Formation of mushroom-like ZnO microcrystals through a solution calcination process

Mushroom-like ZnO microcrystals have been prepared via a solution calcination route, using Zn(NO₃)₂ as Zn source in the absence of any surfactants, templates or catalysts. This is the first example to prepare mushroom-like crystals as semiconductors, which are expected to show particular physical properties. The ZnO products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy and photoluminescence (PL) spectrum measurements. A suitable concentration of Zn(NO₃)₂ solution was important for the growth of the mushroom-like products. The reported synthetic procedure is straightforward and inexpensive, and thus can be readily adopted to produce large quantities of mushroom-like ZnO microcrystals.     

应用均匀设计法研究安息香缩合工艺

利用均匀设计法通过SPSS10.0计算机软件研究了反应条件对安息香缩合的影响。从而获得优化的工艺条件，与正交试验相比，该法试验次数少。工作效率高，并且便于分析各种因素的影响。     

阻燃纤维/棉混纺纱线的力学性能分析

对3种不同混纺比的阻燃腈纶(A)/阻燃黏胶(R)/棉(C)混纺纱线及纯阻燃黏胶纱线、纯阻燃腈纶纱线的力学性能进行了测试与分析.结果表明:5种纱线中纯阻燃腈纶纱线的拉伸断裂性能、耐磨性能、弯曲性能和扭转性能最好,RA50/C50混纺纱线的拉伸弹性、疲劳性能和蠕变性能最好,RA30/C70混纺纱线的压缩性能最好;3种混纺纱线中RA50/C50混纺纱线的拉伸断裂性能最好,RA70/C30混纺纱线的耐磨性能、弯曲性能最好,三者的扭曲性能比较接近.     

Design,Synthesis and Biological Evaluation of Steroidal Glycoconjugates as Potential Antiproliferative Agents

To systematically evaluate the impact of neoglycosylation upon the anticancer activities and selectivity of steroids, four series of neoglycosides of diosgenin, pregnenolone, dehydroepiandrosterone and estrone were designed and synthesized according to the neoglycosylation approach. The structures of all the products were elucidated by NMR analysis, and the stereochemistry of C20-MeON-pregnenolone was confirmed by crystal X-ray diffraction. The compounds′ cytotoxicity on five human cancer cell lines was evaluated using a Cell Counting Kit-8 assay, and structure–activity relationships (SAR) are discussed. 2-deoxy-d -glucoside 5 k displayed the most potent antiproliferative activities against HepG2 cells with an IC₅₀ value of 1.5 μM. Further pharmacological experiments on compound 5 k on HepG2 cells revealed that it could cause morphological changes and cell-cycle arrest at the G0/G1 phase and then induced the apoptosis, which might be associated with the enhanced expression of high-mobility group Box 1 (HMGB1). Taken together, these findings prove that the neoglycosylation of steroids could be a promising strategy for the discovery of potential antiproliferative agents.     

大型号齿形V带质量优化的研究

介绍了对大型号齿形绳芯V带性能优化的主要措施是：①带体内增设横向刚性层；②聚酯短纤维在各胶层中的全面应用；③采用胶套模硫化与模芯电加热结合；④低稳定形齿排的应用。对优化前后的胶带性能作了对比，证明优化措施对提高带体质量起到了明显效果。     

云母钛珠光颜料的研究

综述了云母钛珠光颜料的发展概况，介绍了它的三种类型：银白色型、虹彩型、着色型，着重论述了它的生产工艺和制备方法(气相包覆法和液相沉积法)，并比较了各类方法的优缺点，分析了它的晶型类别(板钛型、锐钛型、金红石型)、包膜的复合机理和虹彩效应形成的原因，并指出国内产品的发展方向。     

羰基结构与亲核加成反应

羰基化合物是一类极为重要的有机化合物，本文从(1)醛酮(2)环酮(3)α，β-不饱和羰基化合物的结构讨论了羰基结构对其亲核加成活性的影响。     

纳米铜锰复合氧化物固相反应法的制备与表征

以乙酸铜、乙酸锰与草酸为原料,采用固相化学反应法制备了纳米铜锰复合氧化物前驱物,利用均匀设计考察了微波功率与加热时间、热分解温度及时间对产物粒径的影响。研究表明热分解温度对产品粒径的影响最大。最小粒径产物的制备条件是：微波功率540 W,微波加热时间15 min;热分解温度370℃,热分解时间2 h。XRD和TEM分析结果表明,此产品主要物相为Cu1.5Mn1.5O4,结构属立方晶系,空间群为Fd3m,平均粒径16.9-19.0 nm。应用TG-DTG和DSC技术研究了纳米铜锰复合氧化物的热分解过程以及热分解动力学,采用Ozawa积分法和Coats-Redfern积分法得前驱体的热分解机理函数均为G（α）=[-ln（1-α）]^2/3。     

硫酸钙-硫酸钠-铬酸钙-铬酸钠-水体系中复盐的生成研究

为配合化工产品新工艺的开发,研究了25～70 ℃硫酸钙-硫酸钠-铬酸钙-铬酸钠-水体系中复盐的生成规律.摇床实验及X射线衍射分析发现,将固体铬酸钙加入不同浓度的硫酸钠和铬酸钠溶液中时,除生成CaSO4·2H2O外,还可能生成4种复盐沉淀,即CaSO4·Na2SO4,CaSO4·Na2SO4·4H2O,CaSO4·2Na2SO4·2H2O和5CaSO4·Na2SO4·3H2O.当温度和溶液浓度发生变化时,复盐的形式会相应变化,低温稀溶液中只有CaSO4·2H2O沉淀,没有复盐沉淀析出,而高温浓溶液中,4种复盐都会析出.     

Dynamic deviation reduction‐based concurrent dual‐band digital predistortion

This article introduces the concurrent dual‐band digital predistortion (DPD) architecture with only one upconvertion unit, which is suitable for the linearization of wideband power amplifiers (PAs) excited by concurrent dual‐band signals. By extending the conventional dynamic deviation reduction (DDR) model to the concurrent dual‐band mode, we propose two DDR‐based concurrent dual‐band models, the dual‐band DDR (DB‐DDR) model and the simplified dual‐band DDR (SDB‐DDR) model. The performance of these two models is experimentally assessed with two types of wideband PAs (a GaN Class F PA and a GaN Doherty PA) driven by the concurrent dual‐band signal, and compared with the prior two‐dimensional digital predistortion (2D‐DPD) model and the two‐dimensional modified memory polynomial (2D‐MMP) model. The results prove the good DPD performance and low computational complexity of the proposed models. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:401–411, 2014.