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A new estimation method and an anisotropy index for the deformation modulus of jointed rock masses

Journal of Rock Mechanics and Geotechnical Engineering 2022年第1期14卷 153-168页

作者： Bohu Zhang Junyan Mu Jun Zheng qing lv Jianhui Deng State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500China Department of Civil Engineering Zhejiang UniversityHangzhou310058China Center for Balance Architecture Zhejiang UniversityHangzhou310007China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

The deformation modulus of a rock mass is an important parameter to describe its mechanical *** this study,an analytical method is developed to determine the deformation modulus of jointed rock masses,which considers the mechanical properties of intact rocks and joints based on the superposition *** to incorporating the variations in the orientations and sizes of joint sets,the proposed method is applicable to the rock mass with persistent and parallel joints as well as that with nonpersistent and nonparallel *** addition,an anisotropy index AIdmfor the deformation modulus is defined to quantitatively describe the anisotropy of rock *** range of AIdmis from 0 to 1,and the more anisotropic the rock mass is,the larger the value of AIdmwill *** evaluate the proposed method,20 groups of numerical experiments are conducted with the universal distinct element code(UDEC).For each experimental group,the deformation modulus in 24 directions are obtained by UDEC(numerical value)and the proposed method(predicted value),and then the mean error rates are *** that the mean error rate is the mean value of the error rates of the deformation modulus in 24 directions,where for each direction,the error rate is equal to the ratio of numerical value minus predicted value to the numerical *** results show that(i)for different experimental groups,the mean error rates vary between 5.06%and 22.03%;(ii)the error rates for the discrete fracture networks(DFNs)with two sets of joints are at the same level as those with one set of joints;and(iii)therefore,the proposed method for estimating the deformation modulus of jointed rock masses is valid.

关键词： Deformation modulus Analytical method Anisotropy index Jointed rock masses Mechanical behavior Discrete fracture network(DFN)

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A universal elliptical disc(UED)model to represent natural rock fractures

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International Journal of Mining Science and Technology 2022年第2期32卷 261-270页

作者： Jun Zheng Jichao Guo Jiongchao Wang Honglei Sun Jianhui Deng qing lv Department of Civil Engineering Zhejiang UniversityHangzhou 310058China Center for Balance Architecture Zhejiang UniversityHangzhou 310007China College of Civil Engineering Zhejiang University of TechnologyHangzhou 310023China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource&HydropowerSichuan UniversityChengdu 610065China

Since natural fractures are often non-equidimensional,the circular disc model still has great *** contrast,the elliptical disc model is more applicable to representing natural fractures,especially for slender *** paper developed a universal elliptical disc(UED)model by incorporating the center point,size,and azimuth of fractures as ***,with respect to the azimuth of elliptical fractures in three-dimensional(3D)space,we proposed a paradigm to construct its probability density function(PDF)by coupling the orientation and rotation angle of long axis based on three coordinate *** illustrate the construction process of the PDF of the fracture azimuth,we took the orientation following the Fisher distribution and the rotation angle following Von Mises distribution as an example.A rock slope is used to show the use of the developed UED model,and the 3D DFNs for the slope rock mass are generated by Monte Carlo *** addition,the DFNs for the rock mass are also generated based on the existing circular disc model and non-universal elliptical disc *** comparison results from the three models clearly illustrate the superiority of the UED model over the existing circular and non-universal elliptical disc models.

关键词： Discrete fracture networks Rock mass Discontinuity Elliptical disc model Fisher distribution Monte Carlo simulation

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一种新型空心圆柱型取能磁芯设计

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水电能源科学 2024年第4期42卷 205-209页

作者：李黎梁鸿元唐诗琪陈益华吕清扬华中科技大学电气与电子工程学院湖北武汉430074 华中科技大学国家脉冲强磁场科学中心湖北武汉430074

针对现有非侵入式磁芯功率密度低、质量大、结构复杂的特点,设计了一种结构简单、可一体化制作的新型空心圆柱型磁芯,经仿真验证,其功率密度与壳层厚度成类反比例关系。此外,建立了空心圆柱型磁芯的准确功率模型,使磁芯设计不再受限于... 详细信息

针对现有非侵入式磁芯功率密度低、质量大、结构复杂的特点,设计了一种结构简单、可一体化制作的新型空心圆柱型磁芯,经仿真验证,其功率密度与壳层厚度成类反比例关系。此外,建立了空心圆柱型磁芯的准确功率模型,使磁芯设计不再受限于有限元仿真软件,简化了磁芯的优化难度。进而试验验证表明,在相同条件下,相较传统圆柱型磁芯,空心圆柱型磁芯的质量减小了49%,功率密度提高了82%,具有良好的工程实用价值和应用前景。

关键词：磁场能量收集非侵入式磁芯高功率密度有限元仿真功率模型

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“要素-系统”视角下西部高校本科生培养问题探究

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昆明学院学报 2024年第2期46卷 79-86页

作者：刘六生吕清越段彦丞云南师范大学教育学部云南昆明650500 泰国朱拉隆功大学研究生院泰国曼谷10330

西部高校本科生培养是振兴西部高等教育、提升西部教育水平的关键一环,也是全国高等教育高质量发展的重要内容和应有之义。当前西部高校本科生培养工作面临诸多问题,从西部高校自身来看,主要有专业设置不够合理、师资队伍力量不强、学... 详细信息

西部高校本科生培养是振兴西部高等教育、提升西部教育水平的关键一环,也是全国高等教育高质量发展的重要内容和应有之义。当前西部高校本科生培养工作面临诸多问题,从西部高校自身来看,主要有专业设置不够合理、师资队伍力量不强、学科特色尚不显著等;从西部高校与社会互动关系来看,主要体现在高校发展与经济发展耦合有限、高校发展受“西部意识”制约等。基于“要素-系统”哲学范畴,研究提出西部高校本科生培养应遵循“对外加强教育支持,对内优化高教系统,培养出色本科生”的协同发展思路。

关键词：西部高校本科生培养 “要素-系统”范畴协同发展

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Impact of Coronary Artery Anatomy in Arterial Switch Operation:In-hospital and Post-discharge Outcomes

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Current Medical Science 2022年第3期42卷 642-649页

作者： Shu-yuan WANG qing-yu ZENG Li ZHANG qing lv Ming-xing XIE Department of Ultrasound Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China Clinical Research Center for Medical Imaging in Hubei Province Wuhan 430022China Hubei Province Key Laboratory of Molecular Imaging Wuhan 430022China Shenzhen Huazhong University of Science and Technology Insititute Shenzhen 518057China

Objective The influence of the coronary artery anatomy on the prognosis of patients receiving an arterial switch operation(ASO)is currently controversial,and the risk factors for this operation may change in more complicated *** study aimed to investigate the influence of coronary artery anomalies on the in-hospital and post-discharge outcomes of ASO in patients with transposition of the great arteries(TGA)and Taussig-Bing anomaly(TBA).Methods We retrospectively reviewed 206 patients who underwent ASO from January 2007 to December *** median age at operation was 33[interquartile range(IQR):20–71]*** follow-up time was 7.2 years(IQR:4.0–10.3 years).Results Coronary anomalies were present in 86 patients(41.7%),with 9(4.4%)of them having a single coronary *** coronary features included intramural courses in 5(2.4%)patients,ostial stenosis in 1(0.5%)patient,and accessory coronary artery orifices in 5(2.4%)*** were 32(15.5%)in-hospital deaths and 8(4.6%)post-discharge deaths,yielding an overall survival of 81.3%,80.7%and 79.9%at 1,5 and 10 years,*** due to ASO has been drastically decreased since *** with a single coronary artery had higher rate of in-hospital mortality,but this finding was not statistically *** earlier surgical era(OR:2.756)and a longer cardiopulmonary bypass time(OR:2.336)were significantly associated with in-hospital mortality,while coronary patterns were *** intramural coronary artery(HR:10.034)and a patient age of older than 1 year at the time of ASO(HR:9.706)were independent predictors of post-discharge *** ASO remains the procedure of choice for TGA with coronary anomalies with acceptable in-hospital and post-discharge outcomes in terms of overall survival and freedom of ***,intramural coronary artery is an independent risk factor for post-discharge *** surgery within the 1st year of life helps improve overall m

关键词： congenital heart disease complex coronary artery early mortality late mortality learning curve

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Numerical Study on Local Flow and Heat Transfer Characteristics of Supercritical CO_(2) in PCHE with Sinusoidal Channels

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Journal of Thermal Science 2024年第1期33卷 41-55页

作者： WENZhexi lv Yigao LI qing WU Jinglin School of Energy Science and Engineering Central South UniversityChangsha 410083China

Local heat transfer and flow characteristics,which is crucial to the overall performance of supercritical CO_(2) recuperators,is rarely examined in details in reported *** this paper,the local heat transfer and flow characteristics of supercritical CO_(2) in sinusoidal channel printed circuit heat exchangers are numerically investigated under the working conditions of *** on the simplified physical model constituted by10 pitches,the variations of Re,heat flux,Nu,secondary flow and other relevant parameters along the flow direction are analyzed *** is further made between the high and low temperature recuperators(HTR and LTR).It's observed that the local heat transfer and flow characteristics vary greatly from the inlet to the outlet,especially in the *** of 127.5% and 61.7% can be observed on the cold side of the LTR for Re and heat transfer coefficient h, *** indicate that the temperature difference and heat transfer coefficient h should not be regarded as constant and the distribution of h should be carefully considered in the design of the *** complicated interactions among the varying thermophysical properties,buoyancy and the periodically changed centrifugal force are believed to be the key that shapes the flow ***,the changes of the wavy angle θ are found to have greater influence than the changes of mass flow rate in reshaping the flow field when θ>25°.Though gravity direction strongly affects the local heat transfer and flow characteristics,it's also found that the effects on the overall thermal-hydraulic performance are relatively *** the installation direction that yields a_y=g should better be avoided for the sinusoidal channel printed circuit heat exchanger.

关键词： printed circuit heat exchanger supercritical CO_(2) sinusoidal channel heat transfer recuperator

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液压泵高低温试验系统设计与应用

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液压气动与密封 2024年第6期44卷 30-33页

作者：周创辉卿绿军晁文雄西安航空学院特种泵系统技术国家地方联合工程研究中心陕西西安710077

针对某型航空齿轮泵在极端温度环境下的工作特性测试需求,设计了一套液压泵高低温性能测试方案,并搭建测试试验台架,完成齿轮泵高低温性能测试。结果表明,被试泵的流量-压力特性满足技术指标要求,液压泵的容积效率与工作温度及加载压力... 详细信息

针对某型航空齿轮泵在极端温度环境下的工作特性测试需求,设计了一套液压泵高低温性能测试方案,并搭建测试试验台架,完成齿轮泵高低温性能测试。结果表明,被试泵的流量-压力特性满足技术指标要求,液压泵的容积效率与工作温度及加载压力成反比。

关键词：液压泵高低温试验容积效率试验研究

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Predicting lymph node metastasis in colorectal cancer:An analysis of influencing factors to develop a risk model

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World Journal of Gastrointestinal Surgery 2023年第10期15卷 2234-2246页

作者： Yun-Peng Lei qing-Zhi Song Shuang Liu Ji-Yan Xie Guo-qing lv Department of Gastrointestinal Surgery Peking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina Department of Gastrointestinal Surgery Shenzhen Peking University-The Hong Kong University of Science and Technology Medical CenterPeking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina

BACKGROUND Colorectal cancer(CRC)is a significant global health issue,and lymph node metastasis(LNM)is a crucial prognostic *** prediction of LNM is essential for developing individualized treatment strategies for patients with ***,the prediction of LNM is challenging and depends on various factors such as tumor histology,clinicopathological features,and molecular *** most reliable method to detect LNM is the histopathological examination of surgically resected specimens;however,this method is invasive,time-consuming,and subject to sampling errors and interobserver *** To analyze influencing factors and develop and validate a risk prediction model for LNM in CRC based on a large patient *** This study retrospectively analyzed 300 patients who underwent CRC surgery at two Peking University Shenzhen hospitals between January and December 2021.A deep learning approach was used to extract features potentially associated with LNM from primary tumor histological images while a logistic regression model was employed to predict LNM in CRC using machine-learning-derived features and clinicopathological variables as *** The prediction model constructed for LNM in CRC was based on a logistic regression framework that incorporated machine learning-extracted features and clinicopathological *** model achieved high accuracy(0.86),sensitivity(0.81),specificity(0.87),positive predictive value(0.66),negative predictive value(0.94),area under the curve for the receiver operating characteristic(0.91),and a low Brier score(0.10).The model showed good agreement between the observed and predicted probabilities of LNM across a range of risk thresholds,indicating good calibration and clinical *** The present study successfully developed and validated a potent and effective risk-prediction model for LNM in patients with *** model utilizes machine-learning-derived features extracted from pr

关键词： Colorectal cancer Lymph node metastasis Machine learning Risk prediction model Clinicopathological factors Individualized treatment strategies

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Identification of multiple risk factors for colorectal cancer relapse after laparoscopic radical resection

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World Journal of Gastrointestinal Surgery 2023年第10期15卷 2211-2221页

作者： Jun Luo Mei-Wen He Ting Luo Guo-qing lv Department of Gastrointestinal Surgery Peking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina Department of Operating Room Peking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina Department of Gastrointestinal Surgery Shenzhen Peking University-The Hong Kong University of Science and Technology Medical CenterPeking University Shenzhen HospitalShenzhen 518036Guangdong ProvinceChina

BACKGROUND Colorectal cancer(CRC)is a common life-threatening disease that often requires surgical intervention,such as laparoscopic radical ***,despite successful surgeries,some patients experience disease *** the risk factors for CRC relapse can help guide clinical interventions and improve patient *** To determine the risk factors that may lead to CRC relapse after laparoscopic radical *** We performed a retrospective analysis using the baseline data of 140 patients with CRC admitted to our hospital between January 2018 and January *** included participants were followed up until death or for 3 *** baseline data and laboratory indicators were compared between the patients who experienced relapse and those who did not experienced *** Among the 140 patients with CRC,30 experienced relapse within 3 years after laparoscopic radical resection and 110 did not experience *** relapse group had a higher frequency of rectal tumors with low differentiation and lymphatic vessel invasion than that of the non-relapse *** expression of serum markers and the prognostic nutritional index were lower,whereas the neutrophil-to-lymphocyte ratio,expression of cytokeratin 19 fragment antigen 21-1,vascular endothelial growth factor,and Chitinase-3-like protein 1 were significantly higher in the relapse group than those in the non-relapse *** groups did not differ significantly based on other *** regression analysis revealed that all the above significantly altered factors were independent risk factors for CRC *** We identified multiple risk factors for CRC relapse following surgery,which can be considered for the clinical monitoring of patients to reduce disease recurrence and improve patient survival.

关键词： Colorectal cancer Laparoscopic surgery Relapse Risk factors

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Cleaner production of ammonium paratungstate by membrane electrolysis-precipitation of sodium tungstate solution

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Tungsten 2023年第1期5卷 145-159页

作者： Afolabi Uthmon Olayiwola Hao Du Shao-Na Wang Biao Liu Ye-qing lv Bo Pan University of Chinese Academy of Sciences Beijing 100049China CAS Key Laboratory of Green Process and Engineering National Engineering Research Center of Green Recycling for Strategic Metal ResourcesInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

The production of ammonium paratungstate(APT) is riddled with the generation of wastewater,which causes environmental *** solve the problem of wastewater generation at source,a membrane electrolysis-NH3·H2O precipitation method,which prevents wastewater generation and recycles the reagents used in the process,was proposed and investigated in this *** electrolysis process was investigated based on parameters such as initial cathodic and anodic NaOH concentrations,and current *** results showed that an increase in current density and initial cathodic NaOH concentration and a decrease in the initial anodic NaOH concentration would enhance the separation of tungsten and *** optimum condition was found at a current density of 666 A·m^(-2),initial anodic and cathodic NaOH concentrations of 69 g·L^(-1) and 40 g·L^(-1),with a current efficiency of 75.40%,and energy consumption for producing 1 ton of NaOH was 2184 kW·*** precipitation process was investigated based on the acidic high W/Na molar ratio solution obtained by the electrolysis process with NH3·H2O as the *** such as excessive coefficient,temperature,and W/Na molar ratio were *** result showed that the variation of excessive coefficient and solution temperature had an opposite effect on the purity of the APT,while an increase in the W/Na molar ratio would increase the product *** precipitation product obtained had a purity of 99.6% and was characterized using X-ray diffraction,inductively coupled plasma,and scanning electron *** methods proposed in this study could provide fundamental information for the design of a cleaner APT production process.

关键词： Membrane electrolysis Ammonium paratungstate Separation of sodium and tungsten ions Ion states of tungsten Cleaner production

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