我国生存环境演变和北方干旱化趋势预测研究（Ⅱ）：研究成果的创新性及项目实施效果

IEECAS SKLLQG

eta-production on the proton via electromagnetic and hadronic probes

The reactions pi(-)p -> eta n and gamma p -> eta p are investigated within a dynamical coupled-channels model of meson production reactions in the nucleon resonance region The meson-baryon channels included are pi N, pi Delta, sigma N, and rho N The direct eta-photoproduction process is studied within a formalism based on a chiral constituent quark model approach, complemented with a one-gluon-exchange mechanism, to take into account the breakdown of the SU(6)circle times O(3) symmetry In the models search, the following known nucleon resonances are embodied S-11(1535), S-11(1650), P-11(1440), P-11(1710), P-13(1720), D-13(1520), D-13(1700), D-15(1675), and F-15(1680). Data for the pi(-)p -> eta n reaction from threshold up to a total center-of-mass energy of W approximate to 2 GeV are satisfactorily reproduced For the photoproduction channel: two additional higher mass known resonances, P-13(1900) and F-15(2000), are also considered However, reproducing the data for gamma p -> eta p requires, within our approach, two new nucleon resonances, for which we extract, mass and width

不同水肥条件对大豆产量的影响

以沈阳生态试验站一组持续17年的长期定位试验为平台,研究了不同降水年景作物对施肥的增产反应,估算了下辽河平原地区水肥交互作用对大豆产量的影响。结果表明,该地区大豆蒸散耗水与其生育期内降水之间关系密切,且不同的施肥处理对大豆消耗水分量影响不大;肥料对产量的影响大于水分的影响,钾肥的施用提高了大豆抗旱能力,随着水分条件的改善磷肥增产作用提高,而水分过多会对大豆造成毒害作用。该地区平、丰水年份磷、钾肥交互作用以叠加效应为主,平水年份各处理大豆产量均达到最高,水肥交互作用对大豆增产贡献亦达到最大。

水土保持发展的战略目标及建议

工程措施和耕作措施是有效实施造林种草的必要条件 ;2 5°以上的陡坡地退耕后主要应作为营造水土保持林灌草的生态保护用地 ;应把天然植被保护、改良放在与退耕还林还草同等重要位置 ;建议将科学技术与专业科技力量直接切入生态环境建设 ,以充分发挥支撑作用

Magnetic control of bioelectrocatalytic processes based on assembled iron oxide particles

A facile magnetic control system was designed in bioelectrocatalytic process based on functionalized iron oxide particles. The iron oxide particles were modified with glucose oxidase, and ferrocene dicarboxylic acid was used as electron transfer mediator. Functionalized iron oxide particles can assemble along the direction of applied magnetic field, and the directional dependence of the assembled iron oxide particles can be utilized for device purposes. We report here how such functionalized magnetic particles are used to modulate the bioelectrocatalytic signal by changing the orientation of the applied magnetic field. (C) 2008 Elsevier B.V. All rights reserved.

Extending electrochemical activity of polyaniline to alkaline media via electrostatic interaction and sol-gel route

The electroactivity of polyaniline was extended to pH = 14 alkaline media by preparation of a novel electrostatic interaction conductive hybrid from water-borne conductive polyaniline and silica network containing carboxyl groups via sol-gel process. In addition, the obtained conductive polyaniline hybrid film displayed very low conductivity threshold percolation and demonstrated excellent stability upon cycling.

Studies on carbosillane liquid crystalline dendrimer with S-c* phase

A liquid crystalline carbosilane dendrimer with Sc* phase has been synthesized in successive steps, resulting in the formation of defined, unimolecular compound. Twelve biphenyl mesogenic units were attached on its periphery and it has a three dimentional, treelike starburst structure. Its phase behavior was K95S(c)*103Ch118I. Compared.with its biphenyl mesogenic unit , 4-(2'-methylbutyl)-4'-(omega-hydroxyhexyl) azobenzene , which was melted at 128 degrees C and is not a liquid crystal, it is a good liquid crystal material with Sc* phase.

含SC相硅碳烷树枝状分子液晶

树枝状化合物具有规整的结构，其分子体积、形状和功能基可在分子水平上精确控制［１］．它的出现对于经典的有机高分子界是一个冲击，它是化学、生命科学和材料科学等多学科的交叉点，成为当前学术界的一大研究热点．我国这方面的研究起步较晚，至今仅有陈永明［２］、薄…

高原鼢鼠挖掘活动的观察

本文通过自制高原鼢鼠挖掘行为观察箱，以直接观察法和摄录像系统观察了在模拟不同土壤坚实度条件下，高原鼢鼠的挖掘行为、掘土速度、掘土持续时间以及在每一掘土回合内的掘土量。结果表明，高原鼢鼠的掘洞活动主要由掘土、扒土、踢土、推土、以及拱土组成；掘土速度和掘土持续时间与土壤坚实度有关；在相同土壤条件下，虽然雄、雌鼢鼠的掘土速度相似，但雄性鼢鼠在每回合内的掘土量明显地高于雌鼠。

一种基于视觉的移动机器人定位系统

具有自主的全局定位能力是自主式移动机器人传感器系统的一项重要功能 .为了实现这个目的 ,国内外均在不断地研究发展各种定位传感器系统 .这里介绍了一种采用光学原理的全方位位置传感器系统 .该传感器系统由主动式路标、视觉传感器、图象采集与数据处理系统组成 .其视觉传感器和数据处理系统可安装在移动机器人上 ,然后可通过观测路标和视角定位的方法 ,计算出机器人在世界坐标系中的位置和方向 .实验证明 ,该系统可以实现机器人的在线定位 ,其采样速率和精度能够满足实用要求 .

Disparity Gradients and Depth Scaling

The binocular perception of shape and depth relations between objects can change considerably if the viewing direction is changed only by a small angle. We explored this effect psychophysically and found a strong depth reduction effect for large disparity gradients. The effect is found to be strongest for horizontally oriented stimuli, and stronger for line stimuli than for points. This depth scaling effect is discussed in a computational framework of stereo based on a Baysian approach which allows integration of information from different types of matching primitives weighted according to their robustness.

Explicit representation of subgrid heterogeneity in a GCM land-surface scheme

Essery, R L H, Best, M J, Betts, R A, Cox, P M & Taylor, C M, Explicit representation of subgrid heterogeneity in a GCM land-surface scheme. Journal of Hydrometeorology 4, pp 530-543 (2003).