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Relationship between sonographically measured median nerve cross-sectional area and presence of peripheral neuropathy in diabetic subjects 被引量:8
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作者 Fredrick ANDrew Attah Christianah Mopelola Asaleye +3 位作者 Adeleye Dorcas Omisore Babatope Ayodeji Kolawole Adeniyi Sunday Aderibigbe Mathew Alo 《World Journal of Diabetes》 SCIE CAS 2019年第1期47-56,共10页
BACKGROUND Neuropathy is a common complication of diabetes mellitus resulting from direct damage by hyperglycemia to the nerves and/or ischemia by microvascular injury to the endoneurial vessels which supply the nerve... BACKGROUND Neuropathy is a common complication of diabetes mellitus resulting from direct damage by hyperglycemia to the nerves and/or ischemia by microvascular injury to the endoneurial vessels which supply the nerves. Median nerve is one of the peripheral nerves commonly affected in diabetic neuropathy. The median nerve size has been studied in non-Nigerian diabetic populations. In attempt to contribute to existing literature, a study in a Nigerian population is needed.AIM To evaluate the cross-sectional area(CSA) of the median nerve using B-mode ultrasonography(USS) and the presence of peripheral neuropathy(PN) in a cohort of adult diabetic Nigerians.METHODS Demographic and anthropometric data of 85 adult diabetes mellitus(DM) and 85 age-and sex-matched apparently healthy control(HC) subjects were taken. A complete physical examination was performed on all study subjects to determine the presence of PN and modified Michigan Neuropathy Screening Instrument(MNSI) was used to grade its severity. Venous blood was taken from the study subjects for fasting lipid profile(FLP), fasting blood glucose(FBG) and glycated haemoglobin(HbA1 c) while their MN CSA was evaluated at a point 5 cm proximal to(5 cmCATL) and at the carpal tunnel(CATL) by high-resolution Bmode USS. Data was analysed using SPSS version 22.RESULTS The mean MN CSA was significantly thicker in DM subjects compared to the HC at 5 cmCATL(P < 0.01) and at the CATL(P < 0.01) on both sides. The presence of diabetic peripheral neuropathy(DPN) further increased the MN CSA at the CATL(P < 0.05) but not at 5 cmCATL(P > 0.05). However, the severity of DPN had no additional effect on MN CSA 5 cm proximal to and at the CATL. There was no significant association between MN CSA and duration of DM and glycemic control.CONCLUSION Thickening of the MN CSA at 5 cmCATL and CATL is seen in DM. Presence of DPN is associated with worse thickening of the MN CSA at the CATL but not at5 cmCATL. Severity of DPN, duration of DM, and glycemic control had no additional effect on the MN CSA. 展开更多
关键词 MEDIAN nerve cross-sectional area SONOGRAPHY DIABETICS Peripheral NEUROPATHY
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Ultrasonographic measurement of median nerve cross-sectional area reference values in a healthy Han population from Guiyang,China 被引量:3
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作者 Jun Chen Shan Wu Jun Ren 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第24期1883-1887,共5页
High-resolution ultrasonography was used to analyze the nerve cross-sectional area (CSA) of the median nerve at 7 sites: the wrist crease, pisiform bone, hamate bone, 6 cm proximal to the tip of the wrist crease, p... High-resolution ultrasonography was used to analyze the nerve cross-sectional area (CSA) of the median nerve at 7 sites: the wrist crease, pisiform bone, hamate bone, 6 cm proximal to the tip of the wrist crease, proximal forearm (where the nerve enters the pronator teres muscle), 4 cm proximal to the tip of the medial epicondyle, and mid-humerus (mid-point between elbow crease and axilla) in 200 healthy volunteers from Guiyang, China. Results showed similar CSA values between the left and right sides, but the CSA 6 cm proximal to the tip of the wrist crease, proximal forearm, 4 cm proximal to tip of the medial epicondyle, and mid-humerus in males was greater than that of females. Moreover, CSA values at the wrist crease, pisiform bone, and hamate bone were greater in the middle-aged and old groups when compared to the young group, and correlated with body mass and height. Thus, reference values of median nerve CSA of the upper limbs can facilitate the analysis of abnormal nerve conditions. 展开更多
关键词 ULTRASONOGRAPHY median nerve cross-sectional area Guiyang Han nationality
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Does the ratio of the carpal tunnel inlet and outlet cross-sectional areas in the median nerve reflect carpal tunnel syndrome severity? 被引量:6
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作者 Li Zhang Aierken Rehemutula +3 位作者 Feng Peng Cong Yu Tian-bin Wang Lin Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第7期1172-1176,共5页
Although ultrasound measurements have been used in previous studies on carpal tunnel syndrome to visualize injury to the median nerve, whether such ultrasound data can indicate the severity of carpal tunnel syndrome r... Although ultrasound measurements have been used in previous studies on carpal tunnel syndrome to visualize injury to the median nerve, whether such ultrasound data can indicate the severity of carpal tunnel syndrome remains controversial. The cross-sectional areas of the median nerve at the tunnel inlet and outlet can show swelling and compression of the nerve at the carpal. We hypothesized that the ratio of the cross-sectional areas of the median nerve at the carpal tunnel inlet to outlet accurately reflects the severity of carpal tunnel syndrome. To test this, high-resolution ultrasound with a linear array transducer at 5–17 MHz was used to assess 77 patients with carpal tunnel syndrome. The results showed that the cut-off point for the inlet-to-outlet ratio was 1.14. Significant differences in the inlet-to-outlet ratio were found among patients with mild, moderate, and severe carpal tunnel syndrome. The cut-off point in the ratio of cross-sectional areas of the median nerve was 1.29 between mild and more severe(moderate and severe) carpal tunnel syndrome patients with 64.7% sensitivity and 72.7% specificity. The cut-off point in the ratio of cross-sectional areas of the median nerve was 1.52 between the moderate and severe carpal tunnel syndrome patients with 80.0% sensitivity and 64.7% specificity. These results suggest that the inlet-to-outlet ratio reflected the severity of carpal tunnel syndrome. 展开更多
关键词 nerve regeneration peripheral nerve injury ultrasonography carpal tunnel syndrome diagnosis cross-sectional area classification clinical laboratory technique electrodiagnosis median nerve 973 Program neural regeneration
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Usefulness of the acromioclavicular joint cross-sectional area as a diagnostic image parameter of acromioclavicular osteoarthritis
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作者 Young Joo Jee Youn Moon +5 位作者 Jung Youn Han Yun-Sic Bang Keum Nae Kang Young Su Lim Young-SoonChoi Young-Uk Kim 《World Journal of Clinical Cases》 SCIE 2022年第7期2087-2094,共8页
BACKGROUND Acromioclavicular joint(ACJ)space narrowing has been considered to be an important diagnostic image parameter of ACJ osteoarthritis(ACJO).However,the morphology of the ACJ space is irregular because of oste... BACKGROUND Acromioclavicular joint(ACJ)space narrowing has been considered to be an important diagnostic image parameter of ACJ osteoarthritis(ACJO).However,the morphology of the ACJ space is irregular because of osteophyte formation,subchondral irregularity,capsular distention,sclerosis,and erosion.Therefore,we created the ACJ cross-sectional area(ACJCSA)as a new diagnostic image parameter to assess the irregular morphologic changes of the ACJ.AIM To hypothesize that the ACJCSA is a new diagnostic image parameter for ACJO.METHODS ACJ samples were obtained from 35 patients with ACJO and 30 healthy individuals who underwent shoulder magnetic resonance(S-MR)imaging that revealed no evidence of ACJO.Oblique coronal,T2-weighted,fat-suppressed SMR images were acquired at the ACJ level from the two groups.We measured the ACJCSA and the ACJ space width(ACJSW)at the ACJ on the S-MR images using our imaging analysis program.The ACJCSA was measured as the cross-sectional area of the ACJ.The ACJSW was measured as the narrowest point between the acromion and the clavicle.RESULTS The average ACJCSA was 39.88±10.60 mm;in the normal group and 18.80±5.13 mm;in the ACJO group.The mean ACJSW was 3.51±0.58 mm in the normal group and 2.02±0.48 mm in the ACJO group.ACJO individuals had significantly lower ACJCSA and ACJSW than the healthy individuals.Receiver operating characteristic curve analyses demonstrated that the most suitable ACJCSA cutoff score was 26.14 mm^(2),with 91.4%sensitivity and 90.0%specificity.CONCLUSION The optimal ACJSW cutoff score was 2.37 mm,with 88.6%sensitivity and 96.7%specificity.Even though both the ACJCSA and ACJSW were significantly associated with ACJO,the ACJCSA was a more sensitive diagnostic image parameter. 展开更多
关键词 Acromioclavicular joint OSTEOARTHRITIS cross-sectional area DIAGNOSIS
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Correlation between current and cross-sectional area of parallel fixed-movable dual electrodes in ESC
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作者 Li-ting Zhao Yun-long Xiong +2 位作者 Rui Chen Zeng-rui Wang An-guo Wang 《China Foundry》 SCIE 2020年第3期245-249,共5页
Electroslag casting with parallel fixed-movable dual electrodes is a new method for achieving better quality of castings in complex mold cavities.In this work,a mathematical model,y=kx^2+(k+1)x,was established to desc... Electroslag casting with parallel fixed-movable dual electrodes is a new method for achieving better quality of castings in complex mold cavities.In this work,a mathematical model,y=kx^2+(k+1)x,was established to describe the ideal correlation between the current ratio(y)and the cross-sectional area ratio(x)of the dual electrodes,where k is the filling ratio.Investigation was conducted on the electroslag casting process with dual electrodes of various cross-sectional areas,but at a constant k value.The experimental results indicated that the ideal correlation was obtained at the stable casting stage,and the fitting results were consistent with the experimental results at certain k values.The experimental findings show that better castings can be obtained when the current ratio is greater than 1.536 and the cross-sectional area ratio is greater than 0.5. 展开更多
关键词 electroslag casting fixed-movable dual electrode current ratio cross-sectional area ratio
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Analysis of the Maximum Consecutive Precipitation Variation in Liaoning Artificial Precipitation Test Area
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作者 杨旭 高杰 +3 位作者 杨青 田广元 陈刚 胡伟 《Meteorological and Environmental Research》 CAS 2010年第9期46-47,96,共3页
According to the daily precipitation data in artificial precipitation season during May to September from 1961 to 2008 in Liaoning Province,the maximum consecutive precipitation in the artificial precipitation test ar... According to the daily precipitation data in artificial precipitation season during May to September from 1961 to 2008 in Liaoning Province,the maximum consecutive precipitation in the artificial precipitation test area is studied based on the maximum consecutive precipitation from May to September in 48 years.The results shows that the period of maximum consecutive precipitation in each month is different,and the variance trends of maximum consecutive precipitation in May,July,August and September are decreasing,while the variance trend of maximum consecutive precipitation in June is increasing. 展开更多
关键词 Artificial precipitation test area maximum consecutive precipitation Variation analysis China
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Characteristics of Suspended Particulate Matter and the Coastal Turbidity Maximum Areas of the Mekong River 被引量:1
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作者 Vu Duy Vinh Tran Anh Tu +1 位作者 Tran Dinh Lan Nguyen Ngoc Tien 《Journal of Environmental Science and Engineering(A)》 2015年第2期67-78,共12页
This paper presents the results of application of a 3D (three-dimensional) numerical model to study on MTZ (maximum turbidity zone) in the coastal zone of Mekong River Delta. In this study, a 3D system model with ... This paper presents the results of application of a 3D (three-dimensional) numerical model to study on MTZ (maximum turbidity zone) in the coastal zone of Mekong River Delta. In this study, a 3D system model with combination of hydrodynamics--wave and suspended sediment transport was set up and validated with measured data in the study area. Based on calculated scenarios for the flood and the dry season, the results have shown appearance of MTZs in the coastal zone of Mekong River with suspended sediment concentration prevalent of 0.04-0.07 kg·m^3 (the dry season) and 0.05-0.1kg·m^3 (the flood season). The position and MTZs scale change with the interaction between fresh water and tidal oscillations. The MTZ occur more in the dry seasons compared to the wet season. The MTZs are prevalent located far away from estuaries about in 12-22 km (in the dry season), and 5-15 km in the flood season. 展开更多
关键词 MODELLING maximum turbidity zone suspended sediment transport Me Kong river coastal area.
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Discussion on Principles and Methods in Estimating the Maximum Potential Earthquakes in Low Seismicity Areas
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作者 Chen Jiageng, Yan Jiaquan, Xu Guangyin and Hao YuqinInstitute of Geophysics, CSB, Beijing 100081, China 《Earthquake Research in China》 2000年第2期89-99,共11页
Five principles and methods are proposed for estimating the maximum potential earthquakesin low seismicity areas,and their applicabilities are discussed,taking Sichuan basin as asample area.The proposed principles and... Five principles and methods are proposed for estimating the maximum potential earthquakesin low seismicity areas,and their applicabilities are discussed,taking Sichuan basin as asample area.The proposed principles and methods are not only on the grounds of thegeological tectonics but also considered fully the mutual complementation between geologicaland seismological methods.They will be helpful to the study of engineering seismology andthe assessment of designing ground motion parameters in low seismicity areas. 展开更多
关键词 Low SEISMICITY area maximum POTENTIAL EARTHQUAKE CAUSATIVE TECTONICS Diffusive EARTHQUAKE
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Age, Maximum Cup Depth, Central Corneal Thickness, Disc Area and Mean Defect in Patients with Open Angle Glaucoma and Ocular Hypertension
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作者 Valentin T. Diaz-Aleman Marta Gonzalez-Hernandez +1 位作者 Denisse Angel-Pereira Andres Blasco-Alberto 《Open Journal of Ophthalmology》 2016年第3期150-157,共9页
Purpose: The main objective was to analyze the relationship between maximum cup depth (MCD), mean defect (MD), central corneal thickness (CCT), age and disc area, in patients with ocular hypertension (OHT) and primary... Purpose: The main objective was to analyze the relationship between maximum cup depth (MCD), mean defect (MD), central corneal thickness (CCT), age and disc area, in patients with ocular hypertension (OHT) and primary open angle glaucoma (POAG). Methods: Cross-sectional study of patients diagnosed with OHT and POAG. Visual fields were obtained using an Octopus 300 analyzer, TOP strategy. MCD and disc area were obtained using a Heidelberg Retina Tomograph. Results: The study sample comprised 234 eyes of 143 patients, 91 women and 52 men, mean age 63.55 years (SD 10.49). Mean values were: MCD 0.52 mm (SD 0.27), MD 2.78 dB (SD 5.02), CCT 543.5 μm (SD 36.63), IOP 16.73 mmHg (SD 2.93), and disc area 2.01 mm<sup>2</sup> (SD 0.39). A significant correlation was observed between MCD and age in patients under 60 years, between MCD and disc area, and between MD and disc area. Conclusions: Our study showed a correlation between MCD and age which was significant in patients under 60 years of age, between MCD and disc area and between MD and disc area, suggesting that the larger the disc area, the greater the MCD and the MD in patients with OHT and POAG. 展开更多
关键词 POAG OHT Disk area maximum Cup *Corresponding
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Delineation of Prospecting Prospect Area Based on Maximum Entropy Model
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作者 Zhen Chen Lianwu Shi 《Journal of Geoscience and Environment Protection》 2023年第11期27-40,共14页
Taking the Dapingzhang copper-polymetallic deposit in Yunnan Province, China as the research object, the maximum entropy model was used to extract the mining information, and the mineral resource prediction model was ... Taking the Dapingzhang copper-polymetallic deposit in Yunnan Province, China as the research object, the maximum entropy model was used to extract the mining information, and the mineral resource prediction model was established by using the exploration data of the deposit and related regions in this area, so as to determine the prospecting prospect area in the study area. In this paper, the Jacknife analysis module of maximum entropy model is used to quantitatively rank the importance of 39 geochemical element variables, and finally obtain the prospecting prospect map of the study area. The research results show that the Dapingzhang mining area has the potential to find hidden ore in the deep and surrounding areas, and the northern and southern ends and western sides of the rock ore control structural belt in the eastern region of the mining area have good prospecting prospects. The research results provide an important basis for the deployment of follow-up exploration work in the study area, and the maximum entropy model has a good application effect in mineral resources exploration. 展开更多
关键词 Target area Demarcation Peripheral and Deep Exploration maximum Entropy Exploration and Prediction Geological Big Data
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Distribution Prediction of Suitable Growth Area for Eucommia ulmoides in China under Climatic Change Background 被引量:3
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作者 Yang Liu 《Meteorological and Environmental Research》 CAS 2013年第8期21-24,共4页
[ Objective] The research aimed to study distribution prediction of suitable growth area for Eucommia ulmoides in China under climatic change background. [ Method] By using the maximum entropy model and many kinds of ... [ Objective] The research aimed to study distribution prediction of suitable growth area for Eucommia ulmoides in China under climatic change background. [ Method] By using the maximum entropy model and many kinds of climate change scenarios, we predicted current and future distribution pattems of suitable growth area for Eucommia ulmoides in China and its change process. [ Result ] At present, highly suitable growth area of E. ulmoides mainly distributed in Sichuan, Shaanxi and Chongqing, Under climate change background, total suitable growth areas in future three decades all drastically reduced when compared with that at present. It was noteworthy that moderately and highly suitable growth areas of wild E. ulmoides all disappeared, and junction between Shaanxi and Gansu and Taibai Mountain would be stable suitable growth area of wild E. ulmoides. [ Condusioa] The research could provide useful reference data for investigation, protection and sustainable development of the wild E. ulmoides resources. 展开更多
关键词 E. ulmoides Suitable growth area Climate change The maximum entropy model Distribution prediction China
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Similarities between Yangshan Harbor area and the Yangtze estuary 被引量:1
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作者 LI Yuzhong, CHEN Shenliang(State Key Laboratory of Estuarine && Coastal Research, East China Normal University, Shanghai 200062, China) 《Journal of Geographical Sciences》 SCIE CSCD 2002年第4期489-494,共10页
By analysis of published papers on the Yangtze estuary and hydrological and sediments data in Yangshan Harbor area, many similarities are found between Yangshan Harbor area and the Yangtze estuary. These similarities ... By analysis of published papers on the Yangtze estuary and hydrological and sediments data in Yangshan Harbor area, many similarities are found between Yangshan Harbor area and the Yangtze estuary. These similarities include the phenomenon of stagnating flow areas, the distributive characteristics of the highest suspended sediment concentration areas, superficial sediments and shoal bars. The stagnating flow area is the major similarity which causes other similarities. These similarities indicate that: 1) Turbidity Maximum and mouth bars in estuaries are mainly caused by the hydraulic balance of stagnating flow areas of estuaries; 2) The stagnating sand area of sands caused by stagnating flow area often locates on the narrower side of the stagnating flow area; 3) The location (or shape) of fine sediments area caused by stagnating flow area reflects the location (or shape) of the stagnating flow area. Both Yangshan Harbor area and the Yangtze estuary are the important developmental areas in the future (man-made similarity). In-depth studies on these similarities between Yangshan Harbor area and the Yangtze estuary will have momentous theoretical and practical significance. 展开更多
关键词 Yangshan Harbor Yangtze estuary SIMILARITY stagnating flow area turbidity maximum mouth bar
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Discussion on applying an analytical method to optimize the anti-freeze design parameters for underground water pipelines in seasonally frozen areas 被引量:1
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作者 Ji Chen JingYi Zhao +1 位作者 Kun Li Yu Sheng 《Research in Cold and Arid Regions》 CSCD 2016年第6期467-476,共10页
Adopting the quasi-three-dimensional (Quasi-3D) numerical method to optimize the anti-freeze design parameters of an underground pipeline usually involves heavy numerical calculations. Here, the fitting formulae bet... Adopting the quasi-three-dimensional (Quasi-3D) numerical method to optimize the anti-freeze design parameters of an underground pipeline usually involves heavy numerical calculations. Here, the fitting formulae between the safe con-veyance distance (SCD) of a water pipeline and six influencing factors are established based on the lowest water temper-ature (LWT) along the pipeline axis direction. With reference to the current widely used anti-freeze design approaches for underground pipelines in seasonally frozen areas, this paper first analyzes the feasibility of applying the maximum frozen penetration (MFP) instead of the mean annual ground surface temperature (MAGST) and soil water content (SWC) to calculate the SCD. The results show that the SCD depends on the buried depth if the MFP is fixed and the variation of the MAGST and SWC combination does not significantly change the SCD. A comprehensive formula for the SCD is estab-lished based on the relationships between the SCD and several primary influencing factors and the interaction among them. This formula involves five easy-to-access parameters: the MFP, buried depth, pipeline diameter, flow velocity, and inlet water temperature. A comparison between the analytical method and the numerical results based on the Quasi-3D method indicates that the two methods are in good agreement overall. The analytic method can be used to optimize the anti-freeze design parameters of underground water pipelines in seasonally frozen areas under the condition of a 1.5 safety coefficient. 展开更多
关键词 Quasi-3D method analytical method maximum frozen penetration underground water pipeline seasonally frozen area
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Glacier variations and rising temperature in the Mt.Kenya since the Last Glacial Maximum 被引量:1
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作者 CHEN An-an WANG Ning-lian +2 位作者 GUO Zhong-ming WU Yu-wei WU Hong-bo 《Journal of Mountain Science》 SCIE CSCD 2018年第6期1268-1282,共15页
High-resolution imagery can be used to reconstruct former glacier boundaries through the identification of glacial erosional and sedimentary geomorphology. We employed moraine mapping and the accumulation–area ratio ... High-resolution imagery can be used to reconstruct former glacier boundaries through the identification of glacial erosional and sedimentary geomorphology. We employed moraine mapping and the accumulation–area ratio method(AAR), in conjunction with Landsat, Google Earth, and SRTM imagery, to reconstruct glacier boundaries and equilibrium-line altitudes(ELAs) for Mt. Kenya in the Last Glacial Maximum(LGM), the Little Ice Age(LIA), and at present. Our results show that the areas of Lewis Glacier and the Tyndall-I glacier system were 0.678 km^2 and 0.390 km^2, respectively, during the maximum of LIA. Those mean that the both glaciers have shrunken by 87.0% and 88.7%, respectively since the LIA. Area change ratios for each glacier were significantly larger in the period of 2000 through 2015 than the former periods, indicating that glacier recession has accelerated. Continuous ice loss in this region has been driven by rising temperature and fluctuating precipitation. Linear regression data for Lewis glacier show that mass balance sensitivity to dry season temperature was –315 mm w.e./℃, whereas the sensitivity to dry season precipitation was 5.2 mm w.e./mm. Our data also show that the ELA on the western slope of Mt. Kenya rose by 716-816 m from the LGM to the modern era, corresponding to that temperature rose by 5.2℃-6.5℃. 展开更多
关键词 Remote sensing Last Glacial maximum Little Ice Age Glacier area Equilibrium-linealtitudes Mt. Kenya
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An Adaptive SVP Simplification Based on Area Difference 被引量:5
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作者 Gen ZHENG Jianhu ZHAO Hongmei ZHANG 《Journal of Geodesy and Geoinformation Science》 2019年第4期53-63,共11页
Sound velocity profile(SVP)data is indispensable in the multi-beam data processing.The sampling density is of great importance for SVP to represent the vertical variation of sound velocity accurately and guarantee the... Sound velocity profile(SVP)data is indispensable in the multi-beam data processing.The sampling density is of great importance for SVP to represent the vertical variation of sound velocity accurately and guarantee the accuracy of sound ray tracing(SRT).However,the SVP also affects the SRT efficiency significantly,especially in deep-sea multi-beam sounding data processing.To improve SRT efficiency and ensure SRT accuracy,an adaptive SVP simplification method based on area difference is proposed in this article.Firstly,the relationship between the area difference of the raw SVP and the simplified one and SRT bias is studied,and the relationship model of them is built.Then,by considering the constraint of SRT accuracy,the SVP simplification method and the simplifying SVP procedure SVP are given.Finally,a deep water experiment is conducted to verify the proposed method.Compared to the existing method,the proposed method improves the robustness,feasibility of SVP simplification as well as the accuracy and efficiency of SRT. 展开更多
关键词 sound velocity profile(SVP)simplification area difference equivalent SVP sound ray tracing(SRT)bias maximum offset of sound velocity(MOV)
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Exposed Cross-section of the Archaean Lower Crustin the Shanxi-Hebei-Inner Mongolia Border Region:Problems and Prospects
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作者 ZHAO Jing QIAN Xianglin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1998年第1期1-13,共13页
The Archaean lower crust represented by granulite facies rocks, which is rare in China, is found to be exposed in the Shanxi-Hebei-Inner Mongolia border region. Studies of the regional structure and deformation and me... The Archaean lower crust represented by granulite facies rocks, which is rare in China, is found to be exposed in the Shanxi-Hebei-Inner Mongolia border region. Studies of the regional structure and deformation and metamorphism of the region indicate that there occurred at least two phases of deformation and metamorphism in the region. Early-phase nearly E-W-directed deformational structure is well preserved in the Zhangjiakou-Xuanhua area. Observations of the features of the geological structure from north to south (in the Hengshan metamorphic terrain) have revealed a possible exposed cross-section through the Archaean lower crust. The structure was superimposed by a NE-SW-trending high-temperature ductile shear zone in the Datong area in the late phase, thus reworking the Archaean sequence. 展开更多
关键词 Archaean cross-section of the lower crust Datong area Zhangjiakou-Xuanhua area high-temperature ductile shear zone
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Propagation Mechanisms of Incident Tsunami Wave in Jiangsu Coastal Area,Caused by Eastern Japan Earthquake on March 11,2011
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作者 袁春光 王义刚 +2 位作者 黄惠明 陈橙 陈大可 《China Ocean Engineering》 SCIE EI CSCD 2016年第1期123-136,共14页
At 13:46 on March 11, 2011(Beijing time), an earthquake of Mw=9.0 occurred in Japan. By comparing the tsunami data from Guanhekou marine station with other tsunami wave observation gathered from southeast coastal a... At 13:46 on March 11, 2011(Beijing time), an earthquake of Mw=9.0 occurred in Japan. By comparing the tsunami data from Guanhekou marine station with other tsunami wave observation gathered from southeast coastal area of China, it was evident that, only in Guanhekou, the position of the maximum wave height appeared in the middle part rather than in the front of the tsunami wave train. A numerical model of tsunami propagation based on 2-D nonlinear shallow water equations was built to study the impact range and main causes of the special tsunami waveform discovered in Jiangsu coastal area. The results showed that nearly three-quarters of the Jiangsu coastal area, mainly comprised the part north of the radial sand ridges, reached its maximum tsunami wave height in the middle part of the wave train. The main cause of the special waveform was the special underwater topography condition of the Yellow Sea and the East China Sea area, which influenced the tsunami propagation and waveform significantly. Although land boundary reflection brought an effect on the position of the maximum wave height to a certain extent, as the limits of the incident waveform and distances between the observation points and shore, it was not the dominant influence factor of the special waveform. Coriolis force's impact on the tsunami waves was so weak that it was not the main cause for the special phenomenon in Jiangsu coastal area. The study reminds us that the most destructive wave might not appear in the first one in tsunami wave train. 展开更多
关键词 Jiangsu coastal area tsunami wave the maximum wave height occurrence position wave train causes analysis
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Optimal Minimum Number of CT Slices Required to Measure Cross Sectional Areas of Small Pulmonary Vessels
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作者 Shingo Sakamoto Shoichiro Matsushita +8 位作者 Akiyuki Kotoku Hayato Tomita Yuki Saito Shinji Saruya Shin Matsuoka Tsuneo Yamashiro Atsuko Fujikawa Kunihiro Yagihashi Yasuo Nakajima 《Open Journal of Medical Imaging》 2015年第2期71-77,共7页
The cross-sectional area (CSA) of small pulmonary vessels can be quantified by CT, which is a reliable method of evaluating vascular alterations in such vessels. However, the optimal number of slices required for accu... The cross-sectional area (CSA) of small pulmonary vessels can be quantified by CT, which is a reliable method of evaluating vascular alterations in such vessels. However, the optimal number of slices required for accurate quantitation remains unknown. We evaluated relationships among all slices at 10-mm interval and all slices at 3-cm interval, 6-cm interval, and 3-slices and found the closest correlation (0.939) between all slices at 10-mm intervals and 3-cm intervals. Thus, all slices at 3-cm intervals are suitable for accurately measuring CSA. 展开更多
关键词 COMPUTED Tomography cross-sectional area PULMONARY VESSELS Quantitative Analysis
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SOME REMARKS ABOUT THE AREA-PRESERVING CONVEX CURVE FLOW IN THE PLANE
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作者 PiLing 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2004年第4期417-428,共12页
Using Picard's theorem and the Leray-Schauder fixed point theorem to reinvestigate the area-preserving convex curve flow in the plane which is considered as a coupled system and thus different from the setting han... Using Picard's theorem and the Leray-Schauder fixed point theorem to reinvestigate the area-preserving convex curve flow in the plane which is considered as a coupled system and thus different from the setting handled by Gage. 展开更多
关键词 Picard's theorem Leray-Schauder fixed point theorem maximum principle area-preserving convex curve flow.
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汶川震区山洪灾害场次洪水最大携沙量预测模型
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作者 许懿娜 段乐 +5 位作者 刘超 聂锐华 李乃稳 刘秀菊 任妮 鲁恒 《时空信息学报》 2024年第2期216-228,共13页
汶川地震后,震区产生了大量松散堆积体,受强降水影响产生了破坏性更强的山洪灾害,加剧了灾害的危险性,增加了灾害防治的困难度,研究震区山洪灾害可为评估灾害的风险性及后续的管理提供依据。本研究以66处历史山洪灾害作为样本数据,进行... 汶川地震后,震区产生了大量松散堆积体,受强降水影响产生了破坏性更强的山洪灾害,加剧了灾害的危险性,增加了灾害防治的困难度,研究震区山洪灾害可为评估灾害的风险性及后续的管理提供依据。本研究以66处历史山洪灾害作为样本数据,进行可量算影响因子的相关性分析,揭示山洪灾害的携沙量影响机制,确定流域面积、主沟长度、相对高差、物源量四个影响因子作为主控因子,基于SPSS进行非线性回归分析,建立了基于场次洪水最大携沙量及最大携沙距离的估算模型,并选取了汶川县和都江堰市的共23处山洪水沙灾害数据进行了模型的验证且与其他模型对比。结果表明,本研究建立的模型可靠性好,精度更高。研究成果有助于预测汶川震区潜在的山洪水沙灾害区域,为山洪水沙灾害的风险评估提供依据。 展开更多
关键词 汶川震区 山洪灾害 携沙量 最大携沙距离 预测模型
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