地下空间规划的决策支持系统

在大城市的发展进程中,中心区地下行人和商业系统变得日渐重要.地下系统的增长引起了人们对于稳定性、长期经济价值和协调发展等问题的关注.虽然我们有可能对发展地区的大部分地下工程进行预测,但要确定这些工程的建设时序和各自精确的特征还非常困难.本文建议推行一个决策系统,而不要试图制定长远性的总体规划.通过这种逐步推进的方法,评估单体项目对整个地下系统和地面发展的影响.由于项目的使用程度、最终的经济价值和公共用途的有效性可以通过最新的研究方法得到预测,因此就有可能对单项提案进行评估.在评估中,审批、成本分摊和系统的连接费用都可以落实到单个项目上.这种方法不仅能够激发开发者的革新和创造力,也能确保系统的长期发展和稳定.     

外接电源能量效率新标准

外接电源(EPS),即那些给各类电子产品--从无绳电话到笔记本电脑--供电的充电器和适配器,近来已经成为新的能量效率标准(见表1)所针对的目标.EPS全球每年的销售量达10亿只以上,而且目前约有100亿只在使用,已经成为最大的一个电源门类.目前正在使用的EPS中,有大约一半属于效率低下的、采用工频变压器和线性稳压器的类型.除了效率低至25～50%,这些装置无负载时的功耗一般为1W或1W以上.每年被低效率的EPS浪费的能量总量--单就美国而言-估计达300亿到600亿千瓦时,即每年的开销达25亿到50亿美元.这一消耗占到美国国内全部发电量的1～2%,等于大约26座平均规模的电站的输出总和.     

A boronic acid-based fluorescent hydrogel for monosaccharide detection

A boronic acid-based anthracene fluorescent probe was functionalised with an acrylamide unit to incorporate into a hydrogel system for monosaccharide detection. In solution, the fluorescent probe displayed a strong fluorescence turn-on response upon exposure to fructose, and an expected trend in apparent binding constants, as judged by a fluorescence response where D-fructose>D-galactose>D-mannose>D-glucose. The hydrogel incorporating the boronic acid monomer demonstrated the ability to detect monosaccharides by fluorescence with the same overall trend as the monomer in solution with the addition of D-fructose resulting in a 10-fold enhancement (≤0.25 mol/L).     

新型羊毛阻燃剂

提供了传统的羊毛阻燃剂Zirpro和自由Firestop化学品公司开发的新的替代产品Naflan深入的技术分析结果.描述了Zirpro处理和Norflan处理的优缺点.讨论了Noflan多用途整理.     

Thin-film composite forward osmosis membranes with substrate layer composed of polysulfone blended with PEG or polysulfone grafted PEG methyl ether methacrylate

To advance commercial application of forward osmosis (FO), we investigated the effects of two additives on the performance of polysulfone (PSf) based FO membranes: one is poly(ethylene glycol) (PEG), and another is PSf grafted with PEG methyl ether methacrylate (PSf-g-PEGMA). PSf blended with PEG or PSf-g-PEGMA was used to form a substrate layer, and then polyamide was formed on a support layer by interfacial polymerization. In this study, NaCl (1 mol?L⁻¹) and deionized water were used as the draw solution and the feed solution, respectively. With the increase of PEG content from 0 to 15 wt-%, FO water flux declined by 23.4% to 59.3% compared to a PSf TFC FO membrane. With the increase of PSf-g-PEGMA from 0 to 15 wt-%, the membrane flux showed almost no change at first and then declined by about 52.0% and 50.4%. The PSf with 5 wt-% PSf-g-PEGMA FO membrane showed a higher pure water flux of 8.74 L?m⁻²?h⁻¹ than the commercial HTI membranes (6–8 L?m⁻²?h⁻¹) under the FO mode. Our study suggests that hydrophobic interface is very important for the formation of polyamide, and a small amount of PSf-g-PEGMA can maintain a good condition for the formation of polyamide and reduce internal concentration polarization.     

Multifunctional iron-carbon nanocomposites through an aerosol-based process for the in situ remediation of chlorinated hydrocarbons

Spherical iron-carbon nanocomposites were developed through a facile aerosol-based process with sucrose and iron chloride as starting materials. These composites exhibit multiple functionalities relevant to the in situ remediation of chlorinated hydrocarbons such as trichloroethylene (TCE). The distribution and immobilization of iron nanoparticles on the surface of carbon spheres prevents zerovalent nanoiron aggregation with maintenance of reactivity. The aerosol-based carbon microspheres allow adsorption of TCE, thus removing dissolved TCE rapidly and facilitating reaction by increasing the local concentration of TCE in the vicinity of iron nanoparticles. The strongly adsorptive property of the composites may also prevent release of any toxic chlorinated intermediate products. The composite particles are in the optimal range for transport through groundwater saturated sediments. Furthermore, those iron-carbon composites can be designed at low cost, the process is amenable to scale-up for in situ application, and the materials are intrinsically benign to the environment.     

混炼试验的潘恩效应和分散率对比(二)

正(接上期)4.1.6 EPDM图20示出了三元乙丙橡胶(EPDM)具有类似于丁基橡胶(IIR)的对炭黑弱的亲和力。就像混炼丁基橡胶(IIR)填充胶那样,所看到的EPDM填充胶的G′潘恩效应曲线都很接近,这点EPDM与IIR很相似,均缺乏与炭黑的亲和     

阵列声波测井传输网络指向性及互易性分析

在声波测井中声束导向的效率除受换能器的几何参数及阵列声波发射单元的激励延迟时间或阵列接收器接收的各道声波信号偏移时间的影响外 ,还受换能器的形状和尺寸的影响。一般声波测井仪是由一维阵列声源和单接收器或由单声源和一维阵列接收器组成。换能器为薄圆管形压电换能器。采用相应的声波测井传输网络理论和指向性权系数的概念 ,计算了换能器的形状及大小对声束导向信号所造成的影响 ,并论证了声波测井仪中阵列声源和阵列接收器的互易性。通过调整声束导向参数和阵列接收器接收到的声波信号的时间偏移量 ,可使得接收首波幅度 (阵列声源 )和叠加波首波幅度 (阵列接收器 )最大。此外 ,运用数值模拟和实验对文中提出的最佳设计方案进行了验证     

“优化之道”洞悉IT服务质量

“优化之道”的每个阶段都规定了在成本和技术可逐步实现的步骤，从而使得企业逐渐实现IT服务优化和完全实现业务服务管理。     

如何将客户变为家人

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