H等离子体处理对Si中He注入空腔引起的效应

室温下分别采用40,160和1550 keV的He离子注入单晶Si样品到相同的剂量5×10¹⁶cm^-2,部分经He注入过的样品然后再分别接受高密度H等离子体处理.利用透射电子显微镜分析比较了随后800°C高温退火引起的空腔形成.结果表明,附加的H等离子体处理对空腔生长所产生的效应明显地依赖于He离子的能量.对于40 keV He离子注入,空腔的形成和热生长似乎不受H等离子体处理的影响,而对于160 keV He离子注入,附加的等离子体处理则促进了空腔的生长并伴随着空腔分布区域的变窄.对于1550keV He离子注入,H等离子体处理对空腔产生的效应介于40和160 keV注入情况之间.结合H等离子体处理在Si中所引起的缺陷的产生及其热演变过程对实验结果进行了讨论.     

Transport of surface-modified iron nanoparticle in porous media and application to arsenic(III) remediation

The surface-modified iron nanoparticles (S-INP) were synthesized, characterized and tested for the remediation of arsenite (As(III)), a well known toxic groundwater contaminant of concern. The S-INP material was fully dispersed in the aqueous phase with a particle size distribution of 2–10 nm estimated from high-resolution transmission electron microscopy (HR-TEM). X-ray photoelectron spectroscopy (XPS) revealed that an Fe(III) oxide surface film was present on S-INP in addition to the bulk zero-valent Fe⁰ oxidation state. Transport of S-INP through porous media packed in 10 cm length column showed particle breakthroughs of 22.1, 47.4 and 60 pore volumes in glass beads, unbaked sand, and baked sand, respectively. Un-modified INP was immobile and aggregated on porous media surfaces in the column inlet area. Results using S-INP pretreated 10 cm sand-packed columns containing ∼2 g of S-INP showed that 100 % of As(III) was removed from influent solutions (flow rate 1.8 mL min⁻¹) containing 0.2, 0.5 and 1.0 mg L⁻¹ As(III) for 9, 7 and 4 days providing 23.3, 20.7 and 10.4 L of arsenic free water, respectively. In addition, it was found that 100% of As(III) in 0.5 mg/L solution (flow rate 1.8 mL min⁻¹) was removed by S-INP pretreated 50 cm sand packed column containing 12 g of S-INP for more than 2.5 months providing 194.4 L of arsenic free water. Field emission scanning electron microscopy (FE-SEM) showed S-INP had transformed to elongated, rod-like shaped corrosion product particles after reaction with As(III) in the presence of sand. These results suggest that S-INP has great potential to be used as a mobile, injectable reactive material for in-situ sandy groundwater aquifer treatment of As(III).     

溶胶-凝胶SiO2薄膜氨热两步后处理

 以正硅酸乙酯为前驱体,氨水作催化剂,采用溶胶-凝胶法提拉镀制SiO₂双面膜,对薄膜进行氨处理和热处理。采用椭偏仪、分光光度计、红外光谱、扫描探针显微镜、静滴接触角测量仪表征薄膜的特性。研究表明：经氨热两步后处理,膜厚持续减小,折射率经氨处理先增大了0.236,再经热处理又减小了0.202,膜层透光性变好,透过率峰值持续向短波方向移动;经两步后处理的膜面平整度明显变好,与水的接触角先增大到58.92°后减小到38.07°。     

Study on hydrogen sulfide plasma passivation of 790-nm laser diode cavity surface

In order to improve the optical properties of the Ⅲ-Ⅴ laser diodes(LDs) by means of H2S plasma passivation technology,H2S plasma passivation treatment is performed on the GaAs(110) surface.The optimum passivation conditions obtained are 60-W radio frequency(RF)power and 20-min duration.So the laser cavity surfaces axe treated under the optimum passivation conditions.Consequently,compared with unpassivated lasers with only AR/HR-coatings,the catastrophic optical damage (COD) threshold value of the passivated lasers by H2S plasma treatment is increased by 33%,which is almost the same as that of (NH4)2Sx treatment.And the life-test experiment has demonstrated that this passivation method is more stable than(NH4)2Sx solution wet-passivated treatment.     

声光调制实验的一种CCD成像改进方法

提出了声光调制实验的一种CCD成像改进的实验方法,即声光调制的入射光和衍射光成像于CCD上,对光斑图像进行编程处理,计算机给出光斑的位置。给出了实验步骤、图像处理算法和实验结果。     

关于液体内大规模声处理中空化研究的几点思考——再论声空化工程

再次强调了大规模液体中超声处理、以及为此目的研究声空化的重要性。提出了对这项应用中声空化行为的几点思考,重点是关于声空化的"强度"以及关于电动力式和流体动力式两类产生空化系统所产生空化的不同特性。     

GaN-based light-emitting diode with ZnO nanotexture layer prepared using hydrogen gas

ZnO films were deposited on indium tin oxide (ITO), which formed the transparent conductive layer (TCL) of a GaN-based light-emitting diode (LED), by ultrasonic spraying pyrolysis to increase the light output power. The ZnO nanotexture was formed by treating the as-deposited ZnO films with hydrogen. The root mean square (RMS) roughness increased from 4.47 to 7.89 nm before hydrogen treatment to 10.82-15.81 nm after hydrogen treatment for 20 min. Typical current-voltage (I-V) characteristics of the GaN-based LEDs with a ZnO nanotexture layer have a forward-bias voltage of 3.25 V at an injection current of 20 mA. The light output power of a GaN-based LED with a ZnO nanotexture layer improved to as much as about 27.5% at a forward current of 20 mA.     

重离子治疗计划系统的构想

对重离子柬治癌的优势进行简要的回顾，并着重介绍了用于重离子放射治疗的治疗计划系统。治疗计划系统是一套软件系统，不同的硬件设施应有与其相匹配的软件系统，即治疗计划系统。在此基础上，针对兰州重离子加速器的特点提出一些关于治疗计划系统方面的构想。After a brief review concerning the advantages of heavy ions in radiotherapy, more interests are concentrated on treatment planning system （TPS） for heavy ion radiotherapy. Compared to the hardware devices such as accelerator and beam delivery system, the TPS is a set of software system, and different therapy facilities require their corresponding TPSs. Based on the specialities of the Heavy Ion Research Facility in Lanzhou （HIIRFL）, some suggestions on the TPS for tumor therapy at HIRFL finally are given.     

ZnO/ZrO2 nanocomposite: Sonosynthesis,characterization and its application for wastewater treatment

ZnO/ZrO₂ nanocomposites with different ZnO: ZrO₂ molar ratios (2:1, 1:1, and 1:2)were prepared by sol gel approach under ultrasonic irradiation. For preparation of the nano-composites, the ZnO gel was directly incorporated into the ZrO₂ gel at different molar ratios. The reaction mixture was stirred continuously for two days and then it was ultrasonoicated for 30 min. The filtrated composite gel was washed, and then calcinated at 300 °C in furnace for 3 h. X-ray powder diffraction patterns exhibited well-formed crystal structures and pure crystalline phases in the synthesized nanoparticles (NPs). The FT-IR analyses indicated that the positions of peaks related to Zn-O and Zr-O absorption bands did not change in nano-composites. In addition, FESEM images indicated uniform spherical morphology of the NPs. The highest photo-degradation performance of Congo red (as a model water pollutant) was obtained by 1:2molar ratio of ZrO₂: ZnO in the nano-composite. The particle size and band gap were considered as important factors on nano-catalysts performance. Furthermore, the effects of ultrasonic irradiation, pH, and the concentration of pollutant in solution were investigated on photocatalytic performance of optimum nanocomposite.     

Effects of in situ plasma treatment on optical and electrical properties of index-matched transparent conducting oxide layer

We investigated the effects of in situ plasma-treatment on optical and electrical properties of index-matched indium tin oxide (IMITO) thin film. To render the IMITO-coated surface hydrophilic and study the optical and electrical characteristics, we performed in situ oxygen plasma post-treatment without breaking vacuum. The 94.6% transmittance in the visible wavelength range (400-700 nm) increased on average to 96.4% and the maximum transmittance reached 98% over a broad wavelength range. The surface roughness and sheet resistance improved from 0.9 nm and 200 Ω/sq to 0.0905 nm and 100 Ω/sq, respectively, by in situ plasma post-treatment. We confirmed by contact angle measurement that the hydrophobic IMITO surface was altered to hydrophilic. The improved optical and electrical characteristics of in situ plasma-treated IMITO makes it adequate for high-resolution liquid crystal on silicon displays.