电视机能源之星7.0版技术规范解读

美国环保署(EPA)发布了电视机能源之星7.0版产品技术规范,于2015年10月30日起正式生效实施.与6.0版相比,修订了多处内容,差异较大.该文从产品定义、范围和功耗要求等方面进行了解读.     

Robust Red Organic Nanoparticles for In Vivo Fluorescence Imaging of Cancer Cell Progression in Xenografted Zebrafish

Bright and red‐emissive organic nanoparticles (NPs) are demonstrated as promising for in vivo fluorescence imaging. However, most red organic dyes show greatly weakened or quenched emission in the aggregated state. In this work, a robust red fluorophore (t‐BPITBT‐TPE) with strong aggregate‐state photoluminescence and good biocompatibility is presented. The NPs comprised of t‐BPITBT‐TPE aggregates encapsulated within 1,2‐distearoyl‐sn‐glycero‐3‐phosphoethanolamine‐N‐[methoxy(polyethylene glycol) (DSPE‐mPEG) micelles exhibit a photoluminescence peak at 660 nm with a high fluorescence quantum yield of 32% in aqueous media. The NPs can be facilely charged by using the same polymeric matrix with different terminal groups, e.g., methoxy (DSPE‐mPEG), amine (DSPE‐PEG‐NH₂), or carboxymethyl (DSPE‐PEG‐COOH) groups. The biocompatibility, toxicity, circulation, and biodistribution of the NPs are assessed using the zebrafish model through whole embryo soaking and intravenous delivery. Furthermore, HeLa and MCF‐7 cells tagged with t‐BPITBT‐TPE in DSPE‐PEG‐NH₂‐TAT polymer NPs are xenografted into zebrafish larvae to successfully track the cancer cell proliferation and metastasis, demonstrating that these new NPs are efficient cancer cell trackers. In addition, the NPs also show good in vivo imaging ability toward 4T1 tumors in xenografted BALB/c mice.     

Facile Synthesis of Red/NIR AIE Luminogens with Simple Structures,Bright Emissions,and High Photostabilities,and Their Applications for Specific Imaging of Lipid Droplets and Image‐Guided Photodynamic Therapy

Red/near‐infrared (NIR) fluorescent molecules with aggregation‐induced emission (AIE) characteristics are of great interest in bioimaging and therapeutic applications. However, their complicated synthetic approaches remain the major barrier to implementing these applications. Herein, a one‐pot synthetic strategy to prepare a series of red/NIR‐emissive AIE luminogens (AIEgens) by fine‐tuning their molecular structures and substituents is reported. The obtained AIEgens possess simple structures, good solubilities, large Stokes shifts, and bright emissions, which enable their applications toward in vitro and in vivo imaging without any pre‐encapsulation or ‐modification steps. Excellent targeting specificities to lipid droplets (LDs), remarkable photostabilities, high brightness, and low working concentrations in cell imaging application make them remarkably impressive and superior to commercially available LD‐specific dyes. Interestingly, these AIEgens can efficiently generate reactive oxygen species upon visible light irradiation, endowing their effective application for photodynamic ablation of cancer cells. This study, thus, not only demonstrates a facile synthesis of red/NIR AIEgens for dual applications in simultaneous imaging and therapy, but also offers an ideal architecture for the construction of AIEgens with long emission wavelengths.     

FE modeling of warm flanging process of large T-pipe from thick-wall cylinder

The large T-branch pipe made from the thick-wall cylinder is an important part in power, petroleum, and chemical equipment. The warm flanging process is used to manufacture the high-performance large T-branch pipe from thick-wall cylinder. The warm flanging process has a bulk-forming characteristic with heterogeneous temperature field and represents very different from the sheet flanging process. The finite element method is adopted to study the warm flanging process of large T-branch pipe due to complex local heating and local deformation. A viscoplastic FE model was built to simulate the whole process in the same process, including heating, forming, cooling, and relevant elastic springback. Only one set of mesh was used to ensure the connection of heating and forming, which was never proposed in the warm flanging process before. The experiment was conducted to verify the proposed model by comparing the geometry and defects. Accordingly, two kinds of typical defects, buckling and wrinkling, were found in both of the simulation and experiment results. And, the reasons of defects were investigated with the stress and metal flow analysis. The short lower die leads to the buckling. Due to the ellipse outer edge, the uneven rebound makes wrinkling at the ends of the process. Three relevant improved methods, lengthening the lower die, increasing the fillet of the upper die, and increasing the radius of the upper die, were proposed and studied to decline the defects.     

A convenient synthesis of alkyl-2-(2-imino-4-oxothiazolidin-5-ylidene)acetate derivatives involving an electrogenerated base of acetonitrile

We report a simple method for the synthesis of alkyl-2-(2-imino-4-oxothiazolidin-5-ylidene) acetate derivatives 3 in good yields under mild conditions. The electrogenerated cyanomethyl base (EGB), obtained from electroreduction of acetonitrile-0.1?M TBABF₄, assists the reaction between thiourea derivatives 1 and dialkyl acetylene dicarboxylate 2. The expected products, 3/4, and the structure obtained from X-ray diffraction confirm that the main products are the five-membered heterocycles 3. Furthermore, a mechanism, to explain the reaction pathways, is proposed based on the thermodynamic and kinetic data obtained from quantum calculations.     

Assessing groundwater contamination risk using the DASTI/IDRISI GIS method: coastal system of western Mamora, Morocco

In this study, the DASTI method was used to evaluate vulnerability to groundwater pollution in the vicinity of Rabat, western Morocco. The model is based on the characterization of five intrinsic parameters: unsaturated zone thickness, saturated zone thickness and lithology, soil texture, topography and hydraulic gradient. A system of classes of the hydrogeological characteristics was applied to evaluate relative vulnerability to groundwater contamination and a susceptibility map was prepared based on land use and the vulnerability index map. The study showed the DASTI method (applied using IDRISI software) can serve as a tool to evaluate vulnerability to pollution and thus facilitate programs to protect groundwater resources. An erratum to this article can be found at     

建筑消防工程实行监理制度之我见

建筑消防工程关系到建筑安全的重要方面 ,随着建筑规模的扩大 ,建筑消防工程的迅猛发展 ,消防系统数量的增加和系统本身的日益复杂 ,实行消防工程监理制度呼声日高 ,笔者就消防工程监理 ,结合工作实践 ,谈谈自己的一些看法 ,并就相关问题试作探讨 ,望能引起有关方面重视 ,加快实行监理的进程。1　实行监理的必要性1.1　消防工程动态监督的需要。消防工程由设计人员根据国家有关规范设计 ,交施工单位施工 ,由消防部门进行验收。由于设计、施工工作的失误 ,致使一些问题无法及时发现 ,形成先天性隐患 ,无法整改 ,近几年来的多起特大火灾暴露了…     

The affordability of “affordable” housing in England: conditionality and exclusion in a context of welfare reform

Abstract

Contemporary debates around affordability have largely focused on homeownership and private renting. This article considers the affordable social rented sector in England, in which reforms to social welfare assistance, reduced security of tenure, and a shift towards mid-market rents, are changing access to ‘affordable’ housing for those on the lowest incomes. Drawing on in-depth interviews with housing associations and stakeholders, the article highlights the increasing use of affordability assessments for prospective tenants. These assessments interact with mid-market rental products to increase the potential for exclusion from affordable housing on the grounds of ability to pay. This conditionality is applied not only at the point of tenancy access, but also at renewal of fixed-term tenancies. The research highlights that the combination of welfare and housing policies, in the context of a financialising housing association sector, has the potential to erode access to social housing for those who are perceived as a financial risk, reshaping the focus of social housing.     

真空相变散热器

本文指出了传统钢制散热器的缺点并详细介绍了新型真空相变散热器的结构和工作原理，从而证实了此种散热器的优越性，这对于推进小型燃气锅炉供热系统的广泛应用具有十分重要的意义。     

玻璃钢覆面木胶合板模板

本文探讨了以酚醛树脂胶马尾松胶合板为基材，表面用玻璃钢覆面改善面板理化性能和提高板材力学性能的生产方法，并检测了板材的静曲强度，弹性模量，表面耐磨性和耐水性能，结果表明，玻璃钢覆面后的马尾松胶合板模板的表面理化性能和力学性能得到了显著的提高。有利于作为混凝土模板使用。