提高嵌入式时栅传感器精度的测头设计方法

为了提高嵌入式时栅传感器的测量精度,结合传感器自身的特点,从布置方式和数据处理方式两方面设计了特殊的测头结构。首先利用谐波分析确定传感器误差的主要频次,然后分别针对长短周期的误差采用多组测头对径和间隔特定空间角度的测头布置方式,测头之间采用数字量相加的数据处理方式,最后通过实验验证了这种测头结构和数据处理方式的有效性。结果表明,与单测头结构相比,这种方式将长周期误差降低了75%,短周期误差降低了83.6%,更有效地提高了嵌入式时栅传感器的测量精度。     

浮选精煤掺粗对其脱水效果的影响

浮选精煤粒度过细会造成浮选消泡困难、浮选精煤水分高等问题,而合理的向浮选精煤中掺入粗颗粒,改善其粒度组成,有利于解决这些问题。通过试验论证了浮选精煤掺粗有利于浮选精煤消泡,并可有效降低浮选精煤水。     

缓蚀剂——N-取代烷氧基烷基苯骈三氮唑衍生物的合成(Ⅱ)

苯骈三氮唑是一种优良的缓蚀剂 ,它能与醛和醇发生加成反应。利用苯骈三氮唑与甲醛或乙醛 ,分别和甲醇、乙醇、正丙醇、异丙醇反应合成了八种烷氧基烷基苯骈三氮唑 ,通过 IR、1HNMR对上述化合物的结构进行了测定 ,并讨论了这类加成反应的历程。     

对甲苯磺酸多聚甲醛固体酸催化Micheal加成的研究

对甲苯磺酸直接缩聚合成聚合物型高酸值的碳基固体磺酸催化剂。用Michael加成反应对催化剂的催化性能进行了研究。结果表明,该催化剂具有适用范围广泛、重用性好、化学选择性高等优点。     

Exo-mechanism proximity-accelerated alkylations: investigations of linkers, electrophiles and surface mutations in engineered cyclophilin-cyclosporin systems

Investigations on the scope and utility of exo-mechanism proximity-accelerated reactions in engineered receptor-ligand systems are reported. We synthesized a series of electrophilic cyclosporin (CsA) derivatives by varying electrophiles and linker lengths, prepared a series of nucleophilic cysteine mutations on the surface of cyclophilin A (Cyp), and examined their reactivity and specificity in proximity-accelerated reactions. Acrylamide and epoxide electrophiles afforded useful reactivity and high specificity for alkylation of engineered receptors in Jurkat cell extracts. We found that remote cysteines (>17 A from the ligand) could be alkylated with useful rates under physiological conditions. The results from mutations of the receptor surface suggest that the dominant factors governing the rates of proximity-accelerated reactions are related to the local environment of the reactive group on the protein surface. This study defines several parameters affecting reactivity in exo-mechanism proximity-accelerated reactions and provides guidance for the design of experiments for biological investigations involving proximity-accelerated reactions.     

Phase‐transfer‐agent‐aided polymerization and graft copolymerization of acrylamide

The use of phase‐transfer catalysts, with water‐insoluble initiators, for polymerization and graft copolymerization reactions was explored. The polymerization of a water‐soluble vinyl monomer, acrylamide (AAm), and the graft copolymerization of AAm onto a water‐insoluble polymer backbone, isotactic polypropylene (IPP), with a water‐insoluble initiator, benzoyl peroxide (BPO), and a phase‐transfer catalyst, tetrabutyl ammonium bromide (Bu₄N⁺Br^?), were carried out in a water/xylene binary solvent system. The conversion percentage of AAm into polyacrylamide (PAAm) and the percentage of grafting of AAm onto IPP were determined as functions of various reaction parameters, such as the BPO, AAm, and phase‐transfer‐catalyst concentrations, the amounts of water and xylene in the water/xylene mixture, the time, and the temperature. The graft copolymer, IPP‐g‐PAAm, was characterized with IR spectroscopy and thermogravimetric analysis. By a comparison of the results of the phase‐transfer‐catalyzed graft copolymerization of AAm onto IPP and the preirradiation method, it was observed that the optimum reaction conditions were milder for the phase‐transfer‐catalyst‐aided graft copolymerization. Milder reaction conditions, including the temperature, the time of reaction, and a moderate initiator (BPO), in comparison with high‐energy γ‐rays, led to better quality products, and the reaction proceeded smoothly with high productivity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2364–2375, 2004     

氯添加对燃煤过程中汞析出规律的影响

首先利用管式炉对燃煤及燃煤加氯后煤中汞排放进行研究,结果表明,对于神混煤而言,原煤燃烧后烟气中单质Hg⁰和氧化态汞Hg²⁺的比例分别为74.3%、25.7%。添加Cl后,烟气中Hg²⁺的比例有所上升,当加氯量为0.015%、0.030%和0.045%时,烟气中Hg²⁺的比例分别上升为32.7%、36.1%和40%,随加氯量的增加,其对汞的氧化作用也随之增强。在现场工程示范试验中,利用脱硫废水中的氯氧化烟气中的汞,以达到脱硫废水与烟气中的汞协同脱除的目的。结果表明,随着脱硫废水喷洒煤的量越大,进入SCR烟气中Hg²⁺比例增大,经过SCR后Hg²⁺的比例随之增大。由于飞灰对Hg²⁺的吸附能力较Hg⁰强,电除尘系统的脱汞效率提高,但脱硫废水喷洒煤对湿电除尘系统的脱汞效率影响不大。总之,脱硫废水喷洒量越大,燃煤机组烟气净化设备对汞协同去除效率也随之提高。     

金属间化合物SbSn的掺Al制备及原油乳液脱硫

将Sn粉、Sb粉和少量的Al粉混合,通过球磨法制备出掺Al的金属间化合物SbSn,再采取碱洗溶脱的方式除Al以期增加SbSn合金的比表面积。采用XRD、BET、DSC等分析方法对其相结构、比表面积和熔点进行表征。当掺Al量为5%时,比表面积扩大7倍多。结果表明：比表面积扩大有利于脱硫率的增加。将比表面积6.43 m2·g^-1的SbSn负载于丝网上作介质,在外置电场电压为12.54 V,表面活性剂用量为0.19%,[JP+2]反应时间为18 h后,W（20）/O（80）乳液的脱硫率可达到37.9%。脱硫的反应机理可解释为在电流的诱导作用下,SbSn与硫化物产生电化学反应和脱Al后合金表面产生的空缺位等活性点的物理吸附共同作用的结果。     

电感耦合等离子体发射光谱法测定白酒的28种微量元素

应用电感耦合等离子体发射光谱仪(ICP-AES),不经消解直接测定8种白酒中的Al,As,B,Ba,Be,Ca,Cd,Co,Cr,Cu,Fe,K,Li,Mg,Mn,Mo,Na,Ni,Pb,Pd,S,Sb,Si,Sr,Ti,V,W,Zn元素并对方法的仪器条件进行了优化。与传统的消解方法进行比较,实验结果表明本方法的测定结果与消解的测定结果基本一致。本方法各元素线性相关系数均大于0.9995,加标回收率在94%~105%之间。本方法不需要消解,大大提高了样品的测试速度并且节省人力物力。本实验为白酒品质的鉴定提供实验数据。     

纳米四方多晶氧化锆粉末的超强碱共沉淀法制备及性能表征

采用引入有机添加剂的超强碱共沉淀法可制备出粉末粒子尺寸为10nm左右的高纯纳米多晶氧化锆粉末。通过控制适当的工艺条件，得到了室温稳定的纳米四方／立方多晶氧化锆粉末。用X射线荧光光谱、X射线衍射、透射电镜、粒度分析仪等手段对粉末性能进行了表征。实验结果表明：超强碱共沉淀法所制备的粉末具有纯度高、氯离子等杂质少等特点；该粉末在室温和小于873K热处理时，均以稳定的立方或四方相存在；经873K处理的粉末粒子尺寸为10nm左右；在1123K处理后，形成固溶完全的稳定纳米四方多晶氧化锆粉末，粒子尺寸小，分散性好，粒度分布窄。与其它湿化学方法相比，添加聚合物的超强碱共沉淀法具有工艺操作简单、节约资源和环境污染小的优点。