温哥华城市规划编制的模式、机制与启示

温哥华的城市规划管理系统被称为“自由裁量规划系统”。这城市规划管理系统融合了英国和美国两种不同的管理模式。英式城市规划管理注重自由裁量权在管理过程中的应用,而美式规划管理则依靠详细的法定分区图则,在决策过程中更偏重对清晰原则的依赖。而在温哥华,看似矛盾的两个系统共同存在,并实现了完美结合。在这一管理系统中,城市规划可分为政策研究、官方发展规划和分区图则3个层面。     

细菌纤维素/聚乙烯醇双网络复合水凝胶的制备与性能研究

利用冷冻-解冻法制备了细菌纤维素（BC）/聚乙烯醇（PVA）双网络复合水凝胶,研究不同BC含量及循环周期对BC/PVA复合水凝胶力学性能和溶胀特性的影响,结果表明,随着BC含量的增多,复合水凝胶的含水率、平衡溶胀比、拉伸强度和压缩强度与普通的PVA水凝胶相比均有一定程度的提高;综合考虑,当BC含量为4%时,各项性能均达到最佳值;随着循环次数的增多,水凝胶内部的物理交联点增多,导致水凝胶的含水率下降,拉伸强度和压缩强度则有明显的上升趋势。SEM观察的结果与之前的分析是一致的。     

BC9型钢丝圈气圈底端张力特性分析

为拓展BC9型钢领钢丝圈的应用领域,通过研究钢丝圈气圈底端张力的特性,在平面钢领钢丝圈系统受力分析的基础上列出BC9型钢领钢丝圈平衡方程,并在考虑空气阻力和哥氏惯性力的情况下得出了气圈底端张力表达式,分析了其变化规律。根据高速摄影技术对气圈底角进行分析,得出气圈底角在-4°~5°之间变化。然后结合上述表达式给出不同卷绕半径下的气圈底端张力值,分析了气圈底角和卷绕半径对气圈底端张力的影响。结果表明,气圈底端张力随卷绕半径增加而减小,随气圈底角增加而增加,且卷绕大小直径时张力差异随气圈底角增加而增加。     

Application of a BC501A Liquid Scintillation Detector with a Gain Stabilization System on the EAST Tokamak

A 2"×2"BC501A liquid scintillation detector with a gain stabilization system is developed and applied to neutron andγ-ray measurement on the EAST tokamak.Energy calibration of a liquid scintillator using a fast coincidence method is presented and compared with the Monte Carlo simulation.Determination of the proton light output function of the BC501A is presented.Results from dedicated experiments with an Am-Be neutron source,γsource and quasi-monoenergetic neutron beams,and from measurements on EAST tokamak are presented and discussed.     

细菌纤维素的制备和应用研究进展

细菌纤维素（Bacterial cellulose,简称BC）又称微生物纤维素,具有独特超细网状纤维结构、不含木质素和其他细胞壁成份,吸水性强、高生物兼容性、可降解性等优良特点,日益成为人们关注的焦点.综述了近年来国内外在细菌纤维素的菌种筛选、碳源优化、发酵工艺方面的研究成果,以及细菌纤维素在肾透析膜、血管支架、皮肤代用品、化妆品膜、减肥代餐食品等方面的应用.     

Pleiotropic Roles of ABC Transporters in Breast Cancer

Chemotherapeutics are the mainstay treatment for metastatic breast cancers. However, the chemotherapeutic failure caused by multidrug resistance (MDR) remains a pivotal obstacle to effective chemotherapies of breast cancer. Although in vitro evidence suggests that the overexpression of ATP-Binding Cassette (ABC) transporters confers resistance to cytotoxic and molecularly targeted chemotherapies by reducing the intracellular accumulation of active moieties, the clinical trials that target ABCB1 to reverse drug resistance have been disappointing. Nevertheless, studies indicate that ABC transporters may contribute to breast cancer development and metastasis independent of their efflux function. A broader and more clarified understanding of the functions and roles of ABC transporters in breast cancer biology will potentially contribute to stratifying patients for precision regimens and promote the development of novel therapies. Herein, we summarise the current knowledge relating to the mechanisms, functions and regulations of ABC transporters, with a focus on the roles of ABC transporters in breast cancer chemoresistance, progression and metastasis.     

Protein Corona Gold Nanoparticles Fingerprinting Reveals a Profile of Blood Coagulation Proteins in the Serum of HER2-Overexpressing Breast Cancer Patients

Breast cancer (BC) is a molecularly heterogeneous disease that encompasses five major molecular subtypes (luminal A (LA), luminal B HER2 negative (LB-), luminal B HER2 positive (LB+), HER2 positive (HER2+) and triple negative breast cancer (TNBC)). BC treatment mainly depends on the identification of the specific subtype. Despite the correct identification, therapies could fail in some patients. Thus, further insights into the genetic and molecular status of the different BC subtypes could be very useful to improve the response of BC patients to the range of available therapies. In this way, we used gold nanoparticles (AuNPs, 12.96 ± 0.72 nm) as a scavenging tool in combination with Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS) to quantitatively analyze the serum proteome alterations in the different breast cancer intrinsic subtypes. The differentially regulated proteins specific of each subtype were further analyzed with the bioinformatic tools STRING and PANTHER to identify the major molecular function, biological processes, cellular origin, protein class and biological pathways altered due to the heterogeneity in proteome of the different BC subtypes. Importantly, a profile of blood coagulation proteins was identified in the serum of HER2-overexpressing BC patients.     

最新USB充电技术与测试

USB2.0规范并没有考虑到使用USB接口为便携式设备的电池进行充电的需求,而这样的应用需求却越来越多。本文首先介绍USB-IF最新颁布的电池充电规范v1.2版本的主要内容;然后对其相关测试规范做简单介绍;最后结合测试经验,对测试中的重点项目和难点内容进行说明。     

A Unified Scaling-Up Technique for Pneumatic Conveying Systems

A major challenge facing the designers of pneumatic transportation systems is how to scale up reliably based on the results from pilot-scale test facilities. Further, even if dense phase flow condition prevails at the start of the conveying system, it may be a dilute phase flow condition at the end of the pipeline. Hence, any scaling-up technique should be able to address the dynamic change of flow condition along the pipeline. The scaling-up technique presented here using the pressure drop prediction models based on modified Darcy-Weisbach equation successfully addresses these dynamic changes. It has been shown that the pressure drop coefficient ‘K,’ as defined by the models, is independent of the pipe diameter. Further, in the case of vertical conveying, ‘K’ has been shown to be independent of particle size distribution for a given material. The predicted pressure values were found to be in reasonably good agreement with the experimental results varying from 3.5% to 19.9%.     

Solid reaction between Al and B4C

Abstract

In the present work, solid reaction products formed by a mixture of aluminium and boron carbide (B₄C) powder heat treated under low pressure were studied. No significant reaction between B₄C and Al could be detected for reaction temperatures of 600°C or less. However, at 640°C, and over a short treatment time (1 h), a solid reaction took place between boron carbide and aluminium with the formation of A1₃BC and AlB₂. Meanwhile, over a longer treatment time (36 h), the detectable product phase between boron carbide and aluminium was AlB₁₂.