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轴压荷载对混凝土碳化的影响机理及模型研究

建材世界 2024年第2期45卷 40-44页

作者：孙书琪熊传胜李媛媛青岛理工大学土木工程学院青岛266525

通过对普通混凝土进行轴压荷载-碳化耦合试验,研究轴压荷载对普通混凝土碳化的影响机理。利用MATLAB对试验数据进行拟合,建立考虑荷载作用的混凝土碳化预测模型,分析轴压荷载对混凝土碳化深度的影响。结果表明:混凝土的碳化深度随载荷(... 详细信息

通过对普通混凝土进行轴压荷载-碳化耦合试验,研究轴压荷载对普通混凝土碳化的影响机理。利用MATLAB对试验数据进行拟合,建立考虑荷载作用的混凝土碳化预测模型,分析轴压荷载对混凝土碳化深度的影响。结果表明:混凝土的碳化深度随载荷(率)的增加而增加,且与CO_(3)^(2-)离子的含量息息相关。对碳化后距离混凝土表面CO_(3)^(2-)离子的含量进行拟合,得到CO_(3)^(2-)离子的扩散系数随时间变化的模型,并通过质量守恒和Fick定律建立了轴压荷载作用下普通混凝土碳化的模型,模拟结果与试验结果具有较好的一致性。

关键词：轴压荷载碳化影响机理碳化模型

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Three-dimensional dynamic contrast-enhanced MR angiography for evaluating recipient vessels in orthotopic liver transplantation

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hepatobiliary & Pancreatic Diseases International 2008年第5期7卷 476-480页

作者： Bian, Jie Sha, Lin Yang, Chao Sun, chuan-shu Dalian Med Univ Affiliated Hosp 2 Dept Radiol Dalian 116027 Peoples R China

BACKGROUND: With the improvement of MR technology, three-dimensional dynamic contrast-enhanced MR angiography (3D-DCE-MRA) may be the optimal vascular imaging method for preoperative evaluation of liver transplantation candidates. This study was undertaken to determine the value of 3D-DCE-MRA in the assessment of recipient vessels in orthotopic liver transplantation (OLT). METHODS: The surgical and pathological records were taken as the 'gold standards'. Eighteen cases of OLT were retrospectively analyzed to assess the image quality of MRA, including the signal-to-noise ratio (SNR) in arteries and veins, depiction of vascular variation and vessel disease, and the accuracy of vascular diameter measurement. RESULTS: 3D-DCE-MRA of 34 cases was carried out before OLT. The rates (excellent and good) showing hepatic arteries and portal vein for 3D-DCE-MRA were 94.1% (32/34) and 88.2% (30/34), respectively. The SNRs of the celiac axis and portal vein measurements from 3D-DCE-MRA were 20.58 +/- 3.74 and 13.43 +/- 4.12, and the mean diameters were 3.4 +/- 0.3 rum and 13.1 +/- 3.2 mm, respectively. There were 5 cases of vessel variation according to the Michel's classification. Of the 34 patients, 18 were compared radiologically and pathologically. The accuracy of depiction of the hepatic artery and portal vein with 3D-DCE-MRA was 100% for both; 3D-DCE-MRA precisely assessed 4 cases of more than moderate stenosis in hepatic arteries, 2 cases of small-caliber hepatic artery, 3 cases of venous stenosis at the second porta hepatis, 6 cases of collateral vasculature, I case of portal vein thrombosis and I case of portal vein aneurysm; all were confirmed pathologically. CONCLUSION: 3D-DCE-MRA may be the first choice for recipient vascular assessment before OLT.

关键词： magnetic resonance angiography liver transplantation

Wnt5a-Frizzled-2通路与缺血再灌注损伤的研究现状

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中国临床药理学杂志 2024年第13期40卷 1972-1976页

作者：孙志鹏董树素马川程王琛莹陈飞王海英济宁医学院临床医学院山东济宁272067 济宁医学院第二临床医学院山东济宁272067 济宁医学院基础医学院山东济宁272067 济宁医学院生理学教研室山东济宁272067

Wnt信号通路包括经典通路和非经典通路,Wnt5a-Frizzled-2通路参与非经典通路中的Wnt/Ca^(2+)信号通路,该通路由Wnt相关蛋白Wnt5a与其配体Frizzled-2结合后被激活,可调控细胞中的部分关键位点影响细胞的信号转导,且与细胞的生长进程密切... 详细信息

Wnt信号通路包括经典通路和非经典通路,Wnt5a-Frizzled-2通路参与非经典通路中的Wnt/Ca^(2+)信号通路,该通路由Wnt相关蛋白Wnt5a与其配体Frizzled-2结合后被激活,可调控细胞中的部分关键位点影响细胞的信号转导,且与细胞的生长进程密切相关。在某些血供丰富的组织,如心脏和脑组织等发生缺血再灌注时,均存在Wnt5a-Fizzled-2通路的激活。Wnt5a-Frizzled-2通路激活后引起细胞内钙超载,最终促进细胞凋亡。本文综述Wnt5a-Frizzled-2信号通路在缺血再灌注损伤类疾病中的异常激活和引起的钙超载导致细胞凋亡,以期为缺血再灌注损伤的生理机制研究提供参考。

关键词： Wnt5a-跨膜蛋白受体2通路细胞凋亡细胞自噬缺血再灌注损伤

Nanostructural thermoelectric materials and their perfor- mance

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Frontiers in Energy 2018年第1期12卷 97-108页

作者： Kai-Xuan CheN Min-Shan LI Dong-chuan MO shu-Shen LYU School of Chemical Engineering and Technology Sun Yat-senUniversity Guangzhou 510275 China Guangdong EngineeringTechnology Research Centre for Advanced Thermal Control Materialand System Integration (ATCMSI) Guangzhou 510275 China

In this review, an attempt was made to introduce the traditional concepts and materials in thermo- electric application and the recent development in search- ing high-performance thermoelectric materials. Due to the use of nanostructural engineering, thermoelectric materials with a high figure of merit are designed, leading to their blooming application in the energy field. One dimensional nanotubes and nanoribbons, two-dimensional planner structures, nanocomposites, and heterostructures were summarized. In addition, the state-of-the-art theoretical calculation in the prediction of thermoelectric materials was also reviewed, including the molecular dynamics （MD）, Boltzmann transport equation, and non-equilibrium Green＇s function. The combination of experimental fabrication and first-principles prediction significantly promotes the discovery of new promising candidates in the thermoelectric field.

关键词： nanostructuml low-dimensional thermoelec-tric material figure of merit first-principles

Large Eddy Simulation of Turbulent Fluid Flow in Liquid Metal of Continuous Casting

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Journal of Iron and Steel Research International 2013年第1期20卷 34-39,46页

作者： JI chuan-bo LI Jing-she YANG shu-feng SUN Li-yuan School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

The transient turbulent flow in continuous casting steel plays a key role in minimizing defects. Compared with the k-ε model, the large eddy simulation （LES） of turbulence provides much more accurate representation of turbulent flow by resolving large-scale dynamics. The turbulent flow in a liquid metal model of continuous casting has been simulated by LES and measured using ultrasonic Doppler velocimetry （UDV）. The result of measurement and LES has been compared to validate the LES model and furthermore enhance the understanding of the transient turbulent feature in the flow field. The results show that the jet exiting from the nozzle port swings, which is not steady, and turbulent velocity variation frequencies decreased with distance from the nozzle port region and also the LES mode can capture the high frequency fluctuation, which the measurement cannot detect.

关键词： LES turbulent flow nozzle mold continuous casting

Synthesis of linear and V-shaped oligo(phenylene ethynylene) derivatives:Geometric effects on photophysical properties

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Chinese Chemical Letters 2010年第1期21卷 97-100页

作者： Yuan, Si Chun Han, shu Liang Ge, Xing Wang, Hui chuan China Agr Univ Fundamental Sci Dept Beijing 102206 Peoples R China Peking Univ Coll Chem Minist Educ Key Lab Bioorgan Chem & Mol Engn Beijing 100871 Peoples R China

A series of linear and V-shaped oligo(phenylene ethynylene) derivatives 1-3 were synthesized through sequent Sonogashira coupling and propargyl alcohol deprotection reaction in high *** alkoxy chains(i.e.,n-hexyloxy groups) were introduced to assure good solubility of compounds 1-3 in common *** photophysical properties of 1-3 in solution depend strongly on the geometries of these compounds.

关键词： Sonogashira coupling Oligo(phenylene ethynylene) derivatives Geometric effect Photophysical property

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钢渣粗集料骨架间隙率变化规律及应用

科学技术与工程 2024年第19期24卷 8290-8296页

作者：俄广迅曹卫东陈鲁川刘树堂丁婷婷山东高速集团有限公司济南250098 山东大学齐鲁交通学院济南250002 山东省交通规划设计院集团有限公司济南250101

为指导钢渣沥青玛蹄脂碎石混合料(stone mastic asphalt,SMA)级配设计,采用混料试验设计方法与粗集料振实试验,研究了不同组合方案的钢渣粗集料、玄武岩粗集料及玄武岩与钢渣混合粗集料骨架间隙率(voids in coarse aggregate,VCA)变化规... 详细信息

为指导钢渣沥青玛蹄脂碎石混合料(stone mastic asphalt,SMA)级配设计,采用混料试验设计方法与粗集料振实试验,研究了不同组合方案的钢渣粗集料、玄武岩粗集料及玄武岩与钢渣混合粗集料骨架间隙率(voids in coarse aggregate,VCA)变化规律,建立了3类粗集料VCA与各档粗集料比例之间的回归模型。结果表明:钢渣粗集料VCA与各档粗集料比例之间呈多元非线性关系,玄武岩粗集料及钢渣与玄武岩混合粗集料的VCA亦为类似规律;相同级配下钢渣粗集料VCA的数值不同于玄武岩粗集料及钢渣与玄武岩混合粗集料。利用建立的回归模型可预测不同级配曲线的VCA大小次序进而预知矿料间隙率(voids in mineral aggregate,VMA)大小顺序,为SMA配合比优化设计中级配的确定提供依据。

关键词：钢渣粗集料骨架间隙率沥青玛蹄脂碎石混合料回归模型级配设计

Waveform Distortions in Femtosecond Laser Pulses Transmitting through Coated Optical Fiber Probes

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Chinese Physics Letters 2010年第6期27卷 221-224页

作者： LIU Gui-Yuan HAN Jun-Ling LIU Man TENG shu-Yun CheNG chuan-Fu College of Physics and Electronics Shandong Normal University Jinan 250014 School of Science Shandong 3ianzhu University Jinan 250101 Department of Electronic Engineering Jinan Vocational College Jinan 250103

We calculate the light field in metal-coated optical fiber probes under illumination of femtosecond laser pulses with the three-dimensional finite-difference time-domain method. By choosing the maximum of the calculated light field data in the time period of one light wave cycle at each spatial point, we obtain the amplitude distributions instead of the conventional light field distribution of a time instant. It is found that with an incident plane wave pulse of y-polarization, the output amplitude distributions of y-polarization have roughly a circled-cross-like pattern with two arc-like zero-amplitude zones. By analyzing the y-polarized waveforms versus time at the points near the arc-like zero-amplitude zones, we find that waveform distortions appear at points in the neighborhood of the zero amplitude lines and in the time intervals when two wave-packets overlap.

关键词： ELECTRIC distortion FEMTOSECOND lasers SURFACE coatings OPTICAL fibers FINITE differences TIME-domain analysis OPTICAL polarization

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堆肥低温启动菌剂的研制与效果评价

生态与农村环境学报 2024年第1期40卷 138-146页

作者：杨明珠许欢欢郭传旭夏燕维缪有志郑树林张瑞福江苏省固体有机废弃物资源化高技术研究重点实验室/南京农业大学资源与环境科学学院江苏南京210095 菏泽金正大生态工程有限公司山东菏泽710000

针对冬季低温堆肥启动困难这一技术问题,优化和复配低温复合菌剂,并在有机肥厂冬季堆肥生产中对菌剂的应用效果进行评估。选取分离于极地的菌株,对菌株低温生长特性、产蛋白酶性能进行测定,选择供试菌株边缘假单胞菌MP-1(Pseudomonas ma... 详细信息

针对冬季低温堆肥启动困难这一技术问题,优化和复配低温复合菌剂,并在有机肥厂冬季堆肥生产中对菌剂的应用效果进行评估。选取分离于极地的菌株,对菌株低温生长特性、产蛋白酶性能进行测定,选择供试菌株边缘假单胞菌MP-1(Pseudomonas marginalis)、硬结节杆菌AS-3(Arthrobacter scleromae)和水稻节杆菌AO-4(Arthrobacter oryzae)进行复配,3个菌株在15℃条件下均可快速生长,菌株MP-1、AS-3和AO-4于15℃条件下培养24 h,蛋白酶活性分别可达82.1、64.3和80.3 U·mL^(-1)。将3个菌株按照体积比2∶1∶1复配复合菌剂(IM)。利用中药渣、鸡粪和茶粕堆肥的原料浸提液进行菌剂生长试验,结果表明,IM菌剂在中药渣堆肥浸提液中24 h生长量为1.04×10^(10)cfu·mL^(-1);在鸡粪堆肥浸提液中生长量为1.41×10^(10)cfu·mL^(-1);在茶粕浸提液中生长量为3.6×10^(6)cfu·mL^(-1)。将IM复合菌剂应用于有机肥厂冬季堆肥生产中,设置市售常规堆肥接种剂为对照,结果表明IM菌剂可有效促进冬季低温环境下鸡粪堆肥快速启动,启动阶段IM处理升温速度为19.4℃·d^(-1),对照组为15.84℃·d^(-1);与对照处理相比,IM提前3 d进入高温期;堆肥35 d时,处理组全磷和全钾含量分别增加2.32和4.27个百分点,IM种子发芽指数(GI)可达到93.3%,比对照组高10.2个百分点。综上所述,接种IM菌剂可有效促进低温堆肥快速启动,缩短堆肥周期,促进有毒物质分解,加快低温堆肥的无害化进程,提高冬季低温堆肥效率。

关键词：堆肥低温启动微生物菌剂农业固体废弃物