基于优化残差网络的复杂纹理表面缺陷检测

产品表面缺陷检测是工业自动化生产的重要环节,准确率是评价自动检测系统可靠性的主要指标。基于复杂纹理表面缺陷检测的特殊性以及对检测方法的实时性、通用性等要求,提出了优化骨干网络并使用迁移学习特征映射构建复杂纹理表面缺陷的检测方法。该方法通过优化残差网络模型并建立仿真数据集的方式进行迁移学习,以解决实际情况中复杂纹理表面产品数据集样本数量少、数据集制作困难、相似问题难以互相兼容等问题。实验结果表明,提出的方法可以准确地检测随机复杂纹理的人造木质板材表面缺陷,平均准确率可达99.6%。现有实验条件下单张人造木质板材的检测时间为305 ms,可以满足在线检测的实时性要求。研究结果可为基于深度学习的复杂纹理表面缺陷检测提供新的思路与理论参考。     

LLRF超导腔体控制系统的测试

中国科学院近代物理研究所自主研发的ADS注入器Ⅱ第一代高频低电平(LLRF)控制系统,工作频率为162.5 MHz;LLRF系统是由基于I/Q采样的正交解调技术构成的全数字闭环反馈控制系统,其主要功能是实现超导腔腔体电压幅值稳定控制、相位稳定控制与腔体谐振频率控制;LLRF控制系统在液氦温区超导腔上进行了系统稳定度和性能的在线测试,根据实验数据计算得超导腔体电压幅度稳定度为±3.4‰,相位稳定度为±0.3°,腔体表面峰值电场(Epk)能长时间稳定在25.1 MV/m。通过实验测试,检验了LLRF控制系统的性能,并对测试过程中出现的问题进行了分析,为将来超导腔LLRF控制系统运行积累了经验。     

主动中子多重性铀质量测量模拟研究

中子多重性技术常用于测量和核查核材料,尤其针对具有较厚屏蔽的对象具有不可替代的优势。钚的自发裂变率较高,可以采用被动测量方法,目前已有多款不同的测量装置。然而铀材料的自发裂变率较低只能采用主动测量方法。现有的主动井型符合计数器（AWCC）能够进行主动中子多重性测量铀材料质量,但依然存在探测效率较低,Am-Li中子源产生偶然符合大等缺点。为提高铀材料测量的效率和精度,对主动中子多重性测量方法开展深入研究非常必要。本文参考AWCC模型,利用Geant4软件对探测器和粒子的输运过程进行建模。研究了多重性移位寄存器的不同符合门宽、不同延迟时间对铀测量结果相对偏差的影响规律。计数器的最佳门宽为44 μs,门宽取值范围在计数器衰减时间的1.5倍左右合适;延迟时间大于3倍计数器衰减时间后,相对偏差显著减少。最后讨论了235U富集度变化对主动中子多重性测量结果的影响。为后续主动中子多重性铀质量测量仪器的设计提供了参考。     

二苯胺磺酸钠共振光散射法测定牛尿中白蛋白的研究

研究了以二苯胺磺酸钠为共振光散射探针测定牛尿中牛血清白蛋白的分析方法.该方法基于在pH=3.0的Britton-Robinson缓冲溶液中,牛血清白蛋白(BSA)与二苯胺磺酸钠结合后有强烈的共振光散射作用,在λ=469 nm处,共振光散射强度最大且光散射的强度与BSA的浓度成正比.方法简便、快速、灵敏度高,对BSA的检出限为0.18 mg/L,线性范围为0.20～16 mg/L,相关系数r=0.996.该法用于牛尿样品的分析测定,结果满意.     

New test and analysis of position-sensitive-silicon-detector

We have tested and analyzed the properties of two-dimensional Position-Sensitive-silicon-Detector （PSD） with new integrated preamplifiers. The test demonstrates that the best position resolution for 5.5 MeV α particles is 1.7 mm （FWHM）, and the best energy resolution is 2.1%, which are notably better than the previously reported results. A scaling formula is introduced to make the absolute position calibration.     

STUDY ON LATE EFFECTS OF RADIOIODINE ON RATS

This paper describes the results observed on 850 male Wistar rats for two years after intraperitoneal injection with ~(131)I, ~(132)I or ~(125)I of different radioactivities. The incidence of thyroid malignant tumor was 45.8% when the dose absorbed by the thyroid gland was 7.8 Gy in the ~(131)I groups, and even tumors of lung and soft tissue, and malfunction of kidney and immune organs could be elicited when the radioiodine was overdosed. Both ~(132)I and ~(125)I have their optimal carcinogenic dose ranges and optimal doses of carcinogenesis. As the dosage decreases to a certain level, a low-limit dose incapable of inducing cancers may be present. ~(131)I induced mainly papillary and mixed type carcinomas, ~(132)I chiefly follicular and undifferentiated type carcinomas, while ~(125)I induced follicular and medullary carcinomas. The paper also discusses cytochemical DNA quantitative assays of different histological types of thyroid gland carcinomas, holding that reference to such data as decreasing serum     

一种新型S-N添加剂与磷酸三甲酚酯在500N加氢基础油中的摩擦学复合效应

合成了一种新型S-N无灰添加剂(DBTT)；利用四球摩擦磨损试验机考察了单剂DBTT、磷酸三甲酚酯(TCP)以及含不同质量比的DBTT和TCP的复合添加剂在500N加氢基础油中的摩擦学性能；用X射线光电子能谱仪和扫描电子显微镜分析了磨损表面形貌和元素化学状态．结果表明：合成的DBTT在500N加氢基础油中有良好的溶解性;所考察的添加剂都能有效提高基础油的承载能力；在一定条件下单剂DBTT和TCP能够有效提高基础油的减摩和抗磨性能；DBTT／TCP复合剂在基础油中表现出协同抗磨效应和增摩效应．含上述添加剂的500N加氢油在摩擦过程中发生摩擦化学反应，生成混合边界润滑膜，从而起减摩抗磨作用．     

铯钨青铜的合成及其对甘油脱水制丙烯醛的催化性能

以仲钨酸铵、硝酸铯为原料,乙二胺四乙酸(EDTA)为模板剂和还原剂,采用水热法合成了铯钨青铜,考察了EDTA用量、水热前驱液浓度、铯钨比等条件对水热产物组成及形貌的影响,并以所得产物为催化剂在固定床反应器中进行甘油脱水制丙烯醛的反应研究,发现铯含量对催化性能有较大影响,在Cs/W摩尔比为0. 2∶1时催化性能最好,甘油转化率达到81. 3%,丙烯醛的选择性达到92. 9%。     

Study of the structure of borromean nucleus 17Ne

The ¹⁷Ne nucleus is a possible candidate with a two-proton borromean halo structure. Since the theoretical model is difficult to handle the three-body system, it is difficult to determine the two-proton halo structure in ¹⁷Ne. In the present research, we try to study the breakup reaction of ¹⁷Ne. For the Borromean nuclei, one-proton knockout results in an unstable nucleus which is decaying further by proton emission. This process will result in an angular correlation between the direction of the aligned recoiling unstable nucleus and its decay products. The angular correlations can give us information about the configuration of the valence proton in the ¹⁷Ne. Furthermore, theoretical calculations indicate that the momentum distributions of ¹⁶F c.m are sensitive to the structure of the halo in ¹⁷Ne. Thus the measurement of momentum distributions of ¹⁶F c.m may also give us conclusive information on the structure of ¹⁷Ne. The present experiment has been done at IMP in Lanzhou using the radioactive beam ¹⁷Ne at 30.8 MeV/u on a 43mg/cm^{2 12}C target. The data analysis is under procedure and the primary results are provided.     

Quasi-Elastic Scattering of 16C from 12C at 47.5 MeV/Nucleon

Differential cross sections for the quasi-elastic scattering of^16 C at 47.5 MeV/nucleon from ^12 C target are measured.Coupled-channels calculations are carried out and the optical potential parameters are obtained by fitting the experimental angular distribution.