Modular and predictable assembly of porous organic molecular crystals

Nanoporous molecular frameworks are important in applications such as separation, storage and catalysis. Empirical rules exist for their assembly but it is still challenging to place and segregate functionality in three-dimensional porous solids in a predictable way. Indeed, recent studies of mixed crystalline frameworks suggest a preference for the statistical distribution of functionalities throughout the pores rather than, for example, the functional group localization found in the reactive sites of enzymes. This is a potential limitation for 'one-pot' chemical syntheses of porous frameworks from simple starting materials. An alternative strategy is to prepare porous solids from synthetically preorganized molecular pores. In principle, functional organic pore modules could be covalently prefabricated and then assembled to produce materials with specific properties. However, this vision of mix-and-match assembly is far from being realized, not least because of the challenge in reliably predicting three-dimensional structures for molecular crystals, which lack the strong directional bonding found in networks. Here we show that highly porous crystalline solids can be produced by mixing different organic cage modules that self-assemble by means of chiral recognition. The structures of the resulting materials can be predicted computationally, allowing in silico materials design strategies. The constituent pore modules are synthesized in high yields on gram scales in a one-step reaction. Assembly of the porous co-crystals is as simple as combining the modules in solution and removing the solvent. In some cases, the chiral recognition between modules can be exploited to produce porous organic nanoparticles. We show that the method is valid for four different cage modules and can in principle be generalized in a computationally predictable manner based on a lock-and-key assembly between modules.     

关于监狱劳务产业管理提升的思考

近几年来,东南沿海省份劳务加工业在监狱经济发展中异军突起,发展迅猛,从制造业向劳务加工转移,监狱企业劳务化,大有席卷全国监狱系统,成为监狱企业未来发展方向的趋势。对于劳务加工产业监狱,如何规范劳务产业的管理和运行,促进监狱经济健康持续发展,已成为摆在监狱警察面前的一项重要任务。本人结合多年来在监狱劳务加工一线生产管理经验认为,监狱劳务产业管理提升需从质量品牌管理、规范基础管理及以人为本三个方面长期全面发展,以此夯实经济发展的管理基础。     

近期新疆工业废水产生量预测

新疆经济快速发展，同时工业废水及污染物产生量也迅速增加，本文采用综合指数法预测到2020年工业废水及污染物产生量，供有关部门决策提供参考，为新疆的可持续发展做出积极的贡献。     

浅析火力发电厂凝汽器铜管的腐蚀控制

凝汽器在运行中的腐蚀泄漏不仅是影响水汽品质的主要因素之一，而且它也是影响火力发电安全经济运行的一个重要因素。本文结合笔者工作经验，从多角度系统的探讨了火力发电厂凝汽器防腐蚀的措施。     

如何提高工程GPS网精度浅析

本文结合新建京石客专石家庄站站房工程西站房基坑监控量测工程基坑监测项目阐述了在建立小型工程GPS网时如何采用行之有效的方法提高其精度,保证首级控制网精度。     

苯丙乳液制备及其电纺微纳米纤维结构的研究

通过乳液聚合的方法制备了水相苯丙乳液(PSBA)，并将其应用于静电纺丝制备出微纳米纤维结构。采用红外光谱、差示扫描量热仪（DSC）和动态光散射仪分析并表征了聚合物的化学组成、热稳定性，并得到了均一稳定的苯丙乳液。通过扫描电镜（SEM）研究了纺丝电压及纺丝液中苯丙乳液与聚乙烯醇（PVA）质量比对苯丙乳液电纺微纳米纤维结构的影响，结果表明，改变纺丝液PSBA、PVA质量比能够得到可控性的纤维结构；纺丝电压对纤维中串珠状结构形成有一定影响，且电压越高，纤维直径越小。     

土建工程造价控制中存在的问题及对策研究

对于土建项目来讲,它的成本管控活动是说有效的明确和掌控成本,该项成本管控不但能够带动设计的进步,把成本管控在建设单位许可的层次之中,而且还能够保证所有的投资内容能够有效的配置,进而保证建设方获取最多的利润。     

Lushan M_S7.0 earthquake:A blind reserve-fault event

In the epicenter of the Lushan MS7.0 earthquake there are several imbricate active reverse faults lying from northwest to southeast,namely the Gengda-Longdong,Yanjing-Wulong,Shuangshi-Dachuan and Dayi faults.Emergency field investigations have indicated that no apparent earthquake surface rupture zones were located along these active faults or their adjacent areas.Only brittle compressive ruptures in the cement-covered pavements can be seen in Shuangshi,Taiping,Longxing and Longmen Townships,and these ruptures show that a local crustal shortening occurred in the region during the earthquake.Combining spatial distribution of the relocated aftershocks and focal mechanism solutions,it is inferred that the Lushan earthquake is classified as a typical blind reverse-fault earthquake,and it is advised that the relevant departments should pay great attention to other historically un-ruptured segments along the Longmenshan thrust belt and throughout its adjacent areas.