数字化技术在服装艺术设计创作中的体现及应用

数码时代的到来,电子计算机等高科技手段的广泛应用,使服装时尚资讯收集、工业生产进程检测及设计方法等领域发生了很大的变化,对实现创新的服装行业来讲,根据流行趋势和主题与创意需要,在电脑中直接生成各种极富创意的产品形象,运用设计软件对其进行各种特技处理,以产生创意独特、令人惊奇的画面效果,为服装生产企业提供最直接、最清晰、最实用的设计指导。     

Dissolution of latex films after γ‐ray treatment

Latex films were prepared by annealing pyrene (Py)‐labeled poly(methyl methacrylate) particles at glass‐transition temperature (100°C). These films were then irradiated by γ‐rays from ⁶⁰Co in a gamma cell at room temperature at the same dose rate (rad/h) for 30 min. Before dissolution films were annealed at elevated temperatures for a 30‐min time interval to complete the film formation process. Steady‐state fluorescence (SSF) technique were used to monitor the dissolution of these irradiated latex films. The dissolution of films in chloroform–heptane (80–20%) mixture was monitored in real time by the Py fluorescence intensity change. Relaxation constants k₀ and desorption coefficients D_d of polymer chains were measured. It was observed that both D_d and k₀ values first increased and then decreased by increasing the annealing temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 129–137, 2002     

光学零件超声波清洗综述

在概述超声波清洗机理之后，着重介绍了光学零件超声波清洗的应用及其使用的清洗剂、脱水剂、干化剂等清洗辅料的进展状况，以及当前清洗辅料的研究动态及面临课题。     

Parallel systems under two sequential attacks

The paper compares the efficiency of single and double attack against a system consisting of identical parallel elements (1-out-of-N system). An attacker tries to maximize the system vulnerability (probability of total destruction). The attacker distributes its constrained resource optimally across two attacks and chooses the number of elements to be attacked in the first attack. The attacker observes which elements are destroyed and not destroyed in the first attack, and applies its remaining resource into attacking the remaining elements in the second attack. First the optimal attack strategy against a system with a fixed number of elements is analyzed. Thereafter a minmax two period game between the attacker and the defender is considered in which the defender distributes its constrained resource between deploying redundant elements and protecting them against the attack.     

成膜温度对自交联含氟乳液成膜的影响

用种子乳液聚合法制备了含氟乳液,借助AFM、XPS对所制备的自交联含氟乳液成膜进行表征、分析,利用Goh模型求算出聚合物链段相互扩散系数,考察成膜温度对自交联含氟乳液成膜的影响.结果表明,成膜温度升高,有利于提高乳胶膜的交联密度和聚合物链段的扩散速度;而涂膜表面氟原子的含量在成膜温度小于50℃时随温度的升高而增大,在50℃以上时随温度的升高而减小,成膜温度并非越高越好.自交联含氟乳液成膜过程中,三维网状结构的形成、氟化组分迁移和聚合物链段相互扩散会出现相互影响和彼此的竞争.     

Enhanced/suppressed interdiffusion of InGaAs-GaAs-AlGaAs strained layers by controlling impurities and gallium vacancies

The interdiffusion of In and Ga at an InGaAs-GaAs interface subjected to different annealing temperatures, times, and environments is demonstrated. The interdiffusion coefficients and activation energies are determined by correlating the shift in the photoluminescence peaks with the calculated quantum well transition energies based on an error function composition profile. The results indicate that a higher In composition In_xGa_1-xGaAs single quantum well (SQW) leads to a higher interdiffusion coefficient of In and Ga in an As overpressure annealing condition. Also, As overpressure increases the interdiffusion, whereas Ga overpressure reduces the interdiffusion. The thermal activation energies for different In composition InGaAs-GaAs SQW’s (x = 0.057, 0.10, 0.15) range from 3.3 to 2.6 eV for an As overpressure environment and from 3 to 2.23 eV for the Ga overpressure situation. With respect to impurity induced disordering by Zn using a Ga or As overpressure significantly effects the depth of the Zn diffusion front but significant mixing does occur in either case when the impurity front reaches the quantum well.     

Influence of laboratory homogenization procedures on trace element content of food samples: an ICP-MS study on soft and durum wheat

Sample contamination as a consequence of abrasion of grinding tools during the homogenization of food materials to be analysed for trace elements was addressed. The possible release of 15 trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sn, V, Zn) from six different grinding and milling devices, operating either continuously or discontinuously, was evaluated. All the devices were commercially available and were representative of models usually employed in food and agricultural laboratories. Wheat grains belonging to one soft and one durum cultivar were used as test material. The determination of the analyte concentrations in subsamples submitted to the different preparation treatments was performed by quadrupole inductively coupled plasma mass spectrometry (Q-ICPMS). Accordingly, a suitable digestion method was developed and the ArC⁺ interference affecting Cr determination was evaluated and corrected. Statistical differences with respect to the control were detected for 10 elements (Al, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb) and in most cases contamination of the samples was traced back to the composition of the grinding equipment. None of the investigated devices was contamination-free with respect to all of the quantified elements. Abrasion of the grinding tools was higher with durum wheat than with soft wheat as a consequence of their different hardness.     

Alternatives for joining Si wafers to strain-accommodating Cu for high-power electronics

Differences in the coefficients of thermal expansion (CTE) between silicon wafers and underlying copper electrodes have led to the use of purely mechanical dry pressure contacts for primary electrical and thermal connections in high-power solid-state electronic devices. These contacts are limited by their ability to dissipate I²R heat from within the device and by their thermal fatigue life. To increase heat dissipation and effectively deal with the CTE mismatch, metallurgical bonding of the silicon to a specially-structured, strain-accommodating copper electrode has been proposed. This study was intended to seek alternative methods for and demonstrate the feasibility of bonding Si to structured Cu in high-power solid-state devices. Three different but fundamentally related fluxless approaches identified and preliminarily assessed were: (1) conventional Sn−Ag eutectic solder; (2) a new, commercially-available active solder based on the Sn−Ag eutectic; and (3) solid-liquid interdiffusion bonding using the Au−In system. Metallurgical joints were made with varying quality levels (according to nonde-structive ultrasonic C-scan mapping, SEM, and electron microprobe) using each approach. Mechanical shear testing resulted in cohesive failure within the Si or the filler alloys. The best approach, in which eutectic Sn−Ag solder in pre-alloyed foil form was employed on Si and Cu substrates metallized (from the substrate outward) with Ti, Ni and Au, exhibited joint thermal conduction 74% better than dry pressure contacts. Formally an M.S. candidate at Rensselaer Polytechnic Institute, Troy, NY. Professor of Materials Science and Engineering/Director of Materials Joining, advised Mr. Faust sponsor of the development effort     

Micro-Raman characterization of plasma nitrided Ti6Al4V-ELI

Titanium nitride surface coatings have been extensively used as wear resistant and biocompatible layers on titanium alloys. Plasma nitriding is a suitable method to obtain these coatings that have to be characterized with phase sensitive techniques, because hardness and wear resistance depend critically on crystallography and stoichiometry. Many of these analytical techniques have very stringent vacuum and sample geometry requirements that frequently do not allow the characterization of surface films ontop of biomedical components (bone or dental implants). Microprobe Raman spectroscopy can be applied without vacuum requirements on samples of variable size and shape. In this work, this technique is used to investigate the TiN layer on a Ti6Al4V-ELI alloy, plasma nitrided at different substrate temperatures, in order to observe the changes in stoichiometry. Changes of the relative intensities of acoustic and optical modes were related to TiN composition, comparing with the results of Nuclear Reaction Analysis, using the ¹⁵N(p, αγ)¹²C reaction induced with 429 keV protons. A linear relationship between the Raman peak area ratio and nitrogen content was observed, that can be used as calibration curve for further Raman measurements of unknown samples.     

携程电子商务模式组成要素分析

目前为止商务模式和电子商务仍然没有统一的定义，本文没有纠缠于概念本身，而是以携程例，从其组成要素分析了企业创造价值和实现利润的过程.