阿佛曼链霉菌的~(12)C离子辐照效应及高产菌株选育；Research on Mutation Breeding of High-producing Strains from Streptomyces Avermitilis Irradiated by Ion Beam of ~(12)C~(6+)

选用12C6+离子辐照诱变阿维菌素B1a产生菌ZJAV-A1,研究其诱变效应。实验结果表明,12C6+离子辐照剂量50Gy时致死率97%,正突变率最高可达到34.2%。通过12C6+离子诱变处理,结合平板培养基及斜面培养基的正突变菌株筛选,最终获得一株稳定性良好,阿维菌素B1a组分产量稳定在4460—4588μg/ml之间,较出发菌株提高11.1%—14.7%的突变株ZJAV-Y1-203。

诱发突变选育小麦新品种的研究探讨；The reseach of wheat variety breeding through radiation

概述了张掖市农科院小麦诱变育种研究的发展历程,介绍了小麦诱变育种的常用方法及辐照处理的参考剂量,并对张掖市小麦诱变育种今后发展的方向进行了探讨。

Selective formation of aromatic amines by selenium-catalyzed reduction of aromatic nitro compounds with CO/H2O under atmospheric pressure

An efficient method for the catalytic reduction of aromatic nitro compounds to the corresponding aromatic amines is reported. In the presence of selenium as a catalyst, the aromatic nitro compounds are quantitively reduced by CO/H2O to form the corresponding amines under atmospheric pressure. The reduction occurs in high selectivity regardless of other reducible functionalities present on the aromatic ring. There exists a phase transfer process of the catalyst selenium in the reaction. (C) 2004 Elsevier B.V. All rights reserved.

CO selective oxidation in a microchannel reactor for PEM fuel cell

It is indispensable to remove CO at the level of less than 50ppm in H-2-rich feed gas for the proton exchange membrane (PEM) fuel cells. In this paper, catalyst with high activity and selectivity, and a microchannel reactor for CO preferential oxidation (PROX) have been developed. The results indicated that potassium on supported Rh metal catalysts had a promoting effect in the CO selective catalytic oxidation under H-2-rich stream, and microchannel reactor has an excellent ability to use in on-board hydrogen generation system. CO conversion keeps at high levels even at a very high GHSV as 500 000 h(-1), so, miniaturization of hydrogen generation system can be achieved by using the microchannel reactor. (C) 2004 Elsevier B.V. All rights reserved.

Pd/sulfated alumina - a new effective catalyst for the selective catalytic reduction of NO with CH4

Sulfated alumina (SA) is firstly found to be an effective support for Pd catalyst used in the SCR of NO with methane. The sulfation is important to increase support's acidity which is essential for the reduction of NO over Pd catalysts. On consideration of the lower cost and easier availability of SA, we believe that SA is more promising to act as the commercial support for Pd catalyst used in the SCR of NO with methane.

Probing into the catalytic nature of Co/sulfated zirconia for selective reduction of NO with methane

In this work, the structural and surface properties of Co-loaded sulfated zirconia (SZ) catalysts were studied by X-ray diffraction (XRD), N-2 adsorption, NH3-TPD, FT-IR spectroscopy, H-2-TPR, UV-vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and NO-TPD. NH3-TPD and FT-IR spectra results of the catalysts showed that the sulfation process of the support resulted in the generation of strong Bronsted and Lewis acid sites, which is essential for the SCR of NO with methane. On the other hand, the N-2 adsorption, H-2-TPR, UV/vis DRS, and XPS of the catalysts demonstrated that the presence of the SO42- species promoted the dispersion of the Co species and prevented the formation Of Co3O4. Such an increased dispersion of Co species suppressed the combustion reaction of CH4 by O-2 and increased the selectivity toward NO reduction. The NO-TPD proved that the loading of Co increased the adsorption of NO over SZ catalysts, which is another reason for the promoting effect of Co. (C) 2004 Elsevier Inc. All rights reserved.

Effects of reaction conditions on the selective oxidation of propane to acrylic acid on Mo-V-Te-Nb oxides

An effective Mo-1 V(0.3)Te(0.23)Nb(0.12)Ox catalysts for the selective oxidation of propane to acrylic acid was successfully prepared by using rotavap method. The catalyst was characterized by XRD and shown to contain (V0.07Mo0.93)(5)O-14, (Nb0.09Mo0.91)O-2.8,3MoO(2)(.)Nb(2)O(5), Mo5TeO16 and/or TeMo4O13, Te4Nb2O13 and a new TeMO (TeVMoO or TeVNbMoO; M = Mo, V and Nb) crystalline phase as the major phase. Regardless of the intrinsic catalytic characteristics of the catalyst, the external reaction conditions would have strong effects on the catalytic performance for propane oxidation. So in this paper, the effects of reaction conditions were investigated and discussed, including temperature, space velocity, V(air)/V(C3H8) ratio and V(steam)/V(C3H8) ratio. A stability test was also carried out on Mo1V0.3Te0.23Nb0.12Ox catalyst. The experimental run was performed during 100 h under the optimized reaction conditions. During the 100 h of operation, propane conversion and acrylic acid selectivity remained at about 59 and 64%, respectively. (C) 2004 Elsevier B.V. All rights reserved.

Sn-modified Pt/SAPO-11 catalysts for selective hydroisomerization of n-paraffins

The hydroconversion of n-paraffins is a key reaction in hydrodewaxing of lubricating base oil. In this paper, we investigate the performance of Pt/SAPO-11 catalysts for isomerization of n-paraffins by the model compound of n-dodecane. Under this experimental condition, yields of feed isomers as well as cracking products are a function of the total n-dodecane conversion. Primary products are methylundecane while multi-brancheds and cracking products are formed in successive reactions. The result shows that the addition of Sn increases the selectivity for isomerization reaction. The most ideal experimental data for hydroconversion of n-dodecane is that the selectivity of isomerized products gets 90% when conversion of n-dodecane is 90% for the Sn-promoted Pt/SAPO-11 catalyst.

Characterization of metal-containing molecular sieves and their catalytic properties in the selective oxidation of cyclohexane

Three types of metal-containing molecular sieves with AFI, AEL and CHA structures (Me = Co, Mn, Cr and V) were synthesized hydrothermally and characterized by XRD, XRF, TG, TPR, NH3-TPD and FT-IR. It was revealed that metals were incorporated into the framework of molecular sieves and induced the presence of charge centers. Both cobalt and manganese in the framework of AIPO-5, AlPO-11 and SAPO-34 were not reducible before the structure collapse. The redox behaviours of these catalysts in cyclohexane oxidation at 403 K using O-2 as oxidant were examined. CoAPO-11 exhibited best activity and good selectivities for the monofunctional oxidation products (88.5%). Cyclohexanol was the major product over most catalysts, whereas for Cr-containing molecular sieves, high selectivity of cyclohexanone was observed. Investigation of reaction mechanism based on CoAPO-11 and CrAPO-5 catalysts indicated that the decomposition of cyclohexyl hydroperoxide (CHHP), the intermediate in cyclohexane oxidation, followed the pathway: cyclohexanone <-- CHHP --> cyclohexanol -->cyclohexanone. (C) 2004 Elsevier B.V. All rights reserved.