基于先进生物材料的心肌细胞力——电微环境体外构建

心血管疾病是当前全球范围内导致人类死亡的首要原因, 心肌组织工程的发展为心血管疾病的治疗, 尤其是心肌组织再生修复提供了最有潜力的解决方案.心血管疾病的发生发展与细胞力--电微环境的变化密切相关. 近十几年, 随着先进生物材料和微纳生物制造技术的发展, 越来越多的研究表明, 细胞力--电微环境的调控对工程化心肌组织的成熟和功能化以及心肌组织再生修复具有重要意义. 本文首先阐明了在体心肌细胞所处力学微环境的生物学基础以及电信号的传导过程, 包括正常和疾病状态下心肌细胞所处的力--电微环境.其次调研了用于心肌组织工程的先进生物材料的研究现状.最后总结用于基底硬度与应力应变细胞微环境以及细胞电学微环境的构建和调控, 以及细胞对力--电微环境的生物学响应.%      

Zn基ZnO纳米线的水热合成及其光催化性能

以Zn片为基底和锌源,采用正丁胺-水热体系原位生长Zn基ZnO纳米线薄膜.薄膜的形貌、结构、比表面积及光谱性质采用X射线衍射仪(XRD)、场发射扫描电镜(FE-SEM)、比表面仪(BET)、荧光光谱仪(PL)及紫外-可见漫反射光谱仪(UV-Vis-DRS)进行分析,薄膜的光催化活性通过紫外光降解甲基橙来评价.结果表明,所生长的Zn基ZnO纳米线薄膜对甲基橙具有良好的光催化活性和循环使用性.水热生长12 h的ZnO样品因长径比大,致密度高,比表面积大,结构中的氧空位浓度高,光催化活性最高.     

高功率光子晶体光纤放大器内超短脉冲的放大传输特性

由速率方程和功率传输方程得到信号脉冲平均功率和增益系数随脉冲传输距离的变化关系.利用Ginzburg-landau方程,在信号脉冲功率的不断增强和增益系数的不断变化的情况下,研究超短脉冲的传输演化特性,发现信号脉冲平均功率、能量和增益系数等参量受到色散和非线性效应的影响相对较小,而信号脉冲的峰值功率、时域和频域特性则易受到色散和非线性效应的影响.探讨了在非线性作用下,脉冲分裂和展宽等所导致的脉宽不稳定性对传输特性的影响,表明研究脉冲传输问题时,引入脉宽不稳定性有利于提高数值模拟准确度.     

基于抑制作用的新型葡萄糖氧化酶传感器测定环境污染物汞离子的研究

本文提出了一种基于抑制作用的新型葡萄糖氧化酶生物传感器用于测定环境样品中二价汞离子。其工作原理是汞离子对电极上葡萄糖氧化酶分子的抑制作用引起响应电流的下降而产生一可测定信号。详细探讨了电极的氧化还原反应机理及测试性能。该传感器对汞离子的检出限是0．49ng／mL,抑制率和汞离子浓度的自然对数值在0．49～783．21ng／mL和783．21ng／mL-25．55μg／mL范围内分别呈良好的线性关系。酶电极在抑制后可以完全恢复活性。考察了铅(Ⅱ)、铜(Ⅱ)、镉(Ⅱ)和铬(Ⅲ)离子对汞离子测定的干扰。测定了汞离子在土壤浸出液中的回收率,结果良好。     

碳钢低压冷喷涂铝涂层的海水耐蚀性

本文以Al和10%体积比Al2O3的混合粉末为原料,使用便携式低压冷喷涂设备,在Q235碳钢基体上喷涂了Al涂层. 测试涂层自腐蚀电位及动电位极化曲线,结合扫描电镜观察涂层表面及截面微观形貌,研究了低压冷喷涂Al涂层在海水中电化学腐蚀行为,并与高压冷喷涂和热喷涂铝涂层的耐蚀性比较. 结果表明,低压冷喷涂铝涂层结构较为致密,其耐蚀性比高压冷喷涂铝涂层的略低,而明显优于热喷涂铝涂层.     

CrTiAlN涂层在800℃和900℃时对H13钢氧化性能的影响

为了提高H13钢的抗高温氧化能力,在H13钢表面沉积了一层CrTiAlN薄膜.采用XRD和SEM分析了H13钢氧化前后的相组成及其表、截面形貌.结果表明:涂层为柱状晶结构,主要有三部分组成:里层为Cr结合层,中间为CrN过渡层,外层是CrTiAlN梯度涂层.H13钢在氧化时,在其表面发生了Cr的选择性氧化,但是Cr含量低,未能形成连续的防护层,最终导致基体元素不断地氧化,生成了大量的α-Fe2O3颗粒.CrTiAlN涂层在800℃时具有良好的抗高温氧化性能,涂层氧化时主要是O向里扩散占优势,没有出现裂纹和剥落,而且观察到了“钉扎效应”.900℃时,涂层失效.     

Synthesis and characterization of p-type boron-doped IIb diamond large single crystals

High-quality p-type boron-doped IIb diamond large single crystals are successfully synthesized by the temperature gradient method in a china-type cubic anvil high-pressure apparatus at about 5.5 GPa and 1600 K.The morphologies and surface textures of the synthetic diamond crystals with different boron additive quantities are characterized by using an optical microscope and a scanning electron microscope respectively.The impurities of nitrogen and boron in diamonds are detected by micro Fourier transform infrared technique.The electrical properties including resistivities,Hall coefficients,Hall mobilities and carrier densities of the synthesized samples are measured by a four-point probe and the Hall effect method.The results show that large p-type boron-doped diamond single crystals with few nitrogen impurities have been synthesized.With the increase of quantity of additive boron,some high-index crystal faces such as {113} gradually disappear,and some stripes and triangle pits occur on the crystal surface.This work is helpful for the further research and application of boron-doped semiconductor diamond.     

利用同质异位素产额比提取对称能的近似方法

在修改的Fisher模型框架下, 利用同质异位素产额比和结合能方程中对称能系数与温度比率的关联, 可以提取对称能系数与温度的比值。 利用3种不同的近似方法得到了重离子核反应产生丰中子余核的对称能系数与温度比（a_sym/T）,并研究了相关物理量对a_sym/T的影响。结果表明, 库仑能对提取丰中子余核的a_sym/T影响较小,且参考核的选取对a_sym/T的提取也有一定的影响。 In the framework of the modified Fisher model, correlations between the symmetry energy coefficient in semi classical mass formula to temperature (a_sym/T) and the isobaric yield ratio in Heavy ion collisions are established. a_sym/Tof neutron rich fragments are extracted using these correlations. It is found that the Coulomb energy term has little effect on a_sym/T of fragments, while the reference isobars adopted have great influence on the extracted a sym/T of fragments.     

Influence of annealing treatment on as-grown Ib-type diamond crystal at a high temperature and high pressure

In this paper,we report on the influence of annealing treatment on as-grown Ib-type diamond crystal under high pressure and high temperature in a china-type cubic anvil high-pressure apparatus.Experiments are carried out at a pressure of 7.0 GPa and temperatures ranging from 1700 C to 1900 C for 1 h.Annealing treatment of the diamond crystal shows that the aggregation rate constant of nitrogen atoms in the as-grown Ib-type diamond crystal strongly depends on diamond morphology and annealing temperature.The aggregation rate constant of nitrogen remarkably increases with the increase of annealing temperature and its value in octahedral diamond is much higher than that in cubic diamond annealed at the same temperature.The colour of octahedral diamond crystal is obviously reduced from yellow to nearly colorless after annealing treatment for 1 h at 1900 C,which is induced by nitrogen aggregation in a diamond lattice.The extent of nitrogen aggregation in an annealed diamond could approach approximately 98% indicated from the infrared absorption spectra.The micro-Raman spectrum reveals that the annealing treatment can improve the crystalline quality of Ib-type diamond characterized by a half width at full maximum at first order Raman peak,and therefore the annealed diamond crystals exhibit nearly the same properties as the natural IaA-type diamond stones of high quality in the Raman measurements.     

CO_2跨临界循环耦合绝热吸收型两级溶液除湿系统性能分析

本文提出了CO_2跨临界循环耦合绝热吸收型两级溶液除湿系统,直接使用跨临界循环压缩机高温排气再生LiCl溶液,充分利用了跨临界循环排气温度高和温度滑移大的特点。本文使用LiCl溶液作为除湿剂,建立了复合系统的热力学模型,分析得到可用排热的温度滑移范围为120～50℃。耦合系统能够实现温湿度独立控制,跨临界循环的蒸发温度得到明显提高。一级除湿器除湿量占比与湿空气入口含湿量呈单调递增关系。一级除湿器进口LiCl溶液温度降低、浓度增大,能够提高溶液除湿循环的性能系数。耦合系统的可用排热与蒸发温度密切相关,存在一个临界蒸发温度使得可用排热满足系统再生需求。对比CO_2跨临界循环冷却除湿,在相同除湿量下,使用本文耦合系统进行除湿,跨临界循环的COP提高5.6%,压缩功减少29%。