直流故障引发直流外送系统新能源脱网问题研究

含高比例新能源的直流外送系统由于送端发电设备支撑能力薄弱，在直流故障发生后新能源发电设备面临着过电压脱网风险。为了防止新能源脱网事故的发生，首先建立新能源直流外送系统仿真模型分析新能源机端暂态过电压形成机理，其次根据无功传输规律分析常规机组、调相机、电气距离等因素对新能源脱网的影响，定量分析常规机组的电压调节灵敏度，在此基础上利用新能源短路比指标对新能源脱网情况进行量化分析，最后根据分析结果提出了提高短路容量、提高风机高压穿越能力等预防直流故障后新能源脱网的策略，采用某规划的直流外送系统BPA仿真算例验证策略的有效性

我国股份公司法人治理结构问题调查

在我国企业改制中,股份公司法人治理结构的确立、规范及有效运转是一个重点,也是一个难点。由于经济体制尚处于转轨过程中,各种规章制度不完善,从而导致了我国股份公司法人治理结构各个组成要素之间的制衡关系不完备,使法人治理结构未能起到应有的作用

Multi-scalar Diagnostics in Complex Flow Field by Laser-induced Fluorescence

&nbsp; 光学诊断技术为流体力学的研究提供了大量可靠的数据。目前，对于湍流燃烧、高焓气流等复杂流场，仍然无法完全依靠计算流体力学（CFD，computational fluid dynamics）进行仿真。激光诱导荧光（laser-induced fluorescence, LIF）技术是一种激光光谱技术。它具有高组分分辨能力和高时空分辨率，是研究流场结构的理想工具。 &nbsp; 本文对LIF的背景与理论进行了阐述。介绍了LIF技术的发展，阐述了这项技术在湍流燃烧、高焓气流这两种复杂流场中的应用，指出现有技术值得改进的方面。然后解释了荧光过程和LIF的定量测量原理，并提出了对向LIF数据的递归处理方法，展示了通过该方法对激光吸收率的有效计算。最后介绍了LIF系统的重要组成设备。 &nbsp; 在湍流火焰的研究工作中，首先展示了利用平面激光诱导荧光（PLIF）技术对旋流火焰全方位的诊断。本文通过PLIF对OH、CH2O指示物的分布进行了定性测量，有效地获得了火焰的结构信息。对比了OH PLIF与OH* 化学发光（chemiluminescence， CL）的信号分布，讨论了两种测量方法所表征现象的异同。另一方面，利用了OH PLIF的双线测温法（two-line thermometry, TLT）测量了火焰的温度分布，利用了对向OH PLIF首次获得了湍流火焰中OH浓度的瞬态分布。此外，利用以上数据，分析了在不同工况下火焰的特性转变。 &nbsp; 随后对火焰的动态特征进行了分析。介绍了本征正交分解（proper orthogonal decomposition，POD）方法，展示了通过POD方法对火焰脉动模态的分析。OH PLIF与OH* CL的POD模态表现出进动涡核（PVC，precessing vortex core）、热声振荡等特征。扩展本征正交分解（Extended POD）展示出OH分布与CH2O、OH*的分布具有极强的相关性。 &nbsp; 最后对大流量贫燃火焰的结构与动态特性进行了研究。使用了同步的OH、CH2O PLIF技术对火焰的反应区与预热区进行了可视化，并提取了OH的POD与CH2O的EPOD模态。实验结果表明，利用OH、CH2O PLIF可以观测到火焰结构与脉动模式随流量的转变。 &nbsp; 在高焓气流的研究工作中，搭建了应用于JF-10激波风洞的LIF诊断系统。对本系统的关键技术：时序控制和波长监测技术进行了详细的叙述。应用NO LIF的TLT，测量出了激波层内外的温度，然后对激波层外的自由流进行了有针对性的温度测量，对各种可能的误差来源进行了深入探讨，获得了精确的结果。最后，展示了利用分子标记测速法（molecular tagging velocimetry, MTV）对JF-10自由流的速度测量的结果。</p

Auditor Partner Stability and Audit Quality -Based on the team perspective

团队领导者行为特征影响团队绩效，本文基于团队理论视角，采用我国上市公司数据考察审计团队领导核心——签字审计师的搭档稳定性对审计质量的影响。研究表明：签字审计师保持稳定搭档关系可以强化团队成员的心理安全感知，促进团队协同效应发挥，提高审计质量；进一步考虑审计师的异质性，“男女搭配”可以产生异性效应并提高审计沟通效率，增强审计师搭档稳匙}生对审计质量的积极效应，但“年龄代沟”易导致审计师搭档的认知差异并削弱这一积极效应，然而这一效应的发挥与审计师个人任期、角色等特征无关。故此。会计师事务所应合理配置审计师资源，鼓励审计师建立并维系稳定的工作搭档关系，提高审计团队协作效率，保障审计业务质量。Team leader＇s behavior affects team performance. Based on the perspective of team theory, we use the data of Chinese listed companies to examine the influence of auditor partner stability on audit quality. We find auditors maintain with stable partner relationship can strengthen team members＇ perception of psychological safety, promote team synergies and improve the audit quality. Furthermore, considered taking into account the heterogeneity of auditors heterogeneity, a team with both men and women collocation can produce heterosexual effect and improve audit communication efficiency, and therefore which enhancing the positive effect of partner stability on audit quality. But the age generation gap easily leads cognitive differences and weakens this effect, though it has nothing to do with the auditors＇ role and tenure. Therefore, accounting firms should reasonably allocate the auditor human resources, support the auditors to establish and maintain stable partner relationship, and improve the efficiency of audit team collaboration and so as to guarantee the audit quality.本文系国家自然科学基金项目（项目批准号：71662021）的阶段成果

Application of NO Laser-Induced Fluorescence in JF-10 Detonation-Driven Shock Tunnel

We have presented our recent progress in the application of γ(0,0) band NO LIF in the hypersonic flow with total enthalpy of 16.2 MJ/kg generated by JF-10, a H2/O2-detonation-driven shock tunnel. The strong luminosity behind the shock wave is competing against the fluorescence signal, and the photon collecting efficiency of such facilities is limited by its large dimension. To cope with the problems, the laser sheet of a conventional planar LIF is rotated 90° along its propagation direction, so that the fluorescence signal collected by the camera concentrates on a sharp line. This setup makes LIF signal stand out even after the shock wave. With this setup, the S/N ratio is also increased; thus single-shot measurement is achievable. In this paper, the rotational temperature of the flow is estimated based on two-line thermometry

Institutional Environment,Inventory Management and Firm Value:Evidence from State-owned Manufacturing Companies

本文发现1998年-2008年我国制造行业的国有上市公司大幅提高了存 货周转速度。在此期间存货周转天数的中位数从135天降低至83天，平均每年降低200。这与过去十多年我国在市场、法制和信息等制度基础方面的发展有关。同时，本文发现制度基础发达地区的公司存货周转速度比制度基础欠发达地区的公司更快，这表明制度基础的发展对存货管理的效率具有显著影响。本文还发现，存货周转越快的公司市场价值越大。本文的研究揭示出改善企业运行的制度环境对我国国有企业的改革具有重要意义。This paper finds that the inventory turnover rate of listed state-owned manufacturing companies in China were reduced dramatically from 1998 to 2008. Specifically the median of inventory turnover days was reduced from 83 days to 135 days during this period. The average rate of this reduction was about 2% per year. The reduction in inventory turnover days was related to institutional development during the same period. Furthermore, firms in institutionally developed regions experienced more reductions than firms in institutionally less developed regions, especially for the inventory holding periods of work-in-process. The results provide direct evidence that institutional development has significant impacts on inventory management efficiency.作者单位：同济大学经济与管理学

Dynamics character of swirling flame investigated by OH and CH2O planar laser-induced fluorescence

The model combustor of aircraft engine under fuel-lean condition is characterized by planar laser-induced fluorescence (PLIF) technique. By imaging the fluorescence from OH and CH2O simultaneously under various operation points, the transient structures of the reaction zone and preheat zone have been investigated. By the application of proper orthogonal decomposition (POD) and extended POD (EPOD) methods to the OH PLIF and CH2O PLIF data, the main dynamics modes of the swirling flame are extracted, as well as the CH2O PLIF signal distribution for each POD mode. The experimental results indicate that as the thermal power of the combustor increases, the time-averaged structure and dynamics modes experience notable transitions. At relatively high flow rate, local extinction occurs and unburnt fuel emerges in the external recirculation zone (ERZ)

重载荷RV减速机基于动力学模型的固有频率特性及灵敏度分析

采用集中参数法建立了16自由度的重载RV减速机动力学模型。以RV-550E型重载减速机为研究对象，通过求解动力学方程得到减速机的固有频率，分析了针齿壳刚度对系统固有频率的影响，为针齿壳的设计提供依据。为了揭示系统参数的变化对整机固有特性影响的规律，进一步分析整机固有频率对系统的转动惯量和刚度的灵敏度。分析结果表明，低阶固有频率对曲柄轴转臂轴承刚度、行星架支撑轴承刚度以及曲柄轴转动惯量的灵敏度较大。研究结果为该类重载减速机结构优化设计提供了理论依据

The semantic component of the short functional depiction affects categorization of the ambiguous naturally formed object

已有研究发现,用自然语言短句描述物体功能会影响人们对两可物体的分类.本研究请96名大学生阅读多个经过设计、筛选的两可物体,用自然语言呈现其＂正常功能＂和＂异常功能＂,以此恒定并且排除掉自然语言中必然出现的句法成分,保留语义成分,以此考察语义成分对物体命名的特异效应.实验结果表明,人们在正常功能条件下将两可物体分类为人造物的比率显著高于在异常功能条件下将两可物体分类为人造物的比率,而且物体功能的合理程度评分越高,被分类为人造物的可能性就越大.研究提示,人们对物体功能的理解在人造物分类过程中起关键作用,研究结果支持基于用途的人造物分类模型. ; Artifacts（e.g., chair, desk, books） are closely related with peoples＇ daily life. Evidences have been accumulated from behavior experiment, brain damage patient, and neural functional imaging to show that the cognitive neural processing mechanisms are different for artifacts and natural kinds. The intention-based model assumes that people categorize an objects＇ by reasoning the creator＇s intent. Evidence for this model are about ＂intended function＂ effect in categorization, naming, and reasoning studies. However, the utility-based model assumes that using-goal is determining how people categorize an object. The interaction between people and objects make object＇s properties related the using-goal so that the semantic organization of an artifact concept is coherent. This model can explain evidence from study on both intended function and non-intended function. From a third-party perspective, the commonalty of these two models is that they are both purpose-based and the key difference between them is that the creator＇s versus the user＇s purpose influences artifact concept＇s categorization and reasoning. Previous studies used a natural language depiction-based free naming task but seldom separate syntactic component from the semantic component in these depictions. In this study, we recruited 96 participants and manipulated the plausibility of 6 objects＇ function by creating plausible and implausible versions of function depiction to explore how the plausibility of an object＇s function affects participants＇ categorization judgment. The study had two key findings： The plausibility of an object＇s function affects participants＇ naming, rating, and reasoning of an artifact. Participants categorize ambiguous depictions of objects as artifacts when objects＇ function is plausible and categorize them as natural kinds when their function is implausible. The correlation analysis showed that the more plausible an object＇s function is the higher possibility that participants categorize it as an artifact. In summary, presenting the semantic component of an object＇s function make ambiguous object categorized more as artifacts. Wang et al. found the role effect which showed that positive role word ＂you＂ can illuminate object history effect on categorization judgment. Namely, the role word can affect both the amount of function listed and the object categorization. These findings suggest that role word, object function, and categorization judgment are in a linear mediation relation： role word activate object function, and object function activation categorization judgment. In this current study, we directly probe and proved that the semantic component of object function has effect on artifact concept processing. If with the assumption that both the object man-made formation history and the second person role word can activate object function, then the purpose-based theory can explain both the formation effect and the role effect indicating that the two effects have a common mediating step： first to activate object＇s function, then have effect on next cognitive output. Therefore, this point developed the purpose-based model.</p

NO激光诱导荧光对高焓气流温度的测量

由于真实气体效应,高超声速流场的研究仍然依赖于大量的实验.流场温度是实验的重要参数,目前只能通过具有非入侵性质的光学测量手段获得,然而,由于多方面的难题,鲜有对高焓流场参数测量的报道.文章介绍了利用激光诱导荧光(laser-induced fluorescence, LIF)技术对JF-10氢氧爆轰激波风洞产生的高焓实验气流温度的测量工作.搭建了用于脉冲式风洞的LIF测量系统,使用了NO分子作为荧光组分.因为高焓流场实验条件苛刻,本实验对传统的激光设置进行了调整,使用了平行于拍摄方向的竖直平面激光激发NO,使荧光信号更为集中,获得了清晰的LIF图像.利用双线测温法(two-line thermometry, TLT)测量高焓自由流中NO分子的转动温度,从而确定气流的平转温度.测量结果表明, JF-10实验气流的平转温度为600 K