细胞膜电穿孔及其肿瘤治疗的研究

电穿孔是在脉冲电场作用下细胞膜暂时出现微孔的物理过程 ,其结果是细胞内外分子交换显著增加 ,有利于细胞吸收各种药物、基因物质、蛋白质和其它大分子等。电场取消后微孔关闭而不会对细胞造成任何影响。电穿孔对于研究脉冲电场作用下细胞的结构和功能有重大意义 ,这种瞬时可逆的膜渗透性增强大大促进了化疗药物的跨膜运送 ,有效地提高了其杀伤力 ,为肿瘤的综合治疗提供了一种新思路     

配电网过电压在线监测系统的设计与实现

介绍了用于10kV配电网大气过电压和内过电压在线监测系统的设计与实现,分析了用于过电压信号采集的阻容分压器的性能和数据采集、波形分析软件、保护措施等关键技术。通过现场监测的结果分析表明,论文方法取得了较满意的效果,为电力系统的事故分析提供了科学依据。     

Synthesis of ZnS Nanoflowers by Composite-Hydroxide-Mediated Approach

Zinc sulfide nanoflowers are synthesized by the composite-hydroxide-mediated (CHM) method, using molten composite hydroxides as a reaction solvent, sodium sulfide and zinc nitrate hexahydrate as reactants at temperature of 200?°C in the absence of organic dispersant or capping agents. The XRD spectrum of the as-synthesized sample indicates a cubic ZnS with lattice group \(F\bar{4}3m[216]\) and lattice constant a=5.318 Å. The scan electron microscopy and transmission electron microscopy display its good crystallization and flower shape with diameter of 800–1000 nm. The photoluminescence results reveal that the ZnS nanocrystal has a band gap of 3.4 eV. The strong blue emission centered at 440 nm demonstrates the existence of defect states. This CHM approach provides a useful route for the synthesis of ZnS crystals, which may be extended to synthesize other II–VI semiconductors.     

Morphology and phase selective synthesis of CuxO (x = 1, 2) nanostructures and their catalytic degradation activity

Cu_xO (x = 1, 2) nanocrystals have been synthesized by the composite-hydroxide-mediated approach. The obtained nanocrystals were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV–vis spectrum. The morphology of the nanocrystals changed from sphere-shaped nanostructures to flower-shaped nanostructures, and finally to nanowires associated with phase transformation from CuO to Cu₂O by increasing the temperature. The possible phase transformation mechanism was discussed. The catalytic degradation activity of the Cu_xO (x = 1, 2) nanocrystals to methyl orange was also investigated. The photocatalytic ability of the sphere-shaped nanostructures is much higher than that of the nanowires, owing to its absorption of wider range of light energy. This work provides a new facile synthesis route of Cu_xO (x = 1, 2) nanocrystals and suggests their possible application in organic pollutants removal.     

Fe-C-Ti机械合金化粉末的电子显微试样制备及分析

论述了用扫描电镜和透射电镜研究Fe-C-Ti机械合金化粉末的制样方法,分析了该合金粉末的形态和组织结构。结果指出,合金粉末的尺寸随球磨时间增加先增大后减小,其形态由球形先变为纺锤形,后又成为球形。将最终得到的复合粉末进行真空热处理,TiC弥散析出,而且层间界面处的TiC尺寸较大。     

放电电压对镁-铝磁脉冲焊接中金属射流及结合界面的影响

近年来,磁脉冲焊接技术凭借其在异种金属焊接中的独特优势展现出广阔的应用前景.放电电压是磁脉冲焊接过程中重要的电气参数,而金属射流可清理工件表面的污秽和氧化层,促进金属的冶金结合.为探究放电电压对金属射流及结合界面的影响,该文对放电电压与金属射流特征、结合界面形貌之间的内在联系进行理论分析,并建立镁-铝磁脉冲焊接综合实验...     

纳米管场发射的电场计算

利用电磁场理论计算出单根纳米管场发射时其尖端附近的电势和电场分布。结果表明 ,纳米管尖端表面电场非常强 ,随着距离尖端表面的距离的增加 ,电场迅速下降 ;尖端附近的场强与纳米管场发射有低的阈值电压相符合。计算还给出在保持极板间距离和电压不变的情况下 ,纳米管长径比越大 ,尖端电场越强 ,因此 ,具有更低的阈值电压     

Remarkably Enhanced Charge Density of Inorganic Material Via Regulating Contact Barrier Difference and Charge Trapping for Triboelectric Nanogenerator

Currently, the research on improving charge density of charge-excitation triboelectric nanogenerators (CE-TENG) mainly focuses on surface modification and thinning of organic polymer materials. However, to increase durability and output, the exploration of high permittivity and high-thickness inorganic materials is important for extensive applications. Meanwhile, the physical mechanism of air ionization caused by air breakdown during secondary self-charge excitation (SSCE) needs to be explored. Herein, this study proposes a new strategy for CE-TENG based on inorganic materials by de-trapping reverse charge and increasing the contact barrier difference to obtain high charge density and achieve secondary self-charge excitation. SSCE of three types of films with different leakage currents are evaluated according to their trapping and de-trapping reverse charges. It is found that the trap distribution of dielectric films with larger leakage currents are mostly shallow-level traps, whose de-trapping ability becomes stronger after reverse charge injection. By regulating the contact barrier difference with thin organic polymer on thick inorganic high permittivity material, this study has achieved a high charge density of 1310 µC m⁻² with a fast start-up time of SSCE, which is a new record for the charge density of inorganic materials. This study promotes TENG of inorganic materials toward high-energy output applications.     

A Nanogenerator Enabled by a Perfect Combination and Synergetic Utilization of Triboelectrification,Charge Excitation and Electromagnetic Induction to Reach Efficient Energy Conversion

Triboelectric–electromagnetic hybridized nanogenerator (TEHG) is confirmed as an effective energy harvesting for Internet of Things. However, it is still a great challenge to gain a high-output triboelectric-nanogenerator (TENG) and to perfectly combine TENG with electromagnetic generator (EMG). Herein, a TEHG composed of space confined multi-layer-stack TENG (SM-TENG) and stack compression promoted flux change EMG is proposed. The interaction of magnets on the rotor with the magnets on the stator makes contact–separation of the SM-TENG and changes the magnetic flux of EMG in rotation process, reducing wear and deformation of TENG. A voltage multiplier circuit (VMC) with a Zener diode is employed to enhance SM-TENG performance and maintain stable output. The output charge and current of four SM-TENG units reach 3.2 µC and 385 µA at rotatory speed 60 rpm, and the voltage of four EMG reaches 8.09 V. The perfect combination and synergetic utilization of triboelectrification, charge excitation, and electromagnetic induction in a single device are realized. The integrated TEHG can power 12 bulbs (2 W) and 16 thermo-hygrometers, and a Bluetooth thermo-hygrometer to transmit wireless signals to a mobile phone. This work provides a new strategy for high efficient integration and utilization various mechanisms in one energy-harvesting device.     

损耗介质透镜实现皮秒脉冲电场在乳房组织模型中的聚焦

为实现ps脉冲电场(ps PEF)经冲激脉冲辐射天线(IRA)发射后在近似实际乳房组织(电导率为0.5 S/m)模型中的有效聚焦,采用计算机仿真技术(CST)Microwave studio软件构建了天线及乳房组织模型并计算了ps PEF在其中的聚焦特性。结果表明:引入优化参数的损耗介质材料(厚度为1 cm,电导率为10 S/m)衰减小路径角电场,最终能够实现ps PEF在焦点F2处的聚焦(电场强度E=0.08 V/m);损耗材料的引入使得焦点F2处的电场强度大大减小,引入损耗介质透镜,不仅实现了ps PEF在乳房组织模型中的良好聚焦,而且焦点F2处的电场强度(E=0.45 V/m)大大增强。因此,优化设计的损耗介质透镜能够实现ps PEF在生物组织中的有效聚焦。