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Evaluation of strongly singular domain integrals for internal stresses in functionally graded materials analyses using RIBEM

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Acta Mechanica Sinica 2014年第6期30卷 917-926页

作者： Hai-Feng Peng Jian Liu Qiang-hua zhu Ch.Zhang School of Aeronautics and Astronautics Faculty of Vehicle Engineering and MechanicsDalian University of Technology Department of Civil Engineering University of Siegen D-57068 Siegen Germany

An accurate evaluation of strongly singular domain integral appearing in the stress representation formula is a crucial problem in the stress analysis of functionally graded materials using boundary element *** solve this problem,a singularity separation technique is presented in the paper to split the singular integral into regular and singular parts by subtracting and adding a singular *** singular domain integral is transformed into a boundary integral using the radial integration *** expressions of the radial integrals are obtained for two commonly used shear moduli varying with spatial *** regular domain integral,after expressing the displacements in terms of the radial basis functions,is also transformed to the boundary using the radial integration ***,a boundary element method without internal cells is established for computing the stresses at internal nodes of the functionally graded materials with varying shear modulus.

关键词： Stress integral equations Functionally graded materials Strongly singular domain integral Singularity separation technique Radial integration method

Contribution of dust produced by binary merger ejecta

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Research in Astronomy and Astrophysics 2015年第1期15卷 55-63页

作者： Zhao-Jun Wang Chun-hua zhu Guo-Liang Lü School of Physical Science and Technology Xinjiang University

By means of a population synthesis code and by constructing a simple toy model of dust produced by asymptotic giant branch（AGB） stars, common envelope（CE） ejecta and binary merger ejecta, we estimate the dust product rates（DPRs） of these processes in the Milky Way. The total DPR from AGB stars is～ 6.7 × 10-4M yr-1, in which about 73% of dust grains are carbon, 24% are silicates and 3% are iron. The total DPR from CE ejecta is ～ 4.2 × 10-4M yr-1, in which about 83% of dust grains are silicates, about 12% are carbon and 5% are *** DPR from binary merger ejecta is less than 1/3 that from AGB stars or CE ejecta,and it could even be negligible under certain circumstances. Therefore, compared with AGB stars and CE ejecta, the contribution of dust produced by binary merger ejecta to total dust grains in the Milky Way is smaller or can be negligible.

关键词： binaries: close stars: evolution circumstellar matter dust

QSBR Study on the Anaerobic Biodegradation of Chlorophenols

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1183-1188页

作者： YANG Da-Sen DAI You-Zhi LI Jian-hua zhu Fei Department of Environmental Engineering Xiangtan Umversity Hunan 411105 China

18 Physicochemical and quantum chemical parameters of 12 kinds of chlorophenols are calculated in this paper. QSBR （quantitative structure-biodegradability relationship） study is performed using simca statistical software by PLS regression analysis method on anaerobic biodegradation data （logKb）, and the QSBR model is developed with favorable prediction. The model shows that the size and energy of the molecule are the dominant factors affecting the anaerobic biodegradation of chlorophenols. And the degradation rate constants （logKb） increase with the increase of core-core repulsion （CCR）, average molecular polarizability （α）, total surface area （TSA）, heat of formation （HOF） and total energy （TE）. while decrease with the increase of molecular connectivity index （^1X^V）, relative molecular mass （Mw） and electronic energy （EE）.

关键词： chlorophenols anaerobic biodegradation QSBR optimal model

Association between serum uric acid level and endothelial dysfunction in elderly individuals with untreated mild hypertension

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Journal of Geriatric Cardiology 2020年第5期17卷 264-269页

作者： Guo-hua zhu Xi-Peng SUN Jing LI Rong-Kun LIU Zheng YANG Qi hua Department of Cardiology Xuanwu Hospital Capital Medical UniversityBeijingChina

Background Endothelial dysfunction is the initial stage in atherosclerotic formation and progression and is associated with high serum uric acid(SUA)*** hypothesized that reactive hyperemia index(RHI),which reflects endothelial function,is associated with SUA levels in elderly individuals with untreated mild *** We recruited 123 patients≥60 years with untreated mild *** association between SUA level and RHI was analyzed using univariate correlation analysis and multiple regression *** receiver operating characteristic(ROC)curve was performed to validate the cutoff value of SUA that can be used to predict endothelial *** The serum uric acid level significantly increased in the RHI<1.67 group,and this result was still observed in the subgroup of *** was inversely associated with SUA level(P=0.006)and the association was still observed after adjusting for factors,such as age,sex,smoking status,and creatinine level(P=0.014).In the subgroup analysis,a positive association was observed only in *** the ROC curve analysis,the optimal cutoff values of SUA for predicting endothelial dysfunction was 293.5μmol/L in elderly mild hypertension patients and 287.0μmol/L in *** A high SUA level was considered an independent predictor of endothelial dysfunction among elderly individuals,particularly men with untreated mild hypertension.

关键词： Endothelial dysfunction Hypertension Reactive hyperemia index Uric acid

Impact of minimally invasive surgery on immune function and stress response in gastric cancer patients

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2484-2493页

作者： Rong-hua zhu Peng-Cheng Li Jie Zhang hua-hua Song Department of General Surgery Chongming Hospital Affiliated to Shanghai University of Medicine and Health SciencesShanghai 202150China Department of Respiratory Medicine Chongming Hospital Affiliated to Shanghai University of Medicine and Health ScienceShanghai 202150China

BACKGROUND Gastric cancer remains a leading cause of cancer-related mortality *** open surgery for gastric cancer is often associated with significant morbidity and prolonged *** To evaluate the effectiveness of laparoscopic minimally invasive surgery as an alternative to traditional open surgery for gastric cancer,focusing on its potential to reduce trauma,accelerate recovery,and achieve comparable oncological *** This study retrospectively analyzed 203 patients with gastric cancer who underwent surgery at the Shanghai Health Medical College Affiliated Chongming Hospital from January 2020 to December *** patients were divided into two groups:Minimally invasive surgery group(n=102),who underwent laparoscopic gastrectomy,and open surgery group(n=101),who underwent traditional open *** compared surgical indicators(surgical incision size,intraop-erative blood loss,surgical duration,and number of lymph nodes dissected),recovery parameters(time to first flatus,time to start eating,time to ambulation,and length of hospital stay),immune function(levels of IgA,IgG,and IgM),intestinal barrier function(levels of D-lactic acid and diamine oxidase),and stress response(levels of C-reactive protein,interleukin-6,and procalcitonin).RESULTS The minimally invasive surgery group demonstrated significantly better outcomes in terms of surgical indicators,including smaller incisions,less blood loss,shorter surgery time,and more lymph nodes dissected(P<0.05 for all).Recovery was also faster in the minimally invasive surgery group,with earlier return of bowel function,earlier initiation of diet,quicker mobilization,and shorter hospital stays(P<0.05 for all).Furthermore,patients in the minimally invasive surgery group had better preserved immune function,superior intestinal barrier function,and a less pronounced stress response postoperatively(P<0.05 for all).CONCLUSION Laparoscopic minimally invasive surgery for gastric cancer not on

关键词： Gastric cancer Laparoscopic surgery Minimally invasive surgery Immune function Intestinal barrier Stress response

Kernel sparse representation for MRI image analysis in automatic brain tumor segmentation

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Frontiers of Information Technology & Electronic Engineering 2018年第4期19卷 471-480页

作者： Ji-jun TONG Peng ZHANG Yu-xiang WENG Dan-hua zhu School of lnformation Science and Technology Zhejiang Sci-Tech UniversityHangzhou 310018China Department of Neurosurgery The First Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310003China State Key Laboratory for Diagnosis and Treatment of lnfectious Diseases Collaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesThe First Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310003China

The segmentation of brain tumor plays an important role in diagnosis, treatment planning, and surgical simulation. The precise segmentation of brain tumor can help clinicians obtain its location, size, and shape information. We propose a fully automatic brain tumor segmentation method based on kernel sparse coding. It is validated with 3D multiple-modality magnetic resonance imaging(MRI). In this method, MRI images are pre-processed first to reduce the noise, and then kernel dictionary learning is used to extract the nonlinear features to construct five adaptive dictionaries for healthy tissues, necrosis, edema, non-enhancing tumor, and enhancing tumor tissues. Sparse coding is performed on the feature vectors extracted from the original MRI images, which are a patch of m×m×m around the voxel. A kernel-clustering algorithm based on dictionary learning is developed to code the voxels. In the end, morphological filtering is used to fill in the area among multiple connected components to improve the segmentation quality. To assess the segmentation performance, the segmentation results are uploaded to the online evaluation system where the evaluation metrics dice score, positive predictive value(PPV), sensitivity, and kappa are used. The results demonstrate that the proposed method has good performance on the complete tumor region(dice: 0.83; PPV: 0.84; sensitivity: 0.82), while slightly worse performance on the tumor core(dice: 0.69; PPV: 0.76; sensitivity: 0.80) and enhancing tumor(dice: 0.58; PPV: 0.60; sensitivity: 0.65). It is competitive to the other groups in the brain tumor segmentation challenge. Therefore, it is a potential method in differentiation of healthy and pathological tissues.

关键词： Brain tumor segmentation Kernel method Sparse coding Dictionary learning

Tropical deciduous forest in Yunnan,southwestern China:Implications for geological and climatic histories from a little-known forest formation

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Plant Diversity 2021年第6期43卷 444-451页

作者： hua zhu Peter Ashton Bojian Gu Shisun Zhou Yunhong Tan Center for Integrative Conservation Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan 666303PR China Arnold Arboretum Harvard University and Royal Botanic GardensKewUK

In the southern mountain ranges of Yunnan province,China,deep valleys of several large rivers create rain shadows with hot dry summers,and are locally designated tropical;towards the north,notably in the Lancang(Upper Mekong)valley,these regions may experience frost during *** woody forest canopy of these valleys is predominantly deciduous,with evergreen elements in the north,where the canopy is open and the forest ***,we here present tall forest with a closed deciduous canopy and semi-evergreen subcanopy observed in hot dry valleys of these rivers and their tributaries in the tropical *** structure and physiognomy of these forests resemble the tall(moist)deciduous forest formation widespread in South Asia and ***,these forests are largely composed of tropical elements at both the generic(80%)and the species level(>70%),indicating that these forests are indeed *** originally hypothesized that these isolated forests represent refugia of a pre-Holocene extension of tall(moist)deciduous forest formation of South Asia and *** sample plot we established to test this hypothesis confirmed that these forests share the structure and physiognomy of the tall(moist)deciduous forest formation;however,the plots also showed that these forests lack the characteristic and dominant species of the formation's Indo-Burmese *** tree flora,in particular,indicates that both deciduous and evergreen elements are instead mostly derived from the adjacent tropical semi-evergreen forests of tropical southern China;yet they also include an important endemic element,which implies that these forests have survived as refuges possibly since the *** exceptional representation of evergreen elements in these forests indicates that they have rarely been subject to hot fires or domestic cattle browsing,adding to the unique nature of the forests and further justifying their strict conservation.

关键词： Floristic composition Physiognomy Biogeography Independent species assembly Tall deciduous forest Southwestern China

Microwave ablation combined with hepatectomy for treatment of neuroendocrine tumor liver metastases

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World Journal of Clinical Cases 2021年第19期9卷 5064-5072页

作者： Jin-zhu Zhang Shu Li Wei-hua zhu Da-Fang Zhang Department of Hepatobiliary Surgery Peking University People's HospitalBeijing 100044China

BACKGROUND Hepatectomy is the first choice for treating neuroendocrine tumor liver ***,most patients with neuroendocrine tumor liver metastases are not suitable for *** combined with hepatectomy can be an alternative to liver *** To explore the clinical effect of microwave ablation combined with hepatectomy for the treatment of neuroendocrine tumor liver *** In this study,the data of patients who underwent microwave ablation combined with hepatectomy for the treatment of neuroendocrine tumor liver metastases from June 2015 to January 2018 were *** the operation,the patients did not receive any treatment for liver neuroendocrine *** a multidisciplinary expert group discussion,all patients were deemed unsuitable for liver *** patients were diagnosed with neuroendocrine tumors by *** overall survival time and progression-free survival time were followed by telephone calls and outpatient visits after *** Eleven patients with neuroendocrine tumor liver metastases were treated by microwave ablation combined with hepatectomy between June 2015 and January *** median number of liver metastatic nodules was 4(range,2 to 43).The median number of lesions resected was 1(range,1 to 18),and the median number of lesions ablated was 3(range,1 to 38).The mean operation time was 405.6(±39.4)*** median intraoperative blood loss was 600 mL(range,50 to 3000).Ten patients had a fever after *** median duration of fever was 3 d(range,0 to 21).Elevated bilirubin levels occurred in all patients after *** median bilirubin on the first day after surgery was 28.5(range,10.7 to 98.9)μmol/*** patient developed respiratory failure,renal insufficiency,and pneumonia after the *** patient died postoperatively during *** mean overall survival time after surgery was 34.1(±3.7)mo,and the median progression-free survival time was 8(range,2 to 51)m

关键词： Liver Neoplasm metastasis Microwave Hepatectomy Neoplasm Endocrine tumor

A method to obtain the wind field characteristics of super-large aperture radio telescope site based on single-point wind tower and numerical simulation

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Research in Astronomy and Astrophysics 2020年第12期20卷 270-278页

作者： Fei-Long He Qian Xu Na Wang Chun-hua zhu School of Physics and Technology Xinjiang UniversityUrumqi 830046China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

The influence of wind on the pointing accuracy of large aperture radio telescopes is becoming increasingly serious, especially at high observing frequency. Obtaining the wind field characteristics efficiently is very important to reduce the wind disturbance on antenna structure. In this paper, an error evaluation of numerical simulation method is established based on the measured data of single point wind tower, and the wind field characteristics are obtained from the evaluated numerical simulation results combined with the measured data for the 110 m aperture Qi Tai radio Telescope(QTT) site. According to the simulation results, compared with the measured data, the root mean square error(RMSE) of wind speed is less than 1 m s^-1, and the minimum wind speed RMSE is 0.2 m s^-1. An analysis of the wind field characteristics of the QTT site suggests that the active wind resistance design of the antenna periphery should focus on the SSW(south-south-west) direction.

关键词： telescopes site testing methods:data analysis