检索结果-南通市图书馆

基于光谱诊断的窄间隙激光填丝焊气孔缺陷检测研究

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2025年第2期45卷 507-514页

作者：佘昆李冬辉杨凯淞杨立军刘金平黄一鸣天津大学电气自动化与信息工程学院天津300350 广东省特种设备检测研究院广东广州510655 天津大学材料科学与工程学院天津市现代连接技术重点实验室天津300350 中国核工业二三建设有限公司核工业工程研究设计有限公司中核集团高效智能化焊接重点实验室北京101300

窄间隙激光焊作为核电领域大型厚壁构件的先进连接工艺,具有热输入小、焊接效率高、接头质量高等优点。然而,受现场复杂施焊环境影响,焊缝内部易因污染物清理不尽而产生气孔缺陷。传统的焊后无损检测费时耗力,且检测结果受零部件尺寸结... 详细信息

窄间隙激光焊作为核电领域大型厚壁构件的先进连接工艺,具有热输入小、焊接效率高、接头质量高等优点。然而,受现场复杂施焊环境影响,焊缝内部易因污染物清理不尽而产生气孔缺陷。传统的焊后无损检测费时耗力,且检测结果受零部件尺寸结构制约及检测人员主观判断影响,因此亟待发展气孔缺陷在线检测技术。本文设计研制了基于发射光谱的窄间隙激光焊质量检测系统,探究工艺参数及水、油等污染物对气孔缺陷的影响规律,分析水对激光致等离子体电子温度、光谱强度的作用机制,开发因污染物导致的气孔缺陷在线预警软件系统。结果表明,窄间隙激光焊时由于受工件侧壁拘束使得等离子体密度高,对激光反射、散射作用强,测得光谱强度值较弱。窄间隙填丝焊时由于激光能量存在损耗、不能完全被母材和丝材吸收,其测得的光谱强度小于窄间隙自熔焊。采用Boltzmann作图法求得窄间隙激光填丝焊光致等离子体电子温度为7201.1 K,电子密度为5.2797×10^(15)cm^(-3),均小于窄间隙激光自熔焊时的热力学状态参数。在本文的6组自熔焊工艺参数范围内,X射线探伤未检测到密集气孔缺陷。当母材表面有水时,焊缝表面有气孔产生,通过X射线探伤观察到焊缝中有大量密集气孔存在。与正常工艺下获得的光谱数据相比,光谱仪全波段上的相对光强均降低,电子温度也下降至6900~7200 K范围内动态波动,但电子密度会增大。采用神经网络模型对主成分分析降维后的光谱数据进行训练,可对窄间隙激光填丝焊时因水、油等污染物导致的气孔缺陷进行高准确率的预测。开发的气孔检测系统可对因污染物导致的气孔缺陷进行有效识别,准确率达90%,响应时间在0.1 s内。

关键词：窄间隙激光焊光谱诊断光致等离子体气孔缺陷在线检测

MACC1激活HGF/c-MET通路促进结直肠癌侵袭迁移的机制研究

在线全文

学校读者我要写书评

暂无评论

西安交通大学学报(医学版) 2025年第1期46卷 86-93页

作者：熊漫谭益冰杨明孙晓宁刘思德宋阳广州中医药大学护理学院广东广州510006 南方医科大学南方医院消化内科广东广州510515

目的探讨结直肠癌转移相关基因-1(metastasis-associated in colon cancer-1,MACC1)对结直肠癌增殖、侵袭的作用及其机制。方法分析TCGA数据库中结直肠癌样本和癌旁样本中MACC1的表达及MACC1高低表达组患者的生存差异;将HCT116细胞分... 详细信息

目的探讨结直肠癌转移相关基因-1(metastasis-associated in colon cancer-1,MACC1)对结直肠癌增殖、侵袭的作用及其机制。方法分析TCGA数据库中结直肠癌样本和癌旁样本中MACC1的表达及MACC1高低表达组患者的生存差异;将HCT116细胞分为Vector(不做任何处理组)、MACC1 OE组(转染pcDNA3.1-MACC1过表达质粒),si-NC组(转染siRNA阴性对照)、si-MACC1组(转染MACC1 siRNA);MTT实验检测细胞活力;EDU和细胞克隆形成实验检测细胞增殖;划痕及侵袭实验分别检测细胞的迁移和侵袭情况;RT-qPCR检测肝细胞生长因子受体(cellular-mesenchymal to epithelial transition factor, c-MET)的mRNA表达水平;Western blotting检测MACC1、c-MET的蛋白表达情况。将转染MACC1 OE的结直肠癌细胞HCT116接种至裸鼠皮下建立肿瘤模型,测量肿瘤体积及质量。结果结直肠癌组织及结直肠细胞株中MACC1表达升高(P<0.05)。MACC1高表达组的患者总生存期低于MACC1低表达组(P=0.003)。MACC1过表达可提高HCT116细胞活力(F=86.070,P<0.001)。与si-NC组相比,si-MACC1组的HCT116细胞增殖能力、迁移、侵袭及克隆形成能力降低(P<0.01)。MACC1与c-MET蛋白的表达呈正相关(r=0.802,P=0.002)。过表达MACC1可提高c-MET的表达(t=13.532,P<0.001),而干扰MACC1可降低c-MET的表达(t=14.626,P<0.001);荧光素酶报告实验表明,MACC1可激活c-MET转录。MACC1过表达可提高裸鼠肿瘤体积及质量(P<0.01)。结论 MACC1可通过激活肝细胞生长因子(hepatocyte growth factor, HGF)/c-MET通路促进结直肠癌的侵袭和迁移。

关键词：结直肠癌结直肠癌转移相关基因-1(MACC1) 肝细胞生长因子(HGF) 肝细胞生长因子受体(c-MET) 侵袭迁移

岩芯高光谱成像及勘查指示意义研究--以西藏邦铺大型多金属矿床为例

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2025年第1期45卷 38-44页

作者：吴畅宇代晶晶宋扬陈伟刘治博刘洪成白龙洋中国地质科学院矿产资源研究所自然资源部成矿作用与资源评价重点实验室北京100037 自然资源部深地科学与探测技术实验室中国地质科学院北京100094 核工业北京地质研究院遥感信息与图像分析技术国家级重点实验室北京100029

西藏邦铺矿床是冈底斯成矿带上重要的斑岩-矽卡岩型矿床,矿区东段矽卡岩矿体研究程度较低。高光谱成像技术可以快速获取岩芯样品“图谱合一”的高光谱数据,选取邦铺矿床东段矽卡岩典型岩芯为样品,应用国产核工业北京地质研究院自主研发... 详细信息

西藏邦铺矿床是冈底斯成矿带上重要的斑岩-矽卡岩型矿床,矿区东段矽卡岩矿体研究程度较低。高光谱成像技术可以快速获取岩芯样品“图谱合一”的高光谱数据,选取邦铺矿床东段矽卡岩典型岩芯为样品,应用国产核工业北京地质研究院自主研发岩芯扫描仪与国外SPECIM岩芯成像仪,开展短波红外(SWIR)高光谱成像测试及对比分析,揭示典型矿物的短波红外光谱特征,并探讨先进的高光谱成像技术应用于矽卡岩勘探的潜力与优势。对同一批岩芯样品分别进行了国内外仪器的高光谱成像测试,利用最小噪声分离变换以及纯净像元指数进行端元提取,而后结合光谱信息散度法选取不同矿物的训练集和验证集样本,采用光谱角填图法进行蚀变矿物填图。共识别出方解石、绿帘石、绿泥石、角闪石、石英、白云母六种矿物,两种仪器矿物填图的结果大体一致,并反映了不同蚀变矿物之间的组合与分布。SPECIM成像仪对两个钻孔样品的平均填图精度为91.5%,Kappa系数为0.87;核工业高光谱成像仪对两个钻孔的填图精度为75%左右,Kappa系数为0.66。两种仪器获取的高光谱数据信噪比均较高,但是由于核工业仪器的数据空间分辨率相对更低,导致图像中存在更多的混合像元,进而影响了填图精度,其空间分辨率的进一步提高是下一步研发的重点。高光谱成像数据表明ZK0010钻孔绿泥石Fe-OH吸收峰波长变化范围为2252.3~2260 nm,ZK0011钻孔绿泥石Fe-OH吸收峰变化范围为2251.7~2258.5 nm,由上至下均向短波方向移动,表明了绿泥石远离矿化中心而相对富Mg,其高值指示了矿体中心位置。高光谱成像技术相较于传统的点测法可以提供更加丰富的空间信息和光谱信息,为指针矿物的光谱特征参数提取与变化规律分析提供了技术支撑。利用高光谱成像提供的大量光谱数据进行绿泥石Fe-OH峰位统计分析,进而可以通过其波长高值位置指示矽卡岩矿床勘查。

关键词：岩芯高光谱成像短波红外矽卡岩邦铺

Inverse dependence of exchange bias and coercivity on cooling field caused by interfacial randomization in nanosystems with Co sparsely distributed in CoFe2O4 matrix

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第3期98卷 258-267页

作者： song yang Yong Hu Department of Physics College of Sciences Northeastern University State Key Laboratory of Rolling and Automation Northeastern University

We conceive a model of nanosystems where Co is uniformly, randomly distributed into a CoFe2O4（CFO）matrix, and study the influences of composition and CFO antiferromagnetic exchange coupling(JCFO) on zero-field-cooled/field-cooled magnetization behavior and the dependencies of exchange bias field（HE）and coercivity（HC） on Co/CFO interfacial coupling(JCo/CFO), composition and cooling field(HFC), based on a modified Monte Carlo method. With decreasing temperature, the zero-field-cooled and field-cooled magnetization curves are overlapped and increasing initially, and then splitting at a critical temperature（TP）,below which the field-cooled magnetization continues increasing while the zero-field-cooled magnetization exhibits a peak and drops, indicating a magnetically frozen state. A larger JCFOinduces an elevated TP and a reduced magnetization, while the opposite results are obtained by a higher Co occupation fraction（PCo）. On the other hand, HEis nonmonotonic with JCo/CFOand the peak decreases and shifts to a lower JCo/CFOvalue for a larger PCo. HCincreases monotonically with increasing JCo/CFO. Moreover, HEis inversely proportional to PCowhen PCovaries from 0.11 to 0.30, indicating the exchange bias is still an interfacial effect. Finally, for a nonzero JCFO, HEmay be suppressed and accompanied by the recovery of HCwith increasing HFC. Otherwise, HCfor zero JCFObecomes high and insensitive to HFC. It is ascribed to the uniform contact between Co and CFO, leading to the Co magnetization reversal and the CFO magnetization precisely controlled by HFC. This work opens a new avenue to control the exchange bias in nanosystems through interfacial randomization.

关键词： Exchange bias Ferromagnetic occupation fraction Cooling field Monte Carlo simulation

Comparative study of a rabbit model of spinal tuberculosis using different concentrations of Mycobacterium tuberculosis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2025年第1期16卷 46-56页

作者： Yong-Jie Qiao Xiao-yang song Lv-Dan Zhang Feng Li Hao-Qiang Zhang Sheng-Hu Zhou Department of Joint Surgery The Second Hospital&Clinical Medical SchoolLanzhou UniversityLanzhou 730050Gansu ProvinceChina Department of Orthopedics The 940th Hospital of Joint Logistic Support Force of Chinese People’s Liberation ArmyLanzhou 730000Gansu ProvinceChina Department of Respiratory Medicine The 940th Hospital of Joint Logistic Support Force of Chinese People’s Liberation ArmyLanzhou 730050Gansu ProvinceChina Department of Orthopaedics The 943rd Hospital of Joint Logistic Support Force of Chinese People’s Liberation ArmyWuwei 733099Gansu ProvinceChina

BACKGROUND Tuberculosis is among the most devastating infectious diseases *** tuberculosis is not easy to detect at an early stage,which without effective treatment often leads to spinal deformity and spinal cord damage which in turn cause complications such as paraplegia and *** this study,we established a model using three concentrations of bacteria and carried out a comprehensive evaluation of the model by imaging,general observations,and histopathological and bacteriological *** To establish a rabbit model of spinal tuberculosis and examine the effect on the model’s efficacy using different concentrations of Mycobacterium tuberculosis(***)*** New Zealand rabbits were randomly divided into experimental,control and blank *** experimental and control animals were sensitized with complete Freund′s adjuvant,a hole was drilled beneath the upper endplate of the L6 vertebral body and filled with gelfoam *** experimental group was divided into three subgroups(experimental 1,experimental 2,experimental 3)and infused with *** suspension at various *** control group was inoculated with saline and the blank group received no *** 12-week post-operative survival rates were 100%,80%and 30%in the experimental groups inoculated with concentrations of 106,107 and 108 CFU/mL bacteria,*** The survival rate of the control and blank groups was 100%.Vertebral body destruction at 8 weeks in the three experimental groups as determined by X-ray analysis was 33.3%,62.5%and 66.7%,and by computed tomography(CT)and 3-dimensional CT 44.4%,75%and 100%,*** 12 weeks,the figures were 44.4%,75%and 100%by X-ray analysis and 44.4%,100%and 100%by CT and 3-dimensional CT,*** surviving rabbits of the experimental groups had vertebral *** positive bacterial culture rates were 22.2%,75%and 66.7%,respectively,in the experimental *** being

关键词： Spinal tuberculosis Animal model H37RV Mycobacterium tuberculosis New Zealand rabbits

Relationships between Springtime Sea Surface Temperatures in Different Indian Ocean Domains and Various Asian Monsoons from Late Spring to the Following Summer

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2023年第3期37卷 307-323页

作者： Kangtai CHEN song yang School of Atmospheric Sciences Sun Yat-sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082 Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen UniversityZhuhai 519082

We investigate the relative importance of spring sea surface temperatures(SSTs)in different Indian Ocean(IO)domains,especially the northern and southern IO,for the development and intensity of the Asian summer *** performing unsupervised neural network analysis,the self-organizing map,we extract distinct patterns of springtime IO *** results show that the uniform warming(cooling)of the southern IO plays a crucial role in the warming(cooling)of both the basin-wide IO and tropical *** southern IO thus well represents the associations of basinwide IO and tropical IO with the Asian summer monsoon,and is instrumental in the relationship between the IO and summer monsoon.A warming in the southern IO is closely related to the weakening of large-scale meridional monsoon circulation in May and summer(June–August),including suppression of the South Asian monsoon development in May and the East Asian monsoon in *** the other hand,a warming in the northern IO appears to be associated with an earlier South Asian monsoon onset and a stronger East Asian *** summer,the connection of the springtime IO SST with the South Asian monsoon weakens,but that with the East Asian monsoon ***,a robust negative correlation is found between the warming of various IO domains and the development and intensity of the Southeast Asian monsoon.

关键词： self-organizing map Indian Ocean sea surface temperature development and intensity of the Asian summer monsoon

BYSpec: An Automatic Data Reduction Package for BFOSC and YFOSC Spectroscopic Data

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2025年第2期25卷 184-198页

作者： Zi-Chong Zhang Jun-Bo Zhang Ju-Jia Zhang De-yang song Jing Chen Ming-Yi Ding Nan Zhou Liang Wang Kai Zhang Nanjing Institute of Astronomical and Optics & Technology Chinese Academy of Sciences CAS Key Laboratory of Astronomical Optics & Technology Nanjing Institute of Astronomical Optics & Technology University of Chinese Academy of Sciences CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences Yunnan Observatories Chinese Academy of Sciences International Centre of Supernovae Yunnan Key Laboratory

BFOSC and YFOSC are the most frequently used instruments in the Xinglong 2.16 m telescope and Lijiang 2.4 m telescope, respectively. We developed a software package named “BYSpec”(BFOSC and YFOSC Spectra Reduction Package) dedicated to automatically reducing the long-slit and echelle spectra obtained by these two instruments. The package supports bias and flat-fielding correction, order location, background subtraction, automatic wavelength calibration, and absolute flux calibration. The optimal extraction method maximizes the signal-to-noise ratio and removes most of the cosmic rays imprinted in the spectra. A comparison with the 1D spectra reduced with IRAF verifies the reliability of the results. This open-source software is publicly available to the community.

关键词： instrumentation: spectrographs methods: data analysis techniques: image processing

太湖县花凉亭水库流域地下水水化学特征及水质评价

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

环境科学 2025年第2期46卷 809-820页

作者：刘海黄健敏宋阳赵国红王旭东魏伟安徽省公益性地质调查管理中心合肥230091 四川农业大学建筑与城乡规划学院成都611830

以太湖县花凉亭水库流域为研究对象,采集了42组井水样品和20组泉水样品测定了主要水化学指标,综合运用数理统计、Piper图、Gibbs图、离子比值和因子分析等方法研究了研究区井水和泉水的特征及控制因素,基于熵权质量指数(EWQI)评价了井... 详细信息

以太湖县花凉亭水库流域为研究对象,采集了42组井水样品和20组泉水样品测定了主要水化学指标,综合运用数理统计、Piper图、Gibbs图、离子比值和因子分析等方法研究了研究区井水和泉水的特征及控制因素,基于熵权质量指数(EWQI)评价了井水和泉水的水质,根据健康风险评价模型(HHRA)对井水和泉水的NO_(3)^(-)的潜在风险进行了评估.结果表明,研究区井水和泉水整体呈弱碱性,优势阳离子和阴离子分别为Na^(2+)、Ca^(2+)和HCO_(3)^(-),水化学类型主要为HCO_(3)-Na·Ca型;井水和泉水形成主要受岩石风化作用和阳离子交替吸附作用控制,井水和泉水中Ca^(2+)、Mg^(2+)和HCO_(3)^(-)的主要来源为碳酸岩盐溶解,农业活动、生活污水排放等导致Na^(+)、Cl^(-)和NO_(3)^(-)的富集;研究区井水和泉水水质整体较好,为良好至优良等级,健康风险评价表现为男人、女人和儿童均具有较低的非致癌风险,但儿童的健康风险明显高于成人.研究成果可为花凉亭水库流域地下水资源可持续开发利用和保护提供参考.

关键词：水化学特征水岩作用熵权质量指数健康风险花凉亭水库

TAVR对重度主动脉瓣狭窄患者心电重构的改善作用

在线全文

学校读者我要写书评

暂无评论

中华心血管病杂志 2025年第1期53卷 56-60页

作者：王裕星杨松于铭刘珍竹梅佳杰曲鹏大连医科大学附属第二医院心内科大连116021

目的探讨经皮主动脉瓣置换术(TAVR)对重度主动脉瓣狭窄患者心电重构的改善作用及其影响因素。方法本研究为队列研究。收集2018年6月至2023年3月就诊于大连医科大学附属第二医院, 明确诊断为重度主动脉瓣狭窄且成功实施TAVR的患者的资料,... 详细信息

目的探讨经皮主动脉瓣置换术(TAVR)对重度主动脉瓣狭窄患者心电重构的改善作用及其影响因素。方法本研究为队列研究。收集2018年6月至2023年3月就诊于大连医科大学附属第二医院, 明确诊断为重度主动脉瓣狭窄且成功实施TAVR的患者的资料, 包括术前、术后1周、术后3个月的标准15导联心电图、超声心动图等, 测量并计算心电图侧壁导联的平均ST段压低程度、T波振幅。观察心电图指标的变化, 采用Spearman相关性分析探讨心电图各指标与超声心动图各指标的相关性, 采用多元线性回归分析探讨TAVR术后重度主动脉瓣狭窄患者心电重构改善的影响因素。结果共纳入33例重度主动脉瓣狭窄患者, 年龄为(73±9)岁, 其中男性15例(45%)。心电图ST段压低程度、主动脉瓣上血流速度、峰值跨主动脉瓣压力、平均跨主动脉瓣压力在术后1周即得到明显改善(P均<0.05);心电图T波低平或倒置、左心室质量、左心室质量指数的显著改善发生于TAVR术后3个月(P均<0.05)。Spearman相关性分析结果显示, ST段压低程度与主动脉瓣上血流速度、峰值跨主动脉瓣压力、平均跨主动脉瓣压力相关(P均<0.05);T波振幅与左心室质量、左心室质量指数、左心室舒张末内径、左心室射血分数相关(P均<0.05)。多元线性回归分析结果显示, 主动脉瓣上血流速度是ST段压低水平的独立影响因素(β=-0.156, P=0.007), 左心室质量指数是T波振幅的独立影响因素(β=-2.007, P=0.001)。结论重度主动脉瓣狭窄患者TAVR术后心电重构得到改善, 可能与主动脉瓣开放后心脏灌注的改善及左心室肥厚的消退有关。

关键词：主动脉瓣狭窄经皮主动脉瓣置换术心电重构