查询词典 catalyst

The results show that the decalescence of catalyst bed affects the process of hydrogen peroxide catalytic decomposition greatly. If the catalyst bed is preheated or made up of materials with low thermal conductivity, that influence can be depressed. At the same time, the response characteristic of catalyst bed and the efficiency of catalytic decomposition can be improved. The low frequency pressure instability of catalyst bed occurs because of the coupling of catalytic decomposition and supplying. The decomposition plane pushes all the way through the catalyst bed during pressure oscillations, causing unreacted liquid hydrogen peroxide to be exhausted from the bed and leading to the appearance of liquid hydrogen peroxide channeling. Consequently, how to prevent or at least limit this channeling is the key to eliminate the pressure instability of catalyst bed. It was found that adding clapboard to the catalyst bed can depress the pressure instability efficiently.

结果表明催化剂床及催化剂的吸热对过氧化氢分解过程影响很大，对催化剂床进行预热或采用热导率低的材料制造催化剂床等措施，可以降低催化剂床壁面吸热对催化分解过程的影响，提高催化剂床的响应特性和催化分解效率；催化剂床的低频不稳定是催化分解过程与供应系统耦合产生的，催化剂床气体界面的波动过程中，液体过氧化氢穿透催化剂床形成过氧化氢液体通道，过氧化氢液体通道的产生和扩大是催化剂床不稳定的主要原因，也是消除催化剂床不稳定的关键，试验中在催化剂床内加入分流板成功地抑制了催化剂床的低频不稳定。

The Pd-Cu/C catalysts were shown to have the face centered cubic crystal structure. This could indicate that the addition of Cu shortened the Pd-Pd distances in the crystal lattice, and therefore –HO(subscript 2ads) and O-O could be better adsorbed on the surface of the catalyst. When NaBH4 was used as the reducing agent, and the atomic ratio of Pd to Cu was 3:1, the resulting catalysts had an average particle size of 3. 4nm and showed the best catalytic performance. The electrochemical active surface are a of Pd3Cu/C was 38.9m^2/gPd and the oxidation reduction reaction activity of the Pd3Cu/C catalyst was much higher than that of the Pd/C catalyst. The electrochemical activity of the Pd3Cu/C catalyst was comparable to that of a commercial Pt/C catalyst.

结果表明：催化剂中Pd与Cu的物质的量之比与预设值相近，Pd和Cu基本被全部还原；Pd-Cu/C催化剂为面心立方结构，元素铜的加入使催化剂的Pd-Pd间距缩小，从而HO(下标 2 ads)和OO键能更好地吸附在催化剂金属表面；当采用NaBH4为还原剂，Pd与Cu物质的量比为3：1时，催化剂(Pd3Cu/C)的平均粒径为3.4 nm，催化剂的催化性能最好，电化学活性表面积EAS达到38.9平方公尺/gPd，电化学性能较Pd/C催化剂有很大提高，接近Pt/C商用催化剂。

At present the company mainly engaged in: ISSI, CATALYST, SIPEX, SST, RICOH, MICROCHIP, AMD, MAXIM, TI brand-name manufacturers such as SRAM, DRAM, SDRAM, EEPROM, MCU Singlechip, FLASH, and interface circuits, power management, protection of electricity, such as lithium related to integrated circuits.

目前公司主要经营：ISSI、CATALYST、SIPEX、SST、RICOH、MICROCHIP、AMD、MAXIM、TI等名牌厂商的SRAM、DRAM、SDRAM、EEPROM、MCU单片机、FLASH以及接口电路、电源管理、锂电保护等相关集成电路。

It was found that Pd-Co/active carbon catalyst was the optimal catalyst, and Pd-Co/γ-Al2O3 was also good, but silica and kieselguhr were not proper carriers for the object reaction, because of their stronger surface acidity, which could result in the formation of polymer, jammed the micro pores of catalyst, and then resulted in its deactivation. Addition of Bi, Ce and Cu promoters could not improve the activity of catalyst, but La and Ba promoter could enhance the activity of catalyst apparently, and the Co was the best promoter, especially Co was impregnate in advance. It was attributed to that the pre-impregnated Co may occupy the micro pores of active carbon, and cover some bad functional groups on the surface of catalyst, so that the active and selectivity of catalyst could be enhanced obviously.

研究结果表明，Pd-Co/活性炭催化剂是目标转移加氢反应的最适宜催化剂，Pd-Co/γ-Al203效果也较好，而硅胶和硅藻土由于表面酸性较强，容易造成生成聚合物而堵塞催化剂微孔、使催化剂迅速失活；此外，添加Bi、Ce、Cu等助剂时对活性并无改善作用，而添加La和Ba助剂时可使Pd的催化活性有所提高，效果最好的是Co助剂，尤其是先浸渍Co的Pd-Co/C催化剂，原因是Co占据了活性炭的微孔、覆盖了某些对目标反应不利的官能团，使其活性和选择性都有较大幅度的提高。

Progress in research of catalyst deactivation in ethylbenzene dehydrogenation was reviewed.Active phase of the catalyst was briefly analyzed.Five main reasons for the catalyst deactivation were discussed,including coke deposition,loss and redistribution of potassium promoter,change in oxidation state of iron,structural transformation of the catalyst,and the catalyst poisoning.

对乙苯脱氢制苯乙烯催化剂失活的研究进展进行了综述，分析了催化剂的活性相，分别探讨了积碳、钾的流失与重新分布、Fe3+的还原、催化剂物理结构的变化和中毒等5个因素对催化剂失活的影响及其失活机理，其中，钾的流失和Fe3+的还原是造成催化剂失活的重要因素。

Eleanor Tabi Haller-Jorden, general manager of Catalyst Europe AG, said the disparity 'doesn't seem to be related to the crisis but magnifies an ongoing issue in Europe -- the challenge of recruitment, retention and development of women.

Catalyst Europe AG的总经理哈勒尔-乔登(Eleanor Tabi Haller-Jorden)说，这一差异似乎与经济危机无关，但加剧了欧洲当前的一个问题──女性在招聘、保留职位以及职业发展方面遇到的挑战。

Based on the studies of moderate temperature isomerization catalysts carried out by domestic and foreign researchers, the paper systematically discussed the influence of a variety of factors in process of commercial preparation on the performance of catalyst which applied Pd as its metal component and HM as its acid carrier. The paper also explored the deactivated reasons of catalyst and its regenerating measure. Preparation of mordenite and scaled up production of catalyst, stability of catalyst was demonstrated in a 100kt/a commercial plant. The findings provide important basis for preparing Pd isomerization catalyst and industrial application.

本文在国内外学者对中温异构化催化剂及工艺研究的基础上，以钯作为金属组份，氢型丝光沸石作为酸性载体，系统研究了工业制备过程中各种因素对催化剂性能的影响，以及催化剂失活的原因及再生方法，进行了丝光沸石及催化剂的放大生产，并在10万吨/年工业装置上考察了催化剂的稳定性，为制备载Pd异构化催化剂及工业应用提供了重要依据。

In this paper, two assemblies of special test equipments have been designed and fabricated by authors in our laboratory: namely Catalyst Molding Process Analyzer and Catalyst Mechanical Process Tester. These new skills are developed for the dynamic studies on whole mold forming process and crushing process of Fe-Cr WGHS catalyst pellet. Based on the orthogonal experimental design, the effects of some factors during the forming process of solid catalyst, such as predensification proportion, calcination time, calcination temperature and content of graphite on the mechanical strength of catalyst pellets are systematically examined, and the molding conditions have been optimized. Based on the experimental data, the relationship between catalyst density and forming pressure are educed, and the physical significances of some related parameters are described. The parameter of macro scopic elastic moduls has been suggested to character the mechanical properties of molding catalyst. The effects of molding pressure on mechanical properties of catalyst pellets are discussed, and results show that there exists a optimal molding pressure for the ideal mechanical properties: when over-high or over-low pressure is applied, the specific surface area and side crushing strength of catalyst pellets will decreased. The "rebound effect" will be undermined by the unsuitable pressure maintain process, resulting in the apparent decrease of mechanical strength of catalyst pellets.

本研究通过自行设计制造的催化剂模压成型过程分析仪（Catalyst Molding Process Analyzer， CMPA）和催化剂力学性质测试仪（Catalyst Mechanical Properties Tester， CMPT），以Fe-Cr系高温变换催化剂片剂为研究对象，对成型过程和受压破碎过程提供了全过程动态研究的新手段；本研究利用正交实验设计方法考察了固体催化剂成型过程中诸因素（包含预密致比例、煅烧时间、煅烧温度和石墨含量等）对催化剂成型体强度的影响，并对成型条件进行了优化；根据实验结果，关联确定了固体催化剂成型过程中的密度－压力关系式，并对方程中诸因子的物理意义进行了描述；提出了一种利用宏观弹性模量来表征成型催化剂的力学性质的方法；研究讨论了成型压力对催化剂成型体强度性质的影响，结果表明：对于催化剂成型体的强度和比表面性质，成型压力存在着一个最佳值，过高的成型压力会导致比表面积和侧压强度的降低；不适当的成型压力的维持时间会破坏&压力回弹&作用，造成催化剂成型体的机械强度明显降低。

In case of failure, Cisco Catalyst 3750G's stacking throughput drops by 50%.

在案件的失败，到Cisco Catalyst三七五〇克的堆叠吞吐量下降了50 ％。

A process for partial conversion and low-temp transform of CO in the synthetic ammonia plant where coal is used to generate gas features that the Fe-Mo catalyst for partial conversion of CO, anti-poisoning agent and Co-Mo catalyst for low-temp conversion are used and the temp of semi-water gas is controlled to 200-260 deg.C at entering anti-poisoning layer, and 150-250 deg.C at the segments of said Co-Mo catalyst layer, and lower than 300 deg.C at bed layer to prevent high-temp reversal of sulfurizing reaction and make the catalyst activity optimal. Its advantages are long service life of catalyst, low system resistance, saving energy and convenient operation.

本发明是中小合成氨厂以一种CO部分转化抗毒保护层配低温变换的工艺，涉及煤造气合成氨厂0.6～2.0MPa半水煤气变换工艺流程，该工艺用铁－钼CO部分转化催化剂、抗毒剂，配钴－钼低变催化剂，半水煤气进入部分转化抗毒层温度为200～260℃，进钴－钼低变催化剂各段温度为150～250℃，床层温度控制在300℃以内，避免高温下反硫化反应发生，保护催化剂活性处最佳状态，寿命延长、系统阻力小、节汽、节电，具有比其他变换工艺更好地节能效果，操作方便，有效生产时间长，经济效益显著等特点。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。