Computer Simulating of Through or part-through Fatigue Crack Propagation

根据疲劳裂纹扩展的规律，对等幅和变幅谱载下CCT及PS（T）试件的疲劳裂纹扩展进行了计算机模拟。其结果经疲劳试验考评，误差在40%以内，能满足疲劳分析的要求。According to characters of Fatigue crack propagation,we imitated the tests of CCT and PS(T) by computer under constant amplitude and varied amplitude spectrum loading.The errors are about 40% aFter comparing the results of computer simulating and experiment test.It is possible that computer simulating may eFFectively take the place of Fatigue crack propagation tests

Establishment of a nude mouse model of glioma orthotopic xenograft with double-fluorescent labeling

目的建立一种稳定、可实时监测的胶质瘤原位移植瘤裸鼠模型。方法用带有荧光素酶（luciferase-Luc）和绿色荧光蛋白（green fluorescent protein-GFP）基因的慢病毒感染U251神经胶质瘤细胞,流式细胞仪筛选稳定表达GFP-Luc荧光的细胞系,并通过CCK-8实验、细胞周期实验、Transwell肿瘤迁移及侵袭实验等评价荧光细胞的增殖、迁移和侵袭能力是否改变;将细胞接种至裸鼠大脑尾状核,建立胶质瘤原位移植瘤模型,利用小鼠活体成像系统监测脑内肿瘤的生长情况,并通过石蜡切片,HE染色评价细胞在裸鼠脑内的病理特征及成瘤能力。结果成功构建稳定表达GFP荧光和luciferase荧光的U251胶质瘤细胞系及动物模型,慢病毒整合并未改变细胞的增殖、迁移及侵袭能力;模型生长周期适中,成瘤率高,瘤体在颅内生长稳定,HE切片符合人胶质瘤特征。结论双荧光标记的胶质瘤细胞相比于传统细胞更有利于胶质瘤动物模型的实验研究;U251-GFP-Luc胶质瘤细胞裸鼠模型,其肿瘤生长和病理特性与人胶质瘤相似,且可实时观察肿瘤生长,可作为胶质瘤实验研究的理想动物模型。Objective To establish a stable and real-time monitorable nude mouse model of orthotopic glioma xenograft. Methods U251 glioma cell line was infected by a leutiviral vector containing green fluorescent protein （GFP） and luciferase （Luc） gene. Ceils stably expressing fluorescence of GFP and Luc were sorted by flow cytometry. CCK-8 test and Transwell tumor invasion and migration assay were used to compare the biological features between the ceils stably expressing GFP-Luc fluorescence and cells without fluorescence. Then the ceils were implanted intracranially in the right caudate nucleus of athymic BaIb/c nude mice to establish the tumor model. The growth of intracerebral tumor was monitored over time by a bioluminescence imaging （BLI） system. Hematoxylin-eosin （HE） staining was used to evaluatethe histopathological features and tumorigenicity of the transplanted glioma cells in the brain of nude mice. Results U251 glioma cell line with stably expressing GFP-Luc fluorescence and the corresponding orthotopic xenograft model were successfully established. There was no statistically significant difference in the proliferation, invasion and migration abilities between the cells with stably expressing GFP-Luc fluorescence and the control cells. This model showed a high tumor formation rate and stable tumor growth, and takes a moderate time to establish this model. Conclusions Compared with the traditional glioma cells, GFP-Luc-transfected human glioma cells are more feasible for the studies of glioma in vivo. The tumor growth and pathological characteristics in this U251-GFP-Luc glioma model are similar to human glioma, and the growth of this tumor can be real-time monitored. It can be used as an ideal animal model for experimental studies of glioma.国家自然科学基金（编号：30970733）

Research and fabrication of silicon based metal-semiconductor-metal photodetector with U-shape trench interdigitated electrodes

为了提高硅MSM结构光电探测器的光电响应度,制备了U型凹槽电极结构的探测器。5 V偏压下,对650 nm波长入射光的绝对光电响应度测试表明,凹槽电极结构的探测器最大光电响应度值为0.486 A/W,比同样尺寸的平版结构光电探测器提高了约6倍。文中也对比了具有抗反射膜和不具有抗反射膜的器件相对响应光谱的差别,并且比较分析了叉指间隙分别为5μm和10μm器件光电响应的不同。The responsivity of silicon based metal-semiconductor-metal(MSM) photodetector(Si-MSM-PD) was improved by placing the planar interdigitated electrodes with U-shape trench interdigitated electrodes.The performance test indicates that the responsivity of Si-MSM-PD with U-shape trench interdigitated electrodes is 0.486 A/W for 650 nm laser at 5 V applied voltage.This responsivity is about 6 times larger than that of Si-MSM-PD with planar interdigitated electrodes whose responsivity is just 0.084 A/W.Besides,the performance of Si-MSM-PDs with different intergitated space of 5 μm and 10 μm was compared.国家自然科学基金资助项目(60576001,60336010,60676027);; 福建省自然科学基金资助项目(A0410008

基于强化学习的能量采集物联网视频编码技术

物联网设备的视频压缩码率和量化参数等编码方案决定着视频质量和物联网设备的使用寿命.针对未知视频传输模型和能量采集模型的物联网设备,提出一种基于强化学习的视频编码方案,能够动态优化视频编码码率和量化参数.该技术根据物联网设备的无线信道带宽、电池水平和采集的能量,结合反馈的视频质量和时延等信息,采用强化学习算法优化选择视频编码码率和量化参数.在动态的网络环境下,物联网设备不需预知视频传输模型就可以综合优化视频质量和设备能量损耗.仿真结果表明,该方案可以提高视频质量,降低设备能量损耗和时延,改善物联网设备效益.国家自然科学基金（61671396）福建省自然科学基金（2019J01843）东南大学移动通信国家重点实验室开放基金（2018D08

聚苯胺对纳米CdS的光致发光增强效应

利用电化学脉冲沉积法在聚苯胺 ( PANI)膜上制备了纳米 Cd S/PANI复合膜 ,并利用扫描电镜光谱、紫外可见光谱、红外光谱、拉曼和荧光等光谱技术表征复合膜的形貌、结构及性质 .Cd S/PANI复合膜中Cd S微粒呈现量子尺寸效应 ;Cd S和 PANI间存在相互作用 ;由于聚苯胺和 Cd S能级的合适匹配 ,聚苯胺对Cd S的光致发光 ( PL)有增强效应 ,增强机理为光生载流子的传递机

Study on the Distributions of Lead and Cadmium in Rats by ICP-MS with Stable Isotope Tracer

采用稳定同位素示踪技术研究重金属元素铅、镉在大鼠体内的分布,通过对大鼠进行浓缩同位素206Pb、112Cd灌喂,解剖取其肝、肾、睾丸和心脏等脏器,通过相应的化学处理,用电感耦合等离子体质谱(ICP-MS)测量铅、镉元素在各个脏器中的含量及其同位素组成变化。根据同位素比值的变化研究Pb、Cd在各脏器中的分布、蓄积规律和各脏器对引入的浓缩同位素利用率。结果发现:重金属Pb和Cd蓄积的最主要场所是肝和肾,其次是睾丸和心脏,而在脑中的积累最少。在肝和肾中Cd的同位素利用率为0.0488%、0.0154%,Pb的同位素利用率为0.0101%、0.0078%,远高于其它脏器。与传统的方法相比较,该法具有更接近慢性中毒、危害性小,能将重金属来源分为天然来源和人为引入等特点。The distributions of lead and cadmium in rats were studied using stable isotope tracer technique.The rats were fed with enriched stable isotope 206Pb and 112Cd,then the liver,kidney,testicle and heart were eviscerated.After chemical treatment,the contents of lead and cadmium and their isotope ratios in each viscera were determined by ICP-MS.Experimental results showed that lead and cadmium accumulated mostly in liver and kidney,next in testicle and heart,and least in brain.The utilization rates of cadmium and lead isotopes in liver were 0.048 8% and 0.010 1%,respectively,and in kidney 0.015 4% and 0.007 8%,respectively.Compared with the traditional methods,the present method can differentiate the origins of lead and cadmium.福建省重大科技项目资助课题(2003Y005-04,2003Y003

福建城市化发展战略博士笔谈

2003年5月,“福建省博士创业促进会”在福州举办了福建省城市发展战略“博士月谈”,与会者主要是省内高校和科研单位的专家、博士。会上,大家用书面发表意见,畅所欲言,崇论宏议。本刊精选部分意见,以飨读者。相信这些意见对福建城市化问题研究的深化将起到积极的推动作用

聚苯胺纳米管在阳极氧化铝模板中电聚合的生长机理

利用阶跃电位、循环伏安等电化学方法,应用金属电沉积理论,研究聚苯胺纳米管在阳极氧化铝模板(AAO)内电聚合的生长机理.结果表明:电聚合初始,苯胺二维非扩散控制的瞬时成核生长形成聚苯胺晶胞链段单层,单层形成以后,聚苯胺的生长过程变为线性扩散控制.XRD实验进一步证实电聚合的聚苯胺同时包含结晶相和无定型相结构

基于核磁共振氢谱技术研究电针“内关”穴对心肌缺血再灌注损伤大鼠血清及心肌组织代谢物的影响

目的:基于核磁共振氢谱(1 H NMR)研究电针\"内关\"穴对心肌缺血再灌注损伤(MIRI)大鼠血清和心肌组织代谢物的影响,探讨电针\"内关\"穴对MIRI大鼠代谢模式的影响。方法:30只SD雄性大鼠随机分为对照组、模型组、电针组。对照组:不予电针,仅用鼠板束缚大鼠,每次20min,每日1次,持续7d;模型组予心肌缺血再灌注造模:至第7天后结扎冠状动脉左前降支40 min后恢复血流60 min;电针组(频率10Hz/50Hz,脉冲宽度0.5ms,强度1mA):每日电针双侧\"内关\"穴1次,时间20min,持续7d,于第7天电针后造模。造模结束后,收集3组大鼠的血清和心肌组织。利用1 H NMR进行代谢物检测并利用多元统计方法主成分分析(PCA)、正交偏最小二乘分析(OPLS-DA)进行模式识别。结果:与对照组相比,模型组大鼠血清的亮氨酸、异亮氨酸、缬氨酸、3-羟基丁酸、乳酸、丙氨酸、赖氨酸、醋酸盐、N-乙酰糖蛋白、丙酮、乙酰乙酸、琥珀酸、谷氨酰胺、多不饱和脂肪酸、肌酸、甘油磷酸胆碱、甘氨酸均浓度下降,低密度脂蛋白/极低密度脂蛋白、葡萄糖浓度上升;其中除丙酮、乙酰乙酸和多不饱和脂肪酸外,低密度脂蛋白/极低密度脂蛋白在电针后下降到接近对照组水平,其它代谢物浓度均在电针后上升到接近对照组水平,电针组大鼠血清的代谢模式更接近对照组。与对照组相比,模型组大鼠心肌组织的乳酸、丙氨酸、赖氨酸、谷氨酸、谷氨酰胺、天冬氨酸、甘油磷酸胆碱、肌酸、牛磺酸、甘氨酸、苏氨酸、腺苷一磷酸、烟酰胺腺嘌呤二核苷酸浓度下降,葡萄糖浓度明显上升;其中肌酸、甘油磷酸胆碱、烟酰胺腺嘌呤二核苷酸浓度在电针后上升,葡萄糖浓度在电针后下降;此外,电针组大鼠心肌组织苏氨酸、腺苷一磷酸浓度较模型组进一步下降;电针组大鼠心肌的代谢模式虽然有向对照组偏移的趋势,但与对照组差异还是较大。结论:电针\"内关\"穴可调节MIRI大鼠糖代谢、脂肪酸代谢、氨基酸代谢及能量代谢,对心肌具有一定的保护作用,但其具体的代谢通路及机制需要进一步研究。国家自然科学基金面上项目(No.81574080);;湖南省中医药管理局课题(No.201521);;湖南省高校创新平台开放基金项目(No.15k093

An Information Transmission System for the Wireless Electronic Balance

设计出一种以电阻应变式荷重传感器作为一次测量元件的无线电子吊秤信息传输系统．该系统利用两片８０Ｃ５１微处理器，通过其串行口加一套高频载波调制解调器，以点对点通讯的方式，实现了测量数据的无线电传输