浅谈理工科分析化学实验课程教学改革

本文介绍在分析化学实验教学中,培养学生独立查阅相关文献,设计相关实验,锻炼学生思维能力和动手能力,提高学生分析问题、解决问题的能力,为培养全面型化学化工人才提供有力保障。     

中国企业参与全球价值链的持续时间及其决定因素

研究目标：考察中国企业参与全球价值链的持续时间及其决定因素。研究方法：采用2000~2007年中国企业面板数据,通过生存分析模型进行研究。研究发现：中国企业进入和退出全球价值链（GVC）的企业数量大体呈上升趋势,企业总体嵌入GVC的持续时间较短,均值为1.827年,且随着持续时间增长企业生存的危险性逐渐降低。其中东部地区企业、加工贸易企业、民营企业和外资企业在GVC中的生存率更高,风险率更低,持续嵌入GVC的能力更强。出口发达国家的企业、加工贸易企业、民营企业、外资企业和具有较好研发能力、全要素生产率较高、规模较大、融资约束较小、年龄较小的企业退出GVC的概率更低,嵌入GVC的持续时间更长。研究创新：构建企业层面价值链嵌入程度指标,并运用生存分析创新性地考察中国企业在全球价值链中的进入退出行为。研究价值：对评析贸易开放的利得以及寻求“中国制造”在全球价值链中持续经营的模式具有重要的理论意义。     

中学化学玻璃仪器的洗涤

在化学实验中,洗涤玻璃仪器不仅是一项必须做的实验前的准备工作,也是一项技术性的工作。     

Donor recognition: A double-edged sword in charitable giving

Previous studies discover confounding results on how donor recognition affects individual charitable giving. To answer the questions of how different donor recognition schemes affect individual giving and what type is more effective as a marketing strategy to meet different fundraising goals, we conducted a field experiment in China with three donor recognition types: voluntary, involuntary, and mandatory donor recognition. We used social media to recognize donors and verified the field experiment results with naturally occurring data. We observed similar behavioral patterns in both samples. The results of this study explain the mixed results from previous studies, suggesting that there is no one-size-fits-all approach for recognizing donors. Decision makers of nonprofit organizations need to select the appropriate type of donor recognition based on their fundraising goals.     

Price of High‐quality Daycare and Female Employment

Using local variation between municipalities, I analyze the degree to which the price of high‐quality publicly subsidized childcare affects female employment following maternity leave. Importantly, prices are income dependent and thus likely endogenous, yet by exploiting information on minimum income compensation during non‐employment, I bypass this problem. The results show that the price negatively affects employment. A price increase of €1 per month decreases employment by 0.08%, which corresponds to a price elasticity of −0.17. These effects prevail during the first 12 months after childbirth. I also find that availability of childcare increases employment.     

Identifying significant characteristics of organic milk consumers: a CART analysis of an artefactual field experiment

The organic dairy category is one of the fastest growing categories of organic foods in the US. Organic milk consumers generally cite perceived health benefits and lower risk of food contamination, as well as perceived superior quality and environmental sustainability of organic farming methods, as the major motivations for preference of organic over conventional milk. While the attributes of organic milk that are valued by consumers are fairly well-known, more ambiguity exists regarding the demographic characteristics of the typical organic milk consumer. This research makes use of experimental data from 148 adult participants and use a Classification and Regression Tree (CART) analysis, a nonparametric modelling approach, to identify how Willingness-to-Pay (WTP) for organic milk varies with the demographic profile of experiment participants. The study finds that perceived taste of organic milk, concern for the risk of consuming conventional milk, being a primary shopper, and the quantity of milk consumed are the major factors that separate experiment participants into groups with high and low WTP for organic milk.     

Textbook Treatments of the Financial Market in the IS-LM Model

Intermediate macroeconomics textbooks introduce financial markets into the IS-LM analysis but typically as a beginning-of-period consideration. Here the financial market is introduced in an end-of-period model.     

Using a Simple Contest to Illustrate Mechanism Design

This article describes a simple classroom activity that illustrates how economic theory can be used for mechanism design. The rules for a set of contests are presented; the results typically obtained from these contests illustrate how the prize structure can be manipulated in order to produce a particular outcome. Specifically, this activity is designed to show how changing the prize structure can impact both the contestants’ average efforts and the effort level of the hardest-working contestant. The activity can be run in a 50-minute class, has instructions that fit on a single piece of paper, and, although it can be run in large classes, requires only six students.     

Cournot Competition and Hit-and-Run Entry and Exit in a Teaching Experiment

Instructors can use a computerized experiment to introduce students to imperfect competition in courses on introductory economics, industrial organization, game theory, and strategy and management. In addition to introducing students to strategic thinking in general, the experiment serves to demonstrate that profits of a firm fall as the number of competitors is increased in a market and that firms enter profitable markets. The authors have used the experiment in undergraduate classes on strategy and management as well as in master of business administration courses with great success.     

A Classroom Tariff-Setting Game

The author outlines a classroom tariff-setting game that allows students to explore the consequences of import tariffs imposed by large countries (countries able to influence world prices). Groups of students represent countries, which are organized into trading pairs. Each group's objective is to maximize welfare by choosing an appropriate ad valorem tariff that may be changed intermittently throughout the game. The game is built on a computable general-equilibrium model, which allows each nation's utility and terms of trade under alternative tariff regimes to be expressed quantitatively. The exercise encourages students to consider terms-of-trade improvements and efficiency losses resulting from large-country tariffs and provides a framework to discuss the Nash equilibrium of a tariff war. The game is a useful supplement to traditional teaching methods.