TiO_2纳米管制备及其在气体传感器中的应用研究进展

由于纳米TiO2材料具有无毒、气敏、湿敏、稳定性好等优点而被广泛应用于太阳能电池、光催化降解和气体传感器等领域中。TiO2纳米管是典型的一维纳米材料,拥有丰富的物理化学性质。由于其制备成本不高,因此蕴藏着广阔的应用前景。特别是近年的研究表明,TiO2纳米管因为其大的比表面积、强的吸附能力和纳米尺寸效应,在光催化、传感器、太阳能电池等领域有巨大的开发潜力,已成为目前纳米材料的研究热点之一。TiO2纳米管的主要制备方法基本成熟,但在气体传感器中的研究比较少。TiO2纳米管的制备是在各领域应用的重要前提,因此,本文先介绍它的主要制备方法,从而了解TiO2纳米管的形态及组成,而在其众多应用中,着重介绍它在气体传感器中应用的研究现状。     

Design of unknown input observer with H_∞ performance for linear time-delay systems

1 .INTRODUCTIONThe dynamic behavior of many physical processes ,such as chemical process , long transmission lineand rolling mill systems , contain ti me-delay anduncertainties . Ti me-delay usually results in unsat-isfactory performance andis frequently a source ofinstability , so control of ti me-delay systems ispractically i mportant , especially state feedbackcontrol . A unknown input observer has i mportantapplications in realization of state feedback con-trol . An UIO is an esti ma…     

含炭难处理金矿石碘法浸出

用非氰试剂——碘从矿石中浸出黄金，目的是研究碘化浸金取代剧毒氰化物提金的可行性；采用了热力学方法对碘-碘化物溶金的可能性进行了简单分析，用碘-碘化物溶液对含炭难处理金矿石进行了浸出工艺条件实验及与氰化浸出的对比实验，取得了较理想的实验结果：浸出4h金浸出率达到95％，氰化法直接浸出12h金浸出率80％；碘化法浸金速度快，金浸出率高。     

Experimental Study on Minimization of Sludge Production by Ozonation Process

Based on the hypothesis of reducing sludge production under cryptic growth conditions, ozone was used as cell lysis agent to treat excess sludge, and then the ozonated supernatant was returned to. the aeration tank. The results show that COD and NH4+-N removal efficiencies in ozonation process were 87.96% and 84.42%, respectively. Meanwhile, a low excess sludge yield coefficient of 0.113 (g SS/g COD removed) was obtained. Compared with that of the control test, the process configuration decreased the excess sludge production by 51.3%.     

Analysis of Circumstance Influence Factors on HMBR for Waste-water Reclamation in Dwelling District

Circumstance influence factors on Hybrid Membrane Bio-Reactor (HMBR) process for the wastewater reclamation in dwelling district was analyzed. The main characteristic of this process is that sludge and nitrified effluent can be recycled automatically, which simplifies the operation of system and is beneficial to get the high removal of organics and nitrogen. Based on the analysis of circumstance influence factors, it is recommended that water temperature of about 20℃, influent pH of 6 -7 and DO of 1. 0 mg/L - 1. 5 mg/L in the aerobic compartment. Under these conditions, COD, BOD5, NH4+ -N, and TN were removed effectively in HMBR and the average removal efficiencies were 94.5%, 99.3%, 99.4% and 84.7%, respectively. SS and coliforms were both below the detection limits in the permeate of UF membrane module, and turbidity was less than 1NTU. The treated effluent meets the Miscellaneous Domestic Water Quality Standard (CJ25.1-89), and can be reused multipurposely such as watering of green belts, cleaning a     

Sliding mode H_∞ control for a class of uncertain nonlinear state-delayed systems

1 .INTRODUCTIONSince ti me delays and uncertainties are frequentlyencounteredin practical engineering,and often re-sult in poor performance or even systeminstabili-ty , much work has been done for the analysis andsynthesis of uncertain ti me-delay systems[1 ~5 ,7 ,8].The sliding mode control (SMC) is regarded as oneof the best approaches for the robust stabilizationof uncertain ti me-delay systems ,because it exhib-its the sliding mode which has anintrinsic propertyof adaptiveness for the…     

Modeling of Non-Coherent Sequential Acquisition Process for DS/SS Signals

A modified non-coherent sequential detection decision logic based on continuous accumulation to achieve fast PN code acquisition is proposed. To simplify the design and analysis, the equivalent relationship between the likelihood ratio of the current sample and that of all the previous samples is deduced. The scheme is proved to be an optimum sequential detection under certain assumptions. Because the average sample number (ASN) can not be calculated through the methods applied to the conventional sequential detection, an algorithm is also provided, which can estimate both the probability density function (pdf) and the upper threshole of ASN. The desired probabilities of false alarm and detection, as well as faster PN code acquisition compared to the conventional sequential detection can be achieved by employing this structure . In addition, Rayeigh-faded reception case is also taken into consideration. Performances of the proposed schemes are obtained, which suggest that the proposed non-coherent seque     

Simulation for CCSDS Advanced Orbiting System (AOS)with BONeS Designer

Abstract: This paper describes the modeling and simulation of the protocol of CCSDS advanced orbiting systems (AOS).The network features modeled in the implementation of CCSDS AOS are to multiplex different kinds of sources into virtualchannel data units (VCDUs) in the data processing module. The emphasis of this work is placed on the algorithm for com-mutating VCDUs into physical channels in the form of continuous data stream. The objectives of modeling CCSDS AOSprotocol are to analyze the performance of this protocol when it is used to process various data.     

Singular analysis of two-dimensional bifurcation system

Bifurcation properties of two-dimensional bifurcation system are studied in this paper. Universal unfolding and transition sets of the bifurcation equations are obtained. The whole parametric plane is divided into several different persistent regions according to the type of motion, and the different qualitative bifurcation diagrams in different persistent regions are given. The bifurcation properties of the two-dimensional bifurcation system are compared with its reduced one-dimensional system. It is found...     

哈尔滨商业大学60周年校庆公告(第一号)

<正>哈尔滨商业大学庄严向海内外校友及社会各界领导、朋友公告:2012年9月教师节期间,学校将隆重举行建校60华诞庆典活动。校庆的主题是:"总结经验、交流学术、亲近校友、提升合作。"哈商大校友为合校后和原黑龙江商学院与原黑龙江财政高等专科学校的全日制、函授、夜大、外国留学生、各类培训学员及曾工作过的人员。