论产品绿色设计

产品的绿色设计是通过产品的设计减少对环境的污染以实现社会和经济的可持续发展,目前国内对绿色设计的理解和运用仍然存在一定的困惑。产品绿色设计是一个系统性工程,地方官员强化绿色设计意识,企业增强绿色生产意识,设计师坚守绿色设计理念,消费者信守绿色生活信念,教育工作者坚持绿色教育,只有这样才能保证产品绿色设计得以推广和实现。     

Accurately computing the optical pathlength difference for a michelson interferometer with minimal knowledge of the source spectrum

Astrometric measurements using stellar interferometry rely on precise measurement of the central white light fringe to accurately obtain the optical pathlength difference of incoming starlight to the two arms of the interferometer. One standard approach to stellar interferometry uses a channeled spectrum to determine phases at a number of different wavelengths that are then converted to the pathlength delay. When throughput is low these channels are broadened to improve the signal-to-noise ratio. Ultimately the ability to use monochromatic models and algorithms in each of the channels to extract phase becomes problematic and knowledge of the spectrum must be incorporated to achieve the accuracies required of the astrometric measurements. To accomplish this an optimization problem is posed to estimate simultaneously the pathlength delay and spectrum of the source. Moreover, the nature of the parameterization of the spectrum that is introduced circumvents the need to solve directly for these parameters so that the optimization problem reduces to a scalar problem in just the pathlength delay variable. A number of examples are given to show the robustness of the approach.     

基于分析软件“CiteSpace”的声景研究英文文献知识图谱分析

国外关于声景的探索经历了数十年的发展,对其进行系统梳理与总结对于中国声景研究具有重要的借鉴价值。文章以"Web of Science"核心数据库中近20年的相关英文文献作为研究对象,依托科学计量分析软件CiteSpace的知识图谱绘制功能,展现国外声景研究的学科及期刊分布特征、理论基础与研究热点。研究发现,国外声景研究呈现出明显的多学科特征。在研究热点上,从接续Schafer的理念、关注人类对声景的感知,到兼顾生物圈中非人类生物对声景的响应,再到以"格局-过程"为指导关注区域层面的声景生态特征与演变机制,是国外声景研究的主要发展脉络。声景研究框架的拓展使国外声景研究得以越来越全面和科学地解释和理解声景现象,并为声景实践的开展奠定了良好的基础。不足之处在于研究内容有待深化、研究学科有待融合、声景标准化建设有待加强、声景普及有待提高,而这也是国内声景研究实现跨越发展需要积极补足的方面。     

Monte Carlo simulation of creep failure in a 0°/90° plain weave SiC/SiC composite lamina

A Monte Carlo model of the effects of fiber creep in a 0°/90° plain weave ceramic-grade Nicalon reinforced SiC composite has been developed. Creep degradation of fibers was predicted to result in stress dependent premature failure of woven ceramic matrix composites, and that premature failure was modeled using a power-law. A power-law exponent of 3.1 ± 0.1 was predicted. The power-law exponent was predicted to be independent of initial crack size for crack length to specimen width ratios of 0.02, 0.10, 0.25, and 0.50. The power-law exponent was also predicted to be independent of the matrix to fiber strength ratio for ratios from 0.25 to 1.0. Premature failure in the 90° (transverse) tows resulted in premature failure of the composite for low values of the matrix to fiber strength ratio (less than 0.75), and decreased creep life was predicted for decreased matrix to fiber strength ratio. For a matrix to fiber strength ratio of 1.0, the creep life of the woven composite was predicted to be equivalent to a unidirectional composite. At small initial crack lengths, a 10% improvement in the creep life was predicted for a reduction in the matrix to fiber strength ratio from 1.0 to 0.75. This improvement was related to the formation of microcracks in the 90° tows and shielding of the macrocrack tip from accelerated creep damage. This improvement in the predicted creep life at a matrix to fiber strength ratio of 0.75 was predicted to be independent of applied stress. However, improvement of the creep life was not predicted to occur for larger values of initial crack length.     

Tutorial on the biology of nanotopography

The aims of this short tutorial are fourfold: 1) to introduce readers unfamiliar with the field to major concepts in the field; 2) to inform the reader of major unresolved questions; 3) to inform readers of a few major sources of relevant literature; and 4) to place the subject in relation to its relevance to other areas of science and practical application.     

论企业家素质

企业家是以自己的洞察力和创造力发现和消除市场的不均衡性，善于抓住商机、占领和拓展市场，为企业赚取利润、更有效地利用生产要素，为社会创造财富的人，企业家在现代企业的生产经营活动中处于中位。在此对企业家的基本素质进行了初步的论述，这对于我国对培养就适应于市场经济条件下的科技、管理人才具有重要的现实意义。     

Scope methodology for safety

The EXTENDED Assessment/Certification task of the ESPRIT project SCOPE is intended to address those issues of Software Assessment/Certification which are not directly covered by its BASIC Assessment/Certification Model. That is it aims to cover some aspects of ‘Fitness of Purpose’ of software products, but, being mindful of the advice emanating from the Legal Study, will not claim to cover all aspects. This may readily be appreciated too, by appreciating the plethora of techniques which are already available to, say, the safety community. The aim is to assess the impact of these techniques upon the SCOPE BASIC model, and to recomment adjustments if necessary.We intend to introduce some of those problems and techniques which may be of relevance to the extended certification task of SCOPE, though it should be borne in mind that the project ultimately has to demonstrate the feasibility of its approach to certification, and that it is not its purpose to develop new tools but rather to investigate, adapt and integrate existing tools to demonstrate the viability of the proposed approach. In the Appendix we introduce a new relativistic software reliability model.This paper is not intended to be complete, it is meant to provoke discussion and reports on progress so far.     

Analytical evaluation of aircraft operational risks from runway rutting

Runway surface distortions such as rutting allow water to accumulate on the runway surface which may cause aircraft operational risks related to hydroplaning and loss of friction. This may increase the runway excursion risk during wet weather conditions. Several standards relating to airfield pavement maintenance have documented that rutting can cause safety hazards to aircrafts due to hydroplaning risk. This paper proposes an analytical approach to evaluate the hydroplaning potential for aircrafts due to the flooded ruts of a runway pavement and evaluate the operational risk. A finite element model is developed to simulate aircraft tyre hydroplaning under given set of operating conditions. By performing this evaluation for different rut depths, an assessment of the relative severity levels of different rut depths with respect to hydroplaning can be made. A numerical example is presented to illustrate the application of the procedure to evaluate operational risks to aircraft from runway rutting.     

Synthesis of nanowires,nanorods and nanoparticles of ZnO through modulating the ratio of water to methanol by using a mild and simple solution method

ZnO nanowires, nanorods and nanoparticles through modulating the ratio of water to methanol have been synthesized by using a mild and simple solution method. The as-prepared ZnO nanostructures have been characterized by atomic force microscopy and X-ray photoelectron spectroscopy. With the increase of the ratio of water to methanol, the morphology of ZnO nanostructures varied form denser nanowires, to sparse nanowires, to nanorods, and then to nanoparticles. The ratio of water to methanol is supposed to play an important role in the formation of ZnO nanostructures. The mechanism of formation is related to the chemical potential, which is simply proportional to their surface ratio.     

Methodology of using delay-time analysis for a manufacturing industry

This paper has been written to give a methodology of applying delay-time analysis to a maintenance and inspection department. The aim is to reduce downtime of plant items and/or reducing maintenance and inspection costs, taking into account the possible environmental impact of a failure in terms of cost, both to the company and the environment. The paper also attempts to give a subjective measure of the consequences of such a failure in terms of cost to the environment, in monetary value to the company and the damaging effect to the company image.     

Electrophoresis-assisted active immunoassay

An active assay can be defined as that in which diffusion-controlled reactions are replaced by active delivery of analytes to probe molecules. The present paper describes an electrophoresis-assisted version of an active ELISA performed in tubes or wells with a dialysis membrane attached to their bottoms. The permeability of such a membrane to small ions allows us to apply electric field perpendicular to the membrane surface and to rapidly transport and concentrate charged macromolecular analytes in its vicinity. Probe molecules were either adsorbed or covalently linked to a modified surface of a membrane from regenerated cellulose. An active assay was performed both in separate cells and in 96-well microplates. It was demonstrated that the active assay format allows one (i) to reduce assay time to minutes instead of hours, (ii) to increase sensitivity by a factor of 10-300, and (iii) to capture within 10 min up to 70% of all the analyte molecules present in 0.36 mL of solution.     

中国传统图案对现代礼品包装设计的启示

论述了中国传统图案如何运用到现代礼品包装设计中,如何结合现代工艺手段,使现代礼品包装充满文化底蕴和艺术性,满足人们的需求,同时,丰富现代包装设计的面貌,为平面设计带来新的形式.     

Efficient structural computations with parameters uncertainty for composite applications

The aim of this paper is to propose a methodology in order to take into account the influence of uncertain data in structural calculations. To attain this goal, an approximation of the responses as a function of the uncertain data response called surface method (RSM) is proposed. In order to decrease the number of identification points necessary for the RSM, a progressive strategy is proposed. Error indicators are also used in order to increase the confidence. This strategy is applied to a laminate plate subjected to bending tests. The results are compared to Monte-Carlo simulations (considered as a reference). The method proposed in the present work permits to estimate correctly the whole response and is very simple to use (pre- and post-processing). This method is applied to asses the robustness of the point-stress method used to predict the rupture of perforated plates.     

Control of mechanical deformation of a laminate by electrical load to piezoelectric actuator considering the effects of damping and transverse shear

In this paper, we treat the control of dynamic deformation of a laminate by applying electrical load to piezoelectric actuators. Dynamic behavior of the laminate is analyzed considering the effect of damping due to interlaminar shear and the effect of transverse shear. The analytical model is a rectangular laminate composed of fiber-reinforced laminae and piezoelectric layers. The model is assumed to be a symmetric cross-ply laminate with all edges simply supported and to be subjected to unavoidable mechanical load and to electrical loads to piezoelectric actuators. Behavior of the laminate is analyzed based on the first-order shear deformation theory. The effect of damping due to interlaminar shear is incorporated into our analysis by introducing the interlaminar shear stresses which satisfy the Newton’s law of viscosity. The following quantities are obtained: (1) natural frequencies of the laminate, (2) weight functions for the deflection and rotations and (3) transient deflection due to loads varying arbitrarily with time. Moreover, the methods to control the deflection due to mechanical load by applying electrical voltage to the piezoelectric actuator are shown.     

Application of structural analysis to the mechanical behaviour of the cornea.

Structural engineering analysis tools have been used to improve the understanding of the biomechanical behaviour of the cornea. The research is a multi-disciplinary collaboration between structural engineers, mathematical and numerical analysts, ophthalmologists and clinicians. Mathematical shell analysis and nonlinear finite-element modelling have been used in conjunction with laboratory experiments to study the behaviour of the cornea under different loading states and to provide improved predictions of the mechanical response to disease and injury. The initial study involved laboratory tests and mathematical back analysis to determine the corneal material properties and topography. These data were then used to facilitate the construction of accurate finite-element models that are able to reliably trace the performance of cornea upon exposure to disease, injury or elevated intra-ocular pressure. The models are being adapted to study the response to keratoconus (a disease causing loss of corneal tissue) and to tonometry procedures, which are used to measure the intra-ocular pressure. This paper introduces these efforts as examples of the application of structural engineering analysis tools and shows their potential in the field of corneal biomechanics.     

Development of an interactive simulation system for the determination of the pressure–time relationship during the filling in a low pressure casting process

An interactive computer simulation system has been developed in this study to aid the determination of the pressure–time relationship during the filling of a low pressure casting to eliminate filling-related defects while maintaining its productivity. The pressure required to fill a casting in a low pressure casting process can be separated into two stages. The first stage is to exert pressure to force the molten metal to rise in the riser tube up to the gate of the casting die, which varies from casting to casting due to the drop of the level of the molten metal in the furnace, whilst the second stage is to add an additional pressure to push the molten metal into the die cavity in a way that will not cause much turbulence and have the proper filling pattern to avoid the entrapment of gas while maintaining productivity.One of the major efforts in this study is to modify the filling simulation system with the capability to directly predict the occurrence of gas porosity developed earlier to interactively determine the proper gate velocity for each and every part of the casting. The pressure required to fill the die cavity can then be obtained from the simulations.The operation principles and the interactive analysis system developed are then tested on an automotive wheel made by the low pressure casting process to demonstrate how the system can aid in determining the proper pressure–time relations, the p–t curve, required to produce a sound casting without sacrificing productivity.     

Risk analysis in safety reports required by the Seveso Directive

The Seveso Directive of the EC requires the operators of certain industrial installations deemed to present a ‘major hazard’ to produce and submit to the appropriate National Regulatory Authority a report (notification) giving information relevant to the safety of the installation. In particular, information has to be given with regard to the quantity and nature of dangerous substances handled, the circumstances under which a major accident might occur and the measures to prevent such accidents and to mitigate their consequences. In effect, this requires some form of risk analysis to be carried out. The laws introduced by Member States have specified to greater and lesser extents how that should be done, in particular the extent to which the consequences and likelihood of possible accidents should be quantified. That, together with the general view of industry that there are real limitations as to how far meaningful quantification of those aspects is possible, has resulted in some differences in the style of reports prepared.When considering the question of risk analysis it is important to recognise that it comprises a number of elements from the identification of causes of possible accidents, through evaluation of their consequences and likelihood to, in the limit, an evaluation of the risk of harm to people. In general, industry takes the view that the identification stage, which is largely qualitative, is the most important and is necessary for the preparation of a safety report. It is also generally accepted that some evaluation of the consequence of possible accidents in quantitative terms is necessary to indicate that management appreciates the potential for harm. But that has to take account of the uncertainties in the analysis procedure. Such uncertainties also limit the extent to which a meaningful quantification can be made of the probability or likelihood of accidents and, even more so, of the probability of harm to people. Hence, industry is largely opposed to the general use of those elements of quantified risk analysis (QRA) in a safety case for reasons discussed by CEFIC in its position paper ‘CEFIC Views on the Quantitative Assessment of Risks from Installations in the Chemical Industry’.     

Intelligent machines in the twenty-first century: foundations of inference and inquiry

The last century saw the application of Boolean algebra to the construction of computing machines, which work by applying logical transformations to information contained in their memory. The development of information theory and the generalization of Boolean algebra to Bayesian inference have enabled these computing machines, in the last quarter of the twentieth century, to be endowed with the ability to learn by making inferences from data. This revolution is just beginning as new computational techniques continue to make difficult problems more accessible. Recent advances in our understanding of the foundations of probability theory have revealed implications for areas other than logic. Of relevance to intelligent machines, we recently identified the algebra of questions as the free distributive algebra, which will now allow us to work with questions in a way analogous to that which Boolean algebra enables us to work with logical statements. In this paper, we examine the foundations of inference and inquiry. We begin with a history of inferential reasoning, highlighting key concepts that have led to the automation of inference in modern machine-learning systems. We then discuss the foundations of inference in more detail using a modern viewpoint that relies on the mathematics of partially ordered sets and the scaffolding of lattice theory. This new viewpoint allows us to develop the logic of inquiry and introduce a measure describing the relevance of a proposed question to an unresolved issue. Last, we will demonstrate the automation of inference, and discuss how this new logic of inquiry will enable intelligent machines to ask questions. Automation of both inference and inquiry promises to allow robots to perform science in the far reaches of our solar system and in other star systems by enabling them not only to make inferences from data, but also to decide which question to ask, which experiment to perform, or which measurement to take given what they have learned and what they are designed to understand.