Positively charged nanofiltration membrane fabricated by poly(acid–base) complexing effect induced phase inversion method for heavy metal removal

Poly(arylene ether ketone)s with carboxylic groups (PAEK-COOH) is a good membrane fabrication material, a kind of polyacids, while polyethylenimine (PEI) is a weak organic base, a kind of polybases. Those polyacids and polybases would form ionic complexation at the interface of two liquid phases. In this paper, PAEK-COOH/ N-methyl pyrrolidone (NMP)/1,4-dioxane (DO) mixture, employed as polymer casting solution and aqueous solution of PEI, used as coagulation bath, respectively. Then ion complexation induced phase inversion process is applied to prepare positively charged nanofiltration membrane with thinner but denser separation skin layer. The complexing reaction at the interface of two liquid phases has great influence on the kinetic aspects of phase inversion process, which in accordance would affect the morphology and performance of the membrane.The obtainedmembrane, fabricated via the ion complexation induced phase inversionmethod, is positively charged, has high water permeability, and possesses high rejection towards divalent cations, such as Mg2+,Ca2+, Pb2+ etc., which could be used for removal of heavy metals from polluted water. At the optimal condition,the pure water flux of the PAEK-COOH-PEI nanofiltration membrane is 24.3 L·m-2·h-1, with MgCl2 rejection of 92.2%.     

Rapid Assembly of Large Scale Transparent Circuit Arrays Using PDMS Nanofilm Shaped Coffee Ring

Rapid and precise assembly of functional nanoparticles into well‐defined structures in large scale is motivated by broad fields. In this study, large‐scale transparent conductive circuit arrays are rapidly self‐assembled by simply pipetting a gold nanoparticles suspension onto a PDMS nanofilm patterned substrate with distinct hydrophilic/hydrophobic areas. The solution firstly self‐confines into predefined hydrophilic geometries, followed by assembly of nanoparticles into well‐defined circuits with 1D patterns by coffee ring effect. Submicrometer height and submicrometer‐ to micrometer‐width circuit arrays with various shapes are precisely generated by varying the PDMS nanofilm patterns. Thousands of circuits with different geometries are self‐assembled simultaneously within 1 min. The conductive circuits show good optical transparency up to 95%. After being transferred into PDMS elastomer sheet by encapsulating, the circuits remain highly conductive during bending and stretching. With the advantages of high‐throughput, equipment‐free, scalability, and precise control, this technique will open an avenue for fabricating large‐scale functional materials for applications in electronics, optoelectronics, and healthcare devices.     

Facile fabrication of multifunctional monolithic polyamide aerogels

The polyamide (PA) aerogels with good-formability via a sol–gel technology were facilely fabricated by using melamine and aroyl chloride followed by CO₂ supercritical drying. The synthesis procedure was straightforward and simple, relying on no nitrogen-based protective atmosphere. The influences of aroyl chloride monomer on the gelation time and aerogel structure were discussed. The structural properties of PA aerogels were characterized by the scanning electron microscopy (SEM) and Brunauer–Emmett–Teller methods (BET). The results indicated that the PA aerogels had a typical three-dimensional porous structure. The PA aerogels exhibited well multifunctional properties, such as flame resistance, thermal insulation, dielectric characteristics and mechanical properties. Due to well multifunctional properties, the PA aerogels had potential for the use in construction and building materials.     

Chemical Synthesis of K34‐Ubiquitylated H2B for Nucleosome Reconstitution and Single‐Particle Cryo‐Electron Microscopy Structural Analysis

Post‐translational modifications (e.g., ubiquitylation) of histones play important roles in dynamic regulation of chromatin. Histone ubiquitylation has been speculated to directly influence the structure and dynamics of nucleosomes. However, structural information for ubiquitylated nucleosomes is still lacking. Here we report an alternative strategy for total chemical synthesis of homogenous histone H2B‐K34‐ubiquitylation (H2B‐K34Ub) by using acid‐cleavable auxiliary‐mediated ligation of peptide hydrazides for site‐specific ubiquitylation. Synthetic H2B‐K34Ub was efficiently incorporated into nucleosomes and further used for single‐particle cryo‐electron microscopy (cryo‐EM) imaging. The cryo‐EM structure of the nucleosome containing H2B‐K34Ub suggests that two flexible ubiquitin domains protrude between the DNA chains of the nucleosomes. The DNA chains around the H2B‐K34 sites shift and provide more space for ubiquitin to protrude. These analyses indicated local and slight structural influences on the nucleosome with ubiquitylation at the H2B‐K34 site.     

石油化工与催化凡士林生产技术研究

介绍中国石化抚顺石油化工研究院以减三线馏分油、减三线脱蜡油和减三线蜡下油替代润滑油基础油调制凡士林原料并经高压一段串联加氢制取医药白凡士林的试验情况。结果表明,减三线馏分油、减三线脱蜡油和减三线蜡下油可以替代润滑油基础油调制物理性质符合产品要求的凡士林原料。减三线馏分油和减三线蜡下油等含石蜡组分在凡士林原料配方中的含量应在合理范围,含石蜡组分含量过高会影响调和物的拉丝性。在试验条件下,以减三线馏分油、减三线脱蜡油和减三线蜡下油为调和组分调制的凡士林原料,可以采用高压一段串联加氢工艺生产符合GB1790-2012医药凡士林标准的白凡士林产品。     

本科生参与药物化学课题研究的几点思考

高校人才的培养模式已经逐渐从传统的被动式传授变为更倾向于鼓励学生参与实践,学以致用。药物化学作为一门实用性极强的学科更是如此。本文以实际的案例讲述了本科生参与药物化学课题研究过程培养方案、具体实施过程并展示了部分科研数据,着重阐述如何通过教师的规范培养提高本科生科研能力,并在经验中总结出本科生参与相关科研课题的几点建议。     

Diesel Engine Valve Clearance Fault Diagnosis Based on Features Extraction Techniques and FastICA-SVM

Numerous vibration-based techniques are rarely used in diesel engines fault diagnosis in a direct way, due to the surface vibration signals of diesel engines with the complex non-stationary and nonlinear time-varying features. To investigate the fault diagnosis of diesel engines,fractal correlation dimension, wavelet energy and entropy as features reflecting the diesel engine fault fractal and energy characteristics are extracted from the decomposed signals through analyzing vibration acceleration signals derived from the cylinder head in seven different states of valve train. An intelligent fault detector FastICA-SVM is applied for diesel engine fault diagnosis and classification.The results demonstrate that FastICA-SVM achieves higher classification accuracy and makes better generalization performance in small samples recognition. Besides,the fractal correlation dimension and wavelet energy and entropy as the special features of diesel engine vibration signal are considered as input vectors of classifier Fast ICASVM and could produce the excellent classification results.The proposed methodology improves the accuracy of feature extraction and the fault diagnosis of diesel engines.     

喷锚网支护法在工程中的应用

介绍了太原某工程成功采用喷锚网支护法进行基坑支护的情况，主要阐述了喷锚网支护设计、施工工艺、施工质量监测等几个环节。并根据工程特点、经济分析、工期分析、施工质量监测等内容，说明喷锚网支护法支护深基坑具有工期短、造价低、安全可靠、适用性广的特点。     

加强建筑节能工作推动绿色建筑发展

2006年2月16日，国务院新闻办召开新闻发布会，建设部仇保兴副部长、王铁宏总工程师出席会议，并回答了来自世界各国记者的提问。会上，建设部仇保兴副部长，再次就中国的建筑节能与绿色建筑的情况和最新的进展作了通报。仇保兴指出：中国的建筑节能与绿色建筑事业从来也没有像现在这样受到国内外、业内外以及普通群众的普遍关注。一方面，我国是建筑业大国，建筑业已成为国民经济的支柱产业之一。建筑节能和建筑业的可持续发展，不仅涉及老百姓的生活质量，而且也是关系国计民生的事业。     

Feasibility analysis of mixed-income housing in China

In this paper, it is demonstrated that mixed-income housing is a feasible and beneficial pattern nowadays. This pattern is propitious for good living and harmonious development of society. Based on practice, data are gathered from the field, and the social investment and social distance analysis of the social network theory are used from the perspective of cross-disciplinary fields. The hypothesis is tested and the feasible and beneficial characteristics of mixed-income housing are pointed out. __________ Translated from Architecture Journal, 2006, 4: 36–39 [译自: 建筑学报]