界存在反抗剥削、反抗商品化、反抗地位歧视三种见解；在关键条件层面,不同的研究者分别强调了新话语的形成、居住空间、组织、国家的重要作用；在形成场域层面,学术界围绕公共领域、生产领域、国家领域展开了争论；在形成模式层面,研究者存在一元论、二元论、多元论等不同的理论主张。
Causes of Poverty and Anti-Poverty Strategies in Resource Rich Area A Case Study in Shanxi Province
资源富集地区经济贫困的成因与对策研究--以山西省为例
WANG Run-ping,CHEN Kai,
王闰平,陈凯
资源科学 , 2006,
Abstract: This paper explored the reasons why Shanxi run into economical predicament,though it holds a great deal of coal resource.The conclusion is that resource advantage in those nations who hold a great deal of natural resource has been lost because transportation cost has been cut down after science and technology take progress.Those nations who hold a great deal of natural resource always are with abnormal industry structure,whose resource industry proportion is always too bigger than others.That can lead into some harmful results.The first one is that their manufacture sectors will comedown because labors and capital tend flowing into export business.The second one is that a great deal of economical value in these nations will vanish because their exports are ordinarily raw materials,but prices of them are usually much lower than finished products imported from developed countries.The third one is that professionals will flow out of these nations.As far as Shanxi province is concerned,coalmining require very simple technology,and most of mineworkers live depending mainly on their physical power.The fourth one is that environment will become worse than before.Mining is tearing up many scenic areas and making a mess of many rivers and wetlands.Coal-fueled power plants are polluting the air.The fifth one is that natural resources in most of nations are state-owned,and this will undoubtedly lead to serious corruption and over-mining.Therefore,for those nations with plenty of natural resource,their economic degree decline is inevitable.Some revolving ways have been discussed.The first,bring forth new ideas and convert natural resource from "dead " to "living" by the way of stock or bond.In order to accomplish this proposal,an institution system that can make stock market running efficiently is very important.The second,adjust industry structure reasonably,stimulate manufacture industry and service industry.In Shanxi province,the government should cut down coal industry proportion in economic gross and improve manufacture industry proportion,and push tourism forward rapidly so as to get rid of abnormal industry structure and drive economic development.
山西省可持续发展状况生态足迹分析
王闰平,崔克勇,陈 凯,赵月红
中国生态农业学报 , 2006,
Abstract: 应用生态足迹模型分析山西省生态经济系统可持续发展状况结果表明，当前山西省生态经济系统处于一种不可持续发展状态，经济发展是以对自然资源的过度掠夺为代价的；化石燃料生态足迹比重很大（79%），是山西省生态赤字最基本部分，资源利用效率相当低下。山西省亟需改变传统的高消耗发展模式，建立资源节约型社会生产和消费体系。
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