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91.
针对改善催化裂化反应微环境研制开发的DCA - 112催化裂化抑焦剂 ,具有抑制生焦、改善产品分布、应用流程简单、加注方便等特点 ,经中石化长炼分公司 1Mt/a重油催化装置工业应用表明 ,在相近的工艺条件下 ,掺渣比提高 4 13个质量百分点 ,总液收提高 1 0 2个质量百分点。 相似文献
92.
93.
Potassium chloride salt pre-treated titanium silicalite-1 (TS-1) zeolite (K-TS-1) was prepared via an ion-exchange method. XRD, EDX and BET were used to identify the structure of the zeolite. The BET surface area and the adsorption/desorption cumulative pore volume of the K-TS-1 catalyst were about 297 m2/g and 0.213 cm3/g, respectively. The average pore diameter of the K-TS-1 catalyst was 29.49 Å. The catalytic activity of K-TS-1 catalyst was studied in the fixed-bed catalytic reactor. 1,4-Diazabicyclo (2.2.2) octane (DABCO) was prepared from ethylenediamine (EDA) over the K-TS-1 zeolite catalyst. The influences of various reaction parameters such as reaction temperature, space velocity and concentration of EDA were discussed. The conversion of EDA was more than 96% and the selectivity of DABCO and PIP were up to 64 and 30%, respectively, in the temperature of 340 °C and weight hourly space velocity of 1.5 h?1 in the presence of water. 相似文献
94.
超临界流体中的酶催化 总被引:3,自引:0,他引:3
与其他非水相酶催化介质相比 ,超临界流体有其独特的优越性。阐述了超临界流体的概念、对超临界流体的选择原则以及在超临界流体中酶催化的各种影响因素 ,还讨论了在此类流体中酶催化的应用和发展前景 相似文献
95.
Jungho Kim Kondratko P.K. Shun Lien Chuang Walter G. Holonyak N. Jr. Heller R.D. Jr. Zhang X.B. Dupuis R.D. 《Quantum Electronics, IEEE Journal of》2005,41(11):1369-1379
A theoretical and experimental study of a particular transverse-electric (TE) mode lasing mechanism of a tunneling injection InP quantum-dot (QD) laser is reported. In the experiment, the TE mode lasing action takes place at the first excited state of InP biaxially compressively strained QDs. This QD state is coupled to the ground state of two tensile-strained InGaP quantum wells (QWs) although the tensile-strained QW structure favors the transverse-magnetic (TM) polarization light emission. The measured TE and TM modal gain spectra show a typical QW gain evolution behavior at low injection currents, which can be theoretically modeled by the quasi-equilibrium of carrier distribution. When the injection current is increased near threshold, a TE gain narrowing and a simultaneous TM gain pinning are observed in the measured modal gain spectra, which cannot be explained via the quasi-equilibrium model. We propose a polarization-dependent photon-mediated carrier redistribution in the QD-coupled-QW structure to explain this TE and TM gain evolution behavior. When the injection current is just below threshold, the strong carrier depletion via stimulated emission due to coupling between the InP QD and InGaP QW states plays an important role in carrier redistribution, which depends on the optical transition energy and polarization. This concept of the polarization-dependent photon-mediated carrier redistribution explains the TE gain narrowing and TM gain pinning behavior. In addition, a coupled rate equation model is established, and the calculated polarization power ratio based on the coupled rate equations explains the experimental observation. 相似文献
96.
总结了目前国内中、小皮化企业中存在的主要问题 :自主开发能力差 ,造成产品品种单一、配套性差 ;新产品市场推广能力也较差 ,造成即使有好的产品 ,也无法打开市场 ;而普遍存在的制革厂欠款 ,皮化企业自身体制陈旧及国外皮化公司的进一步本土化策略 ,使国内皮化企业面临更严峻的挑战。根据自身多年经营皮化材料的经验 ,提出了切实可行的应对措施 相似文献
97.
98.
“两步法”求取双目视觉传感器中摄象机位置关系 总被引:2,自引:1,他引:1
根据平行线“消隐点”理论,提出了用于双目视觉传感器自标定的“两步法”。该方法仅需4对消隐点象面坐标便可线性求解出旋转矩阵,再用2个空间点坐标便可线性求解出平移矢量。 相似文献
99.
100.
Microwave irradiation processing (MIP) was considered as a potential method to synthesize perovskite-type oxides rapidly, cleanly and energy-efficiently. In this paper, La0.7Sr0.3MnO3+λ, a kind of promising catalyst for automobile exhaust purification, was successfully prepared by MIP in not more than 5 min. The sol–gel method was also used for comparison. All the samples were evaluated by catalytic activity tests in the simulated exhaust and characterized by XRD, BET, TEM and XRF analyses. The results showed that the integrated perovskite-type phase and uniform particle size were obtained in the microwave-treated samples. And those ones exhibited a better oxidation activity under slightly oxygen-rich condition than that by sol–gel method, which may be related to more A-site cation vacancies and larger bulk oxygen content generated in MIP. Possible formation mechanism of perovskites in MIP was also discussed. 相似文献