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Value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology
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作者 张凡 《外科研究与新技术》 2011年第4期258-259,共2页
Objective To evaluate the value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology. Methods We treated 36 patients using laparoscopic radical prostatectomy fro... Objective To evaluate the value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology. Methods We treated 36 patients using laparoscopic radical prostatectomy from Oct. 2009 to Jun. 2010. Patients who did not have an MRL /DWI examination or a surgical history of pros- 展开更多
关键词 MRI value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology
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Local Solution of Three-Dimensional Axisymmetric Supersonic Flow in a Nozzle
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作者 Shuai Wang 《Journal of Applied Mathematics and Physics》 2023年第4期1029-1035,共7页
In this paper, we construct a local supersonic flow in a 3-dimensional axis-symmetry nozzle when a uniform supersonic flow inserts the throat. We apply the local existence theory of boundary value problem for quasilin... In this paper, we construct a local supersonic flow in a 3-dimensional axis-symmetry nozzle when a uniform supersonic flow inserts the throat. We apply the local existence theory of boundary value problem for quasilinear hyperbolic system to solve this problem. The boundary value condition is set in particular to guarantee the character number condition. By this trick, the theory in quasilinear hyperbolic system can be employed to a large range of the boundary value problem. 展开更多
关键词 High-Dimensional Axisymmetric Hyperbolic Equations Supersonic Flow in a Nozzle Local Solutions to Boundary value Problems of Quasilinear Hyperbolic Equations
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Self-affine fractal features of earthquake time series before and after moderate earthquakes
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作者 刘长海 刘义高 张军 《Acta Seismologica Sinica(English Edition)》 CSCD 1994年第3期447-456,共10页
In this paper we calculate the local fractal dimension values D of the self-affine feature of earthquake time series by RMS (root-mean-square) error method, and express the fractal dimensionality by the normalized cor... In this paper we calculate the local fractal dimension values D of the self-affine feature of earthquake time series by RMS (root-mean-square) error method, and express the fractal dimensionality by the normalized correlation coefficient R. The fractal dimension values are given for earthquakes occurred in Tangshan, Haicheng, Songpan, Longling, Changshu, I.iyang in China and its vicinity by the moving scanning method with different magnitude thresholds and the fixed-window length (100 events). The results show the D values are characterized by decreasing, continued low level in values or by decreasing first and then increasing before moderate earthquakes. 展开更多
关键词 self-affine fractal local fractal dimension value earthquake prediction
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Altitudinal effect of soil n-alkane δD values on the eastern Tibetan Plateau and their increasing isotopic fractionation with altitude 被引量:2
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作者 BAI Yan CHEN ChiHao +2 位作者 FANG XiaoMin LIU XiaoMing GUO HaiChao 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第9期1664-1673,共10页
Stable isotope paleoaltimetry has provided unprecedented insights into the topographic histories of many of the world's highest mountain ranges. However, on the Tibetan Plateau(TP), stable isotopes from paleosols ... Stable isotope paleoaltimetry has provided unprecedented insights into the topographic histories of many of the world's highest mountain ranges. However, on the Tibetan Plateau(TP), stable isotopes from paleosols generally yield much higher paleoaltitudes than those based on fossils. It is therefore essential when attempting to interpret accurately this region's paleoaltitudes that the empirical calibrations of local stable isotopes and the relations between them are established. Additionally,it is vital that careful estimations be made when estimate how different isotopes sourced from different areas may have been influenced by different controls. We present here 29 hydrogen isotopic values for leaf wax-derived n-alkanes(i.e., δD_(wax) values,and abundance-weighted average δD values of C_(29) and C_(31)) in surface soils, as well as the δD values of soil water(δD_(sw)) samples(totaling 22) from Mount Longmen(LM), on the eastern TP(altitude ~0.8–4.0 km above sea level(asl), a region climatically affected by the East Asian Monsoon(EAM). We compared our results with published data from Mount Gongga(GG). In addition,47 river water samples, 55 spring water samples, and the daily and monthly summer precipitation records(from May to October,2015) from two precipitation observation stations were collected along the GG transect for δD analysis. LM soil δD_(wax) values showed regional differences and responded strongly to altitude, varying from.160‰ to.219‰, with an altitudinal lapse rate(ALR) of.18‰ km^(-1)(R^2=0.83; p<0.0001; n=29). These δD_(wax) values appeared more enriched than those from the GG transect by ~40‰. We found that both the climate and moisture sources led to the differences observed in soil δD_(wax) values between the LM and GG transects. We found that, as a general rule, ε_(wax/rw), ε_(wax/p) and εwax/sw values(i.e., the isotopic fractionation of δD_(wax) corresponding to δD_(rw), δD_p and δD_(sw)) increased with increasing altitude along both the LM and GG transects(up to 34‰ and 50‰, respectively). Basing its research on a comparative study of δD_(wax), δD_p, δD_(rw)(δD_(springw)) and δD_(sw), this paper discusses the effects of moisture recycling, glacier-fed meltwater, relative humidity(RH), evapotranspiration(ET), vegetation cover, latitude,topography and/or other factors on ε_(wax/p) values. Clearly, if ε_(wax-p) values at higher altitudes are calculated using smaller ε_(wax-p) values from lower altitudes, the calculated paleowaterδD_p values are going to be more depleted than the actual δD values, and any paleoaltitude would therefore be overestimated. 展开更多
关键词 Hydrogen isotope values for leaf wax-derived n-alkanes Aparent fractionation factor Surface water evaporation Local water vapor recycling Paleoaltitudinal reconstruction Eastern Tibetan Plateau
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Optimal L_∞ Estimates for Galerkin Methods for Nonlinear Singular Two-point Boundary Value Problems
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作者 Xu ZHANG Zhong-ci SHI 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2015年第3期719-728,共10页
In this paper, we apply the symmetric Galerkin methods to the numerical solutions of a kind of singular linear two-point boundary value problems. We estimate the error in the maximum norm. For the sake of obtaining fu... In this paper, we apply the symmetric Galerkin methods to the numerical solutions of a kind of singular linear two-point boundary value problems. We estimate the error in the maximum norm. For the sake of obtaining full superconvergence uniformly at all nodal points, we introduce local mesh refinements. Then we extend these results to a class of nonlinear problems. Finally, we present some numerical results which confirm our theoretical conclusions. 展开更多
关键词 singular two-point boundary value problems symmetric Galerkin method maximum norm error estimate superconvergence local mesh refinement
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