不同条件下麝香石竹玻璃苗的诱导形成及其生理特性研究

研究了不同培养基及外植体条件下麝香石竹玻璃苗的诱导形成及玻璃苗部分生理特性。本文研究认为：麝香石竹玻璃的形成是培养基和外植体因素相互作用的结果，培养基极端的水分环境可能是导致玻璃苗形成的外在原因。     

背面氩离子轰击改善MOS系统界面特性和击穿特性

在室温下用低能量Ａｒ＾＋轰击ＭＯＳ电容器肾面，能改善ｉＯ２－Ｓｉ系统的界面特性和击穿特性。结果表明，随着轰击时间的增加，固定电荷密度、界面态密度和漏电流减少，高场击穿的比率增大，然后这些参数变化平缓并开始呈恶化趋势。轰击能量为５５０ｅＶ和束流密度为０．５ｍＡ／ｃｍ＾２时的效果比在３５０ｅＶ和０．３ｍＡ／ｃｍ＾２时的好。     

岩体地震破坏后弹性波波动力学参数特征研究──以黄河大柳树地区岩体为例

地震是一种强自然灾害，对工程岩体的破坏实质是对地质体再改造的过程，它不仅改变了岩体原来的工程特性，同时也改变了岩体的赋存条件与环境。本文重点研究了中卫──同心活动断裂带内的黄河大柳树地区岩体地震破坏后的低波速，强衰减，低频率的特征，并研究其空间上的分布规律。按其工程地质分类标准应属碎裂结构和散体结构，即Ⅳ、Ⅴ类岩体。为进一步突出其波动力学特征，相应地与同岩性、同峡谷的小观音地区岩体，同岩性的李家峡坝基岩体做了比较。     

具有非线性迟滞特性的大挠度弹性联轴器建模

本文在对大挠度弹性联轴器振动试验数据进行处理和分析的基础上，用拟合分解法以及阻尼等效原理，提出一个与振动位移幅值有关的非线性迟滞恢复力数学模型，分析表明，该数学模型能很好地描述联轴器的非线性动刚度和阻尼等动态特性对迟滞恢复力的影响，为深入研究船舶推进轴系的振动特性提供了联轴器的数学模型。     

容积—节流联合调速系统性能分析

本文以流体力学、控制理论为基础,对限压式变量泵与调速阀组成的调速系统的工作原理、静动态性能进行了较全面的理论分析,并对系统的设计、调整等问题作了有益的探讨,为容积—节流联合调速系统的推广使用提供理论基础。     

单螺杆泵输送不同粘度液体时的外特性及汽蚀特征

本文用不同粘度的液体对单螺杆泵的外特性和汽蚀特性进行了实验研究,分析了外特性曲线的变化特点,讨论了粘度变化对特性和能量分配的影响,并对单螺杆泵的汽蚀特性曲线和汽蚀条件下的能量平衡关系进行了初步的分析和探讨。     

Hall Effect in Quasicrystals

The relations between Hall effect and symmetry are discussed for all 2- and 3-dimensional quasicrystals with crystallographical|y forbidden symmetries. The results show that the numbers of independent components of the Hall coefficient (R11) are one for 3-dimensional quasicrystals, two for those 2-dimensional quasicrystals whose symmetry group is non-Abelian, and three for those 2-dimensional quasicrystals whose symmetry group is Abelian. respectively. The quasicrysta[s with the same number of independent components have the same form of the components of R11.     

Inhibition of Alkaline Phosphatase from Pearl Oyster Pinctada fucata by o-Phthalaldehyde： Involvement of Lysine and Histidine Residues at the Active Site

Alkaline phosphatase from Pinctada fucata was inactivated by o-phthalaldehyde （OPA）. The inactivation followed pseudo first-order kinetics with a second rate constant of 0.167 （mmol/L）^-1·min^-1 at pH 7.5 and 25℃. A Tsou＇s plot analysis showed that inactivation occurred upon formation of one isoindole group. The OPA-modified enzyme lost the ability to bind with the specific affinity column and the presence of substrates or competitive inhibitors protected the enzyme from inactivation. The results revealed that the OPA-reaction site was at the enzyme substrate binding site. Prior modification of the enzyme by lysine or histidine specific reagent abolished formation of the isoindole derivatives, suggesting that lysine and histidine residues were involved in the OPA-induced inactivation. Taken together, OPA inactivated the alkaline phosphatase from Pinctada fucata by cross-linking lysine and histidine residues at the active site and formed an isoindole group at the substrate binding site of the enzyme.     

In vivo Dynamic Studies of Brain Metabolism

Nuclear magnetic resonance （NMR） can noninvasively monitor intracellular concentrations and kinetic properties of numerous inorganic and organic compounds. A ^31p NMR surface coil was used in vivo to dynamically measure phosphocreatine （PCr）, adenosine triphosphate （ATP）, and intracellular inorganic phosphate （Pi） levels in mouse brain during ischemia-reperfusion to study the damage of cerebral tissues caused by ischemia and effects of herbs on cerebral energy metabolism during ischemia-reperfusion. The study provides dynamic brain energy metabolism data during different periods. The data show that some herbs more rapidly increase the PCr level during the recovery phase than in the control group.     

Adsorption of polyelectrolyte on the surface of ZnO nanoparticles and the stability of colloidal dispersions

How to prevent flocculation is a universal problem in synthesis and application of nanoparticles. Because of high surface activity, nanoparticles tend to form large di-mension of aggregates with some loose contact interface. When solid particles are suspended in polyelectrolyte so-lution, polymer chains are adsorbed on the surface of par-ticles and they render to stabilize the corresponding parti-cles. The stabilizing property of polyelectrolytes is the reason for wide application in many fiel…