共查询到20条相似文献，搜索用时 15 毫秒
1.
通过在底栅顶接触的喷墨打印有机薄膜晶体管的SiO2表面采用原子层沉积方式制备薄层的Al2O3修饰层,并与未修饰前进行比较,发现有源层在ALD-Al2O3修饰后的SiO2表面接触角大大变小,且喷墨打印的有源层线条变粗。而随着ALD-Al2O3修饰层厚度的增加,SiO2表面粗糙度变大。通过测试其电学性能,发现ALD- Al2O3修饰层厚度为1 nm时,OTFT的性能最好,与未修饰前相比,其迁移率提高了近8倍,而开关比提高约4个数量级。 相似文献
2.
The purpose of this study was to evaluate the potential of electron beam to decompose chloramphenicol （CAP） in aqueous solutions. At the absorbed dose of 15 kGy, the decomposition rate of CAP was 95.24%. The degradation of CAP under electron beam irradiation followed pseudo-first-order kinetics. Redox reactions of CAP aqueous solutions with hydroxyl radicals （.OH）, hydrated electrons （eaq） and hydrated atoms （·H） were studied. The increase of the additives would result in the decrease of the degradation efficiency. The concentration of Cl- and NO3- in aqueous solution increased after electron beam irradiation. On the basis of the experimental results, a photocatalytic mechanism was discussed. The rate constant for reactions of .OH and CAP was 9.36×10^7 L/（mol.s） and for reaction of eaq and CAP was 7.33×10^7 L/（mol.s）..OH was supposed to play the key role in the radiation system of aqueous solution. Other free radicals like eaq and .H could also initiate the degradation. 相似文献
3.
4.
To evaluate the performance of newly designed electro-pneumatic valves （EPVs） for the air-powered engine （APE） and study laws of parameters affecting them, a simulation model was established based on the thermodynamics and mechanics theories. Experiments were set up to determine the instantaneous effective orifice area of solenoid valve by the constant volume discharge method. The simulation model was also validated by comparing the measured displacement curve with the simulated displacement curve of the valve in the pressure of 0.16 and 0.49 MPa. Simulation and experimental results showed that maximum working frequency of the designed EPV could reach 30 Hz corresponding to 2000 r/min of engine rotating speed. Based on simulation results, impacts of temperature and pressure of control air on delay time, full opening/closing time and seating velocity of EPV were analyzed. The simulation model could also act as EPV simulation prototype in designing the air exchange control system of APE. 相似文献
5.
在汽车产业高速发展的同时,汽车也带来了大气污染。燃油在不完全燃烧时,所排出的一些有害物质对环境及人体的污染和破坏。汽车尾气成份与汽车的工况有最直接的关系。通过检测汽车不同工况下尾气中不同气体成份的含量,可判断汽车的故障部位。 相似文献
6.
Marius Pretorius 《高等教育研究与发展》2017,36(4):823-837
With increased pressure to publish, academics are pursuing creative ways to achieve enhanced research outputs. One such process is the publication-based thesis (PBT) for both masters and PhD candidates, rather than monographs. While this process is not novel in the sciences, it has not been widely applied by economic and management schools, particularly in South Africa. Despite the apparently limited institutional guidelines and policies, some academics have pursued an article-based thesis writing process. Doing so has several consequences of special interest for supervisors and candidates. This research set out to identify the impediments to the PBT process, so as to guide future consideration by academics. This is an auto-ethnographic study by one senior academic with experience in both masters and PhD supervision, who has embarked on the PBT process purposively, and reflects on a deliberate choice to change from standard monograph thesis writing to the PBT approach. Member-checking interviews with 12 senior academics in management sciences (some supporting and others not supporting PBT) to some extent validated the generalizability of the liabilities expressed here as concerns. I conclude with a conceptual framework containing the experienced and envisaged realities of PBT writing. The aim of the framework is to assist and warn newcomers to the process with guidelines for considering the associated impediments. Five main liabilities that may ‘bind’ progress, covering 13 antecedents to consider, were identified. The findings led to improved understanding by contextualizing the issues underlying the PBT supervision process, giving structure and meaning to possible solutions to overcoming the liabilities. 相似文献
7.
Decomposition of dimethyl sulfide （DMS） in air was investigated experimentally by using a wire-cylinder dielectric barrier discharge （DBD） reactor at room temperature and atmospheric pressure. A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse-forming network （BPFN） was adopted in our experiments. The maximum power output of the pulse voltage source and the maximum peak voltage were 1 kW and 100 kV, respectively. The important parameters affecting odor decomposition, including peak voltage, pulse frequency, gas flow rate, initial concentration, and humidity, which influenced the removal efficiency, were investigated. The results showed that DMS could be treated effectively and almost a 100% removal efficiency was achieved at the conditions with an initial concentration of 832 mg/m3 and a gas flow rate of 1000 ml/min. Humidity boosts the removal efficiency and improves the energy yield （EY） greatly. The EY of 832 mg/m3 DMS was 2.87 mg/kJ when the relative humidity was above 30%. In the case of DMS removal, the ozone and nitrogen oxides were observed in the exhaust gas. The carbon and sulfur elements of DMS were mainly converted to carbon dioxide, carbon monoxide and sulfur dioxide. Moreover, sulfur was discovered in the reactor. According to the results, the optimization design for the reactor and the matching of high pulse voltage source can be reckoned. 相似文献
8.
Nano-Ag particles/polyacrylamide （PAM） composites were synthesized by γ irradiation method and then blended with ethylene vinyl acetate （EVA）. Dielectric behaviors of the Ag/PAM/EVA composites are investigated as a function of both the concentration and size of Ag particles. When concentration of the Ag fillers is rarely low, dielectric anomalies were first observed in contrast to the traditional percolation theory. As concentration of Ag increases, volume resistivity and breakdown field strength are enhanced, loss tangent （tan δ） reduced and dielectric constant kept invariable. In addition, the above variation became larger when the diameter of the Ag nano-particles is smaller. Such dielectric anomalies may be understood by considering the unique ＂Coulomb Blockade Effect＂ of the nano-sized Ag particles. 相似文献
9.
The effects of the concentration of dissolved total organic carbon(TOC),the TOC/Br-ratio,bromide ion levels,the chlorine to ammonia-N ratio(Cl:N),the monochloramine dose and the chlorine dose on the formation of trihalomethanes(THMs)(including chloroform,bromodichloromethane,chlorodibromomethane,and bromoform)from chlorination were investigated using aqueous humic acid(HA)solutions.The profile of the chloramine decay was also studied under various bromide ion concentrations.Monochloramine decayed in the presence of organic material and bromide ions.The percentage of chloroform and brominated THMs varied according to the TOC/Br-ratio.Total THMs(TTHMs)formation increased from 112 to 190 μg/L with the increase concentrations of bromide ions from 0.67 to 6.72 mg/L,but the chlorine-substituted THMs were replaced by bromine-substituted THMs.A strong linear correlation was obtained between the monochloramine dose and the formation of THMs for Cl:N ratios of 3:1 and 5:1.These ratios had a distinct effect on the formation of chloroform but had little impact on the formation of bromodichloromethane or chlorodibromomethane.The presence of bromide ions increased the rate of monochloramine decay. 相似文献
10.
本文对送风口径可调的圆盘形散流器进行了实验研究,该散流器呈倒蘑菇形,设计有不同开口高度对应的三档扇叶位置。本文分别对各出风位置进行不同风量下常温射流特性实验和压力特性实验,比较了不同高径比和净面积比下散流器的最大中心速度、射程、全压损失的变化情况。实验结果表明:开口高度设在最小的档位时向下射流,最大中心速度下降快,全压损失大,风量对扩散半径影响很小。随着开口高度增大,风口变为水平送风,射流最大中心速度随开度的增大下降减慢,全压损失减小,到达一定开口高度后,射程几乎不受风量的变化影响。该圆盘形散流器可在高大空间中满足输送冷、暖风所需的不同送风方式。 相似文献
11.
唐炬 《重庆大学学报(英文版)》2003,2(1)
1. Introduction For suppressing discrete spectrum interference (DSI) in partial discharge (PD) signals, the presently wide-used approaches are hardware filters and Fourier transform based digital notch filters [1], which, definitely having gained effect in some extent, lead to relatively large energy loss of original PD signals and the preset parameters wont work when new interference appears or some center frequency changes. Adaptive filters [2] adjust parameters automatically with poor st… 相似文献
12.
Juan LI Lingfang SHI Xiayao ZHANG Luxi WENG Hong CHEN Jun LIN 《Journal of Zhejiang University. Science. B》2021,22(2):146
Midpalatal corticotomy-assisted rapid maxillary expansion(MCRME)is a minimally invasive treatment of maxillary transverse deficiency(MTD)in young adults.However,the effect of MCRME on respiratory function still needs to be determined.In this study,we evaluated the changes in maxillary morphology and the upper airway following MCRME using computational fluid dynamics(CFD).Twenty patients with MTD(8 males,12 females;mean age 20.55 years)had cone-beam computed tomography(CBCT)images taken before and after MCRME.The CBCT data were used to construct a threedimensional(3 D)upper airway model.The upper airway flow characteristics were simulated using CFD,and measurements were made based on the CBCT images and CFD.The results showed that the widths of the palatal bone and nasal cavity,and the intermolar width were increased significantly after MCRME.The volume of the nasal cavity and nasopharynx increased significantly,while there were no obvious changes in the volumes of the oropharynx and hypopharynx.CFD simulation of the upper airway showed that the pressure drop and maximum velocity of the upper airway decreased significantly after treatment.Our results suggest that in these young adults with MTD,increasing the maxillary width,upper airway volume,and quantity of airflow by MCRME substantially improved upper airway ventilation. 相似文献
13.
邬立灏 《常熟理工学院学报》2008,22(8):58-64
以对苯二甲酸二甲酯和1,4-丁二醇为原料,通过添加第三单体5-磺酸钠间苯二甲酸二甲酯制备出大分子链上含离子基团的聚对苯二甲酸丁二酯离聚物（SPBT）．用差示扫描量热法（DSC）研究其非等温结晶的过程,发现随着离子基团的引入结晶过程变得复杂,其成核与生长机理变化不大,离子基团的存在增加了大分子链表面的自由能从而改变了结晶性能． 相似文献
14.
This study proposes a model of syngas production from municipal solid waste （MSW） gasification with air in fixed bed reactors. The model （using Aspen plus simulator） is used to predict the results of MSW gasification and to provide some process fundamentals concerning syngas production from MSW gasification. The effects of gasification temperature, air equiva- lence ratio and moisture concentration on the composition of syngas, lower heating value （LHV） of syngas, heat conversion efficiency, and carbon conversion are discussed. The results indicate that higher temperature improves gasification, and higher air equivalence ratio increases the carbon conversion while decreasing syngas LHV. Heat conversion efficiency increases and reaches the maximum and then decreases with the increase of air equivalence ratio. Higher moisture concentration increases the carbon conversion and increases the heat conversion efficiency at lower ratios. Higher temperature and a lower equivalence ratio are favorable for obtaining a higher LHV of syngas at the same moisture concentration. 相似文献
15.
环境氡所致肺剂量影响因素的实验研究 总被引：1，自引：0，他引：1
在环境氡水平的房间内，研究各种处理空气的方法所引起室内α潜能浓度、平衡因子、非结合态氡子体份额和气溶胶粒子数目及其大小分布的变化．计算支气管基底细胞层、肺区上皮及总肺的单位氡浓度年当量剂量，并与封闭房间未经任何空气处置的情况比较，结果显示：用正离子加风扇对流时总肺剂量率减少最为明显；而空调通风，对支气管剂量率的减少最为有效；吸烟或施放油烟，肺剂量都明显增加，油烟的影响尤为严重． 相似文献
16.
采用传统固相反应方法制备了(Ba1-xSrxTiO3,BST)(x=0,0.1,0.2,0.3,0.4)陶瓷材料,用X射线衍射方法和介电谱方法研究了所制备陶瓷材料的结构和介电性能,结果表明,所制备样品,Sr2+进入BaTiO3后与Ba2+形成了钙钛矿型连续固溶体;随着Sr2+含量的增加,峰位向高衍射角度移动,晶粒尺寸减小,说明Sr2+的掺入抑制了晶粒的生长;BST的系列样品随着温度的升高,介电常数增大,但是随着频率的增大介电常数减小,且峰值随着Sr2+含量的增加都向低温区移动,Sr2+的掺入,有明显的压峰效应,具有弥散相变的特征. 相似文献
17.
乌江干流总磷污染的严峻形势与环保对策 总被引：2，自引：0，他引：2
乌江干流中、下游多年来遭受严重的总磷(TP)污染。两个大型国有磷化工企业采用湿法工艺生产磷酸所产生的固体废渣磷石膏,长期堆放、积累数量巨大。磷石膏中的可溶性磷化物经雨水冲淋被带入附近的大、小支流,汇入乌江渡水库,并继而沿途向下游构皮滩、思林、沙沱等水库排放,造成乌江中、下游的全面TP污染,经水质取样化验,沿线水质为劣Ⅴ类。文中分析了TP污染的基本情况和危害,提出乌江干流TP污染的若干环保对策。 相似文献
18.
为了研究空芯光纤中氩气的放电特性,利用有限元软件 COMSOL Mutiphysics 基于流体模型对长为50mm 空芯光纤中的气体放电过程进行仿真,得到氩气放电过程中等离子体的主要参数分布,如电子密度、离子密度、电势、空间电荷密度、电场强度等。同时分析了气压对放电过程的影响,结果表明,气压对气体放电的影响主要体现在电子密度与阴极侧的电场强度上,随着气压的逐渐增大,阴极侧的电场强度也随之增加,阴极侧电子密度则保持不变,但在空芯光纤中央区域,电子密度的增大较为明显。 相似文献
19.
袁小明 《泰州职业技术学院学报》2012,12(6):119-121
目的分析高血压治疗费用对高血压治疗控制率的影响,以提高高血压的控制率。方法以内科门诊近一年半以来高血压病患者看病就诊未能很好的控制血压的526例作为随访对象,按照临床高血压的治疗原则,根据患者的个体差异,血压未能控制者,适当增加原来口服药物的剂量或加服另一种降压药。结果265例患者经再次调整价格便宜的降压药物利血平后,部分患者下降明显,血压可以得到较好的控制。其中根据患者体质差异血压完全有效者达到156例,占总数的58．9％。结论针对经济困难的高血压患者,做出相应的对策将明显提高高血压患者的控制率。 相似文献
20.
Design and preliminary experimental investigation of a 4 K Stirling-type pulse tube cryocooler with precooling 总被引：1，自引：0，他引：1
A Stirling-type pulse tube cryocooler （PTC） with precooling was designed and manufactured to investigate its performance at 4 K. Numerical simulation was carried out based on the well-known regenerator model REGEN with an emphasis on the performance of a 4 K stage regenerator of the Stifling-type PTC as influenced by the warm end temperature, pressure ratio, frequency and average pressure with helium-4 and helium-3 as the working fluid respectively. This study demonstrates that the use of a cold inertance tube can significantly improve the efficiency of a 4 K Stirling-type PTC. A preliminary experimental investigation was carried out with helium-4 as the working fluid and a refrigeration temperature of 4.23 K was achieved. The experimental results show that the operating frequency has a significant influence on the performance of the Stirling-type PTC and a relatively low average pressure is favorable for decreasing the loss associated with the real gas effects of a 4 K Stirling-type PTC. 相似文献