CO2激光焊机激光模式检测方法及应用

激光光束模式是评价激光光束质量的重要参数之一,直接影响激光焊机的焊接质量。根据MIEBACH大功率CO2激光焊机使用和维护经验,介绍大功率CO2激光焊机激光模式几种常用的检测方法和在维护中的应用。     

EPO在PEG/(NH4)2SO4双水相体系中的分配研究

探讨了采用PEG/(NH4)2SO4双水相体系纯化EPO的可行性和工艺条件,实验考察了PEG相对分子质量、成相物质质量分数、pH值和NaCl质量分数对EPO分配的不同影响。     

提高纳米TiO2光催化活性的研究进展

在介绍了纳米TiO2光催化机理的基础上,综述了有关提高纳米TiO2光催化活性的方法,包括制备负载型纳米TiO2光催化剂的方法及实现纳米TiO2改性的方法。     

利用廉价金属光催化还原CO2的研究进展

介绍光催化还原CO₂的重要性及廉价金属Fe,Mn,Co配合物的光催化还原CO₂的研究,并对其机理进行介绍。     

光催化还原CO2制甲烷催化剂专利技术研究进展

CO₂甲烷化是实现碳中和的重要途径。光催化还原CO₂制甲烷的关键在于寻找高效的催化剂,尽可能提高CO₂的转化率和甲烷的选择性。文章主要根据国内外光催化CO₂甲烷化催化剂的专利申请,从国内外申请趋势、主要申请人分布、核心专利、各催化剂技术分支的发展状况等方面明晰了光催化CO₂甲烷化的研究进展。同时,指出当前光催化CO₂甲烷化催化剂存在的不足、研究热点和应对策略,并对未来的发展趋势进行展望。     

羧甲基壳聚糖-Cu2+配合物催化分解H2O2的研究

研究羧甲基壳聚糖-Cu²⁺配合物对H₂O₂分解的催化活性及影响因素。以壳聚糖为原料,制备水溶性羧甲基壳聚糖(CMC),再以其为配体制备CMC-Cu²⁺配合物,并将CMC-Cu²⁺配合物应用于催化H₂O₂分解的反应,考察了w(CMC)/w(CuCl₂)、体系pH值对H₂O₂分解的影响。结果表明:温度为25℃,w(CMC)/w(CuCl₂)为5∶1时形成的CMC-Cu²⁺配合物,在pH值为7附近,对质量分数为5%的H₂O₂的分解率12h为92.5%,24h为99.5%,说明CMC-Cu²⁺配合物对H₂O₂分解有良好的催化作用。     

CdS/g-C3N4光催化复合材料的制备与研究

传统的g-C₃N₄光催化材料存在光生电子和空穴复合率高、可见光利用率低、量子效率低、比表面积小和内阻大等问题,光催化性能不佳。采用煅烧、水热反应等一系列方法,以g-C₃N₄纳米片为基底,将不同含量的CdS与g-C₃N₄纳米片复合,通过上转换作用和异质结的构建,制备得到具有不同配比CdS/g-C₃N₄光催化复合材料。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、紫外可见分光光度计、BET等表征仪器或方法,对光催化复合材料的组成、微观形貌、比表面积以及光催化性质进行考察,并将罗丹明B视为污染物,对可见光下的降解性能进行分析。研究发现,7%CdS/g-C₃N₄光催化复合材料对罗丹明B的降解性能明显优于5%CdS/g-C₃N₄光催化复合材料和纯g-C₃N₄纳米片。研究结果表明,上转换作...     

利用氨吸收电厂烟道气中的CO2及对大气减排CO2的分析

对以氨吸收电厂烟道气中CO2生产碳酸氢铵的技术可行性进行了分析,并从氨的来源、各种合成氨工艺的能源消耗、附带CO2排放情况和碳酸氢铵在土壤中被植物吸收情况等方面进行了综合分析。结果表明,由于以天然气为原料合成氨生产过程中附带CO2排放相对较少,用于吸收电厂烟道气中CO2生产碳酸氢铵肥料,在碳酸氢铵能够有效被植物吸收的前提下能够达到减排CO2的综合效果。     

关于CO2精准计量的探讨

本文主要以CO2为例,介绍了CO2从低温液态到常温气态、超临界态及各种气液比的混合态的流量计量方法及流量计选用注意事项,着重论述在气液比例随时变化的情况下的CO2流量计量。     

硅铝二元膜包覆SrAl2O4:Eu2+,Dy3+荧光悬浮液显现潜在手印的研究

采用溶胶-凝胶法对SrAl₂O₄:Eu²⁺,Dy³⁺表面进行硅膜和铝膜包覆,制成硅铝二元膜包覆SrAl₂O₄:Eu²⁺,Dy³⁺荧光粉末,将该荧光粉末配制成小颗粒悬浮液后,应用于疑难复杂客体表面潜在手印的显现。研究表明,硅铝二元膜包覆SrAl₂O₄:Eu²⁺,Dy³⁺荧光悬浮液在365 nm紫外光照射下能够发射出明亮的绿色荧光,显出的手印纹线清晰连贯、细节特征明显,且在撤去灯光后能够持续发光,可以消除客体背景色的干扰。该悬浮液对常见渗透性客体、非渗透性客体、陈旧手印和水浸客体表面潜在手印均具有良好显现效果,特别是对背景颜色复杂、具有自体荧光的客体,其长余辉特性能够实现手印的无背景显现。     

高纯八甲基环四硅氧烷制备工艺研究进展

高纯八甲基环四硅氧烷广泛应用于光通讯行业,更是集成电路等电子工业生产中不可缺少的基础和支撑材料之一。文章重点介绍了高纯八甲基环四硅氧烷(D4)的除杂提纯工艺,包括精馏法、络合精馏法、结晶-真空抽滤法、金属去除剂除杂法,分析了各个方法的优点及限制其广泛应用的制约因素,最后展望了高纯八甲基环四硅氧烷提纯除杂技术未来的发展方向。     

The Impact of the Implementation of Technology Education on In-Service Teacher Education in South Africa (Impact of Technology Education in the RSA)

In this article the impact of technology education, as a new learning area (subject) in the curriculum, on in-service teacher education in South Africa is described in order to ascertain the extent of the impact. The research on which this article is based draws on a variety of experiences and observations in the field at grassroots level (in particular an outreach project in rural communities). The envisaged impact of technology education on South African schools, communities, teacher educators and teachers, the range of in-service teacher education that is required, and the impacts in urban and rural areas are discussed. Finally a number of concluding remarks are made about the extent of the impact of the inclusion of technology education in the new National Curriculum Statement and whether the situation has changed since the implementation of a pilot technology education project in 1998. This revised version was published online in July 2006 with corrections to the Cover Date.     

On the role of acquisition premium in acquisition research

Several studies argue that paying high acquisition premia is value destroying for acquirer shareholders. There are studies that have even used the size of premium as a measure of low‐quality decision making. This paper departs from the earlier research and shows that acquisition premia may be justified when target firms' resources are difficult for the market to value. An analysis of a sample of 458 acquisitions demonstrates that although higher premia are paid for R&D‐related assets, the premia do not cause negative abnormal returns. Abnormal returns are more strongly affected by the overall target price levels independent of premia. Copyright © 2007 John Wiley & Sons, Ltd.     

金属材料及防护涂层在淡水环境中的腐蚀试验研究及应用（二）

通过在三门峡水库和新疆某水库中投放涂层和材料试样进行试验,对比研究了部份碳钢材料、不锈钢材料、有色金属等在淡水环境中的四年腐蚀规律,考察了金属涂层、封闭涂层、复合涂层及涂层系统在两种淡水环境中的腐蚀情况;明确指出在淡水环境中应尽量避免使用喷铝涂层(包括Ac铝)作为保护涂层,聚氨脂涂料不应在水下作为面漆使用等.研究报告共分(一)、(二)两部分,本文为第(二)部分,主要介绍了保护涂层腐蚀试验结果及试验结论.     

Some Implications of the Philosophy of Technology for Science, Technology and Society (STS) Studies

Technology is frequently considered in terms of its impact on entities outside its essential nature: as the impact of technology on the environment and society, but also the impact of human values and needs on technology. By taking particular social implications of technology into account, the Science–Technology relationship can be extended to the field of Science, Technology and Society (STS) studies. STS studies are grounded in socio-technological understanding, that is, systematic knowledge of the mutual relationship between technical objects, the natural environment and social practice. Because technology is a key element of STS, it is expected that the philosophy of technology will have implications for STS studies. The dynamic nature of technology as such leaves its own philosophy in a tentative or flexible state. However, the implications of the philosophy of technology, being in a development phase at the moment with changes in emphasis occuring, for STS studies ought to be determined continuously. The aim of the article is to identify and discuss possible implications of the the philosophy of technology for STS. In order to deduce these implications, the relevant theoretical framework underpinning the article will be discussed in broad outlines. Seeing that the philosophy of technology is such a wide field a delineation of the field needs to be done. Mitcham’s proposed preliminary framework is taken as point of departure for the article. Technology as knowledge (epistemology/theory of knowledge) and technology as activity (design methodology) will be discussed as two key aspects of the modern philosophy of technology which could provide implications for STS. A theory of knowledge usually includes methodology, but seeing that Mitcham classified methodology as one of the modes in which technology is manifested, it is dealt with separately. The epistemology and methodology of technology will each be discussed from a philosophical, historical and practice-based methodological perspective. Some implications of the philosophy for STS are identified and discussed.     

2-氯丙酸生产技术概况

概述了 2 -氯丙酸的应用情况 ,详细介绍了 2 -氯丙酸的三种生产方法以及各种方法的优缺点 ,并简要介绍了国内外的生产和科研现状 ,在此基础上对其开发前景作了展望。     

我国服务业FDI结构、技术进步与经济增长

服务业外商直接投资可分为生产性服务业外商直接投资和消费性服务业外商直接投资,二者对国家经济增长有着不同的影响。本文从技术进步的角度,利用面板模型,研究了我国不同类型服务业外商直接投资对经济增长的影响,并分别讨论了东西部地区服务业外商直接投资对技术进步和经济增长的差异性影响。研究结果表明生产性服务业外商直接投资对经济增长和服务业技术进步均有明显促进作用,消费性服务业外商直接投资对经济增长有促进作用,但对服务业技术进步有阻碍作用,且这一趋势在我国东西部地区之间存在显著差异。     

加快建设资源节约型社会促进经济增长方式转变

我国正处于建设资源节约型社会的关键阶段,由于受资源和环境的双重约束,必须要以节约资源利用总量和提高资源利用效率为手段,通过调整产业结构、技术创新、建立健全相关政策等促进经济增长方式的转变,构建节约型的产业结构、城市化模式和消费模式,着力完善能够反映资源稀缺程度、供求关系和环境破坏程度的外部成本价格机制,推动促进建设资源节约型社会的财政、税收政策和能源法规的制定和出台。     

Ethnographic Case Study (ECS): Abductive modeling of ethnography and improving the relevance in business marketing research

By extending interpretative methods to business settings, this paper formalizes a model of Ethnographic Case Study (ECS) built upon extensive literature review and abductive elaboration of two-year fieldwork on 12 Italian companies. Objectives and related contributions are twofold. First, key compulsory and complementary stages of ECS marketing research are presented for business contexts. Second, the paper envisions the quality of the knowledge generated through the ECS inquiry, and argues that the methodological peculiarities of this approach may help reduce the relevance gap affecting business research. The systematic cooperation between researchers and practitioners along the ECS phases may benefit relevance through (i) the fine tuning of reciprocal expectations, (ii) the sharing of the research experience, (iii) the multiplication of the beneficiaries of the findings granted by ECS, and (iv) the participation in the process of knowledge dissemination. In this light, the ECS model supports the convincement that methods are not only a way to theory validation but also to theory discovery.     

中国新能源上市公司成长性评价研究

发展新能源产业是我国实现能源结构转型和发展低碳经济的重要途径,研究新能源行业上市公司的成长性有助于了解新能源产业的发展态势。本文分析了影响中国新能源上市公司成长性的关键因素,并构建成长性评价指标体系,收集36家新能源上市公司2011～2015年的面板数据,采用因子分析对我国新能源上市公司的成长性进行综合评价,并对不同类型的新能源上市公司成长性进行对比分析。研究表明,我国新能源上市公司整体成长性偏低,多数企业追逐短期盈利,各分项能力发展不均衡;不同类型的新能源上市公司成长性和各分项能力存在较大差异。