Alleviation Effect of Lanthanum on Cadmium Stress in Seedling Hydroponic Culture of Kidney Bean and Corn

Since1970s,rare earths(RE)have been exten-sively used as micro-fertilizers for crops in China.Ithas already been proved that REcani mprove the pro-duction and quality of crops.However,there havebeen a fewinvestigations about using RE as regulatorin pollution ecology.For example,An et al[1]studiedthe effects of O3on wheat growth and the protectiveeffect of RE.Yan and Zhou et al[2,3]discussed theprotective effect of RE on plants under acid rainstress.Jia et al[4]and Hu et al[5]reported th…     

Complete oxidation of methane at low temperature over Pt and Pd catalysts for the abatement of lean-burn natural gas fuelled vehicles emissions: influence of water and sulphur containing compounds

The catalytic activity of fresh Pd and Pt catalysts supported on γ-alumina in the complete oxidation of CH₄ traces under lean-burn conditions was studied in the presence or the absence of water or H₂S. Steam-aged catalysts were also studied in order to simulate long-term ageing in real lean-burn natural gas fuelled vehicles (NGVs) exhaust conditions. Without water or H₂S added to the feed, Pd catalysts exhibit a superior catalytic activity in methane oxidation compared to Pt ones, whatever the catalysts were fresh or aged. The addition of 10 vol.% water vapour to the feed strongly affects the activity of the fresh Pd catalyst, thus being only slightly more efficient than the fresh Pt one. H₂S has a strong poisoning effect on the catalytic activity of Pd catalysts, while Pt catalysts are more resistant. The fresh H₂S-poisoned Pd/Al₂O₃ catalyst was studied by TPD in O₂/He. Poisoning species decompose above 873 K as SO₂ and O₂ in relative concentrations consistent with the decomposition of surface sulphate species. However, a treatment in O₂/He at temperatures as high as 923 K does not allow the complete regeneration of the catalytic activity of H₂S-poisoned Pd/Al₂O₃. A mechanism involving the poisoning of PdO by sulphate species is proposed. Different diffusion processes by which these sulphate species can migrate back and forth between PdO and the support, depending on the experimental conditions, are suggested.     

A new bubble-point-pressure correlation for the binary LiBr/H2O solution

In accord with the increasing concern about the global environmental issues, the absorption refrigeration heat-pump systems are currently being considered very promising and attractive. For the purpose of supporting the advanced R&D technology in this area, we have developed a novel correlation to represent the bubble-point pressures of LiBr H₂O solutions. The developed correlation covers the most extensive range of validity ever proposed: 273–483 K for temperatures, 0.05 kPa to 1.0 MPa for pressures. and 29 76 wt% LiBr for concentrations.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994. Boulder, Colorado, U.S.A.     

以杂多酸为催化剂合成乙二醇-乙醚的研究

研究了杂多酸催化无水乙醇和环氧乙烷(EO)制备乙醇乙醚的醚化反应,考察了不同种类的杂多酸以及醚化反应工艺条件对反应活性和选择性的影响.结果表明,PW_(12)催化剂的反应活性高、反应温度低、选择性好,当用PW_(12)作催化剂,乙醇与环氧化乙烷之比为3.0(mol),反应温度45℃,反应时间1h时,转化率和选择性均超过97%.     

Cu－MnO_2同槽电解半工业试验研究

提出了Ｃｕ－ＭｎＯ＿２同槽电解的新工艺，在同一电解槽同时得到电铜和电解二氧化锰两种产品，该新工艺具有低电耗、低酸雾污染和低酸耗等优点．     

Relationship between CO2 Sensor Voltage Response and Phase Equilibrium of Solid Electrolyte Na, K-β/β"-Al2O3

A type of CO2 sensor based on oxygen concentration cell was designed as following: Cell I: Pt | Au, O2,CO2|Na2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt or Cell Ⅱ: Pt|Au, O2, CO2|K2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt.(Na,K-β/β″-Al2O3 is named by NKBA). The sensor signal is consistent with the Nernstian slope within the region ofphase equilibrium for Na, K-β/β"-Al2O3 material. The relationship between CO2 sensor voltage response and phaseequilibrium of solid electrolyte Na, K-β/β-Al2O3 is discussed in this paper.     

用φ20mm离心萃取器两步法制取高纯钇

本文研究了中钇富镧稀土的氧化物溶液在环烷酸中的萃取行为，测定了镧钇组成、温度变化与分离系数的关系；在Ｐ＿（５０７）体系中研究了ｐＨ值与分配比的关系；提出用环烷酸、Ｐ＿（５０７）两种萃取剂制备高纯钇的工艺流程。用８４台φ２０ｍｍ离心萃取器进行了一个月的台架试验，结果证明两种萃取剂有很好的互补性，在满足钇的纯度要求下有较高收率。离心萃取器具有易分相、体系存留量少、液流密闭性好等优点，它更适宜于粘度大、级数多、产品纯度要求高的体系。     

含H2S井完井液用除硫剂和缓蚀剂

含H_2S井完井液对井下金属管串具有腐蚀性。采用锌基或铁基螯合物除硫剂及咪唑啉缓蚀剂可有效地防止这种腐蚀的发生。本文对H_2S的腐蚀、除硫剂和缓蚀剂产品及其对产层的损害作了介绍与探讨。     

TiB2和SiCW对Al2O3陶瓷材料高温摩擦磨损特性的影响

研究了Ａｌ２Ｏ３、Ａｌ２ｏ３／ＴｉＢ２和Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣＷ三处陶瓷材料在不同条件下的擦靡损特性。结果表明：三种陶瓷材料与硬质合金摩擦副的摩擦系数随温度温度的增加有不同的变化规律，摩擦表面的Ｘ射线衍射分析表明，摩擦系数的变化与陶瓷物膜的和结构有关，在高温下Ａｌ２Ｏ３／ＴｉＢ２陶瓷材料摩擦表面形成了具有优良的高温润性的ＴｉＯ２氧化膜，因而ＴｉＢ２的加入明显改善了Ａｌ２Ｏ３陶瓷材料 摩擦磨损     

Temperature and pressure effects on supercritical CO2 extraction of tomato seed oil

Tomato seed oil was extracted with supercritical carbon dioxide in a semibatch-flow extractor within the temperature range 313–343 K and the pressure range 10.8–24.5MPa. The extraction rates increased with pressure, but decreased with temperature increase because of the variation in solvent density and resultant differences in oil solubility. The fatty acid composition of the extracted oil was similar to that of soybean oil.