Computer-Based Operant Behavioral System for Microwave Bioeffects Research

For the investigation of the interaction of microwave radiation (MWR) with physiologic processes, a means of exposing a large number of animals to uniform and quantifiable MWR dose rates is desired. The design and characteristics of such a system for operant behavioral studies using rats is described. Individual irradiation chambers composed of probe terminated waveguide sections operating at 1.3 GHz are used. All of the 16 active chambers are driven in parallel from a single source via a modulation insensitive hybrid power divider. An additional group of 16 nonenergized chambers provide for parallel controls. Each of the chambers includes provision for presentation of visual discriminative stimulus, detection of operant response, and delivery of food reward. These behavioral components are managed by an 8 bit microprocessor that provides the necessary speed, reliability, and flexibility at low per unit cost. The input/output interface is described briefly and a typical program flow diagram for schedule controiled conditioning sessions is given. The irradiation/behavioral system represents a novel approach to the study of microwave induced alterations in operant behavior and demonstrates the practicability of adapting inexpensive microprocessor components to the management of large operant behavioral systems.     

Design of Nanoparticle Systems by Controllable Assembly and Temporal/Spatial Regulation

Nanoparticles (NPs) have been studied for several decades, and outstanding advancements have been made involving fabrication methods and various properties for many different applications. NP assemblies exhibit collective properties that are superior to the properties of individual NPs, and their assembly behavior is significantly affected by interparticle interactions and surrounding layers. The temporal/spatial regulation of NPs and the active species present in NP systems are crucial for achieving desirable performances. Here, the interparticle interactions, surrounding materials (especially ligands), and temporal and spatial regulation are the main topics discussed. The principles and classical examples of these regulation strategies are provided, and the resulting NPs regulated by these strategies exhibit remarkable properties and have great potential for various applications. Finally, the future prospects of the NPs are outlined with respect to the surface modification, temporal and spatial regulation, as well as the binary cooperative complementary principle.     

Surface Charge Modification on 2D Nanofluidic Membrane for Regulating Ion Transport

2D nanofluidic membranes are capable of regulating ion transport toward various applications concerning energy and environment, which is primarily contributed by the excess charge on the interior surface of narrow nanoscale pores. However, there is still a lack of comprehensive summaries and discussions on the surface charge modification principles and strategies of 2D nanofluidic membranes, as well as the practical applications of charge-modified 2D nanofluidic membranes for regulating ion transport. In this review, the surface charge modification principles and charge modification methods of 2D nanofluidic membranes are first introduced in detail, which is of great significance for improving the ion regulation capability of membranes and realizing the design of nanochannel materials. Next, recent advances in the two typical applications of concentration cells and water treatment based on charge-modified 2D nanofluidic membranes are summarized. Finally, some challenges and prospects related to charge-modified 2D nanofluidic membranes are discussed to indicate directions for future research in this field. It is anticipated that this review will provide valuable strategies for the development of high-performance charge-modified 2D nanofluidic membranes toward energy and environment applications.     

计算机软件数据库设计的原则及问题分析

建立一个完整的数据库管理体系,为用户提供查询、分析、修改和处理等服务,是计算机软件数据库设计的终极目的。但是,数据库设计是一个非常复杂、系统的工作,在设计时,由于缺乏对数据库设计原理和方法的掌握,往往会导致数据库设计得不合理,从而影响数据库的性能。因此,每位软件开发者都必须清楚自己在数据库设计中遇到的问题,掌握其基本原理和方法,并按照有关原则和规范进行数据库的设计,从而有效提高系统的设计质量。文中以数据库设计为切入点,从计算机软件开发的实践出发,探讨了系统的设计原理及设计问题。     

采用周期精确的方法实现一个I2C接口

文章探讨Verilog HDL中采用周期精确方式描述数字系统的基本原则，并以此实现了一个EEPROM的I^2C接口设计，该设计稍作改动后，可以应用于其它器件。     

低温晶片键合技术及在通信光电子器件中的应用

简单介绍了晶片键合的基本原理,指出了实现低温晶片键合的必要性;通过对比低温晶片键合技术的实现方式及其在通信光电子器件中的应用,指明表面改性是实现低温晶片键合的最有效手段.     

测量设备轴角编码器误差修正研究

针对现有测量设备轴角编码器误差修正方法的局限性,在介绍轴角编码器误差检测方法的基础上,给出了多个误差检测实例,对误差进行了分析,并根据不同的误差规律提出了不同的修正模型。结果表明,轴角编码器虽具有相同的工作原理,但误差规律不尽相同,在一定角度范围内对测量设备测角精度的影响可远超编码器本身的精度指标,应根据实际检测结果采用不同的修正方法和模型予以修正。     

基于深度学习的视频行为识别方法综述

近年来,自动学习特征的深度学习方法在视频行为识别领域中不断被挖掘探索。在总结了常用的行为识别数据集的基础上,对传统的行为识别方法以及深度学习的相关基础原理进行了概述,着重对基于不同输入内容与不同深度网络的行为识别方法进行了较为全面、系统性的总结、对比与分析。最后,对深度学习在行为识别领域的发展做了总结并展望了未来的发展趋势。     

Peer Review Anew: Three Principles and a Case Study in Postpublication Quality Assurance

Over the last 15 years, the Internet has enabled new modes of authorship, new forms of open licensing and distribution, and new forms of collaboration and peer production to flourish. But in turn, new anxieties have arisen, especially concerning quality assurance, peer review, reuse, and modification. New innovations are appearing in peer review, endorsement, the measurement of trust, and the understanding of reputation, but without any systematic analysis of the general principles of quality assurance and peer review in this new era. In this paper, we propose a general set of principles for understanding what peer review was in the past and how it should be applied today to different kinds of content and in new platforms for managing quality. The principles stress an analysis not only on the content in materials but also on their context of use. Our focus is on open educational resources, and we present a case study of the open education project Connexions' lens system for quality assurance and review. However, the principles can be applied across multiple levels of knowledge production, including scholarship in engineering and science and reference materials in addition to educational publishing.     

低速率扩展编码标准G.729D

１９９８年 ９月,ＩＴＵ－Ｔ在 Ｇ．７２９的基础上制定了 Ｇ．７２９Ｄ。 Ｇ．７２９Ｄ是 Ｇ．７２９的低速率扩展标准,当速率为 ６．４ｋｂ／ Ｓ时仍能保持很好的话音质量。文章介绍了 Ｇ．７２９Ｄ基本原理,对Ｇ．７２９Ｄ与Ｇ．７２９进行了比较和分析,并给出了主观测试结果。     

Surface-Bound Microgels for Separation,Sensing, and Biomedical Applications

This study presents a comprehensive survey of microgel-coated materials and their functional behavior, describing the complex interplay between the physicochemical and mechanical properties of the microgels and the chemical and morphological features of substrates. The cited literature is articulated in four main sections: i) properties of 2D and 3D substrates, ii) synthesis, modification, and characterization of the microgels, iii) deposition techniques and surface patterning, and iv) application of microgel-coated surfaces focusing on separations, sensing, and biomedical applications. Each section discusses – by way of principles and examples – how the various design parameters work in concert to deliver functionality to the composite systems. The case studies presented herein are viewed through a multi-scale lens. At the molecular level, the surface chemistry and the monomer make-up of the microgels endow responsiveness to environmental and artificial physical and chemical cues. At the micro-scale, the response effects shifts in size, mechanical, and optical properties, and affinity towards species in the surrounding liquid medium, ranging from small molecules to cells. These phenomena culminate at the macro-scale in measurable, reversible, and reproducible effects, aiming in a myriad of directions, from lab-scale to industrial applications.     

无线通信同频中继站的频谱监测、自激检测与隔离度测试功能单元设计

提出了一种实用的应用于现有无线通信直放站的具有频谱检测、自激检测和隔离度测试功能的单元设计方案.给出了设计原理、信号处理算法与仿真结果.这种设计方案为未来的功能扩展留有很大的余地,且不需对直放站原有结构进行大的改动.     

基于Matlab／DSP Builder任意波形信号发生器的两种设计

根据传统型任意波形信号发生器和基于DDS任意波形信号发生器的设计原理,采用Matlab／DSP Builder的建模方法,在DSPBuilder平台上完成两种原理的系统建模和仿真,并用Signal Compiler工具对模型进行编译,产生Quartus Ⅱ能够识别的VHDL源程序,并通过FPGA芯片EP2C8Q208c来实现,最后用SignalTapⅡ进行硬件测试。经系统仿真和硬件测试,证明两种设计方法的正确性。比较传统的硬件描述语言建模,该方法设计简单、修改方便、成本低、不涉及到任何编程,对硬件理论知识要求不高,实现起来容易。     

GaAsSCFL电路的研究

分析了 Ga As源耦合 FET逻辑电路的结构 ,阐述了该电路的工作原理、开关特性和噪声容限 ,分析了该电路的特点。     

Reliability evaluation of a two-unit unrepairable system

As one of the redundancy techniques for an unrepairable system, we suppose an unrepairable two-unit standby redundant system in which each new component for replacement is supplied by an order. We analyze the stochastic behavior of our model applying a unique modification of Markov Renewal Processes. Further, we compare an unrepairable two-unit standby redundant system with an unrepairable one-unit system. Finally, we give numerical examples of the stochastic behavior for our model.     

W波段斜注管高频结构的设计和注波互作用模拟

斜注管是返波管的一种,其基本原理是将电子注稍微倾斜于慢波结构表面,通过改变电子注的倾角来优化有效互作用长度,达到更高的输出功率和效率.本文论述了斜注管的基本原理,对其冷特性进行了研究,初步设计了W波段斜注管慢波结构,并利用3D电磁模拟软件,对其注-波互作用进行了模拟,模拟得到20W的输出功率以及15GHz的带宽.     

A computer method of HF ionospheric propagation prediction and analysis

A method of HF ionospheric forecasting and analysis suitable for digital computers is discussed. The particular parameters which may be computed are the maximum usable frequency (MUF), the optimum traffic frequency (FOT), the lowest useful high frequency (LUF), and the lowest required radiated power (LRRP). Other parameters may be deduced with only slight modification of the basic program. All of the principles and analytical expressions necessary to program a computer are included.     

The Process of Decision Modification in Small Discussion Groups

This study qualitatively examined the interaction patterns associated with group decision-making. Specifically, a category system identified the functions which verbal behavior performs upon tentatively introduced decision proposals and yielded a theory of decision modification within group discussions. Groups do not apparently make decisions gradually by direct amendments but in sudden jumps to different formulations of the same root proposal. That is, proposals were introduced, discussed, dropped, and reintroduced in modified form. Two discernible patterns of decision modification emerged. One pattern involved systematically reformulating the proposal in language at successively lower levels of abstraction until the proposal achieved consensus. The second pattern involved substitute decision proposals at essentially equivalent levels of abstraction until the revised proposal achieved consensus. Unlike previous theories of flight behavior resulting from interpersonal conflict, the present study indicates that periods of task avoidance are inherent within the group process of cumulative decision modification. “I don't think they play at all fairly,” Alice began, in a rather complaining tone, “and they all quarrel so dreadfully one can't hear oneself speak–and they don't seem to have any rules in particular; at least, if there are, nobody attends to them–and you've no idea how confusing it is all the things being alive….”     

Anisotropy of the thermal expansion of CuIn<Subscript>5</Subscript>Se<Subscript>8</Subscript> single crystals in two structural modifications

Thermal expansion in the temperature range 80–700 K is studied for two (trigonal and hexagonal) structural modifications of CuIn₅Se₈ single crystals grown by planar crystallization of the melt. From the data, the thermal-expansion coefficients are calculated for both modifications. It is established that, in the temperature range under study, the thermal expansion of both modifications is anisotropic. For the trigonal modification, the thermal-expansion coefficient in the direction of the c axis (α_c) is larger than that in the direction of the orthogonal a axis (α_a). For the hexagonal modification of the CuIn₅Se₈ crystal, the thermal-expansion coefficient in the direction of the c axis exhibits anomalous behavior: as the temperature is increased, the coefficient α_c increases, after which it decreases to negative values, reaches a minimum, and then increases further. Such behavior of the coefficient α_c is associated with the phase transformation of the hexagonal modification of the CuIn₅Se₈ compound into the trigonal modification.