氮对铬白口铸铁组织和性能的影响

了氮对含铬０．５－１５％白口铁组织和性能的影响，试验结果表明，向铁水中增氮能改善碳化物形态与分布，在低铬白口铸铁中，加氮能促使其共晶碳化物断网；在闹铬白口铸铁咖氮能促进其共晶碳化物由长条状向转告愉状转变在中铬白口铁中，加氮能促使其共晶碳化物由断网状分布向蠕虫状和团块状分布转化，且加氮还能强化铬白口铸铁基体，提高其冲击韧性和硬度，其韧性增幅最高可达５Ｊ／ｃｍ＾２以上，从加氮对铬白口铁的强韧化效果来看     

高血压模型大鼠脑病理新特点

从神经生物学的角度研究高血压模型大鼠脑病理新特点，以期揭示其病因，病变，病程的内在规律，使用硝酸还原酶反应－分光光度法，ELISA法分别测定不同时期脑NO，BDNF的含量，用免疫组织化学技术，在光学显微镜下观察GFAP在脑的分布，结果发现，实现组大鼠全脑星形胶质细胞反应性增生，尤其以海马，壳核，苍白球为重，特别是在胼胝星形胶质细胞密集增生，在侧脑室，第三脑室，第四脑室周形成密集分布的GFAP反应阳性星形胶质细胞带；实验组大鼠BDNF在术后15d显性升高，30d继续升高，45d，60d，75d，有所下降，但仍高于对照组，实验组大鼠NO，在术后15d急剧显性升高，30d有所回落，45d接近对照组，60d，75d显性降低于对照组，结果表明，高血压初期，脑处于相对缺血状态，危及神经细胞的正常功能活动甚至生存，胶质细胞反应性增生在起初是脑的一种保护性机制，增生的胶质细胞产生和释放大量的BDNF，以维护神经细胞的功能活动和存活，但在病程晚期，过量BDNF会启动神经细胞程序性死亡，高血压初期脑NO水平升高，其意义可能在于延缓病程发展。     

洛美沙星离子选择电极的制备与应用

研制了聚苯胺－ ＰＶＣ 膜全固态洛美沙星离子选择电极。该电极在（１ ×１０ － ２ ～３５ ×１０ － ５） ｍｏｌ／Ｌ 浓度范围内对洛美沙星呈能斯特响应, 斜率为２９２ ｍ Ｖ／ｐＬＦ, 检测下限为１３ ×１０ － ５ ｍｏｌ／Ｌ; 用于药物样品中洛美沙星含量测定结果满意, 方法简便快速。     

小穗苎麻素对乳腺癌细胞IκBα降解和NF-κB活化的影响

为探讨小穗苎麻素对乳腺癌MDA-MB231细胞中NF-κB活化的影响,从黄背苎麻中提取生物碱类单体小穗苎麻素,通过蛋白免疫印迹实验检测小穗苎麻素对IκBα磷酸化和降解的影响以及对p65的磷酸化和核转移的影响.结果显示：小穗苎麻素呈剂量依赖性抑制了TNF诱导的NF-κB报告基因的表达,同时抑制了乳腺癌MDA-MB231细胞中IκBα的磷酸化和降解,以及p65的磷酸化和核转移.这表明,小穗苎麻素通过抑制乳腺癌MDA-MB231细胞中IκBα的磷酸化和降解以及p65的磷酸化和核转移,进而抑制了NF-κB的活化.     

腔上囊活性肽(Bursin)免疫生物学特性的研究

以抗Bursin单抗2F9—4，用免疫组织化学的方法，检测Bursin在鸭初生雏(NH)及1至12用龄中根免疫器官(腔上囊、胸腺和管髓)中的定位分布。结果表明：Bursin阳性细胞在中根免疫器官中的分布与强度跟鸭体本身生长发育分化规律呈阶段相关。1至3用龄时，阳性细胞相对集中于类似生发中心的区域，髓质其它部分呈弥散状分布，6至8用龄阳性量强，偶见腺泡、腺管基底膜阳性细胞鱼贯排列，出现异常细胞核。10用龄后阳性强度锐减。尤其在腔上囊滤泡相关上皮(FAE)FAE支持细胞(FAESC)、滤泡间表面上皮(IFSE)(为单层或假复层上皮)、树突网状上皮细胞(DREC)、皮髓分界上皮(CME)和腔上囊T细胞弥散浸润区(TDIA)等区域，获得特征性阳性结果。     

周期性纳米结构光散射分布的模拟仿真

为得到离子束刻蚀蓝宝石所形成的周期性条纹状纳米结构光散射分布特性,采用有限元法多物理场建模与分析,运用射频模块,结合麦克斯韦电磁波理论,引用弗洛奎特周期性边界和端口激发条件,对一维周期性条纹状纳米结构的光散射场进行数值分析.研究结果表明:一维周期性条纹状纳米结构TE与TM波光散射场分布呈周期性;随入射角不断增大,散射场分布沿纵轴呈凸状逐渐增强,入射角达到π/5时,TE波呈圆斑状周期分布,TM波呈斜条纹状周期性分布;经过后处理可得同一入射角下不同级反射系数之和为定值.     

多节状SiC晶须的合成及在矿冶工程材料中的应用

运用ＴＥＭ、ＸＲＤ等分析检测技术对ＳｉＣｗ的形貌结构、长度与直径分布及其应用于复合材料中的特性进行了检测。研究表明：ＳｉＣｗ产品以直晶为主，表面呈多节状，以β－ＳｅＣ为主要晶型直径为０．２～１．５ｕｍ，长度为３０～２００ｕｍ。此外，作者对ＳｉＣｗ在矿冶工程材料中的应用进行了展望。     

SUS304不锈钢点焊接头的超声C扫描及力学性能研究

针对SUS304不锈钢点焊接头进行静力学和疲劳试验,采用三参数幂函数方法建立点焊接头的载荷-寿命曲线;采用超声扫描显微镜对接头点焊区域进行超声波C扫描成像,分析焊接电流对点焊熔核直径及抗拉强度的影响.结果表明:基于熔核C扫描图像的灰度值分布特征,可清晰甄别点焊接头熔核直径以及过烧、飞溅等熔核内部缺陷,实现点焊接头的无损检测;当焊接电流为8.5~10.5 k A时,点焊接头熔核直径从4.03 mm增至5.04 mm,接头抗拉强度呈先增大后减小的变化趋势,在焊接电流10.0 k A时,抗拉强度值出现拐点,接头最大抗拉强度为12.91 k N.在30%载荷水平时,点焊接头疲劳断裂形式为纽扣断裂;在20%和15%载荷水平时,基板呈眉状裂纹疲劳断裂.     

Al－45％Cu合金的熔剂净化与过冷

通过金属熔体过热与氯盐熔剂净化相结合，使Ａｌ－４．５％Ｃｕ合金在金属型锭模中获得了６２℃的形核过冷度．用形核理论对大体积Ａｌ－４．５％Ｃｕ合金极限热力学过冷度进行计算后发现其范围在７４Ｋ到１０７Ｋ之间．     

晶莹的海蜇

<正> 海蜇,为腔肠动物门、钵水母纲、根口水母目、根口水母科水面浮游动物。体呈淡蓝色,分伞与口腕两部。伞部高而厚,半球形馒头状,表面光滑,伞缘直径30-50厘米,大者可达1米。中胶层很发达、坚硬,是由蛋白质和粘多糖形成的凝胶。其中含胶原纤维有很大的弹性,能维持及调节离子的成分及浓度,使身体在海水中保持一定的浮力。中胶层有变形细胞,它对动物的再生和组织修复起重要作用。围绕下伞缘有由外胚层形成的环行肌肉,触手上有纵行肌肉,收缩时造成海蜇的运动。下伞中央的垂唇末端向外延伸形成8个口腕,具触手曩。口腕各有分歧,其上方有8对皱缩的肩板,呈弯刀状。口腕     

Mediation by calcium/calmodulin-dependent protein kinase Ⅱ of suppression of GABAA receptors by NMDA

Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on -aminobutyric acid (GABA)γ-activated whole-cell currents was investigated in neurons freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN). The results showed that: (i) NMDA suppressed GABA- and muscimol (Mus)-activated currents (IGABA and IMus), respectively in the Mg2+-free external solution containing 1 mol/L glycine at a holding potential (VH) of 40 mV in SDCN neurons. The selective NMDA receptor antagonist, D-2-amino-5-phosphonovaleric acid (APV, 100 mol/L), inhibited the NMDA-evoked currents and blocked the NMDA-induced suppression of IGABA; (ii) when the neurons were incubated in a Ca2+-free bath or pre-loaded with a membrane-permeable Ca2+ chelator, BAPTA AM (10 mol/L), the inhibitory effect of NMDA on IGABA disappeared. Cd2+ (10 mol/L) or La3+ (30 mol/L), the non-selective blockers of voltage-dependent calcium channels, did not affect the suppression of IGABA by NMDA application; (iii) the suppression of IGABA by NMDA was inhibited by KN-62, a calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitor. These results indicated that the inhibition of GABA response by NMDA is Ca2+-dependent and CaMKII is involved in the process of the Ca2+-dependent inhibition.     

大壁虎嗅球神经元在香蕉水气味作用下的放电模式

通过细胞外记录方法研究了大壁虎嗅球神经元在香蕉水气味作用下的放电模式。实验中共记录了21只大壁虎主嗅球上的275个神经元,其神经脉冲发放规律可以分为三类:无反应的神经元占43.6%,放电受到抑制的神经元占4.7%,而兴奋性神经元的比例达到51.7%。兴奋性神经元的放电模式又可以分为长时间持续兴奋(持续超过60s)、短时兴奋、延迟兴奋和取消时兴奋4种模式,分别占神经元总数的34.5%,6.25%,6.25%和4.7%,长时间持续兴奋占主导地位。这些神经元在嗅球上的分布范围很广,但在端部背侧和尾部腹侧的分布密度相对更高。本文工作为基于嗅觉的大壁虎运动干预中刺激位置和信号形态等关键参数的选取提供了基础信息。     

Pilot biomechanical design of biomaterials for artificial nucleus prosthesis using 3D finite-element modeling

Pilot biomechanical design of biomaterials for artificial nucleus prosthesis was carded out based on the 3D finite-element method. Two 3D models of lumbar intervertebral disc respectively with a real human nucleus and with the nucleus removed were developed and validated using published experimental and clinical data. Then the models with a stainless steel nucleus prosthesis implanted and with polymer nucleus prostheses of various properties implanted were used for the 3D finite-element biomechanicalanal ysis. All the above simulation and analysis were carried out for the L4/L5 disc under a human worst-daily compression load of 2000 N. The results show that the polymer materials with Young‘s modulus of elasticity E=0.1-100 MPa and Poisson‘s ratio v=-0.35-0.5 are suitable to produce artificial nucleus prosthesis in view of biomechanical consideration.     

大豆黄酮对衰老小鼠脑组织神经递质含量的调节

研究大豆黄酮对D–半乳糖致衰老小鼠脑神经递质水平的调节.连续背部注射D–半乳糖6周,建立衰老模型,然后灌胃大豆黄酮5周（实验组Ⅰ、Ⅱ的剂量分别为5、10 mg/（kg.d））,监测不同脑区乙酰胆碱、乙酰胆碱酯酶、多巴胺和5–羟色胺含量变化,探讨大豆黄酮对衰老小鼠脑组织神经递质水平的影响.结果表明,灌胃衰老小鼠大豆黄酮后,大脑皮质和海马中乙酰胆碱、乙酰胆碱酯酶、多巴胺和5–羟色胺含量明显上升,并且具有一定的剂量效应.说明大豆黄酮可以改善衰老小鼠脑组织中神经递质含量,具有明显的抗衰老作用.     

基于图像处理的小麦品种分类研究

籽粒的外观特征是区别不同小麦品种的重要标志,对小麦的选育工作具有重要的参考价值.首先采用中值滤波和迭代式阈值法对采集到的4类小麦共468粒样本图像进行处理和分割;然后针对每类小麦,提取了其6个颜色特征、5个形态特征和5个纹理特征等共16个参数;最后通过构建神经网络比较了仅使用颜色和形态特征作为网络输入以及3类特征共同作用时的分类效果.试验结果表明:仅使用颜色、形态两方面的11个特征参数时,小麦样本的识别率为87.6%;当增加5个纹理特征时,样本的识别准确率达到93.13%,可有效识别出4类小麦样本.     

Effect of the coordinated reset stimulations on controlling absence seizure

Based on a macroscopic mean-field model associating with the thalamus and cerebral cortex, we investigate how the newly proposed coordinated reset stimulation (CRS) strategy controls the absence seizures as some key parameters are changed. Different from the previous stimulation processes, CRS represents the intermittent pulse current administered to different structures including cortex, specific relay nuclei (SRN) and thalamus reticular nucleus (TRN) at different time by using three different micro-electrodes. In particular, we first simulate a typical absence epilepsy activity under the combined effect of the coupling strength between inhibitory interneurons (IIN)-excitatory pyramidal neurons (EPN) and EPN-TRN pathway. And then we explore the control mechanism of different parameters of 3:2 ON-OFF CRS on spike and slow-wave discharges (SWDs) region. Through analyzing the corresponding two-dimensional bifurcation diagrams, we find CRS is effective on controlling absence seizures in proper ranges of stimulation parameters. Especially, the combination of frequency and positive input duration can inhibit the pathological area more effectively. The obtained results might be helpful to study the pathophysiology mechanism of epilepsy, although the CRS’s feasibility still needs further exploration in clinical experiments.     

吊拉组合索桥的模型建立与初始索力确定

分析了吊拉组合索桥的结构特性后，根据组合索桥损伤检测的需要，利用大型通用有限元软件ANSYS，建立2种吊拉组合索桥动、静力有限元模型：鱼脊式模型和完整型模型．通过对两种有限元模型进行分析比较，指出鱼脊式模型概念比较清晰、直观，结构的刚度和质量处理精确；完整型模型能很好模拟主梁的扭转刚度，局部受力分析更精确．最后结合其施工过程提出确定成桥状态的初始索力的计算方法。通过计算分析发现。施工时悬吊部分主梁配重卸载后，斜索初始索力将发生重分布。跨中斜索索力有所下降，而边跨斜索索力有所上升．     

有机组分二次离子质谱特征及其裂解机理

二次离子质谱(SIMS)技术近年来被广泛用于分析煤和油气烃源岩有机组分化学成分和结构特征。在介绍SIMS质谱图解析方法的基础上,分析了有机组分二次离子组成特征; 在综合研究有机组分SIMS 质谱图特征的基础上,应用化学动力学原理对有机组分SIMS 质谱裂解机理进行了探讨。结果表明:有机组分以芳香核为基本结构单元,且含有杂环并带有多种含氧基团和支链; 有机组分SIMS 质谱裂解由其复杂大分子结构中烷基苯不同化学键的解离能大小决定的; 有机质结构中α碳和β碳之间的α—β键和支链碳的C—C键解离能最弱,有机化学结构中的α—β键和支链碳的C—C键容易断裂; 与苯环相连支链中,(C₆H₅)CH₂—C₂H₅结构中的α—β键和支链碳的C—C键容易断裂而形成(C₆H₅)CH⁺₂(91)、C₂H⁺₅(29)和CH⁺₃(15)等碎片离子,这也是有机组分SIMS质谱图中最主要的碎片离子峰。     

Statistical analysis of one Chinese sun-synchronous satellite anomalies

Based on the data from the Medium-Energy Proton and Electron Detector(MEPED)onboard NOAA-17,141 anomalies of a Chinese Sun-Synchronous satellite(SSO-X)that occurred between 02/01/2010 and 09/31/2012 were studied statistically.About 26 out of the 52 anomalies that occurred outside the South Atlantic Anomaly(SAA)were accompanied by energetic electron storms.Superposed Epoch Analysis(SEA)was used to analyze the properties of the anomalies and the dynamics of the space environments during these 26 events.Then,a Monte Carlo method was utilized to simulate the electron deposition and the interactions of the injected electrons with an aluminum shield and polyethylene dielectric.The average,median,and75th percentile values of the maximum electric field strength inside the dielectric were calculated.The results showed the following.(1)SSO-X anomalies are more likely to occur within the SAA,as 89 out of 141 anomalies(63%)occurred there.(2)Twenty-six of the anomalies that occurred outside the SAA during energetic electron storms were located near the outer boundaries of the outer radiation belts,and these were more frequent in the Southern Hemisphere than in the Northern Hemisphere.(3)Electron flux enhancements occurred around the failure time at all energy levels but were more profound in the lower energy channels.The maximum fluxes of electrons30 ke V,100 ke V,and300 ke V were 106,3.5×10~5,and 1.2×10~6cm~(-2) s~(-1)sr~(-1),respectively.(4)The average,median,and 75th percentile values of the maximum electric field strengths inside the dielectric for the aforementioned 26 events remained in the range from 10~6 to 10~7 V/m for long time periods,which suggests that the‘potential hazards’of internal discharges cause SSO-X anomalies.The above results can provide useful information for the design and protection of sun-synchronous spacecraft.     

98Sr核的X(5)动力学对称性描述

采用最近提出的一种新的动力学对称X(5)及现有的实验数据对Sr同位素核，特别是^98Sr核的低能正宇称态的能谱和电磁跃迁进行了分析研究，计算的结果和实验数据符合得很好，研究也表明，^98Sr核的低能态具有X(5)动力学对称的特性，即^98Sr核可能是1个X(5)核。