实时三维超声心动图与二维斑点追踪成像技术共同评价心肌梗死患者左室收缩功能与同步性

目的探讨二维斑点追踪成像(2D-STI)及实时三维超声心动图(RT-3DE)评价AMI患者左心室收缩功能和各节段运动的同步性.方法 50例急性心肌梗死患者为病例组,30例正常体检者为对照组,应用CMQ软件获取各节段径向圆周应变及应变率曲线,然后转变为RT-3DE模式,得到17节段时间-体积曲线(VTC),并获得收缩功能以及非同步收缩参数.结果 1)与对照组相比,心肌梗死组3个水平所有节段径向应变值和圆周应变值均减低;2)心梗组患者Trs-SD,Tcs-SD,Trsr-SD,Tcsr-SD明显高于对照组(P0.05);3)与单支冠状动脉病变心梗组比较,多支冠状动脉病变心梗组LVEDV,LVESV显著增加,LVEF显著减小;4)病例组患者左室Tmsv17-SD,Tmsv17-Dif,Tmsv17-SD%,Tmsv17-Dif%均较对照组增大(P0.05).结论 RT-3DE和2D-STI可以准确地量化左室收缩功能,评价AMI患者左室运动的同步性,左室收缩功能障碍也影响收缩同步性.     

Products Ranking Through Aspect-Based Sentiment Analysis of Online Heterogeneous Reviews

With the rapid growth of online shopping platforms, more and more customers intend to share their shopping experience and product reviews on the Internet. Both large quantity and various forms of online reviews bring difficulties for potential consumers to summary all the heterogenous reviews for reference. This paper proposes a new ranking method through online reviews based on different aspects of the alternative products, which combines both objective and subjective sentiment values. Firstly, weights of these aspects are determined with LDA topic model to calculate the objective sentiment value of the product. During this process, the realistic meaning of each aspect is also summarized. Then, consumers’ personalized preferences are taken into consideration while calculating total scores of alternative products. Meanwhile, comparative superiority between every two products also contributes to their final scores. Therefore, a directed graph model is constructed and the final score of each product is computed by improved PageRank algorithm. Finally, a case study is given to illustrate the feasibility and effectiveness of the proposed method. The result demonstrates that while considering only objective sentiment values of the product, the ranking result obtained by our proposed method has a strong correlation with the actual sales orders. On the other hand, if consumers express subjective preferences towards a certain aspect, the final ranking is also consistent with the actual performance of alternative products. It provides a new research idea for online customer review mining and personalized recommendation.     

河南省产业转移的创新响应区际差异研究

以产业转移的创新响应系数作为测度产业转移创新响应强度的变量指标,根据标准差和变异系数、相对发展率(Nich)以及离差(Di)和比率(Gi)等方法分析了河南省产业转移创新响应强度的区际差异及其影响因素。结果发现:(1)2007—2015年河南省产业转移的创新响应强度呈现不断增大的态势并呈现出阶段变化的特征。(2)河南省产业转移的创新响应强度从静态格局和动态变化上都呈现出明显的时空差异性,并根据各市的区域特点及产业转移的创新响应强度将河南省18个地市划分为强、较强、中等、较弱以及弱等5种区域类型;(3)创新能力、人才密集度、科技投入对产业转移的创新效应作用较大,技术市场需求和信息化作用相对较小。     

基于电刺激的多模式康复系统设计和研究

针对脑卒中后肢体功能障碍、褥疮及疼痛,分析了临床上常用的治疗参数,设计了多模式电刺激治疗系统。该系统通过触摸屏与主芯片STM32L152RCT6进行通信,控制升压和极性转换电路产生幅值、频率及脉宽均可连续调节的双极性电刺激脉冲,验证了系统的稳定性和镇痛的效果。通过试验验证了系统能稳定工作,且电脉冲幅值与电阻值的变化无关,且能提高受试者的疼痛阈值。能产生临床使用的电刺激疗法的各类参数,有利于临床实验和相关科研的开展。电刺激技术能够缓解人体疼痛,提高疼痛阈值。     

西秦岭中生代花岗岩锆石U-Pb-Lu-Hf同位素特征及地质意义

对西秦岭地区中川岩体、柏家庄岩体和教场坝花岗岩体进行LA-ICP-MS锆石U-Pb同位素年代学分析, 获得其岩浆侵位年龄分别为220±1, 216±6和222±3 Ma, 表明3个岩体均形成于中?晚三叠世。样品的全岩地球化学分析结果表明, 3个岩体具有相似的稀土及微量元素特征, 均表现为显著亏损高场强元素Nb, Ti和P等, 具有明显的右倾式球粒陨石标准化稀土元素配分模式。锆石Lu-Hf同位素分析结果表明, 3个岩体锆石测年样品的ε_Hf(t)值介于?3.31~+1.68之间, 二阶段模式年龄介于1151~1456 Ma之间。岩石成因分析表明, 这些印支期花岗岩体的母岩浆主要来源于新元古代地壳物质的部分熔融。结合岩体形成时代、岩石成因和区域岩浆作用, 认为这些岩体形成于南秦岭与华南板块沿勉略缝合带相碰撞的造山动力学背景, 可能与华南板块的俯冲板片断离有关。     

对太原地区提高小电厂发电计划执行率的探讨

小电厂发电管理是电力调度部门的一项重要任务,是电力系统实现管理现代化的重要手段。其目的就是优化电力资源配置,节约能源和提高资源利用率,确保电网安全稳定运行。     

Nonextensivity and the <Emphasis Type="Italic">q</Emphasis>-distribution of a relativistic gas under an external electromagnetic field

We investigate the nonextensivity and the q-distribution of a relativistic gas under an external electromagnetic field. We derive an expression for the nonextensive parameter q based on the relativistic generalized Boltzmann equation, the relativistic q-H theorem and the relativistic version of the q-power-law distribution function in the nonextensive q-kinetic theory. We thus provide the connection between the parameter q≠1 and the spatial-temporal derivatives of the temperature field of the gas as well as the four-potential, and thereby present a clearly physical meaning for the nonextensivity for the relativistic gas.     

创新工程技术支撑科学发展

回顾了近年特别是2008年中国在信息、能源、制造业及探索宏观、微观世界等领域所取得的重大科学技术进步和工程创新成就；指出了严重自然灾害对科学技术和工程的检验与启示；提出了我国工程科技界值得思考的几个问题，展望了未来我国工程技术的创新使命。     

Influences of ultrasonic irradiation on the morphology and structure of nanoporous Co nanoparticles during chemical dealloying

The Co-61.8 wt% Al nanoparticles of 45 nm were prepared by hydrogen plasma-metal reaction (HPMR) method. The nanoparticles display core shell structure with Al13Co4 and CoAl core and aluminum oxide shell (about 2 nm). Under ultrasonic irradiation, nanoporous fcc-Co nanoparticles were produced successfully by chemically dealloying the Co-Al nanoparticles at room temperature, whereas, without ultrasonic irradiation CoAl phase could hardly react with sodium hydroxide solution. At 323 K the Co-Al nanoparticles could be dealloyed to fcc-Co and hcp-Co phases even without ultrasonic irradiation. The surface area of the dealloyed nanoparticles under ultrasonic irradiation was larger than that of the dealloyed sample without ultrasonic irradiation at the same temperature. It is believed that the microjet and shock-wave induced by ultrasonic irradiation give rise to particles size reduction, interparticle collision and surface cleaning, and accelerate the dealloying process and the phase transformation.