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71.
作者采用高频红外吸收法同时测定Ag中的C和S,对试样的制备、助熔剂的选择、分析条件等进行了较详细的研究.方法快速、简便、灵敏度高,C、S的测定范围分别为0.002%~1%和0.002%~0.1%,对自己配制的合成样进行6次平行测定,其RSD分别为:C = 0.34%和S = 2.01%,C、S的回收率都在95%~105%,获得了满意的结果. 相似文献
72.
Installing pedestrian ramps is a common improvement towards a barrier-free environment. This paper introduces a graph-theoretical method of retrofitting of a single-branch Truss-Z (TZ) ramp in a constrained environment. The results produced by this exhaustive search method are usually ideal and better than those produced previously with meta-heuristic methods.A large case study of linking two sections of the Hongo Campus of Tokyo University using an overpass in an extremely constrained environment is presented. TZ modules with 1:12 (8.3%) slope are used, which is allowable in most countries for ramps for self-powered wheelchairs.The results presented here are highly satisfactory both in terms of structural optimization and aesthetics.Visualizations of the TZ ramp system, composed of 124 units, are presented. 相似文献
73.
《Advanced Engineering Informatics》2015,29(1):87-100
The original prototype of the cellular automaton (CA) shading system (CASS) for building facades was based on rectangular array of cells and used liquid crystal technology. This paper introduces polarized film shading system (PFSS) – an alternative approach based on opto-mechanical modules whose opacity is a function of the rotation of polarized film elements. PFSS in regular tessellations: triangular, square and hexagonal are discussed. Simulations for each type of tessellation are presented and visualized. Visual attractiveness of emergent CA patterns manifested by “particles” and “solitons” is discussed. 相似文献
74.
The analysis of the formation of ultra-thin organic films is a very important issue. In fact, it is known that the properties of organic light emitting diodes and field effect transistors are strongly affected by the early growth stages. For instance, in the case of sexithiophene, the presence of domains made of molecules with the backbone parallel to the substrate surface has been indirectly evidenced by photoluminescence spectroscopy and confocal microscopy. On the contrary, conventional scanning force microscopy both in contact and intermittent contact modes have failed to detect such domains. In this paper, we show that Ultrasonic Force Microscopy (UFM), sensitive to nanomechanical properties, allows one to directly identify the structure of sub-monolayer thick films. Sexithiophene flat domains have been imaged for the first time with nanometer scale spatial resolution. A comparison with lateral force and intermittent contact modes has been carried out in order to explain the origins of the UFM contrast and its advantages. In particular, it indicates that UFM is highly suitable for investigations where high sensitivity to material properties, low specimen damage and high spatial resolution are required. 相似文献
75.
76.
研究了以R142b为循环介质、采用螺杆式膨胀机的低温热能有机朗肯循环发电系统.在热源温度低于80℃的条件下,膨胀机最大能量转化效率为6%,系统总效率5.16%.在系统膨胀效率达97%的情况下,传输能耗导致机械效率仅有48%-65%,因此系统总效率较低,但最大(火用)效率为32%.提高蒸发压力、降低冷凝压力是提升能量转化效率的根本途径.实验研究表明,降低膨胀机入口蒸汽干度对膨胀效率略有促进,主要由于少量液体参与膨胀减少了膨胀环节的渗漏,提高了膨胀效率.实验表明该低温热能发电系统可行,但系统效率较低,有待进一步优化提高. 相似文献
77.
Chad R. Snyder Dean M. DeLongchamp 《Current Opinion in Solid State & Materials Science》2018,22(2):41-48
Organic semiconductors may be processed from fluids using graphical arts printing and patterning techniques to create complex circuitry. Because organic semiconductors are weak van der Waals solids, the creation of glassy phases during processing is quite common. Because structural disorder leads to electronic disorder, it is necessary to understand these phases to optimize and control the electronic properties of these materials. Here we review the significance of glassy phases in organic semiconductors. We examine challenges in the measurement of the glass transition temperature and the accurate classification of phases in these relatively rigid materials. Device implications of glassy phases are discussed. Processing schemes that are grounded in the principles of glass physics and sound glass transition temperature measurement will more quickly achieve desired structure and electronic characteristics, accelerating the exciting progress of organic semiconductor technology development. 相似文献
78.
《工程(英文)》2018,4(3):406-415
The environmentally friendly and resourceful utilization of organic waste liquid is one of the frontiers of environmental engineering. With the increasing demand for chemicals, the problem of organic waste liquid with a high concentration of inorganic pollutants in the processing of petroleum, coal, and natural gas is becoming more serious. In this study, the high-speed self-rotation and flipping of particles in a three-dimensional cyclonic turbulent field was examined using a synchronous high-speed camera technique; the self-rotation speed was found to reach 2000–6000 rad·s−1. Based on these findings, a cyclonic gas-stripping method for the removal of organic matter from the pores of particles was invented. A technological process was developed to recover organic matter from waste liquid by cyclonic gas stripping and classifying inorganic particles by means of airflow acceleration classification. A demonstration device was built in Sinopec’s first ebullated-bed hydro-treatment unit for residual oil. Compared with the T-STAR fixed-bed gas-stripping technology designed in the United States, the maximum liquid-removal efficiency of the catalyst particles in this new process is 44.9% greater at the same temperature, and the time required to realize 95% liquid-removal efficiency is decreased from 1956.5 to 8.4 s. In addition, we achieved the classification and reuse of the catalyst particles contained in waste liquid according to their activity. A proposal to use this new technology was put forward regarding the control of organic waste liquid and the classification recovery of inorganic particles in an ebullated-bed hydro-treatment process for residual oil with a processing capacity of 2 × 106 t·a−1. It is estimated that the use of this new technology will lead to the recovery of 3100 t·a−1 of diesel fuel and 647 t·a−1 of high-activity catalyst; in addition, it will reduce the consumption of fresh catalyst by 518 t·a−1. The direct economic benefits of this process will be as high as 37.28 million CNY per year. 相似文献
79.
A distributed Bragg reflector porous silicon layer for optical interferometric sensing of organic vapor 总被引:1,自引:0,他引:1
Han-Jung KimAuthor Vitae Young-You KimAuthor Vitae Ki-Won LeeAuthor VitaeSeon-Hwa ParkAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(2):673-678
In this study, we successfully demonstrated the rapid, sensitive, and reversible sensing of organic vapor using a distributed Bragg reflector (DBR) porous silicon (PS) layer. We fabricated the DBR PS layer on a p+-type silicon substrate and investigated its reflectance spectra before, during, and after exposure to the different concentrations of various organic vapors. When the DBR PS layer sample was exposed to methanol, acetone, ethanol, and isopropanol vapors, the maximum reflectance peak promptly shifted toward longer wavelengths by about 4.5, 23.2, 26.0, and 38.2 nm, respectively. We determined that the red-shift in the reflectance spectrum could be attributed to the changes in the refractive index induced by the capillary condensation of the organic vapor within the pores of the DBR PS layer. The DBR PS layer showed excellent sensing ability under the different concentrations and types of organic vapors. In addition, a slight hysteresis of the red-shift was observed during repeated exposure to organic vapors at different concentrations. After removing the organic vapors, the reflectance spectrum promptly returned to its original state. 相似文献
80.
Detection of sulfur dioxide (SO2) at high temperature (600–750 °C) in the presence of some interferents found in combustion exhausts (NO2, NO, CO2, CO, and hydrocarbon (C3H6)) is described. The detection scheme involves use of a catalytic filter in front of a non-Nernstian (mixed-potential) sensing element. The catalytic filter was a Ni:Cr powder bed operating at 850 °C, and the sensing elements were pairs of platinum (Pt) and oxide (Ba-promoted copper chromite ((Ba,Cu)xCryOz) or Sr-modified lanthanum ferrite (LSF)) electrodes on yttria-stabilized zirconia. The Ni:Cr powder bed was capable of reducing the sensing element response to NO2, NO, CO, and C3H6, but the presence of NO2 or NO (“NOx”, at 100 ppm by volume) still interfered with the SO2 response of the Pt–(Ba,Cu)xCryOz sensing element at 600 °C, causing approximately a 7 mV (20%) reduction in the response to 120 ppm SO2 and a response equivalent to about 20 ppm SO2 in the absence of SO2. The Pt–LSF sensing element, operated at 750 °C, did not suffer from this NOx interference but at the cost of a reduced SO2 response magnitude (120 ppm SO2 yielded 10 mV, in contrast to 30 mV for the Pt-(Ba,Cu)xCryOz sensing element). The powder bed and Pt–LSF sensing element were operated continuously over approximately 350 h, and the response to SO2 drifted downward by about 7%, with most of this change occurring during the initial 100 h of operation. 相似文献