ICP测定土壤中的K,Na,Ca,Mg,Fe

本论文采用等离子体发射光谱法(ICP-AES)土壤中的K,Na,Ca,Mg,Fe进行了测定,样品以四酸体系溶矿,不经分离杂质,即可直接测定。本法通过优化实验条件确定了最佳分析波长,该测定方法检出限为:0.006~0.0186mg/ml,RSD%为:0.5032%~1.030%,双差均小于1,回收率为99.41%~100%。准确度和精密度较高,方法快速简单,预处理简单,分析流程短,完全满足地质工作要求。     

我国人口资源环境与经济的可持续发展

为了保持经济又好又快的发展,应该正确处理人口、资源、环境与经济的关系;必须长期坚持计划生育的基本国策,控制人口增长的数量,提高人口的质量,减轻过多的人口对资源和环境的压力;提高自主创新能力,转变经济增长方式,发展循环经济,节能减排,建设资源节约型、环境友好型社会,走新型工业化道路,实现可持续发展战略。     

The Nexus of Population,Energy, Innovation,and Complexity

For the past 200 years, humans have benefited from the abundant, inexpensive, and easily obtained energy of fossil fuels. Energy surpluses such as this are unusual in human history. In systems with little surplus energy, population growth is low and complexity emerges slowly due to the energetic costs it carries. On the rare occasions when energy is readily available, societies respond by growing rapidly. They must become more complex in response to the social, economic, and resource challenges of dense population. More complex societies are more expensive, requiring greater energy per capita. The process of increasing complexity necessitates greater energy production, creating a positive feedback cycle. Past societies have collapsed under such pressures. Population and complexity grew rapidly when the Industrial Revolution replaced economies based on annual solar radiation with economies fueled by fossil energy. The Green Revolution of the 20^th century is credited with preventing mass starvation, but it has made food production and sustaining population ever‐more dependent on high‐energy (low‐entropy) inputs. Some believe innovation will overcome the limitations of resources and permit unchecked growth. However, increases in complexity, innovation, and fossil energy are all subject to diminishing returns, and cannot continue to support population at current levels.     

Transversals, systems of distinct representatives, mechanism design, and matching

A transversal generated by a system of distinct representatives (SDR) for a collection of sets consists of an element from each set (its representative) such that the representative uniquely identifies the set it belongs to. Theorem 1 gives a necessary and sufficient condition that an arbitrary collection, finite or infinite, of sets, finite or infinite, have an SDR. The proof is direct, short. A Corollary to Theorem 1 shows explicitly the application to matching problems. In the context of designing decentralized economic mechanisms, it turned out to be important to know when one can construct an SDR for a collection of sets that cover the parameter space characterizing a finite number of economic agents. The condition of Theorem 1 is readily verifiable in that economic context. Theorems 2–5 give different characterizations of situations in which the collection of sets is a partition. This is of interest because partitions have special properties of informational efficiency.     

Short sales,destruction of resources,welfare

A reduction in the output of productive assets (trees) in some contingencies may expand the range of risks spanned by the payoffs of assets and allow for better risk sharing; which may compensate for the loss of output and support a Pareto superior allocation. Surprisingly, if short sales of assets are not allowed, improved risk sharing that results from the destruction of output does not suffice to support a Pareto superior allocation.     

Structural estimation of caloric intake,exercise, smoking,and obesity

The escalating rate of obesity in the US highlights the importance of understanding the causes for this rise. In this paper I employ the First, Second, and Third National Health and Nutrition Examination Surveys to estimate a structural model of the determinants of adult obesity. To control for the potential endogeneity of some explanatory variables, such as caloric intake (adjusted for activity level) and smoking, a set of reduced form equations for these outcomes is estimated simultaneously with the obesity equation. To identify each equation, I use an array of state-level characteristics as instrumental variables. Trends in these variables shed light on the sources of the rapid increase in obesity since 1980.     

Exploring the exit,voice, loyalty,and neglect typology: The influence of job satisfaction,quality of alternatives,and investment size

The current theory proposes that responses to dissatisfaction differ in constructiveness versus destructiveness and activity versus passivity, defining four categories of response: exit, voice, loyalty, and neglect. The manner in which employees react to job dissatisfaction is determined by three variables: overall job satisfaction; quality of job alternatives, and magnitude of investments in the job. This article presents a meta-analysis of the results of five studies in a program of research designed to test the current theory. Ten of 12 theory predictions received good support: Greater job satisfaction was associated with greater tendencies toward voice and loyalty, and with lesser exit and neglect. Superior alternatives were associated with greater tendencies toward exit and voice, and with lesser neglect. Greater investment size was associated with greater tendencies toward voice and loyalty, and with lesser neglect.     

Globalization,political institutions,financial liberalization,and performance of the insurance industry

This paper investigates the impacts of globalization, political institutions, and financial liberalization on the performance and risk-taking of insurance firms covering 1324 individual firms in 30 selected OECD countries. We find that greater globalization and a stable political institution lead insurance companies to exhibit a better performance—i.e., insurers adjust their strategies while being aware of institutional changes. By contrast, financial liberalization has an inverse impact on insurance company performance. Thus, greater globalization and a stable political environment both drive less risk-taking for insurers. These findings are particularly important to insurance markets’ competitors and national policymakers.     

Workfare,welfare, agency,and well-being

Workfare programs are state-instituted programs that require able-bodied persons with children of school age who wish to claim welfare payments to participate in job training programs, and, eventually, to enter the work force. The philosophy of workfare is based on the value of work and the goal of self-determination. However, as a mandatory program for welfare recipients, workfare requires of those recipients certain duties which, according to those who challenge workfare, interfere with the freedom to choose what one will do with one's life. Whether some form of workfare will be adopted as part of our national welfare system remains to be seen. What the debate about such a program suggests is that welfare, in itself, by ignoring the necessity of security and education for full human agency, neither satisfies basic needs nor prepares its recipients for any life other than that of dependency. With all its difficulties workfare nevertheless presents an alternative to welfare that, at least in theory, more closely identifies its purpose with the values of our society.     

The Who,Where, What,How and When of Market Entry

This introductory, along with the eight articles contained within this Special Issue, highlights and brings greater clarity to entrant‐incumbent interactions and to firm movement – when entrants traverse market territories for the creation and/or delivery of offerings, where ‘markets’ include service or product categories, technology or resource spaces, industries, sectors and/or geographies. Collectively, this Special Issues explains that firm movement across market boundaries is highly consequential, influencing resource‐capability mixes inside firms, interfirm relations, market logic and industry value chains, and of course, people, communities and even nations. Specifically, we develop a field‐wide perspective of market entry by expanding on the framework of market entry that Zachary and his colleagues developed (Zachary et al., 2015) – i.e., the who (players such as incumbents, entrants, suppliers, etc.), when (the timing and sequence of entry), how (the strategy, resources, capabilities, etc.), where (the space of entry) and what (product, service, business model, etc.) – to include two additional categories: complements (networks, platforms, ecosystems) and non‐market elements (government, political, social and cultural arrangements). We also summarize the eight highly diverse and insightful articles that make this Special Issue, and conclude with a discussion to highlight foundational questions that point to new directions in future research in this field. In sum, we hope to inspire scholars to go beyond counting outcomes (e.g., entry/exit rates, or profiling successful versus unsuccessful entrants), to consider contexts, processes and contingencies (e.g., cost, time, collaboration, competition, interfirm relations, etc.) and to discover boundary conditions that inform a theory of market entry.     

归纳CAXA-ME中线、面、体转换技巧

各种CAD/CAM软件都有它独自的特点和使用技巧。本文介绍在CAXA-ME中草图线、空间线、曲面、实体之间的转换关系及在造型设计中的灵活应用,归纳了CAXA-ME设计中曲面和实体设计的方法,解决在造型设计中出现的各种难题。可以使初学者快速入门并精通建模理念,可大大缩短自学时间。     

企业文化的“势”、“道”、“法”、“术”、“气”

一、关于企业文化的模式 企业文化是企业在成长发展过程中形成的一系列基本价值观和核心理念以及受此影响和制约的组织行为方式和员工行为方式。关于企业文化的模式,国内外均有较多的论述和实践。     

金属渣、灰、矿(粉)、尘等的混合物分析试样的取样、制样和其品位的计算

金属熔炼工艺中副产品金属渣、金属灰、矿(粉)、尘等的混合物体系。二次制样获四个质量比值K1、K2、K3、K4;三个分析试样;二次加权平均值计算出其成分的质量百分含量。     

Collaboration,Co-Production,Networks: Convergence of theories

Abstract

This article suggests a framework to study service delivery networks that draws on the theories of collaboration, co-production, and networks combined. We introduce four dimensions of co-production under ‘coproduction-oriented collaborations’. This framework allows us to ‘zoom in and zoom out’ when we study networks. Using the case method approach, the framework is applied to analyse four networks in Singapore. Findings suggest that network process, network structure, and characteristics of actors are crucial to a network’s performance and coproduction’s effectiveness. This article also offers implications for practice that in certain contexts the usage of these concepts is for managerial effectiveness and not for enhancing democratic values.