铁电效应调控的高性能p-NiO/i-BaTiO_(3)/n-ITO自供能紫外光电探测器

近年来,自供能的紫外光电探测器由于无需任何外部偏压即可工作而成为军事和民用领域的研究热点。其中,钛酸钡(BTO)作为一种宽禁带铁电材料,拥有良好的铁电、压电和热电性能,可以产生本征自发极化场来分离光生载流子,从而实现自供能紫外光电探测。到目前为止,基于BTO的自供能光电探测器已经取得了巨大进展,然而,除了使用高质量的单晶材料外,所报道的器件往往表现出低响应度(10^(-8)~10^(-7) A·W^(-1))。本文利用低成本的射频溅射技术,制造了一种高性能的NiO/BTO/ITO p-i-n异质结构自供能紫外光电探测器。通过将BTO的铁电去极化场和p-i-n结的内建电场耦合,能有效提高光生载流子的分离和迁移。因此,该器件在正极化态下255 nm波长紫外光照射下的响应度可以达到3.4×10^(-5) A·W^(-1),远远高于其他已报道的基于非晶态和陶瓷BTO制备的紫外光电探测器。此外,该器件具有0.3 s/0.4 s的快速响应时间。本工作为提高BTO光电探测器的性能提供了一种新的策略。

LC-MS法测定艾瑞昔布中基因毒性杂质2,2-二氯-N,N二甲基乙酰胺

目的:建立LC-MS方法测定艾瑞昔布中潜在基因毒性杂质2,2-二氯-N,N二甲基乙酰胺含量。方法:色谱柱为Atlantis^(TM)T3(150 mm×4.6 mm,5μm),以乙腈-0.01%甲酸水溶液为流动相进行梯度洗脱,质谱检测器的离子源采用ESI源,采集方式为多反应检测扫描(MRM)。结果:2,2-二氯-N,N二甲基乙酰胺在0.505~60.6 ng/ml(LOQ~200%)范围内浓度与峰面积线性关系良好(r=0.9991,n=5),定量限浓度为0.505 ng/ml,检测限浓度为0.201 ng/ml,精密度RSD为0.78%,平均回收率为100.6%,RSD为0.53%,溶液稳定性及方法耐用性良好。结论:该方法专属性强,灵敏度高,适用于艾瑞昔布中2,2-二氯-N,N二甲基乙酰胺含量的测定。

S/N对硫化物型自养反硝化性能及NO-2-N积累的影响

以Na 2S为硫源,采用批次实验探究不同初始S/N(摩尔比)对硫化物自养反硝化性能及NO_(2)^(-)-N积累的影响。结果表明,当S/N≤2.80时,NO_(3)^(-)-N及NO-X-N(NO_(2)^(-)-N+NO_(3)^(-)-N)去除效果随S/N的升高而显著提升,S/N由0.35升高到2.80时,前6 h内NO_(3)^(-)-N及NO-X-N去除率分别提高了3.7倍及3.6倍,当S/N继续增至4.20时,NO_(3)^(-)-N及NO-X-N去除效果较S/N为2.80时变化不大;当S/N≤0.70时系统内可以获得一定的NO_(2)^(-)-N积累,反应结束时NO_(2)^(-)-N积累率(0.35,0.7)分别可达47.9%及24.5%,当S/N≥1.40时难以稳定积累NO_(2)^(-)-N,NO_(2)^(-)-N最高积累率(1.40,2.80,4.20)分别为55.0%,33.3%,39.7%。S/N≤0.70时可获得一定的NO_(2)^(-)-N积累,而S/N在1.40~2.80范围内时,升高S/N可以提供更多电子用于反硝化,缓解各种反硝化酶对于电子的竞争,降低中间产物积累,提升脱氮效果。

多孔状Ni-NiO/CdS催化剂的制备及其光催化性能研究

该文以Ni泡沫为Ni源,经不完全氧化得到Ni-NiO,然后通过一锅法水浴合成了一种多孔结构的Ni-NiO/CdS光催化剂.利用SEM、XRD、XPS和BET等表征手段对光催化剂的微观形貌和结构以及表面成分和组成进行了全方位表征,并以光诱导裂解水制氢气的实验对催化剂的光催化活性进行评价.研究了Ni-NiO与CdS的比例和不同硫源对Ni-NiO/CdS光催化剂催化性能的影响.实验结果表明:Ni-NiO/CdS的光催化析氢速率高达19 947.9μmol·h^(-1)·g^(-1),是纯CdS的近8倍,量子效率高达32.6%.这是由于CdS和NiO形成p-n异质结和Ni~0/Ni^(2+)电子对的存在,明显提高载流子分离效率,从而提高了其光催化活性.

Magneto-volume effect in Fe_(n)Ti_(13-n)clusters during thermal expansion

Ab initio molecular dynamics calculations have been carried out to search for the ground state structure of Fe_(n)Ti_(13-n)clusters and measure the thermal expansion of Fe_(n)Ti_(13-n).The volume of Fe_(n)Ti_(13-n)clusters during thermal expansion is jointly determined by anharmonic interaction and magneto-volume effect.It has been found that Fe_(6)Ti_(7),Fe_9Ti_(4),Fe_(11)Ti_(2),and Fe_(13)clusters can exhibit the remarkable magneto-volume effect with abnormal volume behaviors and magnetic moment behaviors during thermal expansion.A prerequisite for the magneto-volume effect of Fe_(n)Ti_(13-n)clusters during thermal expansion has been revealed and the magnitude of the magneto-volume is also approximately determined.Furthermore,the magneto-volume behaviors of Fe_(n)Ti_(13-n)clusters are qualitatively characterized by the energy contour map.Our results shed light on the mechanism of the magneto-volume effect in Fe_(n)Ti_(13-n)clusters during thermal expansion,which can guide the design of nanomaterials with zero expansion or even controllable expansion properties.

Cortactin/N-cadherin信号轴在病理性心肌肥大中的作用

目的探究皮层肌动蛋白结合蛋白(Cortactin)对异丙肾上腺素(isoprenaline,ISO)诱导的病理性心肌肥大的调控作用及其机制。方法采用ISO刺激新生大鼠心肌细胞(neonatal rat cardiomyocytes,NRCMs)24 h,在细胞水平建立心肌肥大模型;C57BL/6小鼠皮下注射ISO 1周,在动物水平建立心肌肥大模型。采用RT-qPCR检测mRNA的变化;免疫印迹法检测相应蛋白含量的变化;免疫荧光法检测Cortactin的亚细胞定位及表达量的变化;采用腺病毒感染的方法过表达Cortactin,通过转染小干扰RNA敲低Cortactin。结果在细胞和动物水平上,成功建立ISO诱导的心肌肥大模型,均观察到ISO引起Cortactin和N型钙黏连蛋白(N-cadherin)水平降低;过表达Cortactin可逆转ISO导致的N-cadherin蛋白水平的降低及心肌细胞肥大反应;敲低Cortactin则显示相反的效应。结论Cortactin可能联合N-cadherin通过增强心肌细胞之间的连接,发挥抗心肌肥大的作用。

Visualizing light-to-electricity conversion process in InGaN/GaN multi-quantum wells with a p-n junction

Absorption and carrier transport behavior plays an important role in the light-to-electricity conversion process, which is difficult to characterize. Here we develop a method to visualize such a conversion process in the InGaN/GaN multiquantum wells embedded in a p-n junction. Under non-resonant absorption conditions, a photocurrent was generated and the photoluminescence intensity decayed by more than 70% when the p-n junction out-circuit was switched from open to short. However, when the excitation photon energy decreased to the resonant absorption edge, the photocurrent dropped drastically and the photoluminescence under open and short circuit conditions showed similar intensity. These results indicate that the escaping of the photo-generated carriers from the quantum wells is closely related to the excitation photon energy.

Thin Film of Perovskite Oxide with Atomic Scale p-n Junctions

Thin films of perovskite manganese oxide Lao.66Ca0.29K0.05MnO3（LCKMO） on Au/ITO（ITO=indium tin oxide） substrates were prepared by off-axis radio frequency magnetron sputtering and characterized by X-ray diffrac- tion（XRD）, high-resolution transmission electron microscopy（HRTEM）, and conductive atomic force microscopy （C-AFM） at room temperature. The thin films with thickness ranged from 100 nm to 300 nm basically show cubic structures with a=0.3886 nm, the same as that of the raw material used, but the structures are highly modulated. C-AFM results revealed that the atomic scale p-n junction feature of the thin films was the same as that of the single crystals. The preparation of the thin films thus further confirms the possibility of their application extending from micrometer-sized single crystals to macroscopic thin film.

Research on high-voltage 4H-SiC P-i-N diode with planar edge junction termination techniques

The planar edge termination techniques of junction termination extension （JTE） and offset field plates and fieldlimiting rings for the 4H-SiC P i-N diode were investigated and optimized by using a two-dimensional device simulator ISE-TCAD10.0. By experimental verification, a good consistency between simulation and experiment can be observed. The results show that the reverse breakdown voltage for the 4H-SiC P-i-N diode with optimized JTE edge termination can accomplish near ideal breakdown voltage and much lower leakage current. The breakdown voltage can be near 1650 V, which achieves more than 90 percent of ideal parallel plane junction breakdown voltage and the leakage current density can be near 3 ×10^-5 A/cm2.

p-Si/n-Ga_(2)O_(3)异质结制备与特性研究

本实验采用金属有机化学气相沉积(MOCVD)工艺,在p(111)型Si衬底上制备了p-Si/n-Ga_(2)O_(3)结构的PN结。通过X射线衍射仪、原子力显微镜等对样品进行了晶体结构、表面形貌、表面粗糙度等的表征分析;通过磁控溅射与蒸镀方法在样品上生长Ti/Au电极并进行I-V特性曲线、开启电压、开关电流比、反向饱和电流、理想因子、零偏压下的势垒高度等结特性测试,研究了掺杂浓度与薄膜厚度对PN结特性的影响,并对其原因进行了分析;通过二步生长法和缓冲层温度优化实验,减少了Si衬底与β-Ga_(2)O_(3)之间的晶格失配与热失配带来的影响,对薄膜与器件特性进行了优化。最终获得了表面粗糙度最低可达到4.21 nm的高质量n型β-Ga_(2)O_(3)薄膜,以及具有较低理想因子(42.1)的PN结。

A Comparative Analysis of the New -3(-n) - 1 Remer Conjecture and a Proof of the 3n + 1 Collatz Conjecture

This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.

Study on Porous Silicon with P-N Junction Sensor for Humidity Measurement

Porous materials used for humidity sensing have been commercialized.In this paper,the preparation and humidity sensing characteristics of porous silicon with P-N junctions (PNJPS)are studied.PNJPS is made by electro-chemical anodic etched method from silicon wafers with P-N junctions.Its porous structure is verified by scanning electronic micrograph. Experiments also show that PNJPS has high sensitivity,short response time (less than 30 seconds),and long-term stability.

Analyses and Simulation of V-I Characteristics for Solar Cells Based on P-N Junction

Through theoretical analyses of the Shockley equation and the difference between a practical P-N junction and its ideal model, the mathematical models of P-N junction and solar cells had been obtained. With Matlab software, the V-I characteristics of diodes and solar cells were simulated, and a computer simulation model of the solar cells based on P-N junction was also established. Based on the simulation model, the influences of solar cell’s internal resistances on open-circuit voltage and short-circuit current under certain illumination were numerically analyzed and solved. The simulation results showed that the equivalent series resistance and shunt resistance could strongly affect the V-I characteristics of solar cell, but their influence styles were different.

The Effect of Light on the CVC of Strained p-n-Junction in a Strong Microwave Field

For the first time the effect of light on the CVC of strained p-n-junction in a strong microwave field is examined. It is shown that the deformation and the microwave field increase the current through p-n-junction, and the light decreases it. The mechanism of this phenomenon is explained by the fact that under heating of the charge carriers by microwave field the recombination current arises, and under the action of light the generation current arises which are directed oppositely. And under the influence of the deformation the band gap of the semiconductor will be changed.

EMF of Hot Charge Carriers Arising at the p-n-Junction under the Influence of the Microwave Field and Light

It is shown that the increase in the current of an asymmetric p-n-junction, caused by perturbation of potential barrier height and increasing recombination current in a strong microwave field, is suppressed by light generated photo carriers, leading to the displacement of current-voltage characteristics of p-n-junction into the direction of smaller current values.

The Nonideality Coefficient of Current-Voltage Characteristics for Asymmetric p-n-Junctions in a Microwave Field

It is shown that the nonideality coefficient m actually depends on the electron temperature Te, and the hole temperature Th. We get more general expression for the nonideality coefficient, taking into account the concentration of electrons and holes, as well as their temperature, coefficient and diffusion length, the temperature of the phonons, the applied voltage, and the height of the potential barrier.

Influence of Deformation on CVC p-n-Junction in a Strong Microwave Field

This paper investigates the current-voltage characteristics (CVC) strain of p-n-junction in a strong microwave (MW) field and shows that the deformation increases the current generated in the p-n-junction. We analyze the current-voltage characteristics of p-n-junction in which three-dimensional space (I,U,e) gives more complete information than the two-dimensional.

硅p-n结太阳电池对DF激光的响应

对硅p n结太阳电池在DF激光辐照下的响应进行了理论和实验研究。推导了p n结反向饱和电流随温度的近似变化关系。根据该近似关系,计算了太阳电池在DF激光辐照过程中输出电压的变化曲线。计算结果和实验结果之间取得了比较好的一致性。

土壤温度、水分和NH_4^+-N浓度对土壤硝化反应速度及N_2O排放的影响

硝化反应是土壤、特别是干旱半干旱地区农业土壤N2O产生的重要途径之一。但是,目前环境条件对硝化反应中N2O排放的影响研究较少,而在国内外通用的几个模型中均用固定比例估算硝化反应过程中N2O的排放。本文通过砂壤土培养试验,研究了土壤温度、水分和NH4+-N浓度对硝化反应速度及硝化反应中N2O排放的影响,并用数学模型定量表示了各因素对硝化反应的作用,用最小二乘法最优拟合求得该土壤的最大硝化反应速度及N2O最大排放比例。结果表明,随着温度升高,硝化反应速度呈指数增长;水分含量由20%充水孔隙度(WFPS)增加到40%WFPS时,反应速度增加,水分含量增加到60%WFPS时反应速度略有降低;NH4+-N浓度增加对硝化反应速度起抑制作用。用米氏方程描述该土壤的硝化反应过程,其最大硝化反应速度为6.67mg·kg?1·d?1。硝化反应中N2O排放比例随温度升高而降低;随NH4+-N浓度增加而略有增加;20%和40%WFPS水分含量时,硝化反应中N2O排放比例为0.43%～1.50%,最小二乘法求得的最大比例为3.03%,60%WFPS时可能由于反硝化作用,N2O排放比例急剧增加,还需进一步研究水分对硝化反应中N2O排放的影响。