[目的/意义]提出一种基于文档向量化和自动化短语挖掘的改进主题建模方法(Doc2Vec-KMeans++-TopMine,DKT),从多维视角识别领域内的技术演化路径,展示领域内技术的发展与现状.[方法/过程]获取研究领域内的论文、专利、产品等多源数据,综合采用文档向量化、聚类算法和短语挖掘算法,完成领域多源数据的融合主题挖掘,通过语义相似度计算进行多源融合主题的关联与演化路径的识别,采用"主题河流图"可视化方法绘制多维度技术演化路径,从前沿研究、技术研发、市场应用等多维度视角出发开展领域演化分析.[结果/结论]选取数控机床领域进行实证研究,实验结果表明,利用DKT方法挖掘到的演化路径信息丰富,可以进行多维技术演化路径分析,并证明了其有效性,同时还得到了多个维度视角下的领域发展过程,发现了数控机床领域的3种技术演化模式.

为实现"碳达峰、碳中和",我国将构建以新能源为主体的新型电力系统,风机将逐步替代同步机成为未来电力系统中的主力电源.迥异于由转子运动方程决定的同步发电机,风机暂态特性由其控制策略决定.这使得系统的同步过程由"物理主导同步"逐渐演变为"控制主导同步",导致电力系统暂态同步机制和稳定问题更为复杂.目前研究多采用数值仿真手段分析风机对同步机相对功角暂态稳定性的影响,对风机与同步机的暂态同步过程以及可能出现的暂态稳定问题认识尚不清晰.文中梳理以风电为主体的电力系统与传统电力系统暂态同步稳定问题的异同,并深入研究基于锁相同步的风电与同步机互联系统的同步过程.接着,以内电势为视角,分析不同控制方式下风机与同步机的转子转速尺度(秒级,与同步机机电尺度对应)暂态同步稳定性及失稳机理.结果表明,风机锁相同步机制会带来额外相位约束,并引发相位慢–快尺度单调失稳新现象;风机坐标变换会导致幅值/相位在装备内部产生耦合,并成为系统幅值–相位联合暂态失稳的新诱因.

The transient of power system is increasingly dependent on and challenged by renewable generation(RG). There are multi-type energy storage elements and controls in the RG, which are massive for system analysis and the simplification is therefore urgent. In the existing RG model for system analysis, the rotor and rotor speed control are usually one of the key components. However in this paper, they are found not to be activated in some cases, where the system dynamic is hardly influenced by them. This characteristic then allows for simplification to RG’s model. Taking the DFIG-based wind turbine(WT) as example, this paper analyzes the activation mechanism of WT’s rotor and rotor speed control in the transient, and how this activation is impacted by WT’s different structure to form its current reference. The suggestion to WT model’s simplification is then proposed.

目的:调查医生基于“以患者为中心”理念对医院文化的评价情况.方法:采用自编医院文化量表调查5家公立医院的临床医生,获得232份有效问卷.量表使用李克特4点计分.结果:因子分析显示,该量表包含精神/制度文化、行为/物质文化和负向评价3个维度.医生对总量表和3维度的评分分别是3.16、3.46、2.98和2.80.回归分析显示,医生工作时间影响行为/物质文化的评分(P＜0.05).行为/物质文化、负向评价2个维度评分均存在医院差异(P＜0.05).精神/制度文化评分不受人口统计学变量、工作时长的影响,也不存在医院差异(P＞0.05).结论:以患者为中心的医院文化量表具有较好的信效度.医院文化总体状况较好,行为/物质文化和负向评价维度有待改进.

Objective:To investigate nurses' evaluate ion of practice environmentand explore the relationship between practice environment and turnover intention.Methods:Self-administrated questionnaires including:Profession Practice Environment scale and turnover intention scale were distributed to 129 nurses in a tertiary hospital in Hengshui,Hebei Province.Results:Thegross average score of nursing practice environment was 3.04±0.34,and the scores of the eight dimensions ranged from 2.67±0.84 (nurse participation in hospital affairs) to 3.29±0.49 (nurse/physician collaboration).Path analysis showed that nurses' evaluation of practice environment had a direct negative effect on turnover intention;professional identity and work abilities had an indirect effect on turnover intention through nurses' evaluation of practice environment.Conclusions:Nurses displayed high level of satisfaction with practice environment.They should be given more chances to participate in policy making.Their professional identities and work abilities should be cultivated,so that their turnover intention will be reduced.

Objective:To investigate the Quality of Nursing Work Life (QNWL) and its influence factors,probe into its relevance with turnover intention.Methods:143 nurses from a secondary-level hospital in Wuhan were investigated using the quality of nursing work life scale made by ourselves.Results:The score of QNWL was low(1.81零0.57),and self-actualization had the highest score (2.52零0.77),hospital systemhad the lowest score (1.13 零0.70).There were statistically significant differences in QNWL scores among nurses with different ages,nursing ages,professional titles,times of night shift per month,annual salary,and ways of employment(P＜0.05).Path analysis showed QNWL had a direct negative effect on turnover intention,annual salary and professional identity had an indirect effect on turnover intention through QNWL.Conclusion:QNWL was in the bottom of the list.The hospital management should improve remuneration and professional self-identity and rationalize shifts to improve QNWL and decrease turnover rate.

目的:了解当前医生对医疗执业环境和工作环境的评价,探索执业和工作环境评价与其离职意向等的关系.方法:采用自编的医疗执业环境、工作环境问卷,用5点计分(0-4)对武汉市两家二级医院的119名临床医生进行调查.结果:医生对当前医疗执业环境的满意度得分为1.23±0.57,舆论环境的满意度最低(0.78±0.67).医生对所在医院的工作环境满意度为1.80±0.48,排名最末两位为人身安全有保障(0.90±0.86)和个人收入(0.94±0.96).临床医生执业与工作环境评价和离职意向、转行意愿呈显著负相关,与专业认同度呈显著正相关.结论:临床医生对执业环境和工作环境评价较低,应该重点改善舆论环境和医生的人身安全,减少医生离职意愿.

Aiming at the optimization of hydropower system consisted of 15 reservoirs in Yangtze Riv-er ,a partition optimization control method was proposed .An optimal operation model was developed in the purpose of maximizing the cascaded hydropower plants′ total generated energy .The decision vectors were divided into small ones according to reservoir′s relative position and hydraulic relation-ship so as to reduce the high dimensions of decision space .To deal with constrained coupling problem , the constraint-corridor method was adapted .Finally ,this novel strategy was applied to the real casca-ded reservoir groups in Yangtze River .Results show that compared with the conventional method ,the proposed method has a competitive performance in not only convergence but also the computing time , w hich offers a new approach to solve high-dimensional and complicated optimization of reservoir dis-patching .

上世纪80年代以来，我国房地产业取得了突飞猛进的发展，企业数量日益增多，企业规模不断扩大，逐步成为我国国民经济中的一个重要产业，尤其是从1998年开始，房地产业表现出非常迅速的上升态势。随着房地产的不断升温，国家出台了一系列的调控措施，而在对房地产的调控政策当中，房产税一直是个争议性的话题。上海与重庆两市已于2011年1月28日正式开启了房产税改革的试点工作，2013年以来，国务院、国家发改委、财政部、国家税务总局等相关机构都先后表态，要逐步扩大房产税改革试点范围。但房产税的推广并非易事，房产税的全面征收牵涉面太广，在公民权利日益觉醒的情况下，如何提高房产税纳税人的纳税遵从度，是一个我们必须去思考的新问题。

An improved quantum evolution algorithm is presented, which has better global optimization ability and faster convergence speed, because traditional methods have some problems, such as "disaster of dimension" problem, poor convergence performance and so on. The proposed method takes the improved QEA for the outer unit combination and the DP for inner economic load dispatch, the economic operation is solved by the two sub-problems alternating iterative optimization. Meanwhile, the minimum up/down time repair strategy and system reserve capacity repair technique are also used to deal with multiple complex constraints, which effectively improve the convergence speed on the premise of ensuring calculation precision. The proposed method is applied in solving unit commitment problem in Xiluodu Station. Compared with DP and IBPSO methods, the results show that this method is easier and faster, and has better global optimization ability with a strong practical engineering value.

<正>随着房地产的不断升温,国家出台了一系列调控措施,从2004年的"831大限"提高拿地门槛开始,其后不断加码。自2009年12月份以来,调控政策越来越严厉,短短3年时间经历了五次升级,分别是2010年1月的"国十一条"、4月的"国十条"、9月的"9.29新政",2011年1月的"新国八条",以及2013年2月20日出台的"国五条"。2013年5月19日,又有媒体报道,房产税试点扩容已提上日程,今年有望新增数个城

为减小水电站日发电计划与实际运行的偏差,提出一种基于机组综合状态评价策略的大型水电站精细化日发电计划编制方法。依据机组综合运行状态评价策略,确定机组优先开停次序;考虑水量、水库库容、机组运行限制等多重安全生产约束条件,以发电量最大为目标建立大型水电站日发电计划精细化模型,将其分解为机组组合子问题和开机机组最优流量分配子问题;采用原始量子进化算法和实数差分量子进化算法循环嵌套求解,获得水电站精细化日发电计划最优解。将所提算法应用于葛洲坝水电站并与其他求解方法对比,结果表明所提精细化日发电计划编制方法求解精度高,优化效果好。

自从1997年亚洲金融危机尤其是2007年次贷危机以来,学术界兴起了对巩固经济和金融风险管理的研究热潮。本文首先分析了金融危机的外部冲击的主要形式——投机冲击,然后构建了金融危机传导的时间层面和空间层面框架,最后系统地阐述了金融危机传导的具体途径。

Objective To study the effect of green tea polyphenols(GTPs) on metabolic syndrome-related vascular hyperpermeability in rats.Methods Male Wistar rats were randomly divided into 5 groups:normal control,high fat diet control,low,moderate,and high dose GTPs(100,200,400 mg/kg · bw · d) treated groups.GTPs intervention were applied when the body weight of the rats were up to 180 g.After 30 weeks,the permeability of aortic artery were measured with Evans blue injection method.The nitric oxide(NO) levels in the serum,the activity of inducible nitric oxide synthase(iNOS) and ehdothelial nitric oxide synthase(eNOS) was measured with commercial kit.The aortic artery of the rats were harvested and frozen slides were prepared.The reactive oxygen species(ROS) levels were tested by dihydroethidium(DHE) fluorescent probe.Results The vascular permeability of the high fat diet group(0.19±0.006 μg/mg) was significantly higher than that of the control group(0.16±0.007 μg/mg).GTPs treatment downregulated the vascular permeability(0.16±0.004,0.14±0.010,and 0.15±0.010 μg/mg,respectively) compared with that of the high fat diet group.The ROS level in GTPs treated groups was significantly lower than that of high fat diet group.Compared with the high fat diet group,GTPs upregulated eNOS activity and downregulated iNOS activity.Conclusion GTPs treatment has protective effects on metabolic syndrome related vascular hyperpermeability in rats.The mechanism might be related to the alleviation of oxidative damage.

本文构建了一种新的附加税收收入分享的情报交换制度,通过建立一个两国模型对比研究了两种不同的国际资本课税处理方式,即税收情报交换与预提税制度下的均衡税率及税收收入状况,并分析了收入分享参数对结果的影响。该结论对促进国际税收情报交换有重要的现实意义。

多重均衡是金融危机研究中重要的理论之一。本文研究了金融危机多重均衡区间的生成机理,并在此基础上详细探讨了公众(投资者)、政府以及投机者之间的两两博弈,确定了政府在金融危机多重均衡中的重要地位。研究结论对政府在金融危机多重均衡区域中应该如何应对金融危机有一定的启示。

By modeling optimal income taxation in different ways of avoiding double taxation,we analyze optimal government revenue function and get corporate income tax policy in tax competition equilibrium.We find out that it is optimal for a small open economy to levy corporate income tax under deduction tax system or foreign tax credit system,or in an asymmetric system of exemption and foreign tax credit.The conclusion is different from the classic international tax theory.

金融服务的所得课税问题,实际上主要是资本所得课税的最优政策制定问题。公司税作为对股东税收的预提会造成一定的税收扭曲,建立在经济租金理论基础上提出的现金流量税能够提供一种简化而有效的资本所得课税方法,可以作为对金融服务所得课税的政策指导。

文章介绍了第一代货币危机模型和第二代货币危机模型的基本观点,在此基础上讨论了亚洲货币危机中货币危机的蔓延机理,并对我国货币危机的防范提出了几点建议。

Early warning systems help detect financial vulnerabilities and prevent financial crises. This paper establishes a new Early Warning System(EWS)for predicting financial crises based on P-S method and conducts empirical researches with the data of China and those countries that broke out financial crisis in 1997 like Thailand, Korea, Indonesia, Malaysia from 1992 to 1996.