Performance optimization of the neutron-sensitive image intensifier used in neutron imaging

As a non-destructive testing technology,neutron imaging plays an important role in various fields,including material science,nuclear engineering,and fundamental science.An imaging detector with a neutron-sensitive image intensifier has been developed and demonstrated to achieve good spatial resolution and timing resolution.However,the influence of the working voltage on the performance of the neutron-sensitive imaging intensifier has not been studied.To optimize the performance of the neutron-sensitive image intensifier at different voltages,experiments have been performed at the China Spallation Neutron Source(CSNS)neutron beamline.The change in the light yield and imaging quality with different voltages has been acquired.It is shown that the image quality benefits from the high gain of the microchannel plate(MCP)and the high accelerating electric field between the MCP and the screen.Increasing the accelerating electric field is more effective than increasing the gain of MCPs for the improvement of the imaging quality.Increasing the total gain of the MCP stack can be realized more effectively by improving the gain of the standard MCP than that of the n MCP.These results offer a development direction for image intensifiers in the future.

Obstructive Effects of Ultrasonic Microbubble Intensifier on CHG-5 Cell with Survivin Antisense Oligonucleotides Transfection

Objective： To study the effects on human glioma cell line CHG-5 by ultrasonic microbubble intensifier with survivin antisense oligonucleotides （ASODN） transfection. Methods： Antisense oligonucleotides targeting survivin mRNA was designed and synthesized. Four regimen groups were designed, group A： survivin antisense oligonucleotides transfected with ultrasonic microbubble intensifier combined with ultrasound irradiation, group B： survivin antisense oligonucleotides transfected with lipofectamine combined with ultrasound irradiation, group C： survivin antisense oligonucelotides with lipofectamine transfection, group D： blank control. The expression changes of surviving protein were measured by immunohistochemical staining and Western blotting, and MTT assay was used to measure the changes of proliferation. Results： Survivin protein expression in group A was decreased significantly in human glioma cell line CHG-5 than other groups（P〈0.05）, and the proliferating rate of CHG-5 in group A was also significantly inhibited（P〈0.05）. Conclusion： Ultrasonic microbubble intensifier transfection combined with ultrasound irradiation is a promising method in gene transfection effectively and noninvasively.

Optimization Study on Expansion Energy Used Air-Powered Vehicle with Pneumatic-Hydraulic Transmission

Pneumatic-hydraulic transmission has been developed for years. However, its dynamic properties are not good enough for application. In this paper, in order to increase the output characteristics, a late-model air-powered vehicle using expansion energy is proposed which can boost energy through a pneumatic-hydraulic transmission. The dynamic characteristics of the air-powered vehicle is modeled and verified by conducting experiment. In addition,the influence of the key parameters of the air-powered vehicle is researched for the optimization of the system performance. Through the results, the author got the conclusion that, firstly, comparison of the results of model and experiment proves the built model to be effective; secondly, input air pressure should be set according to the request of the practical loads, and range of 0.65 to 0.75 MPa can be chosen; thirdly, as a key structure parameter of the airpowered vehicle, ratio of the areas is considered to be set to approximate 8; what’s more, a bigger orifice with a limit will promote the system dynamic characteristic property, and the limit is about 3.5 mm; last but not the least, not too farther position of the rings will increase the quality of output dynamic characteristics. This paper can be a reference for system design of air-powered vehicle and dynamic improvement.

PROCESS AND PROPERTIES OF THE MODERN MULTIALKALI PHOTOCATHODE USED IN A CASCADE IMAGE INTENSIFIER

A new processing technology and the properties of multialkali antimonide photocathodesare described.The technique requires an initial antimony layer to be deposited on a fiber-optic window at asuitable temperature.After that.the layer is activated by multialkali and antimonide.Thus.the multialkaliphotocathodes named“The Modern Multialkali Photocathode”are obtained.It has been found that aphotocathode thus processed gives a sensitivity of 200 to 300μA/Im for white light at a color temperature of2854K.This paper shows the variation of photosensitivity during processing of a Modern MultialkaliPhotocathode and the variatioon of spectral sensitivity at different wavelengths.The author discusses theresults.gives a supposition of“photoemission center”,and discusses the role of Cs in multialkaliphotocathodes.

Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate

The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine(4-HP) with tributyl phosphate(TBP), di(2-ethylhexyl) phosphoric acid(D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio(D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50-4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate(i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP,(ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA(1:1) and 4-HP:2D2EHPA(1:2) type complexes, while(iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA(1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

用于X射线像增强器便携成像的观瞄目镜设计研究

结合X射线像增强器便携成像这一特殊需求,分析了针对该类观瞄目镜开展人体工程学设计的必要性。从像增强器器件的层面,给出了该类观瞄目镜的系统设计约束与要求。在此基础上,给出了一个该类观瞄目镜的具体设计示例,分析了该类光学系统的具体优化设计方法,并分别从厚度、曲率半径、圆锥系数3个维度开展了具体的系统优化设计。最终,基于光学传递函数评价方法,逐步地对比分析了优化设计与系统性能提升之间的内在联系与对应关系。

非氰浸金剂的研究进展与展望

随着国家对企业绿色生产要求的提高,传统氰化法浸金工艺的劣势愈加明显,无法满足当前的环保要求。在浸金领域,亟需寻找一种能替代氰化物的非氰浸金剂。本文对非氰浸金剂进行了分类总结,更新了传统浸金剂(含硫浸金剂、卤化物浸金剂、微生物、氨基酸等)的研究与应用进展;综述了目前热度较高的新型环保合成浸金剂的合成方法与研究现状;除单一成分的浸金剂外,本文还对多种不同浸金剂组成的共强化体系进行了系统总结,为非氰浸金剂领域的学者提供了重要的参考。

磁链分区的磁场增强型永磁电机全速域模型预测直接转矩控制

磁场增强型内置式永磁(flux intensifying interior permanent magnet,FI-IPM)电机的反凸极(L_(q)<L_(d))特性,使得正向d轴电流增强磁场,提高输出转矩的同时,也使得弱磁升速时d轴电流正负交替变化,电流角度变化大,磁链波动大,进而造成转矩脉动大、电流畸变振荡、响应速度慢等问题。针对这些问题,该文提出一种基于磁链分区的磁场增强型内置式永磁电机全速域模型预测直接转矩控制控制策略。根据FI-IPM电机速度运行区域与磁链状态映射关系,构建磁链和转矩预测模型。在此基础上,提出磁链分区控制,引入磁链差值判断增磁和弱磁运行区,并进行磁链补偿,解决不同速度运行域之间切换的震荡和不稳定问题。最后,通过实验验证所提出控制策略的有效性,为该类电机在电驱动系统中的应用提供技术方案。

手术室强化式护理干预在鼻内镜鼻窦手术患者中的应用

目的探讨手术室强化式护理干预在鼻内镜鼻窦手术患者中的应用价值。方法回顾性分析,采集2023年1—6月于郑州大学第一附属医院接受常规护理干预的50例鼻内镜鼻窦手术患者资料,纳入对照组;采集2023年7—12月于医院接受手术室强化式护理干预的50例鼻内镜鼻窦手术患者资料,纳入观察组。患者疾病资料、手术资料、干预资料等资料均保存完整。整理患者资料,记录并对比两组患者情绪状态[汉密尔顿焦虑量表(HAMA)、汉密尔顿抑郁量表(HAMD)]、苏醒期躁动发生情况[Richmond镇静躁动评估量表(RASS)评估]、术后恢复时间(苏醒时间、拔管时间、苏醒室停留时间)。结果干预前,两组患者的HAMA、HAMD评分对比,差异无统计学意义(P>0.05);干预后,两组患者的HAMA、HAMD评分均降低,且观察组低于对照组(P<0.05)。相较于对照组,观察组苏醒期躁动发生率较低,且苏醒时间、拔管时间、苏醒室停留时间均较短(P<0.05)。结论为鼻内镜鼻窦手术患者实施手术室强化式护理干预,可以改善患者不良情绪,减少苏醒期躁动的发生,缩短术后恢复时间。

基于改进支持向量回归的空战飞行动作识别

针对空战中飞机的飞行动作愈发复杂导致识别准确率低的问题,提出了改进支持向量回归的空战飞行动作识别方法,该方法采用高斯核函数作为线性核函数,利用混沌初始化和反向学习策略改进麻雀搜索算法,利用改进后的麻雀算法优化支持向量回归算法,具体表现为对支持向量回归算法中高斯核函数的参数进行优化,通过优化后的支持向量回归算法进行飞机动作识别。采用了五种基本的飞行动作和几种复杂的飞行动作验证该方法的识别准确率。仿真表明,优化后的支持向量回归算法与传统的支持向量回归算法、模糊支持向量机算法、传统聚类算法、神经网络算法相比,对基本飞行动作的平均识别率至少提升了2.2%,对复杂飞行动作的平均识别率至少提升了3.7%。

基于离散系数与Harris角点的微光像增强器闪烁噪声测试方法

为了弥补信噪比无法在二维空间上准确定位分析像增强器闪烁噪声特性的不足,本文针对像增强器闪烁噪声特性设计了一种基于离散系数与Harris角点检测的微光像增强器闪烁噪声测试方法。本方法采用基于Gsense400BSI CMOS图像传感器的高帧频图像采集系统实现与像增强器荧光屏余晖时间相匹配的闪烁噪声图像采集。通过对连续多帧采集到的图像进行像素级离散系数计算,热点图实现可视化,与Harris角点检测算法能够准确分析像增强器荧光屏各区域内的闪烁噪声情况并准确标记荧光屏上的高亮噪点。实验结果表明,该方法能够实现像增强器闪烁噪声的二维分析与定位,从而为像增强器性能优化以及噪声特性测试提供技术支持。

紫外像增强器在航空发动机燃烧诊断中的应用

航空发动机燃烧过程中,OH^(*)、NO^(*)、NH^(*)等激发态自由基伴随着紫外波段的微弱自发光,且随燃烧的进程而快速变化。紫外像增强器最高具有百万倍电子增益、纳秒量级快门,可以实现紫外波段燃烧流场瞬态结构的捕获,为定量化测量、阐释燃烧特性随多物理参数的变化规律奠定基础。本文总结紫外像增强器在航空发动机燃烧光学诊断中的应用,包括针对OH^(*)自发光进行成像的被动光学诊断技术、利用激光激发OH成像的主动光学诊断技术等。最后,结合新型航空发动机高时空分辨探测的要求,指出紫外像增强器在燃烧诊断中的发展方向。

影响电晕检测仪用紫外像增强管成品率因素分析

总结归纳了影响电晕检测仪用紫外像增强管成品率的因素,分析了器件不合格原因和机理,针对问题采取了有效的优化措施,较好地提升了紫外像增强管成品率,降低了生产成本,有利于促进产品的推广应用。

直耦增强型CMOS相机技术研究

直耦增强型CMOS(intensified complementary metal-oxide-semiconductor,ICMOS)相机通过将像增强器输出窗与CMOS直接耦合而成,具备灵敏度高、响应速度快、光谱范围可调等特点。本文根据ICMOS的组成结构,分析了阴极、微通道板、荧光屏、CMOS等各组成部件对直耦ICMOS成像性能的影响,提出ICMOS用像增强器、CMOS成像器件的选型依据,并结合公司对像增强器的加工优势,基于18 mm NVT-7像增强器和1英寸CMOS开展了实际微光成像验证。结果表明,采用直耦方式的ICMOS相机能够在5×10^(-4)lx条件下清晰成像,分辨力达到16 lp/mm。此外,用于ICMOS耦合的像增强器增益不宜过高,4000 cd/(m^(2)·lx)比较适宜,另外,在增益适宜的条件下,荧光屏输出亮度对其性能影响不大。

微光像增强器光晕消失时间测试方法

光晕(halo)效应对微光像增强器探测的应用造成了不利影响且不可避免。微光像增强器的光晕消失时间缺乏测试方法,因此提出了基于数字目视的光晕消失时间测试系统。该系统通过开关电源给LED光源提供频率为25 Hz、占空比可调的脉冲信号,利用高帧率相机连续采集1500张像增强器经直径为3.5 mm小孔后的图像,其中包含若干个完整的明暗周期。通过重复计算标准差,去除偏离平均值的周期序列来优化周期信息,获得亮暗周期内光源熄灭的图片索引,同理可获得光晕消失的图片数量,从而计算得到光晕消失时间。编号为GZ318118A的像增强器光晕消失时间为3.33 ms。测试结果表明,测量装置的重复性为0.863%,可以对光晕消失时间进行有效测试。

微界面强化CO_(2)和环氧丙烷催化合成碳酸丙烯酯

应用离子液体催化剂,建立CO_(2)与环氧丙烷合成碳酸丙烯酯的微界面强化间歇和连续工艺。优选离子液体催化剂种类,采用在线成像测量技术观测MIR(微界面强化反应器)和BCR(鼓泡塔反应器)的气液体系特征参数,对比不同反应条件下2种反应器的反应效能,讨论传质强化对PC收率的影响。结果表明:相较于鼓泡塔反应器,微界面反应强化技术将反应体系气液界面尺度由mm-cm级调控为μm级,大幅度提高了相界面积和质能传递效率,导致相同间歇反应工况下反应速率提升77%,CO_(2)利用率提高40%;在较温和条件(110℃,2 MPa)、催化剂用量(摩尔分数)0.375%、空时3.3 h、n(CO_(2)):n(PO)=1.25:1下进行连续化反应,PC收率稳定在98%以上。研究结果为微界面反应强化技术应用于碳酸丙烯酯的工业化生产提供了数据支撑。

AgVO_(3)类氧化酶对槲皮素的信号增强型比色传感研究

目前,纳米酶的设计合成及比色传感应用是分析化学领域的研究热点,开发一种具有高活性、良好稳定性、不依赖过氧化氢的单一类氧化酶活性材料是实现高效比色传感的关键。采用适合大规模制备的溶液共沉淀法,合成了长度为10—20μm、直径为100—200 nm的AgVO_(3)纳米棒(AgVO_(3)NRs)。研究发现,AgVO_(3)NRs能催化无色的3,3′,5,5′-四甲基联苯胺(TMB)氧化生成蓝色产物oxTMB。机理研究发现,AgVO_(3)NRs显示单一且高效的类氧化酶活性,并对不同底物具有广谱性。以TMB为底物时,底物诱导活化材料表面吸附的化学氧,并将其转化为超氧自由基(·O_(2)^(-))。超氧自由基作为电子受体,将底物TMB氧化并触发显色反应,该过程近似为一级反应。当有槲皮素存在时,TMB的氧化得到促进,oxTMB浓度增加导致其吸光度显著上升,蓝色加深。基于该过程,构建了一种具有信号增强型“关-开”模式的槲皮素比色传感检测系统,即AgVO_(3)NRs+TMB+槲皮素。研究结果表明,在25℃下、缓冲溶液pH=4条件下,槲皮素(浓度在0—1.0μmol·L^(-1))与oxTMB在652 nm处的吸光度呈良好的线性关系,检测限为11.82 nmol·L^(-1)。说明,AgVO_(3)NRs是一种性能优良的类氧化酶材料,可实现多酚类化合物槲皮素的比色检测。本研究揭示了AgVO_(3)NRs在化学分析检测、食品安全、生物医学领域的应用潜力。

铝基复合材料制备方法及成型工艺的最新进展

介绍了铝基复合材料当前的发展状况,总结了铝基复合材料的多种制备方法。增强相不同,铝基复合材料的制备方法也不同。铝基复合材料的增强相按照其不同的形貌特征主要分为颗粒增强相、纤维增强相、片状增强相。首先介绍了铝基复合材料的典型制备方法,之后以三种增强相为中心,对其成型工艺进行了说明,列举了不同方法当前的研究进度,最后总结了各种方法在目前研究中存在的问题,并对不同增强相的铝基复合材料的发展前景进行了展望。

Only With Talent,Can There Be Productivity

The Chinese government attaches great importance to the legal protection of innovation and intellectual property rights.At the parallel forum named"Rule of Law and Innovation"with the theme of"Intellectual Property and the Development of New Productive Forces"held during the Global Business and Law Conference2024,experts had a heated discussion.Zhang Shaogang,Vice Chairman of the CCPIT,said at the forum,"At present,the momentum of world economic growth is insufficient,and the competition in the frontier areas of the new round of scientific and technological revolution and industrial transformation has intensified.

某高硫难选铜钼矿浮选工艺优化及工业应用研究

某铜钼矿原矿铜品位0.45%,钼品位0.015%,硫品位2.47%,含金0.12 g/t,是典型的斑岩型铜钼矿。因长期暴露而氧化率逐渐升高,导致目的矿物可浮性变差。原有药剂制度及工艺条件对其适应性较差,生产指标不理想。针对该难选矿石开展了实验室工艺优化试验研究,制定了"铜钼快速浮选-铜硫混合浮选再分离"的工艺流程,工业试验结果相比优化前铜回收率提高了0.60个百分点,钼回收率提高了5.33个百分点。