减阻沟槽边界层相干结构展向拓扑的分层可视化

采用高时间分辨率粒子图像测速系统(TR-PIV),分别对沟槽壁面及光滑壁面平板湍流边界层速度矢量场的时间序列进行了精细测量,并利用新象限分裂法及新条件采样与相位平均技术,在李山等人对数区结果的基础上,对光滑壁面和沟槽面湍流边界层近壁区及外区相干结构二维空间拓扑的形态进行了进一步地对比研究。结果表明:在近壁区和对数区内,与光滑壁面相比,不论喷射事件还是扫掠事件,减阻沟槽使得相干结构法向脉动强度降低最为明显,即相干结构在法向上的动量和能量交换减弱,削弱了其对湍流产生的贡献;而进入外区以后,减阻沟槽对法向脉动速度分量和展向涡量在喷射和扫掠过程中影响比内区要小,说明沟槽主要影响湍流边界层内区结构,且以..

Electroless Copper Deposition Using Sodium Hypophosphite as Reductant

研究了以次磷酸钠为还原剂、硫酸镍为再活化剂的化学镀铜工艺和镀层结构,指出工艺的基本特性。结果表明,在含有次磷酸钠和硫酸镍的镀液中,化学镀铜过程可以持续进行并呈现自催化特性;只有在合适的镀液pH范围内才可获得铜镀层;铜镀层为面心立方结构,没有明显的晶面择优取向现象,镀层结构的晶面间距d和晶胞参数a与标准Cu粉末的相比均较大,说明铜镀层仍存在应力和缺陷。The primary characterstics for the process of electroless copper deposition, using sodium hypophosphite as reducing agent and nickel sulfate as re-activation agent, and the deposit structure were studied. The results showed that in the solution containing sodium hypophosphite and nickel sulfate the copper deposition was sustainable and was presented in self-catalyzation. The deposit could only be obtained in a proper pH range. The deposit was in face-centered cubic structure without obvious crystal face preferred orientation. Its lattice distanced and lattice parameter a were larger than those of standard copper powder, which indicated that the obtained deposit was still present internal stress and defects

Current Efficiency and Deposit Microhardness of Nickel-Tungsten Alloy Electrodeposition

通过调节镀液中不同的 nI/ W 比例、温度和沉积电流密度，研究在焦磷酸盐体系中镍钨合金电沉积的电流效率、沉积层组成和显微硬度。实验结果表明：合金共沉积的电流效率不高。为了尽量提高合金的沉积电流效率，主要途径宜增大镀液中硫酸镍和钨酸钠的浓度；提高合金沉积电流密度，降低镀液中［ nI］/［ W］ 比例，则镀层中的钨含量增大；合金沉积层的显微硬度随镀层中的 W 含量提高而增大。Current efficiency, deposit composition and microhardness of nickel-tungsten alloy electrodeposition in pyrophosphorus bath were studied by adjusting Ni/W ratio in plating solution, temperature and deposition current density.The results showed that the current efficiency of the alloy codeposition was not high.For the purpose to raise current efficiency as far as possible the suitable solution was to increase the concentration of nickel sulfate and sodium tungstate in the bath, Tungsten content in the alloy deposit can be increased by raising electrodeposition current density and decreasing [Ni]/[W] ratio in the plating solution.The microhardness of the alloy deposit increases with the raise of tungsten content in the deposit.国家自然科学基

New Process of Palladium Electroplating Form Potassium Citrate Bath

研究在柠檬酸钾和草酸铵镀液体系中镀钯工艺。结果表明，采用本实验室研制的添加剂XP-4和XP-7以及PPS和ff，则可在电流密度0.5~3.5A/dM2、温度40~60℃的宽范围内获得全光亮的钯电沉积层。钯沉积的电流效率和沉积速度在镀液中钯含量为10g/l、1.0A/dM2的条件下分别可达到92.0%和0.25μM/MIn，并随电流密度和镀液中钯含量的变化而改变。XP-4和XP-7均阻化钯的电沉积，提高钯电沉积的过电位。它们共存时可使把电沉积的电位负移达240MV。Process of Pd plating From system of potassium citrate and ammonium oxalate is investigated.Results show, with additives of XP-4, XP-7, PPS and FF prepared in our laboratory, Full bright Pd electrodeposit can be obtained in wide range of 0.5-3.5 A/dm2 and 4a-60℃ and at 1.0 A/dm2 and Pd 10 g/L contg in bath, current eFFiciency and deposition rate are 92.0% and 0.25μm/min respectively,which will be changed with change of c.d.and Pd content in bath.Both XP-4 and XP-7 inhibit Pd electrodeposition and cause increase of deposition overpotential.Their co existence can make Pd electrodeposition potential shiFt to negative value, up to 240mV

用近红外光学漫射成象方法观测语义编码在前额叶的响应

本文彩和近红外光学漫射成象技术成功观测了左右前额区在知觉与语义编码中的活动。发现大脑在完成耻述两任务时，左前额的活动显著地强于右前额，语义加工引起的活动显著地强于知觉加工，对于每一侧而言，与浅加工相比，深加工时的活动主要集中在下前额叶。上述结果进上步主宰了有额叶在语义加工中的作用

汶川大地震影响下唐山市民心理和谐状况调查分析

本文采用中科院心理所提供的《民众心理和谐量表》对唐山317位市民进行了调查。唐山市民的心理和谐平均分为3.75,与全国民众平均水平相比,唐山市民的自我状态、人际关系,尤其是家庭氛围的和谐程度高一些(P<0.05),而社会态度明显低于全国水平(P<0.01)。进而得出结论:汶川地震对唐山人们的心理和谐造成了一定影响,主要体现在社会态度方面

基于欧拉方法的减阻沟槽壁面湍流涡结构的辨识

基于欧拉方法,使用准则和准则,旨在对减阻沟槽壁面湍流涡结构进行辨识,分析减阻沟槽壁面边界层内瞬时涡结构的分布及演化规律;并采用线性随机估计方法进一步讨论涡包结构的时空统计特征,进而从沟槽对壁面涡结构影响的角度分析其减阻的物理机理

Effect of self consistency and congruence and self-confidence on time management disposition among medical students

目的探讨某医学院校本科生自我和谐和自信心对时间管理倾向的影响。方法采用自我和谐、自信心和时间管理倾向问卷的形式对某医学院在校208名本科生进行调查。结果①医学院校本科生的时间管理倾向与其自信心和自我灵活性呈显著正相关,同自我和谐总分和自我经验与不和谐分数呈显著负相关。②医学院校大学生的自信心和自我灵活性能够预测时间管理倾向29.5%的变异量。结论医学院校大学生的自我和谐和自信心对医学院校大学生的时间管理倾向具有预测作用

Composition, Structure and Morphology of Ph-Zn Alloy Electrodeposit

采用X-射线衍射（Xrd）、金相显微镜技术及电化学方法研究了铅锌合金电沉积层和zn经阳极溶出后的镀层结构、组成和表面形态。结果表明，Pb-zn合金电沉积层不能形成固溶体。Xrd图仅出现与铅面心立方结构以及与锌密集六方结构相对应的各品面衍射线，其中较低Pb含量的Pb-zn合金中Pb基本上为无序取向的晶体，而zn则为（002）晶面择优，但择优度不高。沉积层经控电位阳极溶出后，其Xrd图仍存在铅晶体的各晶面衍射线，而锌晶休各晶面衍射线消失；同时也出现表征正棱形PbSO4晶体的各晶面衍射线。金相实验结果表明：铅锌电沉积层表面由排列整齐的棱锥状晶粒构成；随镀层中zn含量的增大，沉积层表面逐渐平整，棱锥状晶粒变小，最终形成团粒状态。锌溶出后的铅晶电极表面由原来的凹凸不平变成平整，且晶粒显著细小。The Composition, structure and morphology of Pb-Zn alloy electrodeposit and the one in which zinc was anodically dissolved were investigated by XRD and OM.The experimental results showed that the Pb-Zn alloy deposit could not be formed in solid solution.There were only diffraction peaks of different crystal planes corresponding to lead FCC and zinc HCP structures.Lead crystals in Pb-Zn alloy with lower Pb content were mainly with random orientation, whereas zinc crystals were with (002) plane preferred orientation.After the deposits were anodically dissolved, the diffraction peaks of lead crystals still existed but that of zinc crystals disappeared, and the diffraction peaks of orthorhombic PbSO.crystals emerged instead.PbZn alloy deposits consisted of taper grains in a regular but tough arrangement.As the zinc content increased the surfaces of deposits gradually become smooth, the taper grains smaller and in granular groups.福建省自然科学基