TiCl4水解法制备TiO2薄膜的表征及光催化性能

TiCl4水解法制备TiO2薄膜的表征及光催化性能;TiCl4水解;TiO2薄膜;光催化;乙酸     

基于神经网络的GPS深度融合弹载惯导模型

针对传统弹载惯性导航系统误差修正采用线性化模型,无法对非线性误差进行修正的缺点,提出一种基于神经网络的GPS深度融合弹载惯导模型。构建IMU六路脉冲数到发射惯性坐标系下视速度增量的非线性映射关系,利用GPS信息对网络误差模型进行训练,为GPS信号失效后的长航时惯性导航系统提供更高精度的误差修正模型。仿真实验结果表明,相较于纯惯性导航系统,所提模型能够在GPS信号失效后抑制惯导系统误差发散,速度精度提高76.56%,位置精度提高91.61%。     

固体超强碱催化环戊酮的Self-Aldol Condensation反应研究

2-环亚戊基环戊酮是一种重要的香料中间体,本文以环戊酮为原料,固体超强碱为催化剂,分别选用环己烷、苯、石油醚为带水剂,通过Aldol自缩合反应合成了环戊酮的二聚体2-环亚戊基环戊酮。考察了催化剂用量、带水剂种类、反应时间对环戊酮二聚体2-环亚戊基环戊酮收率的影响,最终确定最佳实验方案:环己烷为带水剂,催化剂用量为环戊酮质量的13 wt%,反应时间8小时,最佳条件下2-环亚戊基环戊酮收率可达90.8%。     

Generation and application of high-contrast laser pulses using plasma mirror in the SULF-1PW beamline

The plasma mirror system was installed on the 1 PW laser beamline of Shanghai Superintense Ultrafast Laser Facility [SULF)for enhancing the temporal contrast of the laser pulse. About 2 orders of magnitude improvement on pulse contrast was measured on picosecond and nanosecond time scales. The experiments show that high-contrast laser pulses can significantly improve the cutoff energy and quantity of proton beams. Then different target distributions are assumed in particles in cell simulations, ...     

新高考Ⅰ卷函数试题考点探析

函数是新高考Ⅰ卷占比最大的考点,约占20%.纵观2021—2023年新高考Ⅰ卷函数题,考点主要涉及函数单调性、奇偶性、极值最值问题、切线问题,其中解答题主要考查函数构造,学生需要构建起研究函数问题的思想方法体系.函数学习需要重视通性通法并优化解题方法,同时提升数学抽象、逻辑推理、数学运算、直观想象等核心素养.     

反射式单级衍射光栅

介绍了单级衍射光栅的发展趋势, 从理论上论证了单级衍射光栅的可行性, 引入了一种新型衍射光学元件—-准正弦反射式单级衍射光栅(QSRG). 它能有效抑制高级衍射, 可用于提高光谱系统的信噪比和精度. 而通过QSRG的实验结果也验证了此新型色散元件确实具有良好的单级衍射特性, 二级及以上的高级衍射被有效地抑制, 与理论预测几乎一致. 本文的结果可望在反射式光谱测量系统中得到广泛应用.     

He 离子注入引起的高纯钨硬化

完成了不同注量或温度下100 keV 的He 离子注入高纯钨的实验,并利用纳米压痕技术测量了材料的微观力学性能。所有注入样品的纳米硬度值都高于未注入样品的纳米硬度值。对于室温注入样品,随着注量的增加,样品抗弹性变形能力下降;当注量不高于5x1017 ions/cm2 时,钨的纳米硬度峰值随着注量的增加而增加;注量为1x1018 ions/cm2 的钨样品的纳米硬度峰值反而降低。高温注入样品的抗弹性变形能力优于室温注入样品的抗弹性变形能力;随着注入温度的增加,样品的平均纳米硬度值和弹性模量略有下降。分析讨论了He 注入钨硬化和抗弹性形变能力降低的可能原因。Tungsten has been selected as divertor materials in fusion reactors because of its high thermal conductivity,high melting point, low expansion coefficient and high threshold energy for sputtering etc. The paper presents the hardening behaviour of high pure tungsten by 100 keV He+ with different fluences from 5x1016 ions/cm2 to 1x1018ions/cm2 at room temperature, and with fluence of 1x1018 ions/cm2 at higher temperatures (400, 600 and 800 °C). The microscopic mechanical properties of these samples were investigated by nano-indentation technology. The results show that all of the implanted samples harden obviously. The reason for hardening may be that defects of interstitial dislocation loops or dense helium bubbles etc induced by helium implantation obstacle the movement of dislocation. The peak nanohardness of the samples increased with the fluences increasing when the fluence is not more than 5x1017 ions/cm2, while the nano-hardness value of the implanted sample with the fluence of 1x1018 ions/cm2 decreases and the nano-hardness changes little in the region of 50 nm to 200 nm from surface. For all the implanted samples with 1x1018 ions/cm2 at higher temperatures, their nano-hardness values are similar, but show a trend of decrease with increasing temperature.The reason may be the decrease of the defects’ density during implantation at higher temperatures. In addition, the capability of resisting deformation for the implanted tungsten reduces with increasing fluence and increases a little at higher temperatures.     

点籽晶定向生长70％DKDP晶体的研究

磷酸二氢钾(KDP)类晶体快速生长主要采用点籽晶快速生长方法,三维生长的点籽晶不可避免的会使晶体产生柱锥交界线,从而影响晶体的性能和质量.本文通过所设计的载晶架,改进传统点籽晶快速生长方法,采用点籽晶定向生长方法,成功生长出磷酸二氘钾晶体(70%DKDP),避开生长晶体中的柱锥交界线取片,并对其氘含量、透过率、抗激光损伤性能以及光学均匀性等指标进行了测试.结果表明:所生长的晶体氘含量符合设计要求,晶体透过率和抗激光损伤性能和传统点籽晶快速生长晶体保持一致.光学均匀性结果表明样片内部无柱锥交界线,对于大口径70%DKDP晶体的生长具有指导意义.     

Microstructure of Hydrogen-Implanted Polycrystalline α-SiC after Annealing

Microstructural evolution in H-implanted polycrystalline α-SiC upon thermal annealing at temperature 1100℃ is studied. After annealing, the samples are examined via cross-sectional transmission electron microscopy(XTEM)analysis. H_2 gas bubbles are formed during H implantation and some H2 molecules are released from the bubble to form cavities during thermal annealing. The distribution and size of the observed cavities are related to the implantation fluence. The results are compared to H implanted single crystal SiC and He implanted polycrystallineα-SiC. The possible reasons are discussed.