浅谈建筑节能设计要点

建筑节能主要是从建筑设计规划、维护结构、遮阳设施等方面考虑。建筑节能是近年来世界建筑发展的一个基本趋势,也是当代建筑科学技术的一个新生长点。文章主要对建筑节能设计要点进行了分析。     

中医耳鼻喉科中文名词术语选词、定名与释义规范表述

中医耳鼻喉科中文名词术语规范与审定工作作为中医临床术语规范与审定工作中的一环,遵循中医临床术语规范与审定工作的普遍规律,同时又有着自身的特点。文章介绍了中医耳鼻喉科中文名词术语的选词、定名工作和注释的规范表述方法等,以期为中医临床各科术语规范与审定方法的探讨提供借鉴和参考。     

High-frequency, scaled graphene transistors on diamond-like carbon

Owing to its high carrier mobility and saturation velocity, graphene has attracted enormous attention in recent years. In particular, high-performance graphene transistors for radio-frequency (r.f.) applications are of great interest. Synthesis of large-scale graphene sheets of high quality and at low cost has been demonstrated using chemical vapour deposition (CVD) methods. However, very few studies have been performed on the scaling behaviour of transistors made from CVD graphene for r.f. applications, which hold great potential for commercialization. Here we report the systematic study of top-gated CVD-graphene r.f. transistors with gate lengths scaled down to 40 nm, the shortest gate length demonstrated on graphene r.f. devices. The CVD graphene was grown on copper film and transferred to a wafer of diamond-like carbon. Cut-off frequencies as high as 155 GHz have been obtained for the 40-nm transistors, and the cut-off frequency was found to scale as 1/(gate length). Furthermore, we studied graphene r.f. transistors at cryogenic temperatures. Unlike conventional semiconductor devices where low-temperature performance is hampered by carrier freeze-out effects, the r.f. performance of our graphene devices exhibits little temperature dependence down to 4.3 K, providing a much larger operation window than is available for conventional devices.     

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.     

Silane as Electrolyte Additives for Lithium Ion Batteries

1 Results In order to overcome the inherent incompatibility of PC with graphite in the lithium ion battery system, improve their electrochemical performance at low temperature,phenyl tris-2-methoxydiethoxy silane (PTMS) has been studied as an additive to the PC-based electrolyte of lithium ion batteries with graphite anode. From the cyclic voltammogram for the graphite anode in the PC-based electrolyte,we find that in the case of the electrolyte without the additive,there is a large irreversible peak ne...     

A New Theoretical Framework of Pyramid Markov Processes for Blockchain Selfish Mining

In this paper,we provide a new theoretical framework of pyramid Markov processes to solve some open and fundamental problems of blockchain selfish mining under ...     

装备维修性数据收集与分析系统

维修性数据收集与分析系统是装备信息化管理的重要组成部分。介绍了装备使用阶段维修性数据收集与分析系统的任务、功能和体系结构设计,重点阐述了数据收集与数据分析评估模块的功能设计,并采用Access数据库管理系统,运用Visual Basic程序开发语言进行了维修性数据收集与分析原型系统开发。     

浅议存款保险制度

阐述了存款保险制度的内涵及其发展,分析了在我国建立显性存款保险制度的意义,给出了我国存款保险制度的框架。     

西湖凹陷西部斜坡带花港组、平湖组储层裂缝发育特征及有效裂缝测井识别

以西湖凹陷西斜坡花港组、平湖组致密砂岩储层为研究对象,通过录井资料分析及岩心和显微薄片观察,研究裂缝的宏观与微观发育特征及其影响因素.结果显示其主要发育层理缝和构造缝.层理缝主要为水平缝和低角度缝,且已被充填;构造缝主要为垂直缝和高角度缝,充填缝和未充填缝各占一半.裂缝的发育受岩性、单层厚度、断裂及地应力场的综合影响....