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91.
目的是建立中试生产葡萄酒中白藜芦醇的含量测定方法。方法系采用高效液相色谱法测定了白藜芦醇的含量,C_(18)色谱柱(250 mm×4.6 mm,5μm),流动相为甲醇∶水=40∶60,流速1mL/min,检测波长306 nm,柱温30℃。结果显示白藜芦醇与样品中其他组分分离效果较好,白藜芦醇在0.271 3~4.340 0μg范围具有良好线性关系,相关系数r=0.999 9;平均回收率为94.6%,RSD为1.97%(n=6)。结论为采用此法准确可靠,可用于该葡萄酒的质量控制。  相似文献   
92.
针对造价人才的执业环境的改变,分析行业在新形势下对咨询业务的新需求,并根据业务实践总结出BIM、PPP、全过程工程咨询等技术和管理模式的出现对造价人才的需求,在此基础上构建新形势下工程造价人才的能力指标体系,并提出了与能力标准体系呼应的核心课程体系设置思路。  相似文献   
93.
This paper employs network analysis to study world trade from 1995 to 2014. We focus on the main connective features of the world trade network (WTN) and their dynamics. Results suggest that countries’ efforts to attain the benefits of trade have resulted in an intertwined network that is increasingly dense, reciprocal, and clustered. However, these features do not correspond to a linear aggregation of the characteristics of its constituents (trade sectors). Trade linkages are distributed homogeneously among countries, but their intensity (i.e. their value) is highly concentrated in a small set of countries. The main connective features of the WTN were not affected by the 2007–2008 international financial crisis. However, we find that the crisis marks a turning point in the evolution of the WTN from a two-group (led by the US and Germany) to a three-group (led by the US, Germany, and China) hierarchical structure.  相似文献   
94.
This study summarizes the main conclusions from a systematic review of the empirical literature regarding the impact on firms of the use of knowledge external sources (universities, research institutes and knowledge intensive business services). With the aim to organize the literature, we classify the different works according to the research question addressed: (i) which firms use knowledge external sources?; (ii) Do firms using knowledge external sources achieve better results?; And (iii) which firms benefit the most from using knowledge external sources? Stylized facts are that larger, more R&D intensive and high tech firms are more likely to use knowledge external sources and that use of knowledge external sources is associated to firms higher technical results. Less attention has been paid to the third question and evidence is not conclusive. Several recommendations for future research emerge. First, to take in greater consideration methodological issues so that potential biases in the results caused by sample selection and endogeneity are handled properly. Second, to pay more attention to heterogeneous outcomes. Third, to use continuous indicators of depth and breadth of links allowing for non‐linear relationships and fourth, to extend evidence for developing countries and service industries.  相似文献   
95.
It is estimated that world military spending in 2011 amounted to over 2.5% of the world's Gross Domestic Product (GDP). This corresponds to a spending of $233 per person in the world at 2010 constant prices, an amount close to the GDP per capita of the poorest country in the world. Therefore, it is important for economists to understand the allocation of resources to this sector of the economy. I present a model that explores the determinants of a country's level of military spending. I show how greater gains from trade can lead to greater military expenditures to protect them. It is also found that expansion in the demand for a country's tradable commodities, that is, an improvement in that country's terms of trade, will impact defense spending. Several other propositions emerge from the model which are then empirically tested using both pooled and time series data. The statistical results support the model's propositions.  相似文献   
96.
Profit sharing schemes have been analysed assuming Cournot competition and decentralised wage negotiations, and it has been found that firms share profits in equilibrium. This paper analyses a different remuneration system: employee share ownership. We find that whether firms choose to share ownership or not depends on both the type of competition in the product market and the way in which workers organise to negotiate wages. If wage setting is decentralised, under duopolistic Cournot competition both firms share ownership. If wage setting is centralised, only one firm shares ownership if the degree to which goods are substitutes takes an intermediate value; otherwise, the two firms share ownership. In this case, if the union sets the same wage for all workers neither firm shares ownership. Therefore, centralised wage setting discourages share ownership. Finally, under Bertrand competition neither firm shares ownership regardless of how workers are organised to negotiate wages.  相似文献   
97.
There have been a number of previous studies that examined the effects of yield- or revenue-based crop insurance products on input use of farmers. However, no study has specifically investigated the input use impacts of a cost-of-production (COP) crop insurance policy, even though this type of crop insurance is the predominant one used in several other countries outside of the United States (such as the Philippines and China). This article aims to theoretically and empirically examine the effect of a COP crop insurance product on farmers’ chemical input use. Our theoretical model suggests that the effect of COP insurance on input use can either be positive or negative, with the resulting impact depending on the strengths of (a) the traditional moral hazard effect of insurance (i.e., an input use decreasing effect); versus (b) the marginal incentives to apply more inputs due to input levels being the main determinant for expected indemnity amounts in this type of insurance (i.e., an input use increasing effect). A survey data set from corn farmers in the Philippines is then used to empirically illustrate how a particular COP insurance product influences input use in a real-life context. In this case, we find that COP insurance increases the use of chemical inputs (e.g., fertilizers and total chemical expenditure), implying that the positive marginal incentive to apply more inputs dominates the negative moral hazard effect.  相似文献   
98.
This work analyses the firms' internationalisation strategies of importing intermediates and exporting output, and the potential rewards of these activities in terms of total factor productivity (TFP), as a proxy for marginal costs, and markups. It further deepens into the study of the relationship between internationalisation strategies and markups by disentangling whether it operates through affecting firms' marginal costs and/or firms' prices. The panel database employed in this paper is the Spanish Survey on Business Strategies (ESEE) for the period 2006–14. Results in the paper distinguish between SMEs and large firms and indicate that there is high persistence in the performance of these activities and in firms' TFP and markups. For SMEs, we obtain rewards from importing inputs as well as exporting output in terms of TFP and markups. For large firms, we obtain rewards in TFP from the importing activity and rewards in markups from the exporting activity. Finally, we find evidence that the effects of internationalisation strategies on markups are due to both a price channel and a marginal cost channel.  相似文献   
99.
目的了解某院药品不良反应(ADR)的发生特点及规律,为临床安全用药提供参考。方法对合肥市第二人民医院2016年至2018年上报的ADR报告进行回顾性分析。结果1864例ADR中,66~89岁患者所占比例最高(768例,占41.20%);女性患者984例,略多于男性(880例);静脉给药引发的ADR最多,占81.33%;发生ADR的药品主要为抗菌药品,其次为抗肿瘤药和中药制剂;ADR主要累及消化系统、皮肤及附件;ADR类型主要为一般ADR,导致严重的ADR主要是抗肿瘤药;ADR转归情况以痊愈和好转为主,两者占94.31%。结论老年患者更易发生ADR;抗菌药、抗肿瘤药等ADR发生率较高;所有剂型中注射剂型ADR发生率最高;消化系统、皮肤及附件损害最为常见。  相似文献   
100.
A strand of the literature documents no effects or even positive effects of a higher minimum wage on employment. This evidence is frequently linked to the existence of monopsonistic labor markets or search frictions. However, empirical studies show that these findings could be related to a low short‐term minimum wage–employment elasticity in a competitive labor market. We show that mixed theoretical employment effects of a minimum wage policy can be predicted in the short term in assignment economies with price‐taker agents and no search frictions.  相似文献   
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