属间远缘杂交水稻耐旱性生理特性的比较研究

采用在ＹＯＳＨＩＤＡ水稻专用培养营养液中添加一定量的ＰＥＧ ６０００的方法，比较研究了模拟干旱胁迫条件下属间远缘杂交新型水稻品种“远诱１号”（Ｙ）及其水稻亲本“圭６３０”（Ｇ）、高梁亲本“桃长红”（Ｔ）以及生产推广杂交组合“汕优６３”（Ｓ）等试验材料某些生态生理特性的差异。研究结果表明，在－１．０ＭＰａ的高渗胁迫下，Ｙ、Ｇ、Ｔ的萌发系数均有不同程度的下降，正常培养条件下的萌发系数ＧＣ分别为３６．９     

Al-pillared clays supported rare earths and palladium catalysts for deep oxidation of low concentration of benzene

Al-pillared clays supported rare earths (RE/Al-PILC) are prepared and used as supports of palladium catalysts for deep oxidation of low concentrations of benzene (130-160 ppm). The supports and catalysts are characterized by X-ray powder diffraction (XRD), FT-IR, BET, transmission electron microscopy (TEM) and temperature-programmed reduction (H₂-TPR). The results show that Al-pillaring results in a strong increase in the basal spacing (d_0 0 1) from about 1.2 to 1.8 nm, and an increase in the BET surface area from 63.6 (±3.2) to 238.8 (±11.9) m²/g. Activity tests of deep oxidation of low concentration benzene show catalysts supported on Al-PILC and RE/Al-PILC are obviously more active than that on raw clay. Pd/6% Ce/Al-PILC, in particular, can catalyze the complete oxidation of low concentration benzene at a temperature as low as about 290 °C.     

New ligands for the Fe(III)‐mediated reverse atom transfer radical polymerization of methyl methacrylate

A series of (di)picolinic acids and their derivates are investigated as novel complexing tridentate or bidentate ligands in the iron‐mediated reverse atom transfer radical polymerization of methyl methacrylate in N,N‐dimethylformamide at 100 °C with 2,2′‐azobisisobutyrontrile as an initiator. The polymerization rates and polydispersity indices (1.32–1.8) of the resulting polymers are dependent on the structures of the ligands employed. Different iron complexes may be involved in iron‐mediated reverse atom transfer radical polymerization, depending on the type of acid used. ¹H NMR spectroscopy has been used to study the structure of the resulting polymers. Chain‐extension reactions have been performed to further confirm the living nature of this catalytic system. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2912–2921, 2006     

HgCl2/I2复合催化剂协同催化合成异丙醇钇的研究

以金属钇和异丙醇为原料，以HgCl2/I2为复合催化剂，通过对金属钇的机械加工以增加其比表面，并将异丙醇脱水使其含水量降低至0．05％，体系在82℃回流5h，经过滤、减压蒸馏，得到了白色海绵状异丙醇钇，其产率高达83％，合成时间比文献报道的缩短了19h，产率提高了8％。文章确定了催化剂的最佳用量为20gY加入60mg HgCl2/I2，研究了合成产率与HgCl2/I2催化剂和HgCl2催化剂的依赖关系及异丙醇中含水量对合成产率的影响，并对HgCl2/I2的催化作用机理进行了初步探讨。     

Synthesis of coumarins by Pt-catalyzed hydroarylation of propiolic acids with phenols

Synthesis of coumarins from phenols and propiolic acids was examined by using a Pt catalyst such as PtCl₂/AgOTf, K₂PtCl₄/AgOTf, and K₂PtCl₄/AgOAc. Propiolic acid reacted even with less reactive phenols in trifluoroacetic acid to give coumarins and dihydrocoumarins. In the case of substituted propiolic acids, phenylpropiolic acid and 2-octynoic acid, the reactions proceeded selectively to afford coumarins in good to high yields.     

催化剂薄层内甲烷水蒸气重整反应强化管内对流换热的数值模拟

本文以竖直圆管内壁催化剂薄层内发生甲烷水蒸气重整反应强化对流换热作为研究对象,对其进行了数值模拟．结果发现,催化剂薄层内的吸热化学反应可以有效地强化对流换热,降低流体和壁面温度,从而对壁面起到保护作用;极限热流密度的大小与流体的入口温度有关,存在最佳入口温度使极限热流密度最大．     

混合判断矩阵排序方法研究

本文介绍了混合判断矩阵及完全一致性混合判断矩阵的概念，提出了混合判断矩阵排序的一种最小偏差法，并给出了其收敛性迭代算法，最后通过算例说明了方法的可行性。     

A solvent-free synthesis of coumarins using a Wells-Dawson heteropolyacid as catalyst

Substituted coumarins are synthesized from phenols and β-ketoesters by the Pechmann reaction, using a Wells-Dawson heteropolyacid (H₆P₂W₁₈O₆₂·24H₂O) as catalyst by a solvent-free procedure. This one requires low reaction times, 130 °C temperature and as little as 1 mol % of Wells-Dawson acid, obtaining good to excellent yields of coumarins. The catalyst showed to be reusable with no differences in the yields. The results are compared with those of the reactions performed in toluene solution. The presented synthetic procedure is a convenient, clean and fast alternative for synthesizing 4-substituted coumarins (17 examples).     

Preparation of rhodium–phyllosilicate catalysts without leaching in liquid-phase 1-hexene hydrogenation

Rhodium catalysts have been prepared on palygorskite and montmorillonite (clay) supports by reduction with hydrogen (1 atmosphere) at room temperature of a cationic organometallic rhodium compound anchored to the support. The activity of these catalysts for the hydrogenation of liquid-phase 1-hexene remains constant with increase of prehydrogenation time and with re-use for several runs. No rhodium leaching is observed.     

The Analysis and Improving of the Microwave Exciter in the Lower Hybrid Wave System

When we carry out lower hybrid wave heating and current driving plasma experiment at tokamak, we need mega-watt order of microwave power. The microwave signal at frequency of 2450 MHz is generated by a microwave exciter. According to the experiment＇s demands, the microwave exciter must provide output power of 1.5～ 2. 5 W with stabilized frequency and amplitude tobe used as the klystron input. Being amplified by the klystron, the microwave signal is transmitted through the transmitting system to the antenna and is emitted into the HL-2A tokamak. So we can see that the microwave exciter＇s function is very important to the lower hybrid wave heating and current driving plasma experiment.