离心式血液泵水力特性设计及其试验研究

借助商业软件NREC开展离心式血液泵的水力特性设计,其设计流量为5 L/min,设计转速为5000 r/min,得到离心叶轮和蜗壳的三维结构设计方案,并针对其全通道网格进行设计工况下三维流场的定常数值模拟研究.对其溶血性指标进行分析,发现离心式血液泵中95％ 区域切应力小于150 Pa,最大切应力小于500 Pa,满足人体对血液泵溶血性的要求.搭建离心式血液泵流量-压升特性试验测试平台,以质量分数为0.06％ 的黄原胶溶液为流动介质进行试验研究,试验结果显示在设计转速下的实际体积流量偏大于设计流量,整体压升在6550 Pa左右.     

基于主体功能定位的湖北省县域乡村性空间分异研究

[目的]确立与主体功能区定位相协调的乡村发展类型与乡村政策,是促进城乡融合、乡村振兴的重要措施。[方法]以湖北省县域为空间单元,构建乡村性评价指标体系,并基于三次产业的产值结构,划分县域的乡村发展类型。[结果](1)2016年湖北省县域乡村性指数相对较高,乡村性呈现出东低西高的空间分布格局。乡村发展类型可划分为农业主导型、工业主导型、商旅服务型和均衡发展型,分别占县域总数的25.29%、16.1%、10.71%和48.28%。(2)重点开发区的乡村类型以工业主导型和商旅服务型为主,乡村类型主要是城镇化和工业化带动,市场、资本推动力和农民的自主选择突出;农产品主产区和重点生态功能区的乡村类型均以农业主导型和均衡发展型为主,不同的是农产品主产区的农业自然和生产条件优越、农耕文化根植,农业政策扶植,乡村类型是由农业现代化和产业化推动;重点生态功能区乡村类型受资源环境约束、经济基础及行政干预的推动。[结论]三大主体功能区下的乡村类型及驱动机制存在差异,并提出不同乡村振兴发展的政策建议。     

军民科技协同创新要素融合机制研究

构建一体化国家战略体系和能力是新时代实施军民融合战略的重要目标，军民科技协同创新则是实现该目标的必然选择。基于扎根理论建立军民科技协同创新影响因素体系，通过分析影响因素间的交互关系构建系统动力学模型。根据模型对案例进行仿真分析，考察单因素作用、多因素协同作用、多因素非协同作用条件下协同创新水平变化情况。从军民科技协同创新内涵、结构、功能实现3个层面揭示要素融合机制。据此，为国家军民深度融合提供相应政策建议。     

Does an economic incentive affect provider behavior? Evidence from a field experiment on different payment mechanisms

Aims: This study analyzed discrepancies in the quantity of medical services supplied by physicians under different payment systems for patients with different health statuses and illnesses by means of a field experiment.

Methods: Based on the laboratory experiment of Heike Hennig-Schmidt, we designed a field experiment to examine fee-for-service (FFS), capitation (CAP), and diagnosis-related group (DRG) payment systems. Medical students were replaced with 220 physicians as experimental subjects, which more closely reflected the clinical choices made by physicians in the real world. Under the three payment mechanisms, the quantity of medical services provided by physicians when they treated patients with different health statuses and illnesses were collected. Finally, relevant statistics were computed and analyzed.

Results: It was found that payment systems (sig. = 0.000) and patient health status (sig. = 0.000) had a stronger effect on physicians’ choices regarding quantity of medical services than illness types (sig. = 0.793). Additionally, under the FFS and CAP payment systems, physicians overserved patients in good and intermediate health while underserving patients in bad health. Under the DRG payment system, physicians overserved patients in good health and underserved patients in intermediate and bad health. Correspondingly, under FFS and CAP, the proportional loss of benefits was the highest for patients in bad health and the lowest for patients in good and intermediate health; while under DRGs, patients in good and intermediate health had the largest and smallest loss of benefits, respectively.

Limitations: In order to increase external effects of experiment results, we used the field experiment to replace laboratory experiment. However, the external effects still existed because of the blurring and abstraction of the parameters.

Conclusions: Medical treatment cost and price affected the quantity of medical services provided by physicians. Therefore, we proposed that a mix of payment systems could address the common interests of physicians and patients, as well as influence incentives from payment systems.     

河南省新型城镇化质量与生态环境承载力耦合分析

[目的]合理分析新型城镇化质量与生态环境承载力耦合程度是探索可持续发展的基础,文章对2005—2016年河南省新型城镇化及生态环境承载力耦合程度作出动态评价,在此基础上提出应对政策和建议。[方法]以河南省为研究区,通过熵权法确定指标权重,同时,分别构建新型城镇化质量及生态环境承载力评价体系指标,并借助耦合度模型分析河南省新型城镇化质量与生态环境承载力之间的耦合关系。[结果]2005—2016年河南省新型城镇化水平呈现出不断上升的趋势,生态环境承载力评价结果呈现出中间短暂下降但整体上升的态势,耦合程度介于0.9～1缓慢上升趋势,其中,郑州、洛阳、鹤壁处于高水平耦合状态,焦作、濮阳、安阳、新乡、漯河处于较高水平耦合状态,南阳、开封、驻马店、平顶山、许昌处于较低水平耦合状态,周口、信阳、商丘、三门峡处于低水平耦合状态。[结论]河南省应在强化生态意识、调整优化产业结构及规划生态空间布局方面进行完善。     

现代征信理论与实践研究综述及展望

本文通过梳理近年来国内外征信研究的前沿文献,并按照理论、实践两个层面进行总结.首先在理论层面阐述了信息不对称、信息共享等基础理论研究,其次在实践层面归纳总结了信用评价体系和指标、商业征信模式和大数据征信等研究领域的基本情况,在此基础上,对未来可能的征信研究方向进行了展望.     

大跨度天基数据链的TDD时隙调度分析与优化

针对天基数据链系统卫星间的传播时延较大且节点间距离变化较大等特点，提出了一种提高时频资源利用率、提升系统容量、减小时延的方法。在时分多址与空分多址相结合的接入方式下，进行了时隙调度的分析与优化，利用卫星星座的空间复用与大跨度传播时延特性，采用时隙编排、收发状态调整、帧格式优化等手段，将信道利用率和系统容量提升了1倍，将卫星节点在某一方向获得服务的平均等待时间缩短为原来的1/4，提高了天基数据链系统的服务质量。     

The Interaction Between Suppliers and Fraudulent Customer Firms: Evidence from Trade Credit Financing of Chinese Listed Firms

Journal of Business Ethics - This study investigates the interaction between suppliers and fraudulent customer firms from the perspective of reputation damage and reputation recovery. Specifically,...     

我国新型农村社会养老保险制度改革探讨

“新农保”缘起于2002年,是农村社会经济发展的必然要求,也是解决农村人口老龄化问题的根本出路,更是统筹城乡发展的现实需要,但该制度在建立过程中存在资金相对缺乏、制度衔接困难、法律法规不完善、基金管理机制不健全等问题,应进一步加强法制建设、实施法律保障,优化制度设计、解决制度碎片化问题,加强政府财政投入力度、夯实物质基础,改进管理方式、提升养老金增值水平。