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A Novel Three-parameter Flow Cytometric Analysis for Cell Cycle
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作者 冯永东 陶德定 +5 位作者 覃吉超 高纯 申漫里 冷艳 余源 龚建平 《The Chinese-German Journal of Clinical Oncology》 CAS 2005年第2期76-82,共7页
To set up a three-parameter method for cell cycle analysis by two-laser flowcy-tometer, which can detect two types of cyclin plus DNA content in one measurement, and thatanalyze unscheduled expression of cyclins. Meth... To set up a three-parameter method for cell cycle analysis by two-laser flowcy-tometer, which can detect two types of cyclin plus DNA content in one measurement, and thatanalyze unscheduled expression of cyclins. Methods: Three-color fluorescence was used for analysisof two types of cyclins and DNA content simultaneously in individual cells by two-laser flowcytometry. MOLT-4 cells were used to study the expression of major cyclins in mammalian cells. ATriton-X100 permeabilization procedure was optimized for detection of two types of cyclins. Onecyclin was stained directly with a FITC-conjugated monoclonal antibody (mAb), and the other,indirectly with RPE-Cy5-conjugated secondary antibody, while DNA was stained with the fluorochromeDAPI. mAMSA and mimosine treated MOLT-4 cells were used to test this three-parameter method.Results: Permeabilization with 0.5% Triton-XlOO in PBS containing 1% BSA for 5 min on ice providedoptimal conditions for the simultaneous labelling of two cyclins plus DNA in single cells. It wasfound that the emission spectrum of the three dyes (DAPI, FITC and RPE-Cy5) could be measured withno compensation. Based on cyclinA/cyclinE/DNA flow cytometric analysis, asynchronously growingMOLT-4 cells could be divided into 6 compartments (G1o, G1e, G1l, S, G2, and M) simultaneously,allowing for analysis of cell cycle phase specific perturbations without the necessity of cellsynchronization. Unscheduled cyclin B1 expression was observed in G1 cells treated with mimosine andcyclin E in G2 cells treated with mAMSA. We found that unscheduled cyclin expression paralleledexpected cyclin expression. Conclusion: Thus, three-color FCM analysis of cells may not only beapplied to measure unscheduled vs. expected cyclin expression but may also be used to estimate thefraction of cycling cells in up to 6 cell populations. 展开更多
关键词 cell cycle flow cytometry CYCLIN three-parameter ANALYSIS
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A three-parameter single-step time integration method for structural dynamic analysis 被引量:5
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作者 Huimin Zhang Yufeng Xing 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第1期112-128,I0004,共18页
The existing three-parameter single-step time integration methods, such as the Generalized-a method, improve numerical dissipation by modifying equilibrium equation at time points, which cause them to lose accuracy du... The existing three-parameter single-step time integration methods, such as the Generalized-a method, improve numerical dissipation by modifying equilibrium equation at time points, which cause them to lose accuracy due to the interpolation of load vectors. Moreover, these three-parameter methods do not present an available formulation applied to a general secondorder non linear differential equatio n. To solve these problems, this paper proposes an innovative three-parameter single-step method by introducing an additional variable into update equations. Although the present method is spectrally identical to the Generalized-cx method for undamped systems, it possesses higher accuracy since it strictly satisfies the equilibrium equation at time points, and can be readily used to solve nonlinear equations. By the analysis of accuracy, stability, numerical dissipation and dispersion, the optimal second-order implicit and explicit schemes are generated, which can maximize low-frequency accuracy when high-frequency dissipation is specified. To check the performance of the proposed method, several numerical experiments are conducted and the proposed method is compared with a few up-to-date methods. 展开更多
关键词 three-parameter SINGLE-STEP OPTIMAL SCHEME HIGHER ACCURACY
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Selection Method of Evaluation Indicators with Three-Parameter Interval Grey Number 被引量:1
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作者 Fanlin Meng Na Wang Bingjun Li 《Open Journal of Applied Sciences》 2015年第12期833-840,共8页
The evaluation problem with three-parameter interval grey number (T-PIGN) widely exists in real world. To select effective evaluation indicators of the problem, this paper puts forward evaluation index system selectio... The evaluation problem with three-parameter interval grey number (T-PIGN) widely exists in real world. To select effective evaluation indicators of the problem, this paper puts forward evaluation index system selection principle of T-PIGN based on distance entropy model, and gives out evaluation index system selection judgment criterion of T-PIGN. Furthermore, for the redundancy of evaluation index system with T-PIGN, a selection method of evaluation index system with T-PIGN is proposed. Finally, the applicability of the proposed method is verified by concrete examples. 展开更多
关键词 Evaluation INDICATORS Selection three-parameter INTERVAL GREY NUMBER GREY DISTANCE ENTROPY
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Two Probability Plots of the Three-Parameter Lognormal Distribution
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作者 蒋仁言 《Journal of Donghua University(English Edition)》 EI CAS 2014年第6期757-759,共3页
The two-parameter lognormal distribution is a variant of the normal distribution and the three-parameter lognormal distribution is an extension of the two-parameter lognormal distribution by introducing a location par... The two-parameter lognormal distribution is a variant of the normal distribution and the three-parameter lognormal distribution is an extension of the two-parameter lognormal distribution by introducing a location parameter. The Q-Q plot of the three-parameter lognormal distribution is widely used. To obtain the Q-Q plot one needs to iteratively try different values of the shape parameter and subjectively judge the linearity of the Q-Q plot. In this paper,a mathematical method was proposed to determine the value of the shape parameter so as to simplify the generation of the Q-Q plot. Then a new probability plot was proposed,which was more easily obtained and provided more accurate parameter estimates than the Q-Q plot. These are illustrated by three realworld examples. 展开更多
关键词 three-parameter lognormal distribution probability plot correlation coefficient model selection parameter estimation
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An Optimal Policy with Quadratic Demand, Three-Parameter Weibull Distribution Deterioration Rate, Shortages and Salvage Value
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作者 Pandit Jagatananda Mishra Trailokyanath Singh Hadibandhu Pattanayak 《American Journal of Computational Mathematics》 2016年第3期200-211,共12页
The present paper focuses an optimal policy of an inventory model for deteriorating items with generalized demand rate and deterioration rate. Shortages are allowed and partially backlogged. The salvage value is inclu... The present paper focuses an optimal policy of an inventory model for deteriorating items with generalized demand rate and deterioration rate. Shortages are allowed and partially backlogged. The salvage value is included into deteriorated units. The main objective of the model is to minimize the total cost by optimizing the value of the shortage point, cycle length and order quantity. A numerical example is carried out to illustrate the model and sensitivity analyses of major parameters are discussed. 展开更多
关键词 EOQ Quadratic Demand Salvage Value SHORTAGE three-parameter Weibull Deterioration Rate
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Study on Prediction Method of Structural Three-parameter Power Function P-S-N Curve
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作者 LIU Yujie DAI Zongmiao 《International Journal of Plant Engineering and Management》 2018年第2期65-70,共6页
This paper applies weighted least square method to estimate the three-parameter power function equation of the fatigue life curve, and uses comprehensive fatigue life coefficient to correct the equation, and at the sa... This paper applies weighted least square method to estimate the three-parameter power function equation of the fatigue life curve, and uses comprehensive fatigue life coefficient to correct the equation, and at the same time combines probability statistics method to bring out the prediction method of structure's three- parameter power function P-S-N curve, finally applies the prediction method to a ship's frame-type elevate, based on the fatigue test data of it's material-SA06 aluminium alloy, to obtain it's structure's three-parameter power function P-S-N curve. Compared with the conventional least square method, the presented method can give 展开更多
关键词 P-S-N curve comprehensive fatigue life coefficient three-parameter power function fatigue life
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[PMo_9V_3O_(40)]^(6-)硫代物的合成及光谱研究 被引量:1
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作者 陈达贵 张汉辉 +3 位作者 杨融生 孙瑞卿 杨齐瑜 余秀芬 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2000年第5期712-714,共3页
通过H2 S与杂多化合物 (NH4 ) 4H2 [PM9V3 O4 0 ]·10H2 O在DMF中反应合成了其硫代产物 。
关键词 杂多化合物 钒异金属硫桥簇合物 硫化物 光谱
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三氟乙氧基取代的吡啶衍生物的核磁氢谱及质谱研究 被引量:1
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作者 钱旭红 钱枫 +2 位作者 唐军 张荣 陈卫东 《分析化学》 SCIE EI CAS CSCD 北大核心 1994年第9期942-944,共3页
本文报道了三个由三氟乙氧基取代的氯代三氟甲基吡啶化合物的核磁共振氢谱及电子轰击质谱,结果表明,与己氧基化合物相对照,在'H-NMR中,由于三氟甲基的强吸电子作用,其次甲基移向低场,并给出了一组具有较大偶合常数的四重峰。在EIMS中,... 本文报道了三个由三氟乙氧基取代的氯代三氟甲基吡啶化合物的核磁共振氢谱及电子轰击质谱,结果表明,与己氧基化合物相对照,在'H-NMR中,由于三氟甲基的强吸电子作用,其次甲基移向低场,并给出了一组具有较大偶合常数的四重峰。在EIMS中,均存在较多的骨架重排离子峰,其中C—O,C—F,C—CF_3,键断裂及失去CO形成的五元,四元含氮杂环离子是重要质谱特征. 展开更多
关键词 三氟乙氧基 吡啶衍生物 NMR 氢谱
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食管癌患者血清蛋白指纹图谱的检测及食管癌诊断模型的建立 被引量:1
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作者 刘丽华 单保恩 +2 位作者 王士杰 孟君 王玲 《中国肿瘤生物治疗杂志》 CAS CSCD 北大核心 2009年第3期272-276,共5页
目的:利用蛋白质组学基质辅助激光解析离子化飞行时间质谱(matrix-assisted laser desorption/ionization time-of-flight mass spectrometry,MALDI-TOFMS)技术检测食管癌患者血清蛋白指纹图谱,建立食管癌蛋白指纹图谱诊断模型,探讨其... 目的:利用蛋白质组学基质辅助激光解析离子化飞行时间质谱(matrix-assisted laser desorption/ionization time-of-flight mass spectrometry,MALDI-TOFMS)技术检测食管癌患者血清蛋白指纹图谱,建立食管癌蛋白指纹图谱诊断模型,探讨其临床应用价值。方法:收集河北医科大学第四医院2008年5月至9月间胸外科食管癌患者血清32例和健康志愿者血清28例,采用弱阳离子交换蛋白质芯片(WCX磁珠)提纯血清蛋白,MALDI-TOFMS技术进行血清蛋白质质谱检测,所得结果用ZUCI-蛋白芯片数据分析系统进行分析。运用遗传算法结合支持向量机运算建立食管癌蛋白指纹图谱诊断模型;将60例标本随机分成训练组和盲法测试组,训练组为21名食管癌患者和19名健康人,盲法测试组为11名食管癌患者和9名健康人,验证诊断模型的特异性和敏感性。结果:采集食管癌患者和健康对照者的血清蛋白指纹图谱,经数据对比分析找到44个有显著性差异的质荷比峰(P<0.05);从中筛选出差异最显著的6个蛋白质荷比峰(m/z分别为2210、2864、6634、4068、2083和8131),并以此建立食管癌蛋白指纹图谱诊断预测模型;验证该模型诊断食管癌的特异性为88.9%、敏感度为100%。结论:应用MALDI-TOFMS技术检测食管癌患者血清蛋白指纹图谱建立的食管癌蛋白指纹图谱诊断模型在食管癌的诊断中具有较高的敏感度和特异性。 展开更多
关键词 食管癌 基质辅助激光解析离子化飞行时间质谱 蛋白指纹图谱 诊断模型
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PbSnS_3纳米棒的光学性质
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作者 侯俊钦 杨一军 王春瑞 《淮北煤师院学报(自然科学版)》 2002年第4期31-33,共3页
本文用拉曼谱和光致发光谱研究了PbSnS3纳米棒的光学性质.PbSnS3纳米棒的拉曼谱可用两种声子模式解析.PbSnS3纳米棒在紫外线激发下发蓝光.
关键词 PbSnS3纳米棒 光学性质 拉曼谱 光致发光谱 纳米材料 三元半导体
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F/Cl比与BaFCl:Eu^(2+)中的F心 被引量:2
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作者 王振家 熊光楠 徐叙瑢 《功能材料》 EI CAS CSCD 1993年第1期55-59,共5页
BaFCl:Eu^(2+)是一种优良的X射线存储成像材料,其X射线存储及光释光过程与晶体中的F心有紧密关系。本文制备了BaF_xCl_(2-x):Eu^(2+)系列粉末样品。利用正电子湮灭技术及光谱手段,测得这些样品的正电子湮灭谱和光激励谱。我们分解了3种... BaFCl:Eu^(2+)是一种优良的X射线存储成像材料,其X射线存储及光释光过程与晶体中的F心有紧密关系。本文制备了BaF_xCl_(2-x):Eu^(2+)系列粉末样品。利用正电子湮灭技术及光谱手段,测得这些样品的正电子湮灭谱和光激励谱。我们分解了3种不同F/Cl配比的光激励谱,得到443nm和561nm附近的2个峰,其相对强度随F/Cl比的不同发生了变化,而峰位并未改变。其实验结果表明:当其晶体中的F/Cl<1时,可以有效地产生F^-离子的空位缺陷。而当F/Cl>1时,不利于Cl^-离子空位缺陷的形成。另外,我们简单地讨论了BaF_xCl_(2-x):Eu^(2+)系列样品光激励发光强度的变化。 展开更多
关键词 F心 正电子湮灭谱 光激励谱 材料
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无规聚甲基丙烯酸甲酯立构复合的红外光谱研究 被引量:2
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作者 顾群 沈德言 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2000年第5期603-605,共3页
用红外光谱研究了无规聚甲基丙烯酸甲酯的丙酮、苯、氯仿溶液成膜样品的立构复合状况。结果表明无规聚甲基丙烯酸甲酯在丙酮和苯中确能形成立构复合结构 ,结构的形成主要是依靠分子链中间规和等规链段的相互作用。对丙酮样品的退火实验... 用红外光谱研究了无规聚甲基丙烯酸甲酯的丙酮、苯、氯仿溶液成膜样品的立构复合状况。结果表明无规聚甲基丙烯酸甲酯在丙酮和苯中确能形成立构复合结构 ,结构的形成主要是依靠分子链中间规和等规链段的相互作用。对丙酮样品的退火实验表明 ,在退火过程中能够发生间规链段的自聚集现象。 展开更多
关键词 无规聚甲基丙烯酸甲酯 立构复合 红外光谱 退火
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南海北部三参量风浪频谱数值模拟 被引量:1
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作者 张仁富 程用胜 王福新 《科学技术与工程》 北大核心 2019年第23期24-31,共8页
基于OpenFOAM开源程序,采用侯一筠的三参量风浪频谱构造了适用于中国南海北部海域的不规则波浪。首先,在waves2Foam程序中开发了解析松弛法进行消波处理并选用速度入口法造波,进而选用JONSWAP谱进行计算以验证不规则波造波程序的准确性... 基于OpenFOAM开源程序,采用侯一筠的三参量风浪频谱构造了适用于中国南海北部海域的不规则波浪。首先,在waves2Foam程序中开发了解析松弛法进行消波处理并选用速度入口法造波,进而选用JONSWAP谱进行计算以验证不规则波造波程序的准确性;其次,以适用于中国南海北部海域的三参量风浪频谱为理论基础进行编程,将三参量风浪频谱嵌入到waves2Foam程序中,替换JONSWAP谱,通过设定风区长度、风速等参量构造模拟南海北部的不规则波浪。经验证,构造的不规则波的模拟值与理论值之间的误差在精度允许范围内,表明该方法能较好地模拟南海北部真实海况下的不规则波浪。 展开更多
关键词 南海 不规则波 三参量谱 数值模拟
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3-D consistency dynamic constitutive model of concrete 被引量:4
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作者 Xiao Shiyun,Li Hongnan and Lin Gao School of Hydraulic Engineering,Dalian University of Technology,Dalian 116024,China 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第2期233-246,共14页
Based on the consistency-viscoplastic constitutive model,the static William-Warnke model with three-parameters is modified and a consistency-viscoplastic William-Warnke model with three-parameters is developed that co... Based on the consistency-viscoplastic constitutive model,the static William-Warnke model with three-parameters is modified and a consistency-viscoplastic William-Warnke model with three-parameters is developed that considers the effect of strain rates. Then,the tangent modulus of the consistency viscoplastic model is introduced and an implicit backward Elure iterative algorithm is developed. Comparisons between the numerical simulations and experimental data show that the consistency model properly provides the uniaxial and biaxial dynamic behaviors of concrete. To study the effect of strain rates on the dynamic response of concrete structures,the proposed model is used in the analysis of the dynamic response of a simply-supported beam and the results show that the strain rate has a significant effect on the displacement and stress magnitudes and distributions. Finally,the seismic responses of a 278 m high arch dam are obtained and compared by using the linear elastic model,as well as rate-independent and rate-dependent William-Warnke three-parameter models. The results indicate that the strain rate affects the first principal stresses,and the maximal equivalent viscoplastic strain rate of the arch dam. Numerical calculations and analyses reveal that considering the strain rate is important in the safety assessments of arch dams located in seismically active areas. 展开更多
关键词 CONCRETE strain rate constitutive model consistency-viscoplastic William-Warnke three-parameter model algorithm arch dams seismic responsesimulation
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On the Loads for Strength Design of Cutterhead of Full Face Rock Tunnel Boring Machine 被引量:2
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作者 Meidong Han Zongxi Cai Chuanyong Qu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第6期60-71,共12页
Cutterhead loads are the key mechanical parameters for the strength design of the full face hard rock tunnel boring machine(TBM).Due to the brittle rock-breaking mechanism,the excavation loads acting on cutters fluctu... Cutterhead loads are the key mechanical parameters for the strength design of the full face hard rock tunnel boring machine(TBM).Due to the brittle rock-breaking mechanism,the excavation loads acting on cutters fluctuate strongly and show some randomness.The conventional method that using combinations of some special static loads to perform the strength design of TBM cutterhead may lead to strength failure during working practice.In this paper,a three-dimensional finite element model for coupled Cutterhead–Rock is developed to determine the cutterhead loads.Then the distribution characteristics and the influence factors of cutterhead loads are analyzed based on the numerical results.It is found that,as time changes,the normal and tangential forces acting on cutters and the total torque acting on the cutterhead approximately distribute log normally,while the total thrusts acting on the cutterhead approximately show a normal distribution.Furthermore,the statistical average values of cutterhead loads are proportional to the uniaxial compressive strength(UCS)of cutting rocks.The values also change with the penetration and the diameter of cutterhead following a power function.Based on these findings,we propose a three-parameter model for the mean of cutterhead loads and a method of generating the random cutter forces.Then the strength properties of a typical cutterhead are analyzed in detail using loads generated by the new method.The optimized cutterhead has been successfully applied in engineering.The method in this paper may provide a useful reference for the strength design of TBM cutterhead. 展开更多
关键词 TBM cutterhead Strength design Numerical simulation three-parameter model Random cutter forces
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Implementation of Dynamic System Control Circuit Board Test System of Pure Electric Vehicles 被引量:2
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作者 BI Wei, WANG Jianming, DOU Ruzhen, GAO Hua (Department of Information and Communication, Tianjin Polytechnic University, Tianjin 300160, CHN) 《Semiconductor Photonics and Technology》 CAS 2010年第4期167-172,共6页
The dynamic system control circuit board(DSCCB)is one of the most important components for dynamic system of pure electric vehicles. The current detection of the DSCCB is done manually, which is not only inefficient i... The dynamic system control circuit board(DSCCB)is one of the most important components for dynamic system of pure electric vehicles. The current detection of the DSCCB is done manually, which is not only inefficient in the detection but also difficult to guarantee the data accuracy. In order to improve the detection efficiency and accuracy, a new testing system is designed by Labview. The total test time can be further reduced by about 75% compared with the results of the manual detection. In this paper, the three-parameter sine wave curve-fit algorithm theory is applied to the phase delay detection of the current sensor sampling circuit on the DSCCB. This method solves the problem of big error in the phase delay detection. 展开更多
关键词 PURE electric VEHICLES automatic test system PXI platform three-parameter SINE wave curve-fit algorithm
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Three-dimensional nonlinear analysis of creep in concrete filled steel tube columns 被引量:1
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作者 程晓东 李广宇 叶贵如 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第8期826-835,共10页
This paper proposes a based on 3D-VLE (three-dimensional nonlinear viscoelastic theory) three-parameters viscoelastic model for studying the time-dependent behaviour of concrete filled steel tube (CFT) columns. Th... This paper proposes a based on 3D-VLE (three-dimensional nonlinear viscoelastic theory) three-parameters viscoelastic model for studying the time-dependent behaviour of concrete filled steel tube (CFT) columns. The method of 3D-VLE was developed to analyze the effects of concrete creep behavior on CFT structures. After the evaluation of the parameters in the proposed creep model, experimental measurements of two prestressed reinforced concrete beams were used to investigate the creep phenomenon of three CFT columns under long-term axial and eccentric load was investigated. The experimentally obtained time-dependent creep behaviour accorded well with the cu~'es obtained from the proposed method. Many factors (such as ratio of long-term load to strength, slenderness ratio, steel ratio, and eccentricity ratio) were considered to obtain the regularity of influence of concrete creep on CFT structures. The analytical results can be consulted in the engineering practice and design. 展开更多
关键词 Three-dimensional virtual laminated element (3D-VLE) Creep analysis Three-dimensional viscoelastic theory three-parameters viscoelastic model Concrete filled steel tube columns
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Parametric and Non-Parametric Analysis of the Survival Times of Patients with Multiple Myeloma Cancer 被引量:1
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作者 Lohuwa Mamudu Chris P. Tsokos 《Open Journal of Applied Sciences》 2020年第4期118-134,共17页
Multiple myeloma (MM) is a type of cancer that remains incurable. In the last decade, most research into MM has focused on investigating the improvement in the therapeutic strategy. Our study assesses the survival pro... Multiple myeloma (MM) is a type of cancer that remains incurable. In the last decade, most research into MM has focused on investigating the improvement in the therapeutic strategy. Our study assesses the survival probability of 48 patients diagnosed with MM based on parametric and non-parametric techniques. We performed parametric survival analysis and found a well-def- ined probability distribution of the survival time to follow three-parameter lognormal. We then estimated the survival probability and compared it with the commonly used non-parametric Kaplan-Meier survival analysis of the survival times. The comparison of the survival probability estimates of the two methods revealed a better survival probability estimate by the parametric method than the Kaplan-Meier. The parametric survival analysis is more robust and efficient because it is based on a well-defined parametric probabilistic distribution, hence preferred over the non-parametric Kaplan-Meier. This study offers therapeutic significance for further enhancement in the treatment strategy of multiple myeloma cancer. 展开更多
关键词 Multiple MYELOMA CANCER three-parameter LOGNORMAL Kaplan-Meier Maximum LIKELIHOOD Estimation Health Science
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Energy Spectrum for a Short-Range 1/r Singular Potential with a Non-Orbital Barrier Using the Asymptotic Iteration Method 被引量:1
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作者 Abdullah J. Sous Abdulaziz D. Alhaidari 《Journal of Applied Mathematics and Physics》 2016年第1期79-85,共7页
Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the f... Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the first attempt at calculating the energy spectrum for this potential, which was introduced by H. Bahlouli and A. D. Alhaidari and for which they obtained the “potential parameter spectrum”. Our results are also independently verified using a direct method of diagonalizing the Hamiltonian matrix in the J-matrix basis. 展开更多
关键词 Short-Range three-parameter Central Potential Asymptotic Iteration Method Potential Parameter Spectrum Method J-Matrix Diagonalizing Method Energy Eigenvalues
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Variation of Out-of-Plane Constraint and Its Effects on Fracture
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作者 Fei Xu Yulong Li Wanlin Guo 《上海交通大学学报》 EI CAS CSCD 北大核心 2004年第z2期212-216,共5页
The limitations of using one-parameter to describe the crack-tip fields have prompted investigators to consider better descriptions of the crack tip fields. The two-parameter descriptions, such as J-Q theory, have bee... The limitations of using one-parameter to describe the crack-tip fields have prompted investigators to consider better descriptions of the crack tip fields. The two-parameter descriptions, such as J-Q theory, have been an important development in this field. But under the consideration of plane strain and three-dimensional problem, the effects of the out-of-plane stress can not be neglected In this paper, effects of the in-plane constraint as well as the out-of-plane constraint are studied by aid of the finite element method on the plane strain condition. It is obvious that both the in-plane constraint (Q factor) and the out-of-plane constraint (Tz = σzz/(σxx + σyy) ) affect the crack tip fields.Several important features of the out-of-plane constraint are described out based on the simulation results. At the end of this paper, a three-parameter formulation is proposed, in which both the in-plane constraint and the out-of-plane constraint are considered. Comparing with the results of the FEM numerical simulation, the three-parameter description can provide a better prediction near the crack tip. 展开更多
关键词 IN-PLANE CONSTRAINT OUT-OF-PLANE CONSTRAINT three-parameter FORMULATION crack TIP field ELASTIC-PLASTIC
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