饲用复合酶对肉鸡生产性能的影响

本研究旨在探讨应用复合酶提高肉鸡生产性能与适当降低代谢能及蛋白,使加酶后的饲料配方更趋合理。试验中对照组喂常规肉鸡浓缩料,试验1组喂加酶常规肉鸡浓缩料,试验2组喂加酶减豆粕浓缩料,三组中的玉米添加比例相同,调饲料配方后的1t浓缩料可降低成本126元。试验结果表明,试验1组与试验2组分别比对照组提高肉鸡增重9.4%与6.3%,经济效益提高24.3%与14.1%。

选择性化学萃取对自然水体生物膜上微生物的影响

用平板计数法、显微镜直接计数法及培养法分别研究了选择性萃取剂对自然水体生物膜上细菌、原生动物和藻类的影响.结果表明,随着选择性萃取剂萃取能力的增强,生物膜上存活下来的微生物数量呈减少趋势.经0.01mol.L-1NH2OH.HCl+0.01mol.L-1HNO3、0.4mol.L-1Na2S2O4(pH6.0)和0.2mol.L-1草酸氨(pH4.0)萃取后存活的微生物总量分别下降到原膜的27.6%、14.1%和0.01%;经15%HNO3萃取后,膜上只有极少数的细菌存活;而经H2O2/HNO3萃取后则无细菌存活、原生动物和藻类存活,说明选择性化学萃取剂的使用影响生物膜的活性.比较萃取前后生物膜吸附痕量重金属的能力发现,随着生物膜上微生物数量的减少,生物膜吸附痕量重金属的能力逐渐降低.

Model analysis of dissolved inorganic phosphorus exports from the Yangtze river to the estuary

In this paper, we estimate the inputs of phosphorus (P) to the Yangtze River Basin and exports of dissolved inorganic phosphorus (DIP) from the river to the estuary for the period 1970-2003, by using the global NEWS-DIP model. Modeled DIP yields range from 2.5 kg P km(-2) yr(-1) in 1970 to 4.6 kg P km(-2) yr(-1) in 1985, and then dramatically increase to 14.1 kg P km(-2) yr(-1) in 2003. No significant difference between the modeled and measured values at the level of P = 0.05 is observed. The study also demonstrates variable source contributions of P to the modeled DIP during the period 1970-2003. Point sewage P input accounted for approximately 100% in the period 1970-1985 and substantially decreased to 24.8% in 2003. Chemical fertilizer contributed 25.4% of DIP yields in 1986 and increased continuously to 50.3% in 2003, while a stable trend in manure P contribution averaging 22.9% of DIP yields was shown in the same period. The study concludes that P inputs to the Yangtze River Basin and the river DIP export to the estuary have substantially increased during the study period consequence to human pressure.

Hydrothermal synthesis and crystal structure of a sulfur-bridged binuclear copper(II) coordination polymer generated by a spontaneous reduction

A simultaneous reduction SO42- to S2- by 2,5-pyridinedicarboxylate under hydrothermal conditions produced a new binuclear copper(II) coordination polymer [CuS(4,4'-bipy)](n) (4,4-bipy = 4,4'-bipyridine) (1). Single crystal X-ray analysis revealed that compound I consisted of sulfur-bridged binuclear copper(II) units with Cu-Cu bonding which were combined with 4,4-bipy to generate a three-dimensional network constructed from mutual interpenetration of two-dimensional (6,3) nets. Crystal data for 1:C10H8CuN2S, tetragonal 14(1)/acd, a = 14.0686(5) Angstrom, b = 14.0686(5) Angstrom, c = 38.759(2) Angstrom, Z = 32. Other characterizations by elemental analysis, IR, EPR and TGA analysis were also described in this paper.

无机氯化物对顺丁橡胶原位环化反应的影响

在稀土顺丁橡胶原位环化反应的后期加入无机氯化物PCl3,BCl3,SiCl4等,考察了无机氯化物对该反应体系的影响。结果表明,加入PCl3后得到了环化产物,其环化度为14.1%;加入BCl3后得到了完全偶联产物;加入SiCl4后得到了部分偶联产物。

Synthesis and characterization of ferrocene-terminated ruthenium phenylacetylide complexes with alligator clips

Ferrocene-terminated trans/Ru(dppm)(2) (dppm=Ph2PCH2PPh2)-contained molecular wires with alligator clips were prepared. They are suitable for self-assembly on gold electrode to investigate the influence of metal incorporation on the electron transportation property of the molecular wires.

Electrochemical biosensing in extreme environment

This review presents recent developments of electrochemical biosensors in extreme working environments. After a brief introduction to the electrochemical biosensor, the applications of biocatalytic biosensors and bioaffinity biosensors in harsh working conditions, in organic solvent, in gas-phase, in vivo measurement and in toxic environments, are discussed by means of several examples. Methods for improving the stability and extending the biosensor application scope are suggested, and new trends about biosensor development are also discussed.

Study of color centers and trace oxygen in KMgF3 : Eu single crystal

Using the Bridgeman-Stockbarger method, the KMgF3:EU2+ single crystal was grown. The color centers in unirradiated KMgF3:Eu crystal were studied. By thermal annealing, we confirmed the 422-nm emission resulted from color centers and oxygen centers, and we proved the energy transfer from EU2+ to color centers. From spectra, the relative oxygen content in crystal was calculated, and the relationships of oxygen displacing fluorine were studied.

含环己烯氮杂环结构的聚醚砜酮三元共聚物合成

用 1 -甲基 -4 ,5-二 ( 4-氯代苯甲酰基 )环己烯与 4 -( 4-羟基苯基 ) -2 ,3 -二氮杂萘 -1 -酮、4 ,4′-二氯二苯砜经亲核共缩聚反应 ,合成了含环己烯结构的杂环联苯型聚醚砜酮三元共聚物。用FT -IR、1H -NMR、DSC、X -射线衍射等方法对聚合物进行了表征 ,并研究了聚合物的溶解性能。结果表明 ,聚合物是一种具有较高的玻璃化转变温度的可溶性无规共聚物。聚合物含有不饱和双键结构 ,是一种反应性高分子。