智能功率模块的封装结构和发展趋势

在消费电子和一般工业应用的电机驱动领域智能化模块封装结构研发过程中,设计人员和制造厂商面临如何实施稳健设计,优化工艺流程、提高良率、降低成本、扩大产能等很多实际问题。解决这些问题的首要突破口是智能功率模块结构设计本身,其中模块结构和互连方式设计对产品开发人员的想象力提出极大挑战,而器件应用、可靠性及市场等因素又极大地制约了开发人员创造性的发挥。文章介绍了功率半导体器件及智能功率模块的发展,分析了常用（一般低于1500V）智能功率模块的特点、结构和工艺流程,以及封装过程所使用的材料和产生的问题,最后探讨了封装设计的发展趋势。     

一种视觉导航机器人的设计

介绍了一种为机器人添加视觉模块而进行智能导航的设计。主要通过为广茂达AS-UII型机器人添加无线模块将图像信息发至计算机,经图像处理后对机器人进行遥控操作达到闭环控制的目的。此设计价格低廉、运行稳定。     

网络环境下智能化学习模式构建与实践研究

随着计算机技术和网络技术的飞速发展,以及各种移动设备的应用与普及,网络环境下的学习方式已经成为新时期现代化教学方式发展的新方式.但目前网络环境下的学习方式还存在如上课形式单一、学习资源不足、学生自主学习能力弱、课堂互动较少、各种教学活动不易于控制等问题,那么就急需构建网络环境下新的学习方式.将智能化融入教学过程中不仅能...     

A simple polymer electrolyte membrane system for enrichment of low-level tritium (3H) in environmental water samples

Tritium (³H) is an essential tracer of the Earth's water cycle; yet widespread adoption of tritium in hydrologic studies remains a challenge because of analytical barriers to quantification and detection of ³H by electrolytic pre-concentration. Here, we propose a simple tritium electrolytic enrichment system based on the use of solid polymer electrolyte membranes (PEMs) that can be used to enrich ³H in 250–3000?mL environmental water samples to a 10-mL final volume. The IAEA PEM-³H system reported here can produce high enrichment factors (>70-fold) and, importantly, removes some of the deterrents to conventional ³H enrichments methods, including the use of toxic electrolysis and neutralization chemicals, spike standards, a complex electrolysis apparatus that requires extensive cooling and temperature controls, and improves precision by eliminating the need for tracking recovery gravimetrics. Preliminary results with varying operating conditions show ³H enrichments to 70-fold and higher are feasible, spanning a wide range of tritium activities from 5 to 150 TU with a precision of ～4.5?%. Further work is needed to quantify inter-sample memory and to establish lower ³H detection limits. The IAEA PEM-³H system is open source, with 3-D CAD and design files made freely available for adoption and improvement by others.     

0Interacting model of new agegraphic dark energy:observational constraints and age problem

Many dark energy models fail to pass the cosmic age test because of the old quasar APM 08279+5255 at redshift z=3.91,the ΛCDMmodel and holographic dark energy models being no exception.Inthis paper,we focus onthe topic of the age problem inthe new agegraphic dark energy(NADE)model.We determine the age of the universe in the NADE model by fitting the observational data,including type Ia supernovae(SNIa),baryon acoustic oscillations(BAO)and the cosmic microwave background(CMB).We find that the NADE model also...     

TD-LTE主设备节能新技术简介

如何在节能减排的大背景下,不断开拓新思路、运用新技术,在不影响网络质量的情况下尽可能的提升设备能效是网络发展的必由之路,本文重点介绍了应用于TD-LTE主设备的几种节能新技术,通过对4G系统架构的分析,从硬件和软件2个方面着重阐述了新技术的原理及节能效果。     

信息时代下经济管理类应用型人才培养模式研究

随着经济和科技的发展，信息时代已经成为当代社会的发展趋势，信息时代对于人才的要求也在不断提高，经济管理类专业人才对于经济社会的发展有着重要意义，本文旨在从我国高校在教学和管理中的现状以及存在的问题出发，探究信息时代下经济管理类的人才培养模式，并与广大经济管理类教育工作者进行交流。     

Temperature and pH dual‐sensitive polyaspartamide derivatives for antitumor drug delivery

The pH‐sensitive tertiary amino groups were introduced to synthesize temperature and pH dual‐sensitive degradable polyaspartamide derivatives (phe/DEAE‐g‐PHPA) containing pendant aromatic structures and ionizable tertiary amino groups. The thermo/pH‐responsive behavior of phe/DEAE‐g‐PHPA polymer can be tuned by adjusting the graft copolymer composition. Due to the pH sensitivity of the phe/DEAE‐g‐PHPA‐g‐mPEG polymer with hydrophilic long PEG chain, the micelles and the anticancer drug‐loaded micelles were prepared by a quick pH‐changing method without using toxic organic solvent. The obtained polymeric micelles, paclitaxel‐loaded micelles and doxorubicin‐loaded micelles were stable under physiological conditions. Both the drug‐loaded micelles showed much faster release at pH 5 than at pH 7.4. The doxorubicin‐loaded micelles showed obvious and better anticancer activity against both HepG2 and HeLa cells than free doxorubicin. Thus these nontoxic, dual thermo‐ and pH‐sensitive phe/DEAE‐g‐PHPA‐g‐mPEG micelles may be a promising anticancer drug delivery system. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 879–888     

Logging damage and injured tree mortality in tropical forest management

Using insights from the forest ecology literature, we analyze the effect of injured trees on stand composition and carbon stored in above‐ground biomass and the implications for forest management decisions. Results from a Faustmann model with data for a tropical forest on Kalimantan show that up to 50% of the basal area of the stand before harvest can consist of injured trees. Considering injured trees leads to an increase in the amount of carbon in above‐ground biomass of up to 165%. These effects are larger under reduced impact logging than under conventional logging. The effects on land expectation value and cutting cycle are relatively small. The results suggest that considering injured trees in models for tropical forest management is important for the correct assessment of the potential of financial programs to store carbon and conserve forest ecosystem services in managed tropical forests, such as reducing emissions from deforestation and forest degradation and payment for ecosystem services. Recommendations for Resource Managers

• Considering the role of injured trees is important for managing tropical forests
• These trees can cover up to 50% of basal area and contain more than 50% of the carbon stored in above‐ground biomass
• Reduced impact logging leads to a larger basal area of injured trees and more carbon stored in injured trees than conventional logging
• Injured trees play an important role when assessing the potential for carbon storage in the context of payment for forest ecosystem services.