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一种新的基于factor curve的变形控制方法 被引量:4
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作者 金小刚 鲍虎军 彭群生 《软件学报》 EI CSCD 北大核心 1996年第9期537-541,共5页
本文提出了一种新的基于factorcurve的变形控制方法.Barr的整体非线性变形和Watt的时空因子曲线方法都不同程度地依赖于某种解析表达式,不便于进行统一的控制.作者首次对因子曲线进行了分类,提供了一种统一的控... 本文提出了一种新的基于factorcurve的变形控制方法.Barr的整体非线性变形和Watt的时空因子曲线方法都不同程度地依赖于某种解析表达式,不便于进行统一的控制.作者首次对因子曲线进行了分类,提供了一种统一的控制方式,因而非常适合于动画系统.把因子曲线本身作为可变参数的动画控制方法不仅包含了Barr的tapering和twisting操作,而且还包含了Watt的因子曲线变形控制方法.因而动画师有更多的余地对变形进行有效的控制. 展开更多
关键词 空间变形 因子曲线 计算机动画 变形控制
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Effects of geometrical and physical factors on light particles dispersion by agitation characteristic curve 被引量:1
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作者 Meng Li Yangbo Tan +3 位作者 Yufeng Liu Jianglong Sun De Xie Zeng Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第10期2313-2324,共12页
In this study,the effects of geometrical and physical factors on light particles dispersion in stirred tank were investigated by agitation characteristic curve.The experiments and CFD simulations with discrete phase m... In this study,the effects of geometrical and physical factors on light particles dispersion in stirred tank were investigated by agitation characteristic curve.The experiments and CFD simulations with discrete phase model(DPM)and volume of fluid model(VOF)were conducted in this paper.Five factors,which include four geometrical factors(submergence,impeller-to-tank ratio,number of impeller blades and baffling mode)and a physical factor(liquid viscosity)were considered.For each factor,the power consumption curve and agitation characteristic curve were drawn to compare the power consumption and mixing results in the stirred tank.Characteristics of the agitation characteristic curves were compared with the previous published literatures and theories.It is found that the agitation characteristic curves reflect the tendency of power consumption and particles distribution well in stirred tank.The good agreement indicates the applicability of the agitation characteristic curves for the study of light particles distribution in stirred tank. 展开更多
关键词 AGITATION characteristic curve GEOMETRICAL and physical factors LIGHT PARTICLES Solid–liquid mixing Stirred TANK
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A novel type curve for estimating oil recovery factor of gas flooding 被引量:1
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作者 TANG Yong ZHANG Haochuan +6 位作者 HE Youwei GUO Xiaodong FAN Kun WU Zangyuan ZHOU Daiyu TAO Zhengwu LI Jinlong 《Petroleum Exploration and Development》 CSCD 2022年第3期605-613,共9页
A novel type curve is presented for oil recovery factor prediction suitable for gas flooding by innovatively introducing the equivalent water-gas cut to replace the water cut,comprehensively considering the impact of ... A novel type curve is presented for oil recovery factor prediction suitable for gas flooding by innovatively introducing the equivalent water-gas cut to replace the water cut,comprehensively considering the impact of three-phase flow(oil,gas,water),and deriving the theoretical equations of gas flooding type curve based on Tong’s type curve.The equivalent water-gas cut is the ratio of the cumulative underground volume of gas and water production to the total underground volume of produced fluids.Field production data and the numerical simulation results are used to demonstrate the feasibility of the new type curve and verify the accuracy of the prediction results with field cases.The new type curve is suitable for oil recovery factor prediction of both water flooding and gas flooding.When a reservoir has no gas injected or produced,the gas phase can be ignored and only the oil and water phases need to be considered,in this case,this gas flooding type curve returns to the Tong’s type curve,which can evaluate the oil recovery factor of water flooding.For reservoirs with equivalent water-gas cuts of 60%-80%,the regression method of the new type curve works well in predicting the oil recovery factor.For reservoirs with equivalent water-gas cuts higher than 80%,both the regression and assignment methods of the new type curve can accurately predict the oil recovery factor of gas flooding. 展开更多
关键词 gas flooding reservoir equivalent water-gas cut type curve of gas flooding oil recovery factor prediction chart Tong’s type curve
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Area under the curve of methotrexate and creatinine clearance are outcome - determining factors in primary CNS lymphomas 被引量:9
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作者 FerreriAJ GuerraE +14 位作者 RegazziM PasiniF AmbrosettiA PivnikA GubkinA CalderoniA SpinaM BrandesA FerrareseF RognoneA GoviS Dell’OroS LocatelliM VillaE ReniM 《中国神经肿瘤杂志》 2004年第1期12-12,共1页
Although high-dose methotrexate(HD-MTX)is the most effective drug against primary CNS lymphomas(PCNSL),outcome-de-termining variables related to its administration schedule have not been defined.The impact on toxicity... Although high-dose methotrexate(HD-MTX)is the most effective drug against primary CNS lymphomas(PCNSL),outcome-de-termining variables related to its administration schedule have not been defined.The impact on toxicity and outcome of the area under thecurve(AUC(MTX)),dose intensity(DI(MTX))and infusion rate(IR(MTX))of MTX and plsamatic creatinine clearance(CL(crea))was investigated in a retrospective series of 45 PCNSL patients treated with three different HD-MTX-basedcombinations.Anticon-vulsants were administered in 31 pts(69%).Age>60 years,anticonvulsant therapy,slow IR(MTX)(</=800 mgm(-2)h(-1)),and reduced DI(MTX)(</=1000 mgm(-2)wk(-1))were significantly correlated with low AUC(MTX)values.Seven pa- 展开更多
关键词 PCNSL Area under the curve of methotrexate and creatinine clearance are outcome determining factors in primary CNS lymphomas AUC MTX CNS
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STUDY ON THE METHOD OF CONSTRUCTING RATIONAL CUBIC CURVES AND CURVED SURFACE INCLUDING CONTROLLING PARAMETERS
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作者 孙兰凤 高天真 +1 位作者 梁艳书 陈健 《Transactions of Tianjin University》 EI CAS 1998年第1期31-36,共6页
By adopting the method of controlling parameters this paper describes the construction of various kinds of cubic curve segment and curved surface fragment with rational and non rational parameters, and discusses the ... By adopting the method of controlling parameters this paper describes the construction of various kinds of cubic curve segment and curved surface fragment with rational and non rational parameters, and discusses the relationship between controlling parameters, weighted factors and types, kinds and characteristics of curve segments and curved surface fragments. A mathematical method is provided for CAGD with abundant connotations, broad covering region, convenience, flexibility and direct simplicity. 展开更多
关键词 controlling parameter weighted factor rational and non rational curve segment curved surface fragment matrix of parametric coefficient
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Application of artificial neural networks for operating speed prediction at horizontal curves: a case study in Egypt 被引量:5
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作者 Ahmed Mohamed Semeida 《Journal of Modern Transportation》 2014年第1期20-29,共10页
Horizontal alignment greatly affects the speedof vehicles at rural roads. Therefore, it is necessary toanalyze and predict vehicles speed on curve sections.Numerous studies took rural two-lane as research subjectsand ... Horizontal alignment greatly affects the speedof vehicles at rural roads. Therefore, it is necessary toanalyze and predict vehicles speed on curve sections.Numerous studies took rural two-lane as research subjectsand provided models for predicting operating speeds.However, less attention has been paid to multi-lane highwaysespecially in Egypt. In this research, field operatingspeed data of both cars and trucks on 78 curve sections offour multi-lane highways is collected. With the data, correlationbetween operating speed (V85) and alignment isanalyzed. The paper includes two separate relevant analyses.The first analysis uses the regression models toinvestigate the relationships between V85 as dependentvariable, and horizontal alignment and roadway factors asindependent variables. This analysis proposes two predictingmodels for cars and trucks. The second analysisuses the artificial neural networks (ANNs) to explore theprevious relationships. It is found that the ANN modelinggives the best prediction model. The most influential variableon V85 for cars is the radius of curve. Also, for V85 fortrucks, the most influential variable is the median width.Finally, the derived models have statistics within theacceptable regions and they are conceptually reasonable. 展开更多
关键词 Artificial neural networks Horizontal curve Multi-lane highways Operating speed Prediction models Regression models Roadway factors
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Integral Points on a Class of Elliptic Curve 被引量:2
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作者 ZHU Huilin CHEN Jianhua 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第3期477-480,共4页
We prove all integral points of the elliptic curve y^2=x^2-30x+133 are (x,y) = (-7,0),(-3,±14),(2, ±9),(6,±13), (5143326,±11664498677), by using the method of algebraic number theory a... We prove all integral points of the elliptic curve y^2=x^2-30x+133 are (x,y) = (-7,0),(-3,±14),(2, ±9),(6,±13), (5143326,±11664498677), by using the method of algebraic number theory and p-adic analysis. Furthermore, we develop a computation method to find all integral points on a class of elliptic curve y^2= (x+α)(x^2-α)(x^2-αx+b) ,α ,b∈Z,α^2〈4b and find all integer solutions of hyperelliptic Diophantine equation Dy^2=Ax^4 + Bx^2 +C,B^2〈4AC. 展开更多
关键词 Diophantine equation elliptic curve fundamental unit algebraic number factorization p-adic analysis method
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Scattering of SH-wave from interface cylindrical elastic inclusion with a semicircular disconnected curve 被引量:1
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作者 赵嘉喜 齐辉 苏胜伟 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第6期779-786,共8页
Scattering of SH wave from an interface cylindrical elastic inclusion with a semicircular disconnected curve is investigated. The solution of dynamic stress concentration factor is given using the Green's function an... Scattering of SH wave from an interface cylindrical elastic inclusion with a semicircular disconnected curve is investigated. The solution of dynamic stress concentration factor is given using the Green's function and the method of complex variable functions. First, the space is divided into upper and lower parts along the interface. In the lower half space, a suitable Green's function for the problem is constructed. It is an essential solution of the displacement field for an elastic half space with a semi-cylindrical hill of cylindrical elastic inclusion while bearing out-plane harmonic line source load at the horizontal surface. Thus, the semicircular disconnected curve can be constructed when the two parts are bonded and continuous on the interface loading the undetermined anti-plane forces on the horizontal surfaces. Also, the expressions of displacement and stress fields are obtained in this situation. Finally, examples and results of dynamic stress concentration factor are given. Influences of the cylindrical inclusion and the difference parameters of the two mediators are discussed. 展开更多
关键词 dynamic stress concentration factor (DSCF) a semicircular disconnected curve Green's function scattering of SH-wave
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ANTIPLANE MULTIPLE CURVED CRACK PROBLEM IN CIR-CULAR INCLUSION AND MATRIX MATERIAL
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作者 陆建飞 王建华 沈为平 《Journal of Shanghai Jiaotong university(Science)》 EI 1998年第2期39-44,共6页
Antiplane multiple curved crack problem in circular inclusion and matrix material is considered. In order to solve the proposed problem, two kinds of elementary solutions corresponding to a point screw dislocation in ... Antiplane multiple curved crack problem in circular inclusion and matrix material is considered. In order to solve the proposed problem, two kinds of elementary solutions corresponding to a point screw dislocation in inclusion and matrix material respectively are presented. Utilizing the elementary solutions and taking the density of dislocation along cracks surfaces as unknown functions, by the principle of superposition, a group of weakly singular integral equations with log kernels can be obtained. After the numerical solution of the integral equations, the discrete values of dislocation density are obtainable. So stress intensity factors at the cracks tips can be calculated, and several numerical examples are given. 展开更多
关键词 antiplane curved CRACK CIRCULAR INCLUSION stress INTENSITY factor
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C^n-CONTINUOUS B-TYPE SPLINE CURVES WITH ITSLOCALIZATION INTERPOLATION AND APPROXIMATION
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作者 Wu HongyiDept.ofMath.,HefeiPolytechnicUniv.,Hefei230009,China 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第2期215-226,共12页
This paper presents a class of Cn- continuous B- type spline curves with some paramet- ric factors.The length of their local support is equal to4.Taking the different values of the parametric factors,the curves can ... This paper presents a class of Cn- continuous B- type spline curves with some paramet- ric factors.The length of their local support is equal to4.Taking the different values of the parametric factors,the curves can become free- type curves or interpolate a set of given points even mix the both cases.When the parametric factors satisfy the certain conditions,the degrees of the curves can be decreased as low as possible.Besides,when all the parametric factors tend to zero,the curves globally approximate to the control polygon. 展开更多
关键词 Cn- continuous B- type spline curve parametric factor free- type and interpolation- type curveS alternate spline curve.
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Spin-orbit ab initio curves of ^(80)Se_2^+ ion and the assignment of photoelectron spectra of ^(80)Se_2 molecule
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作者 闫冰 潘守甫 郭庆群 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第9期3318-3321,共4页
This paper carries out ab initio calculations to study the ^80Se2(X^3Σg^-) state and ^80Se2^+(X^2Πg), ^80Se2^+(a^4Πg) states by using completed active space self-consistent field and multi-reference second ... This paper carries out ab initio calculations to study the ^80Se2(X^3Σg^-) state and ^80Se2^+(X^2Πg), ^80Se2^+(a^4Πg) states by using completed active space self-consistent field and multi-reference second order perturbation theory. The electronic curves of these states including spin-orbit coupling are calculated, and then the spectroscopic parameters are obtained. The photoelectron spectra of ^80Se2 molecule in gas phase are assigned according to Franck-Condon analysis based on calculated potential energy curves. The ionization energies of ^80Se2 molecule are determined by the present calculation. 展开更多
关键词 potential energy curves spin-orbit coupling Franck-Condon factor ionization energy
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ANTIPLANE CIRCULAR INCLUSION WITH A CURVED CRACK CROSSING THE BOUNDARY
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作者 Lu Jianfei Wang Jianhua Shen Weiping 《Acta Mechanica Solida Sinica》 SCIE EI 2000年第3期271-276,共6页
The weakly singular integral equation sued to solve the problem ofthe curved crack crossing the boundary of the antiplane circularinclusion is presented. Using the principal part analysis method ofthe Cauchy type inte... The weakly singular integral equation sued to solve the problem ofthe curved crack crossing the boundary of the antiplane circularinclusion is presented. Using the principal part analysis method ofthe Cauchy type integral equation, the singular stress index at theintersection and the singular stress of angular Regions near theintersection are obtained. By using the singular stress obtained, thestress intensity factor at The intersection is defined. After thenumerical solution of the integral equation, the stress intensityfactors at The end points of the crack and intersection areobtainable. 展开更多
关键词 antiplane circular inclusion curved crack stress intensity factor
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Potential energy curves, transition dipole moments, and radiative lifetimes of KBe molecule
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作者 万明杰 金成国 +2 位作者 虞游 黄多辉 邵菊香 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第3期291-296,共6页
An ab initio calculations on the ground and low-lying excited statesX2∑+,2^2∑+,3^2∑+,1^4∏,2^4∏,1^4∑+,2^4∑+,and 3^4∑+of KBe molecule have been performed using multireference configuration interaction (M... An ab initio calculations on the ground and low-lying excited statesX2∑+,2^2∑+,3^2∑+,1^4∏,2^4∏,1^4∑+,2^4∑+,and 3^4∑+of KBe molecule have been performed using multireference configuration interaction (MRCI) plus Davidsoncorrections (MRCI+Q) approach with all electron basis set aug-cc-pCV5Z-DK for Be and def2-AQZVPP-JKFI for K.3^2∑+,1^4∏,2^4∏,1^4∑+,2^4∑+and3^4∑+states are investigated for the first time. Inner shell electron correlations are computed on the potential energy curves (PECs) calculations. The spectroscopic and molecular parameters are also predicted. In addition, The transition properties including transition dipole moment, Franck-Condon factors qv′v″, Einstein coefficients Av′v″, and the radiative lifetimesτ′for the2^2∑+-X2∑+,3^2∑+-X2∑+,and 2^4∏-1^4∏ transitions are predictedat the same time. 展开更多
关键词 potential energy curves transition dipole moment Franck-Condon factors Einstein coefficients
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General solutions of plane problem for power function curved cracks
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作者 郭俊宏 袁泽帅 卢子兴 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第5期563-570,共8页
A new exact and universal conformal mapping is proposed. Using Muskhelishvili's complex potential method, the plane elasticity problem of power function curved cracks is investigated with an arbitrary power of a natu... A new exact and universal conformal mapping is proposed. Using Muskhelishvili's complex potential method, the plane elasticity problem of power function curved cracks is investigated with an arbitrary power of a natural number, and the general solutions of the stress intensity factors (SIFs) for mode I and mode II at the crack tip are obtained under the remotely uniform tensile loads. The present results can be reduced to the well-known solutions when the power of the function takes different natural numbers. Numerical examples are conducted to reveal the effects of the coefficient, the power, and the projected length along the x-axis of the power function curved crack on the SIFs for mode I and mode II. 展开更多
关键词 power function curved crack conformal mapping Muskhelishvili's complex potential method stress intensity factor (SIF) plane problem
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Evaluation of the quality of olanzapine orally disintegrated tablets by multiple dissolution curves
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作者 Hao-Fei Fan Cai-Qi Chen +5 位作者 Wen-Li Xiao Gui-Fang Yang Jun Wang Bo Yang Qi-BingLiu Guo-Hui Yi 《Journal of Hainan Medical University》 2018年第18期5-9,共5页
Objective: To investigate the dissolution behavior similarity between Self-made praeparatum and reference praeparatum in different pH menstruum,using the Olanzapine Orally Disintegrating Tablets listed in abroad as th... Objective: To investigate the dissolution behavior similarity between Self-made praeparatum and reference praeparatum in different pH menstruum,using the Olanzapine Orally Disintegrating Tablets listed in abroad as the reference praeparatum. Methods: The dissolution curve of olanzapine in Self-made praeparatum and reference praeparatum was measured,the similarity of the dissolution curve was evalued by F2 similar factor. Results: The single-point dissolution of both Self-made praeparatum and reference praeparatum within 15 min was more than 85%. Conclusion: Self-made praeparatum and reference praeparatum were similar in dissolution behavior. 展开更多
关键词 OLANZAPINE Orally disintegrating TABLETS DISSOLUTION curve F2 SIMILARITY factor
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Identifying the risk factors for pancreatic fistula after laparoscopic pancreaticoduodenectomy in patients with pancreatic cancer
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作者 Hang Xu Qing-Cai Meng +1 位作者 Jie Hua Wei Wang 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第6期1609-1617,共9页
BACKGROUND Laparoscopic pancreaticoduodenectomy(LPD)is a surgical procedure for treating pancreatic cancer;however,the risk of complications remains high owing to the wide range of organs involved during the surgery a... BACKGROUND Laparoscopic pancreaticoduodenectomy(LPD)is a surgical procedure for treating pancreatic cancer;however,the risk of complications remains high owing to the wide range of organs involved during the surgery and the difficulty of anastomosis.Pancreatic fistula(PF)is a major complication that not only increases the risk of postoperative infection and abdominal hemorrhage but may also cause multi-organ failure,which is a serious threat to the patient’s life.This study hypothesized the risk factors for PF after LPD.AIM To identify the risk factors for PF after laparoscopic pancreatoduodenectomy in patients with pancreatic cancer.METHODS We retrospectively analyzed the data of 201 patients admitted to the Fudan University Shanghai Cancer Center between August 2022 and August 2023 who underwent LPD for pancreatic cancer.On the basis of the PF’s incidence(grades B and C),patients were categorized into the PF(n=15)and non-PF groups(n=186).Differences in general data,preoperative laboratory indicators,and surgery-related factors between the two groups were compared and analyzed using multifactorial logistic regression and receiver-operating characteristic(ROC)curve analyses.RESULTS The proportions of males,combined hypertension,soft pancreatic texture,and pancreatic duct diameter≤3 mm;surgery time;body mass index(BMI);and amylase(Am)level in the drainage fluid on the first postoperative day(Am>1069 U/L)were greater in the PF group than in the non-PF group(P<0.05),whereas the preoperative monocyte count in the PF group was lower than that in the non-PF group(all P<0.05).The logistic regression analysis revealed that BMI>24.91 kg/m²[odds ratio(OR)=13.978,95%confidence interval(CI):1.886-103.581],hypertension(OR=8.484,95%CI:1.22-58.994),soft pancreatic texture(OR=42.015,95%CI:5.698-309.782),and operation time>414 min(OR=15.41,95%CI:1.63-145.674)were risk factors for the development of PF after LPD for pancreatic cancer(all P<0.05).The areas under the ROC curve for BMI,hypertension,soft pancreatic texture,and time prediction of PF surgery were 0.655,0.661,0.873,and 0.758,respectively.CONCLUSION BMI(>24.91 kg/m²),hypertension,soft pancreatic texture,and operation time(>414 min)are considered to be the risk factors for postoperative PF. 展开更多
关键词 Pancreatic cancer LAPAROSCOPY PANCREATICODUODENECTOMY Pancreatic fistula Risk factors Receiver-operating characteristic curve
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New Formulation for Arbitrary Cracks Problem and Its Stress Intensity Factor of Plane Elasticity 被引量:4
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作者 杨晓春 范天佑 刘士强 《Journal of Beijing Institute of Technology》 EI CAS 1999年第4期364-369,共6页
Aim The general arbitrary cracked problem in an elastic plane was discussed. Methods For the purpose of acquiring the solution of the problem, a new formulation on the problem was proposed. Compared with the classic... Aim The general arbitrary cracked problem in an elastic plane was discussed. Methods For the purpose of acquiring the solution of the problem, a new formulation on the problem was proposed. Compared with the classical plane elastic crack model, only the known conditions were revised in the new formulation, which are greatly convenient to solve the problem, and no other new condition was given. Results and Conclusion The general exact analytic solution is given here based on the formulation though the problem is very complicated. Furthermore, the stress intensity factors K Ⅰ, K Ⅱ of the problem are also given. 展开更多
关键词 complex variable function method general curve cracks Riemann Hilbert boundary value problem closed form solution stress intensity factors
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甘肃黄河流域水沙动态及其归因分析
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作者 王逸飞 武磊 +6 位作者 杨致远 高祖桥 申娜 李美静 张旭阳 刘源文 李常斌 《水资源保护》 北大核心 2025年第1期131-139,共9页
以甘肃黄河流域中洮河、祖厉河和泾河流域3个支流典型流域为研究区,基于SWAT模型对典型流域的水沙过程进行模拟。采用双累积曲线划分水沙变化特征时段,通过对比分析各特征时段SWAT模型的模拟结果,进行气候和下垫面因素对3个典型流域水... 以甘肃黄河流域中洮河、祖厉河和泾河流域3个支流典型流域为研究区,基于SWAT模型对典型流域的水沙过程进行模拟。采用双累积曲线划分水沙变化特征时段,通过对比分析各特征时段SWAT模型的模拟结果,进行气候和下垫面因素对3个典型流域水沙过程影响的贡献分离。结果表明:SWAT模型对3个典型流域水沙模拟精度较好,不同典型流域径流深和输沙模数空间分异显著,洮河流域水多沙少,祖厉河和泾河流域水少沙多;3个典型流域降水-径流和径流-泥沙双累积曲线的斜率存在明显变化,以斜率表征的径流系数和输沙量均呈减小趋势;1980—2020年,3个典型流域水沙俱减,气候和下垫面因素对各特征时段水沙变化的贡献存在差异,前期气候因素影响显著,后期下垫面因素贡献有所提升;人类活动参与改造的下垫面因素是甘肃黄河流域水沙俱减的主要原因。 展开更多
关键词 水沙动态 SWAT模型 双累积曲线 气候因素 下垫面因素 甘肃黄河流域
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Analysis of quality factors for Rayleigh channel waves 被引量:5
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作者 杨小慧 曹思远 +2 位作者 李德春 于鹏飞 张浩然 《Applied Geophysics》 SCIE CSCD 2014年第1期107-114,118,共9页
To facilitate investigation of the effect of imperfect elastic dissipation on the propagation of Rayleigh-type channel waves and use of their quality factors in investigations of the properties of coal seams, a simple... To facilitate investigation of the effect of imperfect elastic dissipation on the propagation of Rayleigh-type channel waves and use of their quality factors in investigations of the properties of coal seams, a simple method for calculating the quality factor QR is proposed in this paper. Introduction of complex velocities into the dispersion function allows calculation of the dispersion function of Rayleigh-type channel waves in coal seams. By the control variable method, we analyzed changes in QR with changes in coal seam thickness and P- and S-wave Q-factors within the coal seam and adjacent rock layers. The numerical results show that the trend of the QR curve is consistent with the group velocity curve. The minimum QR value occurs at the Airy phase frequency; the Airy phase frequency decreases as coal seam thickness increases. The value of QR increases with increasing QS2(quality factor for S wave in coal seam). We can compensate for the absorption of Rayleigh-type channel waves using the computed QR curve. Inversion of the QR curve can also be used to predict the thicknesses and lithologies of coal seams. 展开更多
关键词 Coal seam RAYLEIGH channel wave DISPERSION curve attenuation quality factor
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宫颈息肉相关高危因素分析
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作者 赵超 余璐 +2 位作者 刘迎 党丽娟 杨林青 《国际医药卫生导报》 2025年第1期89-93,共5页
目的探讨宫颈息肉的相关临床高危因素,建立预测模型以提高人群对该疾病的警惕。方法本研究为回顾性研究。选取2021年12月1日至2022年12月1日于济宁医学院附属医院行宫腔镜手术的239例患者作为研究对象,根据术后病理结果将患者分为宫颈... 目的探讨宫颈息肉的相关临床高危因素,建立预测模型以提高人群对该疾病的警惕。方法本研究为回顾性研究。选取2021年12月1日至2022年12月1日于济宁医学院附属医院行宫腔镜手术的239例患者作为研究对象,根据术后病理结果将患者分为宫颈息肉组和非宫颈息肉组。宫颈息肉组患者131例,年龄27~77岁,中位年龄49岁;非宫颈息肉组患者108例,年龄15~58岁,中位年龄44岁。采用单因素分析以及多因素二元logistic回归分析宫颈息肉发生的危险因素,采用受试者操作特征曲线(ROC)检验相关高危因素对宫颈息肉发生风险的评估价值。统计学方法采用Mann-Whitney U检验、χ^(2)检验或Fisher确切概率法。结果单因素分析结果显示,宫颈息肉组与非宫颈息肉组的年龄、体重指数、肥胖(体重指数≥25 kg/m^(2))、孕次、产次以及绝经、高血压[收缩压≥140 mmHg(1 mmHg=0.133 kPa)和(或)舒张压≥90 mmHg]、子宫肌瘤、子宫内膜息肉发生率比较,差异均有统计学意义(均P<0.05)。多因素二元logistic回归分析结果显示,肥胖[比值比(OR)=5.080,95%置信区间(95%CI)1.769~14.588,P=0.003]、高血压(OR=6.629,95%CI 2.456~17.890,P<0.001)、子宫肌瘤(OR=2.018,95%CI 1.020~3.993,P=0.044)、子宫内膜息肉(OR=3.623,95%CI 1.806~7.265,P<0.001)和孕次(OR=1.349,95%CI 1.037~1.755,P=0.026)均是宫颈息肉的临床危险因素。ROC分析结果显示,肥胖、高血压、子宫肌瘤、子宫内膜息肉、孕次单一因素检测宫颈息肉发病的诊断价值均较低[均曲线下面积(AUC)<0.7];上述指标联合检测AUC=0.808(95%CI 0.753~0.864),联合检测对宫颈息肉发病的诊断价值为中等(AUC>70)。结论肥胖、高血压、子宫肌瘤、子宫内膜息肉、孕次均是宫颈息肉发病的高危因素,上述指标联合检测的诊断价值高于单一指标检测,便于临床医生早期筛选高危人群。 展开更多
关键词 宫颈息肉 危险因素 临床调查 受试者操作特征曲线
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