奥贝胆酸有关物质的分析及合成

为了控制奥贝胆酸药品的质量,从奥贝胆酸原料药中分离并鉴定了3种有关物质:3α-羟基-6-乙基-7-酮-5β-胆烷-24-酸(A),3α,7α-二羟基-6-亚乙基-5β-胆烷-24-酸(B)和3α(3α,7α-二羟基-6α-乙基-5β-胆烷-24-酰基氧基)-7α-羟基-6α-乙基-5β-胆烷-24-酸(C)。分析了这些物质产生的原因并进行了设计合成,其结构经过核磁共振氢谱得以确认。研究表明,3个有关物质与奥贝胆酸粗品中的主要有关物质的相对保留时间完全一致,合成的有关物质与分离得到的有关物质的核磁共振氢谱图相符合,可以判定奥贝胆酸产品中的主要有关物质就是合成得到的有关物质A、有关物质B、有关物质C。解决了有关物质研究所需对照品的问题,提高了原料药的质量,为奥贝胆酸的质量研究和有关物质的控制提供了一定的帮助。     

Assessing recreation carrying capacity of the environment attributes based on visitors’ willingness to pay

Recreation carrying capacity (RCC) is one of the most important indictors used in measuring the usage limits for the forest park resources. However, the consensus has not been reached with respect to the RCC’s content and its measuring metrics. In this paper, we attempt to establish a new RCC theoretical framework based on the demand theory of the tourism product characteristics. In the process, the choice experiment and orthogonal design methods are used in questionnaire designs and the conditional Logit model is used for parameter estimates. More than 700 park visitors are surveyed for data collection at the Shenyang National Forest park of Liaoning province in China. The primary park attributes being considered encompass vegetation, coverage, water quality, number of rubbish on the park trail path, admission fees, and congestion. The carrying capacity threshold for each specific attribute is identified.     

论精准扶贫政策的不精准执行与治理——基于扶贫案例的分析

精准扶贫政策要求精准识别、精准帮扶、精准管理与精准考核,但地方政府实践中却存在着不精准执行现象,出现"任人唯亲"式脱贫、"靠贷"式脱贫、"低保"式脱贫和"捐款"式脱贫等错误行径。此现象是诸多因素共同作用之结果,主要有对精准扶贫认识尚不到位,精准扶贫考核机制不科学,精准扶贫过程公民参与少,扶贫干部的素质高低有别以及扶贫反馈救济效果不显著。倘要在精准扶贫中消除这种不良现象,须推进全面认识精准扶贫步伐,改善精准扶贫基层考核机制,引入公民参与精准扶贫过程,规范扶贫干部的选培与退出,落实扶贫反馈的甄别与处理。     

“荷兰病”型旅游地:内涵解析与识别流程

"荷兰病"是一个经济学领域的概念,指一国或地区某一产业部门异常繁荣,而其它产业发展相对滞后的现象。在中国旅游产业发展实践中,存在着以丽江市、张家界市、三亚市、黄山市和阿坝州为代表的以旅游业为单一支柱产业,区域经济发展高度依赖旅游业的旅游地。文章创造性地提出了"荷兰病"型旅游地的概念,并系统阐述了"荷兰病"型旅游地的内涵特征、形成条件和识别流程,运用Eviews7.0软件对上述五个城市进行"荷兰病"识别的计量经济分析,发现都属于典型的"荷兰病"型旅游地。     

贯通培养试验项目基础阶段激发学生英语学习兴趣的探索

2015年北京市启动了高端技术技能人才贯通培养试验项目,是北京市落实职业教育改革的重要举措.英语教学是贯通项目基础阶段的主干课程.本文针对该项目下学生英语学习动力不足的现状,提出从课程设置、教学设计、师生情感交流及评价体系等多角度地激发学生英语学习兴趣,从而促进英语教学效果的提升.     

Households transport-home energy conservation strategies in response to energy price policies: A stated adaptation experiment based on portfolio choices and cross effects designs

This article explores consumer investment choice in long-term energy conservation technology and assesses trade-offs in energy saving behaviour between the housing and transportation domains. The long-term energy conservation choice problem is conceptualized as a portfolio choice problem. Consequently, to measure trade-offs between investments in housing and transport options, a cross effects choice design is developed in which respondents were shown one or more alternate ways to reduce their current energy consumption: (1) investing in new technology in the house, such as solar panels; (2) exchanging the current car for a more energy efficient car; (3) buying a new energy-efficient car, such as EV or solar car; (4) moving house to reduce current travel distances. To help respondents linking these options to their current energy consumption, a new Web-based survey system (SINA) to implement and administer stated adaptation experiments was developed. The system was used to collect two sets of data. First, data about out-of-home and in-home energy consumption, together with detailed time use data, was collected. Second, using a cross effects design, respondents were asked to select a portfolio of energy-saving strategies in response to different energy pricing policy scenarios. Results reported in this paper are based on 572 respondents who completed the survey and responded to seven adaptation questions based on their current energy expenditures. A random parameters logit model is estimated to predict the probability of choosing a particular portfolio of energy-saving options. Estimation results indicate that individuals from different socio-demographic groups exhibit varied preferences. The saving option characteristics, especially cost related characteristics have significant effects on individuals' preferences. Moreover, the results also showed significant effects of choice set composition on energy saving options. Further, the energy pricing policies had showed mixed effects on individual's preferences.     

2016年中国油气管道建设新进展

截至2016年底,中国境内在役油气管道总里程累计约12.6万千米。2016年,油气市场消费增速放缓,资源供应宽松,管道建设节奏企稳;国家多项规划、政策密集发布,推进油气管道基础设施市场化;油气管网设施信息首次集中公布,公平开放迈出重要一步;中俄原油管道二线、陕京四线等国家重点管道工程正式开工;下游用气中间环节费用治理初步取得成效,天然气市场监管覆盖面不断延伸;中国石油天然气管道和销售业务分离,天然气领域改革进程加快。2017年,多项规划和改革政策将助力油气管网基础设施实现稳健发展;应加强天然气多元通道、互联互通工程、联络线管道和储气调峰设施建设,持续完善管网;油气管网第三方准入将逐步走向操作规范化、规则标准化、价格市场化、监管正常化。     

知识视角下区域创新绩效研究——基于PCA-DEA模型和Malmquist指数的实证分析

本文综合关于区域创新绩效的研究文献,构建了知识视角下的区域创新绩效指标评价体系。在此基础上,首次运用PCA-DEA模型和Malmquist指数分析方法对我国30个省域创新绩效进行了动态实证分析。研究发现我国区域创新绩效整体呈上升趋势,但是近年遇到瓶颈,区域创新效率的主要限制因素是PECH（纯技术效率）值较低。东部区域创新绩效高于西部地区,而中部区域创新绩效最低。西部地区创新技术效率已经赶超东部,呈持续领先态势。北京、内蒙、福建、河南、贵州、云南、宁夏、新疆等8个省市是创新活动生产可能性前沿外移的主要推动者。基于实证分析的结果,为提高我国区域创新绩效提供相应思路。     

供给侧改革背景下我国城市建设用地最优规模分析

本文基于边际等值原理,综合城市经济效益、社会效益、环境效益以及建设效益,构建多因子城市建设用地最优规模决策模型,并结合我国城市建设用地供给实际进行分析。结果显示：2001～2015年,我国城市发展经历了从建设用地短缺到最优及至过剩的过程,对建设用地增长的强依赖逐渐转变为弱依赖。城市建设用地增长与边际建设效益弱相关;与边际经济效益之间呈库兹涅茨倒U型曲线关系;与边际社会效益呈正相关、边际环境效益呈负相关。目前我国城市建设用地已经达到最优规模,其中建设用地供给与经济发展失调,是导致净效益下降的主要动因。     

新疆边境农牧团场扶贫效果调查研究

贫困是一个全球性的问题,被联合国列为社会发展三大问题之首.中国扶贫工作取得了举世瞩目的成绩,但扶贫成效的巩固、贫困地区的持续发展问题也很突出.兵团团场的贫困问题更有其复杂的自然、经济、政治等特殊背景,扶贫的难度更大.本文基于对具有代表性的边境贫困团场农九师的调查,通过对边境贫困团场的发展现状及问题,扶贫政策的落实及效果进行了实地调查和分析.进一步的了解到新疆边境农牧团场扶贫的效果及其原因,同时也为政府下一步的扶贫提供现实依据.