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涂层刀具圆孔与直槽混合微织构激光制备工艺研究

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机械研究与应用 2024年第1期37卷 36-39页

作者：王栋梁易湘斌张继林兰州工业学院绿色切削加工技术及应用甘肃省高校重点实验室甘肃兰州730050 兰州工业学院甘肃省精密加工技术及装备工程研究中心甘肃兰州730050

针对刀具微织构激光制备质量欠佳的问题,文章研究了激光工艺参数对混合型织构表面形貌、几何尺寸和表面成分的影响规律。实验结果表明:对于涂层刀具表面圆孔和直槽混合微织构的制备,较为合理的激光参数为:加工次数N=6,扫描速度v=10 mm/s... 详细信息

针对刀具微织构激光制备质量欠佳的问题,文章研究了激光工艺参数对混合型织构表面形貌、几何尺寸和表面成分的影响规律。实验结果表明:对于涂层刀具表面圆孔和直槽混合微织构的制备,较为合理的激光参数为:加工次数N=6,扫描速度v=10 mm/s,激光功率P=20 W,激光频率f=120 kHz。涂层刀具织构底部和侧壁的结构以氧化物为主,在合理选择激光参数的情况下,刀具表面织构以外的涂层不会被破坏。通过涂层刀具混合微织构激光制备工艺的研究发现,织构宽度和深度的控制是制备微织构刀具的关键,所得规律为提高刀具织构加工质量提供参考依据。

关键词：涂层刀具激光微织构 EDS分析

母乳宏量营养素水平与婴儿生长发育关系的研究

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中国食物与营养 2024年第4期30卷 83-88页

作者：陈佐倩杨振宇赖建强蒋俊俊梁浩广西医科大学生命科学研究院南宁530021 中国疾病预防控制中心营养与健康所北京100050

目的:分析母乳中蛋白质、脂肪、碳水化合物这三类宏量营养素水平与婴儿生长发育的关系。方法:本研究来源中国母乳成分数据库,采用横断面调查设计。在华北、东北、华东、华南、西南、西北招募6481名健康乳母,采用随机抽样抽取858份母乳,... 详细信息

目的:分析母乳中蛋白质、脂肪、碳水化合物这三类宏量营养素水平与婴儿生长发育的关系。方法:本研究来源中国母乳成分数据库,采用横断面调查设计。在华北、东北、华东、华南、西南、西北招募6481名健康乳母,采用随机抽样抽取858份母乳,利用Miris人乳成分分析仪测定母乳中蛋白质、脂肪、碳水化合物水平,并测量婴儿体重、身长、头围等生长指标。采用GLM模型(Generalized linear Model)分析母乳宏量营养素水平与婴儿体格发育指标之间的关联。结果:母乳蛋白质水平与WAZ(年龄别体重z评分)显著正关联(β=0.17,P0.05;LAZ中,β=-0.008,P>0.05;HCZ中,β=0.033,P>0.05;WAZ中,β=0.043,P>0.05;WLZ中,β=0.054,P>0.05)。母乳碳水化合物水平与LAZ(年龄别身长z评分)显著正关联(β=0.19,P<0.01)。结论:母乳蛋白质水平与婴儿体重、母乳碳水化合物水平与婴儿身长可能存在正关联。

关键词：母乳宏量营养素婴儿生长发育

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溃坝的二维和三维数值模拟分析

工程与建设 2024年第2期38卷 351-355,386页

作者：方卓然孙亮王圣浩杨泽旺李纪森武汉理工大学船海与能源动力工程学院湖北武汉430063

为了分析溃坝水流在演进过程中的水位变化和建筑物所受到的冲击荷载,基于开源计算流体力学工具箱OpenFOAM建立了二维和三维溃坝的数值模型,并使用流体体积法追踪水和空气的自由界面。二维分析中考虑了下游只有水、下游同时有水和建筑物... 详细信息

为了分析溃坝水流在演进过程中的水位变化和建筑物所受到的冲击荷载,基于开源计算流体力学工具箱OpenFOAM建立了二维和三维溃坝的数值模型,并使用流体体积法追踪水和空气的自由界面。二维分析中考虑了下游只有水、下游同时有水和建筑物两种工况下的水位变化过程。三维分析中考虑了下游无水、下游无水但有建筑物时两种工况下的水位变化过程和建筑物上的冲击压力变化过程。通过将数值结果与模型试验数据进行对比,验证了二维和三维数值结果的准确性。进一步分析了三维溃坝过程中多个建筑物所受到的冲击荷载,为洪水中建筑物的安全评估提供一定的依据。

关键词：溃坝两相流 OpenFOAM 冲击荷载

Early electrical field stimulation prevents the loss of spinal cord anterior horn motoneurons and muscle atrophy following spinal cord injury

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Neural Regeneration Research 2018年第5期13卷 869-876页

作者： Cheng Zhang Wei Rong Guang-hao Zhang Ai-Hua Wang Chang-Zhe Wu Xiao-lin Huo Beijing Key Laboratory of Bioelectromagnetism Institute of Electrical Engineering Chinese Academy of Sciences Beijing China Department of Orthopedics Beijing Tsinghua Changgung Hospital Medical Center Tsinghua University Beijing China University of Chinese Academy of Sciences Beijing China

Our previous study revealed that early application of electrical field stimulation（EFS） with the anode at the lesion and the cathode distal to the lesion reduced injury potential, inhibited secondary injury and was neuroprotective in the dorsal corticospinal tract after spinal cord injury（SCI）. The objective of this study was to further evaluate the effect of EFS on protection of anterior horn motoneurons and their target musculature after SCI and its mechanism. Rats were randomized into three equal groups. The EFS group received EFS for 30 minutes immediately after injury at T_（10）. SCI group rats were only subjected to SCI and sham group rats were only subjected to laminectomy. Luxol fast blue staining demonstrated that spinal cord tissue in the injury center was better protected; cross-sectional area and perimeter of injured tissue were significantly smaller in the EFS group than in the SCI group. Immunofluorescence and transmission electron microscopy showed that the number of spinal cord anterior horn motoneurons was greater and the number of abnormal neurons reduced in the EFS group compared with the SCI group. Wet weight and cross-sectional area of vastus lateralis muscles were smaller in the SCI group to in the sham group. However, EFS improved muscle atrophy and behavioral examination showed that EFS significantly increased the angle in the inclined plane test and Tarlov＇s motor grading score. The above results confirm that early EFS can effectively impede spinal cord anterior horn motoneuron loss, promote motor function recovery and reduce muscle atrophy in rats after SCI.

关键词： nerve regeneration spinal cord injury electrical field stimulation anterior horn motoneurons vastus lateralis muscle Tarlov's motor grading scale inclined plane test choline acetyltransferase transmission electron microscopy neural regeneration

基于超导单光子探测器的红外光学系统噪声分析和优化

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物理学报 2024年第6期73卷 360-367页

作者：周飞陈奇刘浩戴越魏晨袁杭王昊涂学凑康琳贾小氢赵清源陈健张蜡宝吴培亨南京大学电子科学与工程学院超导电子学研究所南京210023 网络通信与安全紫金山实验室南京211111

高灵敏度的红外探测系统对于远距离探测有巨大的潜力,但光学系统内部的噪声会抑制探测系统的信噪比,从而降低探测灵敏度与探测距离.本文基于红外超导纳米线单光子探测器,设计了一个工作在中红外波段的光学系统,构建了红外光学系统自发... 详细信息

高灵敏度的红外探测系统对于远距离探测有巨大的潜力,但光学系统内部的噪声会抑制探测系统的信噪比,从而降低探测灵敏度与探测距离.本文基于红外超导纳米线单光子探测器,设计了一个工作在中红外波段的光学系统,构建了红外光学系统自发辐射计算模型,理论分析了红外光学系统的信噪比和噪声特性.首次提出了利用高性能超导单光子探测器精确表征红外光学系统的微弱背景辐射光信号,为优化设计红外系统提供了依据.并且基于超导单光子探测器的光子计数能力,研究了光学系统的背景辐射对红外探测系统性能的影响,并优化了光学系统的性能.实验结果表明,超导单光子探测器对于分析红外光学系统具有较高的灵敏度,最小可分辨移动距离为2.74×10^(-2)mm,在黑体温度为100℃时,光子计数率提高了6.4×10^(4)cps(1 cps=1 cycle per second),光学系统的耦合效率提升了97%;在黑体温度为102℃时,光子计数率提高了9.1×10^(4)cps,光学系统的耦合效率提升了114%,降低了杂散辐射对探测系统的影响,同等条件下系统信噪比提升2.7倍,对于超导红外探测系统的应用研究具有重要意义.

关键词：红外光学系统超导单光子探测器灵敏度信噪比

Combination therapy of hydrogel and stem cells for diabetic wound healing

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World Journal of Diabetes 2022年第11期13卷 949-961页

作者： Jia-Na Huang hao Cao Kai-Ying liang Li-Ping Cui Yan Li School of Biomedical Engineering Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument Sun Yat-sen UniversityGuangzhou 510006Guangdong ProvinceChina Endocrinology Department Panyu Central HospitalGuangzhou 511400Guangdong ProvinceChina

Diabetic wounds(DWs)are a common complication of diabetes mellitus;DWs have a low cure rate and likely recurrence,thus affecting the quality of patients’*** traditional therapy cannot effectively improve DW closure,DW has become a severe clinical medical problem *** routine wound healing,DW is difficult to heal because of its chronically arrested inflammatory *** mesenchymal stem cells and their secreted cytokines can alleviate oxidative stress and stimulate angiogenesis in wounds,thereby promoting wound healing,the biological activity of mesenchymal stem cells is compromised by direct injection,which hinders their therapeutic *** form a three-dimensional network that mimics the extracellular matrix,which can provide shelter for stem cells in the inflammatory microenvironment with reactive oxygen species in DW,and maintains the survival and viability of stem *** review summarizes the mechanisms and applications of stem cells and hydrogels in treating DW;additionally,it focuses on the different applications of therapy combining hydrogel and stem cells for DW treatment.

关键词： Combination therapy Mesenchymal stem cells Hydrogel Diabetic wound Cells delivery Wound healing

Genome-wide association study of callus induction variation to explore the callus formation mechanism of rice

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Journal of Integrative Plant Biology 2019年第11期61卷 1134-1150页

作者： Zhaoyang Zhang Hu Zhao Wei Li Jiemin Wu Zaihui Zhou Fei Zhou hao Chen Yongjun lin National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University

Rice(Oryza sativa) is one of the most widely cultivated food crops, worldwide. Tissue culture is extensively used in rice breeding and functional genome research. The ability to induce callus determines whether a particular rice variety can be subjected to tissue culture and Agrobacterium-mediated transformation. Over the past two decades, many quantitative trait loci(QTLs)related to callus induction traits have been identified;however, individual genes associated with rice callus induction have not been reported. In this study, we characterized three callus-induction traits in a global collection of 510 rice accessions. A genome-wide association study of the rice population in its entirety as well as subpopulations revealed 21 significant loci located in rice callus induction QTLs. We identified three candidate callus induction genes, namely CRL1, Os BMM1, and Os SET1, which Rese are orthologs of Arabidopsis LBD17/LBD29, BBM, and SWN,respectively, which are known to affect callus ***, we predicted that 14 candidate genes might be involved in rice callus induction and showed that RNA interference(RNAi)-mediated disruption of Os IAA10 inhibited callus formation on tissue culture *** growth in the Os IAA10 RNAi line was not inhibited by synthetic auxin(2,4-D) treatment, suggesting that Os IAA10 may perceive auxin and activate the expression of downstream genes, such as CRL1, to induce callus formation. The significant loci and candidate genes identified here may provide insight into the mechanism underlying callus formation in rice.

关键词： breeding crops

基于列线图建立儿童双眼屈光不均衡的风险因素模型及应用价值探讨

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中国现代医学杂志 2024年第11期34卷 14-19页

作者：邱明忠邹美波赵晨皓钱汉良江苏大学附属医院眼科江苏镇江212001

目的探讨儿童双眼屈光不均衡的风险因素。方法回顾性分析2020年1月—2022年12月在江苏大学附属医院眼科接受视力检查的156例儿童的临床资料,根据检查结果分为屈光正常组82例和屈光不均衡组74例。收集两组儿童的性别、年龄、体质量指数... 详细信息

目的探讨儿童双眼屈光不均衡的风险因素。方法回顾性分析2020年1月—2022年12月在江苏大学附属医院眼科接受视力检查的156例儿童的临床资料,根据检查结果分为屈光正常组82例和屈光不均衡组74例。收集两组儿童的性别、年龄、体质量指数、睡眠时间、用眼时间、阅读距离、眼部家族病史等资料;采用眼科光学生物测量仪和角膜地形图仪等仪器检测两组儿童的视力测试指标,包括眼压、角膜前表面平均屈光力、等效球镜度、眼轴长度、瞳孔直径、功能性光学区、球差和彗差;采用多因素Logistic回归模型分析筛选儿童双眼屈光不均衡的风险因素,构建列线图预测模型,并评价模型的拟合效果。结果屈光不均衡组儿童的用眼时间更长(P<0.05),眼部疾病家族史比例、双眼眼压、屈光力、等效球镜度、眼轴长度和瞳孔直径的差值及高阶像差均高于屈光正常组(P<0.05),而每日睡眠时间、阅读距离和功能性光学区均低于屈光正常组(P<0.05)。多因素Logistic回归分析结果显示,眼部家族病史[OR=13.523(95%CI:3.358,54.461)]、睡眠时间[OR=0.064(95%CI:0.023,0.179)]、用眼时间[OR=21.424(95%CI:6.121,74.983)]、阅读距离[OR=0.087(95%CI:0.036,0.211)]、眼压差值[OR=86.960(95%CI:14.687,514.897)]、角膜屈光力差值[OR=1.736(95%CI:1.043,2.890)]、等效球镜度差值[OR=12.937(95%CI:4.300,38.925)]、眼轴长度差值[OR=29.077(95%CI:10.166,83.170)]、瞳孔直径差值[OR=14.179(95%CI:4.880,41.198)]、功能性光学区差值[OR=0.495(95%CI:0.291,0.844)]、球差[OR=68.843(95%CI:16.304,290.687)]、彗差[OR=2.085(95%CI:1.007,4.318)]均是儿童双眼不均衡的风险因素(P<0.05)。结论儿童的用眼习惯和眼部检测指标均是影响其双眼屈光不均衡的重要因素,针对这些因素可以及时采取干预措施,防止儿童屈光异常的发生。

关键词：屈光不均衡列线图模型角膜前表面平均屈光力等效球镜度多因素分析

Numerical investigation of natural convection characteristics of a heat pipe-cooled passive residual heat removal system for molten salt reactors

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Nuclear Science and Techniques 2020年第7期31卷 25-33页

作者： Cheng-Long Wang hao Qin Da-lin Zhang Wen-Xi Tian Guang-Hui Su Sui-Zheng Qiu Department of Nuclear Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

The limited availability of studies on the natural convection heat transfer characteristics of fluoride salt has hindered progress in the design of passive residual heat removal systems(PRHRS)for molten salt *** paper presents results from a numerical investigation of natural convection heat transfer characteristics of fluoride salt and heat pipes in the drain tank of a *** results are compared with experimental data,demonstrating the accuracy of the calculation *** distribution of fluoride salt and heat transfer characteristics are obtained and *** radial temperature of liquid fluoride salt in the drain tank shows a uniform distribution,while temperatures increase with increase in axial height from the bottom to the top of the drain *** addition,natural convection intensity increases with increase in height of the heat pipes in the *** between heat pipes has no obvious effect on the natural convection heat transfer *** study will contribute to the design of passive heat removal systems for advanced nuclear reactors.

关键词： passive characteristics pipes