我国土地利用研究现状分析

本文分析了目前我国在土地利用领域的研究现状 .认为 :当前我国在土地利用 /覆被变化研究是土地利用研究领域的重点 ,不仅在研究内容上注重土地利用变化的动态过程、强调其驱动机制的分析及其生态环境效应的反映 ,而且在研究方法上不断探索 ;同时 ,土地利用结构的合理化及土地的可持续利用为核心内容的土地利用优化配置 ,也成为部分学者土地利用变化研究的重要内容 .     

清代东北天花的预防及其嬗变

天花流行对清朝的统治造成极大危害,东北虽处边塞但仍未能幸免。清代东北天花的预防经历了逃疫、局部种人痘、大面积种牛痘三个阶段的变化,随着医疗技术的提高,天花逐渐被遏制。清代东北的天花预防工作及其嬗变过程,见证了东北地区的医疗近代化。     

“健康中国2030”的机遇与挑战

 健康中国已上升为国家战略。介绍了《"健康中国2030"规划纲要》的主要内容,剖析了影响健康中国建设的主要问题,并提出了相应的应对措施。指出健康中国的建设关键在落实,在于政府主导、多部门合作、全社会参与的合作机制的建立。     

中国杉木害虫名录（二）（昆虫纲：鞘翅目）

通过调查和查阅文献资料，整理了危害我国杉木的害虫名录（二），主要包括昆虫纲（ Isecta）鞘翅目（ Co-Leoptera）害虫18科101属142种。并列出每种害虫的中名、学名和分布省份，为杉木的鞘翅目害虫的监测与综合治理提供依据。     

Effect of Ce addition on hot tearing behavior of AZ91 alloy

A small amount of cerium (below 1.0 wt%) addition to AZ91 alloy have been investigated on the hot tearing susceptibility (HTS) at a cooling rate of 1.5Ks^?1. The HTS increased to a maximum value with a cerium addition of 0.6 wt% and then decreased to a stable status as cerium was gradually added. Due to high chemical activity, cerium into the melts can react with aluminum to form an Al₁₁Ce₃ intermetallic compound. X–ray diffraction results also confirmed the existence of Al₁₁Ce₃. The Al₁₁Ce₃ increased with the presence of the needle-like and block morphology. As cerium levels increased, the amount of Mg₁₇Al₁₂ decreased. The variations between Mg₁₇Al₁₂ and Al₁₁Ce₃ resulted in a similar normal distribution of the HTS in AZ91 alloy. The findings were further verified through the microstructure evolution and the surface morphology of fracture.     

The species of Encarsiella Hayat (Hymenoptera: Aphelinidae) from China

Four species of Encarsiella are recorded from China, including Taiwan, of which two species, E. nepalensis and E. amabilis sp. n. are new records for China. An illustrated key for their identification is provided, including the as yet extralimital species E. boswelli, which is almost certainly present in China, though currently unrecorded.     

中国城市化进程中的环境抗争

城市化是经济社会发展的必然选择。然而,随着中国城市化飞速发展,也产生了城市水、大气、固体废弃物和噪声污染等一系列生态环境问题。同时,随着环境意识的增强,人们对居住环境质量的要求不断提高,致使城市化过程中环境抗争事件不断涌现。本文回顾了已有研究文献,以国外环境抗争、国内农村环境抗争与城市环境抗争作对比,突出城市环境抗争的特点;从抗争的情感基础、精英力量、弱组织化和互动过程四个方面对城市的环境抗争进行建构;从抗争力量、制度化因素、发展观念和社会力量四个方面分析当前环境抗争所面临的一系列困境。培育公民社会、更新地方政府的发展观念、加强社会科学与自然科学和管理科学之间的交叉研究等是应对当前困境最根本的出路。     

和而不同:英语中的中国因素

中国从19世纪初到现在接触和使用英语已有近两百年的历史,由于中西文化的相互影响和渗透,许多汉语的词汇逐渐进入英语,成为英语的一部分。中国英语以英国英语为核心,但有着鲜明的中国特色。本文拟从语言变异:中国因素的融入根源、顺应理论:验证中国因素的表现特色、英语全球化、本土化:引导中国因素的发展趋势三个方面阐释英语中的中国因素。     

Studies of world carbon fiber industry from a perspective of patent analysis

Patents are the manifestation of the industry R&D endeavor;therefore, World carbon fiber in-dustry from the perspective of patent analysis is studied .Findings from the analysis show a continual increase of carbon fibers patents since 1969 , and the growth rate began even faster after the year of 2005.Five countries (Japan, China, US, Germany and Korea) took dominant positions in global carbon fibers R&D , and the sum of patents applied in these five countries accounted for 80%of the total patents in the world .Corporations do play an active role in global carbon fibers R&D , and over 60%of patents were applied by corporations .Among them , the top 3 corporations were all from Ja-pan, which had much more patents than the other patent assignees .Furthermore, most corporations were not active in cooperation with others , except Toyota Motor Corp .Global carbon fibers R&D fo-cused on sheet manufacture cloth , core wire layer , heat connect provide and filter activated draw . And there is big difference between Japan and China in the R&D focus .China ’ s corporations have exhibited rapid growth in the number of patent applications in recent years , but there is still a large gap between China and foreign countries in view of global patent layout and influence .By providing the insight into the evolution of global carbon fibers industrial and technological development through the perspective of patent analysis , this study hopes to provide an objective statistic reference for fu-ture policy directions and academic researches .     

Effects of Cr and Mo elements on the microstructures and compressive properties of the in situ (TiC_xN_y–TiB_2)/Ni cermets

In-situ(TiC_xN_y–TiB_2)/Ni cermets with 70 wt%TiC_xN_y–TiB_2 were successfully fabricated by combustion synthesis and hot pressing sintering in Ni-Ti-B_4C-BN powder systems.The microstructures,density,compressive properties,and hardness of the TiC_xN_y–TiB_2/Ni cermets with the addition of 0–8 wt%Cr/Mo to the Ni-Ti-B_4C-BN powder systems were compared and analysed.The results showed that the ceramic particles distributed uniformly in the cermets,and the size of the ceramic particles reduced with the Cr/Mo addition.Both Cr and Mo addition can improve the hardness,compressive properties,and fracture strains of the cermets.The hardness,compressive strength,and fracture strain of the(TiC_xN_y–TiB_2)/(Ni+Cr)cermets increased from 1561 HV,2.94 GPa,and 2.9%to 1864 HV,3.65 GPa,and 3.4%,respectively when the Cr content increased to 5 wt%.The hardness and compressive strength of the(TiC_xN_y–TiB_2)/(Ni+Mo)cermets increased from 1561 HV and 2.94 GPa to 1902 HV and 3.43 GPa,respectively when the Mo content increased to 8 wt%.The cermets with Cr had better compressive properties than the cermets with Mo.