Laser slotting: a new laser machining technique

This work describes a new technique for the selective removal of steel using a conventional CO2 laser beam and a novel arrangement of inert and reactive gas jets to produce the gas equivalent of a rotary cutter.

中国野青茅属的分类学修订

　　通过野外观察和标本研究，本文分析了中国野青茅属植物主要形态性状的变异式样，对其叶片表皮进行了光镜和电镜观察，对外稃表皮进行了电镜观察，分析了该属植物的生态和地理分布。在此基础上，对中国野青茅属植物进行了分类修订。 1．形态性状分析 分析结果显示：野青茅属植物形态变异极其复杂，性状之间大多缺少相关性，属内有分类价值的性状较为贫乏。一般来说，颖片表面特征、基盘毛与外稃的相对长度、外稃的质地及表皮结构、外稃背部具芒与否、芒的伸出位置等性状在种内较为稳定，是本属首要的分类性状。植株疏丛型或密丛型、花序宽大开展或短小紧缩、小穗的大小等性状在分类上具有第二位的重要性。而叶鞘、叶舌、叶片的长宽、颖片边缘是否具睫毛等性状往往在种内没有稳定性，在分类中应该审慎对待。但是，应该特别指出，即便是通常比较稳定可靠的性状， 在少数类群中也可能存在较为复杂的变异，而那些通常没有稳定性的性状，在个别类群中又可能表现出稳定性，在分类上具有重要的价值。 2．叶表皮 在光镜和扫描电镜下观察了叶表皮结构，结果表明：上表皮结构无规律性可循，难以用来分类;下表皮结构为典型的狐茅型，脉间长细胞、刺毛、硅细胞的形态具有一定的分类学意义。 3．外稃表皮 在扫描电镜下观察了外稃表皮结构，结果表明：所有类群的外稃表皮均由长细胞和刺毛组成，偶见硅细胞而无气孔。根据外稃表皮的结构特征可将本属植物分为4类，第1类：长细胞厚壁，边缘显著波状弯曲，刺毛基部浅表型;第2类：长细胞厚壁，边缘微波状或波状弯曲，刺毛基部浅表型;第3类：长细胞薄壁，边缘波状弯曲，刺毛基部下陷;第4类：长细胞厚壁，边缘微波状或波状弯曲，刺毛基部下陷。 4．生态与地理分布 野青茅属植物分布于南北半球的温带地区以及热带的山区，主要生于较潮湿的环境，如林缘、灌丛、低海拔的湿草甸、高山和亚高山草甸、山坡草地等。该属植物在中国主要分布在西南山区和青藏高原，分布种类在海拔3000-4000米最为丰富。 5．区系地理成分分析 中国野青茅属植物的区系地理成分以中国一喜马拉雅成分、中国特有成分为主体，包括环北极成分、旧世界温带成分、中国一日本成分等共5种。认为中国的西南山区至喜马拉雅一带为野青茅属植物的多样性中心之一。 6．根据标本资料，绘制了每一种在中国的地理分布图，以及大部分种的垂直分布柱状图。并首次提供丁8个种的标本绘图。 在．上述工作的基础上，本文对中国野青茅属进行了分类学修订，归并12种，12变种，其中包括新异名16个;作出新组合2个，其中包括1个改级新组合。本文确认了产于中国的该属植物3 1种，3变种（不包括原变种）;另有8种1变种暂存疑。经本文修订后，原中国植物志记载的43种14变种，目前被确认27种2变种。

Cementation liquefaction remediation for existing buildings

Many typical liquefaction remediation techniques are not appropriate for application under existing buildings and more novel techniques are required. This paper describes centrifuge tests investigating the performance of cementation as a liquefaction remediation method. Two soil profiles with the same superstructure were tested under earthquake shaking. The first profile consisted of a deep layer of loose, liquefiable sand. The second comprised a shallow layer of loose sand overlying dense sand. Centrifuge tests were carried out with a cemented zone underneath the structure, through the full depth of the liquefiable layers and also partial depth. The superstructure was modelled as a single-degree-offreedom system. It is found that a cemented zone through the full depth of a liquefiable layer results in considerable reduction of structural settlements. Increased magnitude and higher frequency accelerations are transmitted to the structure but, depending on the building characteristics, it is likely that improved overall seismic performance can be achieved. Improvements in structural settlements can also be obtained with partialdepth remediation, if the depth of the cemented zone is greater than the depth of liquefaction. This type of remediation seems to have little effect on the accelerations transmitted to the structure.

Sustainable binders for soil stabilisation

Portland cement is the most commonly and widely used binder in ground improvement soil stabilisation applications. However, many changes are now affecting the selection and application of stabilisation additives. These include the significant environmental impacts of Portland cement, increased use of industrial by-products and their variability, increased range of application of binders and the development of alternative cements and novel additives with enhanced environmental and technical performance. This paper presents results from a number of research projects on the application of a number of Portland cement-blended binders, which offer sustainability advantages over Portland cement alone, in soil stabilisation. The blend materials included ground granulated blastfurnace slag, pulverised fuel ash, cement kiln dust, zeolite and reactive magnesia and stabilised soils, ranging from sand and gravel to clay, and were assessed based on their mechanical performance and durability. The results are presented in terms of strength and durability enhancements offered by those blended binders.

酸性抗菌肽及其基因和在制药中的应用

本发明涉及一种酸性抗菌肽及其基因和在制药中的应用，属于生物医学领域。酸性抗菌肽，是中国两栖类动物大蹼铃蟾基因编码的一种单链多肽，分子量2021.4，等电点4.8，多肽氨基酸全序列一级结构为：Ile Leu Gly Pro Val LeuGly Leu Val Ser Asp Thr Leu Asp Asp Val Leu Gly Ile Leu-AMIDATION。编码酸性抗菌肽的基因由632个核苷酸组成，其中编码成熟酸性抗菌肽为第418-477位核苷酸。人工化学合成的酸性抗菌肽具有显著的抑制细菌生长的作用，可以作为制备抗微生物感染疾病药物的应用。

Tailored sustainability assessment for urban masterplanning

Tailored sustainability assessment represents one approach to addressing sustainability issues on large-scale urban projects with varying geographical, social and political constraints and diverse incentives among stakeholders. This paper examines the value and limitations of this approach. Three case studies of tailored systems developed by the authors for three unique masterplanning projects are discussed in terms of: contextual sustainability drivers; nature and evolution of systems developed; outcomes of implementation; and overall value delivered. Analysis Leads to conclusions on the key features of effective tailored assessment, the value of tailored sustainability assessment from various perspectives (including client, designer, end-users and the environment), and the limitations of tailored assessment as a tool for comparative analysis between projects. Although systems considered here are specific to individual projects and developed commercially, the challenges and lessons learned are relevant to a range of sustainability assessment approaches developed under different conditions.

Losses in self-oscillating ballasts for electrode-type compact fluorescent lamps

Commercially available integrated compact fluorescent lamps (CFLs) use self-resonant ballasts on grounds of simplicity and cost. To understand how to improve ballast efficiency, it is necessary to quantify the losses. The losses occurring in these ballasts have been directly measured using a precision mini-calorimeter. In addition, a Pspice model has been used to simulate the performance of an 18 W integrated CFL. The lamp has been represented by a behavioural model and Jiles-Atherton equations were used to model the current transformer core. The total loss is in close agreement with measurements from the mini-calorimeter, confirming the accuracy of the model. The total loss was then disaggregated into component losses by simulation, showing that the output inductor is the primary source of loss, followed by the inverter switches. © 2011 The Institution of Engineering and Technology.

Dynamics of in-plane arch rocking: An energy approach

This study employs an analytical model to describe the rocking response of a masonry arch to in-plane seismic loading. Through evaluation of the rate of energy input to the system, the model reveals the ground motions that cause maximum rocking amplification. An experimental investigation of small-scale masonry arches subjected to past earthquake time histories is used to evaluate the analytical model and to explore arch rocking behaviour. The results demonstrate that rocking amplification can occur, but is highly sensitive to slight variations in the ground motion. Thus, the accuracy to which the arch response can be predicted is brought into perspective. The concept that the primary impulse of an expected ground motion is fundamentally important in predicting arch collapse is evaluated in light of the developed energy approach. Finally, a statistical method is proposed for predicting the probability of arch collapse during seismic loading.

Soil mix technology for land remediation: Recent innovations

The past 15 years have seen increasing applications of soil mix technology in land remediation, mainly in stabilisation/solidification treatments and the construction of low-permeability cut-off walls and permeable reactive barriers; clear evidence of the versatility of the technology and its wide-ranging applications. This paper provides an overview of some of the recent innovations of soil mix technology in land remediation covering equipment developments and applications, including systems for rectangular panels and trenching systems, treatments, such as chemical oxidation, and additives, such as modified clays, zeolites and reactive magnesia. The paper also provides case studies for such innovations. The paper concludes with an overview of an on-going research and development project SMiRT (Soil Mix Remediation Technology) which will involve field trials on a contaminated site and will employ some of the innovations discussed in the paper. The range of significant advantages that soil mix technology now offers compared to other remediation techniques is likely to place this remediation method at the forefront of remedial options for future brownfield projects.

Strategies for designing and developing services for manufacturing firms

Product/service-systems (PSS) are in effect an approach to designing integrated products and services with a focus on both customer and product life cycle activities. A range of service-oriented design strategies can be found in current literature, from product-oriented DfX approaches to more customer-oriented approaches, such as integrated solutions. In this article, design strategies related to different types of services are mapped. Case studies from two industrial companies are used to confront the existing literature in order to improve the understanding of how manufacturing companies may align their product and service development activities with their business strategies. © 2010.