车用天然气储气技术

天然气用作汽车的代用燃料,具有储量丰富、价格便宜;辛烷值高、燃烧充分;低硫、低氮、无灰、环境污染少等优点。但是,目前的压缩天然气储气技术存在储气压力高、储气量小、续驶里程短等缺点,严重制约着天然气汽车应用领域的扩展。对5种车用天然气储气技术进行了分析讨论后,指出了吸附储存和近临界流体储存天然气技术在天然气汽车领域将有着广阔的应用前景。     

A new approach to statistical efficiency of weighted least squares fitting algorithms for reparameterization of nonlinear regression models

We study nonlinear least-squares problem that can be transformed to linear problem by change of variables. We derive a general formula for the statistically optimal weights and prove that the resulting linear regression gives an optimal estimate (which satisfies an analogue of the Rao-Cramer lower bound) in the limit of small noise.     

How to Evaluate Government Performance while Building a Rule of Law Government in China*

Building a law-based government is a central element of the comprehensive framework for promoting the rule of law in China, while using evaluation to catalyze growth is in line with the incentive principle of management studies. Since China started to implement reform and opening up over thirty years ago, rule of law development and organizational evaluation have gone through several stages, each with different characteristics. Efforts to build a law-based government have met with success, but what the country now has is essentially still goal-oriented assessment. At present, this suffers from the lack of a clear goal orientation or definition of functions, an imperfect technical system and unsound motivation mechanisms, not to mention the practical problems of each government department going its own way, duplicating evaluations or being left rudderless. Drawing on a combination of value rationality and instrumental rationality and using government performance evaluation to promote the building of a law-based government not only conforms to the spirit of the rule of law and value rationality in government performance, but also strengthens the role of evaluation as an instrument for organizational management. Therefore, we need to create new evaluation theories, expand public participation, introducing diversified evaluating entities, improve technical systems, strengthen institutional buildup, and foster a performance-based culture. In addition, replacing goal-oriented assessment with performance evaluation will help the emergence of a new discipline—the performance evaluation of rule of law government, thus promoting multidisciplinary efforts to integrate and create new public administration theories in China.     

《庄子·天下》与中国古代学术史

《庄子·天下》在中国古代学术史上的意义久被学者们所认识,但诸如:《庄子.天下》对道术体性的真正期望何在?其在论列旧法世传之史、邹鲁六经及百家之学时,其背后的学术内涵是什么?其对百家之学究竟是肯定还是否定?原因何在?所有这一切最终对中国古代学术文化有何等影响?这些问题至今似仍罕为学者所尽数参透,因而有必要再予诠衡论析,考订评量。但其中最为重要的是,中国古代政教制度实践对社会文化的辐射、影响之大,必须予以充分关注。     

DS18B20在油气井场温度监控系统中的应用

油气井场温度监控系统属于井场重要的安全保护装置,此系统用单片机+串行智能传感器来组成,广泛使用了串行芯片。介绍了系统硬件流程图,以及温度传感器芯片DS18B20的工作流程,详细说明了获取温度传感器序列号的ROM操作命令、存储器操作命令。     

上海西南地区形成发展热点研究

强化上海西南地区发展特质,应以先进制造业引领打造长三角制造业标杆,建设"上海制造"品牌重要承载区.加快头部企业和高端人才引入,提升产业链带动能力.在企业引入方面,推进"生物医药、美丽健康、绿色化工、节能环保、新型显示、集成电路"为核心的具有牵引力和影响力的重大项目向该区域高度集聚,建设高品质产业集聚区,扩大头部企业在沪产能.借助产业联盟等形式,建立园区内企业供需对接、政企交流平台,打造稳固的产业生态.     

Adaptive modeling of the human-environment relationship applied to estimation of the population carrying capacity in an earthquake zone

Natural catastrophes such as earthquakes can, in addition to causing loss of life, disrupt the urbanization process through the need for forced population redistribution and the modification of resource and environmental carrying capacity. The population carrying capacity (PCC) of an altered environment following an earthquake is a crucial determinant in the relocation of displaced persons. We use data adaptive methods to model the correlation between the physical environment and human population density in estimating PCC in areas affected by the 2008 Wenchuan earthquake. Comparing actual population distributions with ideal population distributions allows for the identification of villages where population exceeds PCC, or conversely, areas where the environment can support a higher population. Such a comparison can provide the basis for a relocation plan, a critical element of post-catastrophe policy-making.     

河道冰体的可爆性研究

冰是一种特殊的固体介质,具有非均匀性、各向异性、应变速率及温度敏感性等特点。本文以黄河爆炸破冰为背景,针对-10℃冰体结构与物理力学性能进行检测,以及冰体在不同加载条件下,所表现的响应特征与破坏特征进行了试验研究。通过分析冰晶体结构与冰内气泡特征,冰体在静载条件下的塑性破坏特征,以及对冰体对爆炸冲击载荷的响应特征,获得冰体的可爆性能与破碎单位体积冰体所需炸药能量计算公式。研究成果可为黄河冰体爆破作业提供理论依据。     

矿渣MTC胶结物抗腐蚀性能研究

随着矿渣MTC技术的发展和应用,矿渣MTC胶结物的抗腐蚀性能日益受到人们的关注。矿渣MTC胶结物的抗腐蚀性能直接关系到矿渣胶结物后期性能,并影响井和套管的使用寿命。分析了矿渣MTC胶结物可能受到的几种腐蚀类型及其机理,实验验证了矿渣胶结物具有较强的抗NaCl、Na₂CO₃、Na₂SO₄、MgSO₄侵蚀的能力,但易受酸性介质腐蚀;实验发现了加入胶乳能较大幅度提高矿渣胶结物抗酸性介质腐蚀的能力,并对胶乳提高矿渣胶结物抗酸蚀能力的原因进行了分析。     

分数阶长短波方程的整体光滑解

本文研究了分数阶长短波方程组的周期初边值问题,运用一致先验估计和Galerkin方法证明了分数阶长短波方程整体光滑解的存在性和唯一性.