一种适用于降压DC-DC的改进型电流检测电路

基于电流模式控制能够较好地改善DC-DC的性能,设计一种适用于降压DC-DC的改进型电流检测电路,所提出的电流检测电路提高了电流感应的速度和精度。通过对电路的理论分析与设计,采用SMIC 0.18μm CMOS工艺模型,利用Cadence工具对电路进行仿真验证,所提出的电流检测电路在负载电流为50 mA~500 mA时都能够达到96%的效率以及小于40 ns的建立时间。在开关频率为2 MHz时,输入电压范围为2.5 V~4.2 V,所需电感值为4.7μH,电容值为10μF,输出电压纹波小于18 mV。     

气相法合成纳米颗粒的制备技术进展

本文综述了气相法合成纳米颗粒材料的主要制备技术，并介绍了制备方法的最新进展－化学气相冷凝技术制备纳米颗粒材料，提出了制备纳米颗粒技术研究中面临的问题及今后的发展方向。     

硅橡胶合成催化剂氢氧化四甲铵的制备新工艺

采用有效面积为4.5dm~2的全氟阳离子交换膜,在阳极室容积为500mL、阴极室容积为580mL的二室单膜电渗析槽内,以四甲基氯化铵为原料,制备了合成有机硅橡胶及其他有机硅产品聚合用催化剂氢氧化四甲铵(Me_4NOH)。阳极室四甲基氯化铵浓度为30％(质量),阴极室可得到纯度为 13％-15％、Cl~-<0.01％、Na~+<0.0001％和 K~+<0.000 5％的 Me_4NOH。产品经减压浓缩即得到 Me_4NOH·5H_2O晶体。     

Interaction‐Feature Enhanced Multiuser Model Learning for a Home Environment Using Ambient Sensors

Activity recognition (AR) is a key enabler for a context‐aware smart home since knowing what the residents’ current activities helps a smart home provide more desirable services. This is why AR is often used in assistive technologies for cognitively impaired people to evaluate their abilities to undertake activities of daily living. In a real‐life scenario, multiple‐resident AR has been considered as a very challenging problem, primarily due to the complexity of data association. In addition, most prior research has not considered the potential interpersonal interactions among residents to simplify complexity, especially in an environment monitored by ambient sensors. In this study, we propose two types of multiuser activity models, both of which are derived from an interaction‐feature enhanced multiuser model learning framework. These two models consider interpersonal interactions and data association for multiuser AR using ambient sensors. We then compare their performance with the other two baseline models with or without consideration of data association and interpersonal interactions. The experimental results show that the derived models outperform other baseline classifiers. Therefore, the proposed approach can increase the opportunities for providing context‐aware services for a multiresident smart home.     

Interactive topic modeling

Topic models are a useful and ubiquitous tool for understanding large corpora. However, topic models are not perfect, and for many users in computational social science, digital humanities, and information studies—who are not machine learning experts—existing models and frameworks are often a “take it or leave it” proposition. This paper presents a mechanism for giving users a voice by encoding users’ feedback to topic models as correlations between words into a topic model. This framework, interactive topic modeling (itm), allows untrained users to encode their feedback easily and iteratively into the topic models. Because latency in interactive systems is crucial, we develop more efficient inference algorithms for tree-based topic models. We validate the framework both with simulated and real users.     

Lower Bounds for Eigenvalues of Elliptic Operators: By Nonconforming Finite Element Methods

The paper is to introduce a new systematic method that can produce lower bounds for eigenvalues. The main idea is to use nonconforming finite element methods. The conclusion is that if local approximation properties of nonconforming finite element spaces are better than total errors (sums of global approximation errors and consistency errors) of nonconforming finite element methods, corresponding methods will produce lower bounds for eigenvalues. More precisely, under three conditions on continuity and approximation properties of nonconforming finite element spaces we analyze abstract error estimates of approximate eigenvalues and eigenfunctions. Subsequently, we propose one more condition and prove that it is sufficient to guarantee nonconforming finite element methods to produce lower bounds for eigenvalues of symmetric elliptic operators. We show that this condition hold for most low-order nonconforming finite elements in literature. In addition, this condition provides a guidance to modify known nonconforming elements in literature and to propose new nonconforming elements. In fact, we enrich locally the Crouzeix-Raviart element such that the new element satisfies the condition; we also propose a new nonconforming element for second order elliptic operators and prove that it will yield lower bounds for eigenvalues. Finally, we prove the saturation condition for most nonconforming elements.     

240kt／aDAP装置运行情况

介绍安徽六国化工股份有限公司24万t/a DAP的工艺概况及试车、运行、技改情况.针对2001年7月试车初期出现的问题,例如中和槽到氨化粒化器料浆泵送管线及泵易堵,造粒机管梁定位设计缺陷、氨分布器角度设置不合理等进行了整改.并对中和造粒尾气洗涤系统和磷铵产品外观质量提出了改进意见.     

灰霉病的化学防治进展

灰霉(Botrytiscinerea)是一种世界性的病菌,能造成葡萄、蔬菜和浆果严重的经济损失。近几年开发成功的防治灰霉病的主要药剂有嘧啶胺类(anilinopyrimidines)杀菌剂如:嘧霉胺(pyrimethanil)、嘧菌环胺(cyprodinil)、嘧菌胺(mepanipyrim);吡咯类(anilinopyyols)杀菌剂咯菌腈(fludioxonil)和酰胺类(hydroxyanilides)杀菌剂环酰菌胺(fenhexamid)。嘧啶胺类最初抑制靶标位点是胱硫醚β裂解酶,以及抑制病原菌胞外蛋白酶(包括水解酶)的分泌;吡咯类咯菌腈作用于渗透调节的信号传递途径;而环酰菌胺的作用靶位尚不完全清楚,但研究表明其作用机理不同于其他类杀菌剂,因此,环酰菌胺将有可能成为治理杀菌剂抗性的有效药剂之一。     

新颖除草剂研究进展

综述了新型除草剂研制的方向、重点和特点。涉及磺酰脲类除草剂 ,环状亚胺类除草剂 ,苯氧羧酸类除草剂 ,有机磷类除草剂。主要介绍了具有除草活性好的丙酮酸脱氢酶抑制剂研究新进展。     

利用南水北调工程改善济宁水生态环境的措施

通过对济宁市防治水污染技术研究, 提出水污染防治在政策措施上实施治污抓源头, 杜绝不达标排放; 在城市 建设规划上, 把河湖生态湿地建设、 改善居住生活环境与城市建设有机结合; 在河湖治理上, 坚持工程、 生物措施并 举; 在工程管护上, 坚持依法治水。利用南水北调东线工程建设, 实施水污染防治建设, 通过对济宁市水污染防治成 果的阐释, 为今后水污染治理提供成功的经验和做法。