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Effects of thermal treatment on physical and mechanical characteristics of coal rock

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Journal of Central South University 2016年第9期23卷 2336-2345页

作者： YIN tu-bing WANG Pin LI Xi-bing SHU Rong-hua YE Zhou-yuan School of Resources and Safety Engineering Central South University Changsha 410083 China School of Energy and Safety Engineering Hunan University of Science and Technology Xiangtan 411201 China

To study the physical and mechanical properties of coal rock after treatment at different temperatures under impact loading, dynamic compression experiments were conducted by using a split Hopkinson pressure bar(SHPB). The stress–strain curves of specimens under impact loading were obtained, and then four indexes affected by temperature were analyzed in the experiment: the longitudinal wave velocity, elastic modulus, peak stress and peak strain. Among these indexes, the elastic modulus was utilized to express the specimens' damage characteristics. The results show that the stress–strain curves under impact loading lack the stage of micro-fissure closure and the slope of the elastic deformation stage is higher than that under static loading. Due to the dynamic loading effect, the peak stress increases while peak strain decreases. The dynamic mechanical properties of coal rock show obvious temperature effects. The longitudinal wave velocity, elastic modulus and peak stress all decrease to different extents with increasing temperature, while the peak strain increases continuously. During the whole heating process, the thermal damage value continues to increase linearly, which indicates that the internal structure of coal rock is gradually damaged by high temperature.

关键词： rock mechanical property split Hopkinson pressure bar (SHPB) high temperature coal rock dynamic mechanical property

Preparation of Spherical Microfine Silicon Powder

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Journal of Wuhan University of Technology(Materials Science) 2008年第4期23卷 440-442页

作者： SHENG Yong ZOU Jun LI bing tu Mingjing College of Material Science and Engineering Sichuan University Chengdu 610065 China

Under certain conditions of proper temperature and pH value, sodium silicate was hydrolyzed in liquid ammonia chloride, and spherical microfine SiO2 powder in micrometer-size was prepared. In this experiment, the relationship between needed time and proper pH value, temperature, density of the solution, and its current capacity were found .The optimum conditions are pH 8.5, 70 ~C, and the concentration of sodium silicate is 0.6 mol/L for the density of the solution. The structure of spherical microfine silicon was characterized by SEM and XRD.

关键词： SiO2 powder spherical-structure

Structural form selection of the high-rise buildingwith the improved BP neural network

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High Technology Letters 2020年第1期26卷 92-97页

作者： Zhao Guangzhe Yang Hanting tu bing Zhou Meiling Zhou Chengle School of Electrical and Information Engineering Beijing University of Civil Engineeringand ArchitectureBeijing 100044P.R.China College of Information and Communication Engineering Hunan Institute of Science and TechnologyYueyang 414000P.R.China

As civil engineering technology development,the structural form selection is more and more critical in design of high-rise ***,structural form selection involves expertise knowledge and changes with the environment which makes the task *** approach utilizing improved back propagation(BP)neural network optimized by the Levenberg-Marquardt(L-M)algorithm is proposed to extract the main controlling factors of structural form ***,an intelligent expert system with artificial neural network is constructed to design high-rise buildings structure *** experiment tests the model in 15 well-known architecture samples and get the prediction accuracy of 93.33%.The results show that the method is feasible and can help designers select the appropriate structural form.

关键词： back propagation(BP)neural network high-rise building structural form selection Levenberg-Marquardt(L-M)algorithm

Laparoscopic liver resection for hepatocellular carcinoma complicated with significant portal hypertension:A propensity score-matched survival analysis

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Hepatobiliary & Pancreatic Diseases International 2023年第4期22卷 358-365页

作者： Zhang-You Guo Yuan Hong bing tu Yao Cheng Xiao-Mei Wang Department of Minimally Invasive Interventional Therapy Yunnan Cancer HospitalThe Third Affiliated Hospital of Kunming Medical UniversityYunnan Cancer CenterKunming 650118China Medical Laboratory The First Affiliated Hospital of Kunming Medical UniversityInstitute of Experimental Diagnostics of Yunnan ProvinceKey Laboratory of Laboratory Medicine of Yunnan ProvinceKunming 650032China Department of Hepatobiliary Surgery The Second Affiliated HospitalChongqing Medical UniversityChongqing 400010China

Background: Significant portal hypertension(SPH) is a relative contraindication for patients with resectable hepatocellular carcinoma(HCC). However, increasing evidence indicates that liver resection is feasible for HCC patients with SPH. Methods: HCC patients with cirrhosis who underwent laparoscopic liver resection(LLR) in two centers from January 2013 to April 2018 were included. Surgical and survival outcomes were analyzed to explore potential prognostic factors. Propensity score matching(PSM) analysis was performed to minimize bias. Results: A total of 165 patients were divided into two groups based on the presence(SPH, n = 76) or absence(non-SPH, n = 89) of SPH. Patients in the SPH group had longer operative time, more blood loss, and more advanced TNM stage than patients in the non-SPH group( P 0.05). After PSM, alpha-fetoprotein(AFP) ≥ 400 μg/L [hazard ratio(HR) = 4.71, 95% confidence interval(CI): 2.69-8.25], ascites(HR = 2.18, 95% CI: 1.30-3.66), American Society of Anesthesiologists(ASA) classification(Ⅲ vs. Ⅱ)(HR = 2.13, 95% CI: 1.11-4.07) and tumor diameter > 5 cm(HR = 3.91, 95% CI: 2.02-7.56) independently predicted worse OS. Conclusions: LLR for patients with HCC complicated with SPH appears feasible at the price of increasing operative time and blood loss. AFP, ascites, ASA classification and tumor diameter may predict the prognosis of HCC complicat

关键词： Hepatocellular carcinoma Significant portal hypertension Laparoscopic liver resection Propensity score matching analysis

Spectral‐spatial sequence characteristics‐based convolutional transformer for hyperspectral change detection

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CAAI Transactions on Intelligence Technology 2023年第4期8卷 1237-1257页

作者： Chengle Zhou Qian Shi Da He bing tu Haoyang Li Antonio Plaza School of Geography and Planning Sun Yat‐sen UniversityGuangzhouChina Guangdong Provincial Key Laboratory for Urbanization and GeoSimulation Sun Yat‐sen UniversityGuangzhouChina Institute of Optics and Electronics Nanjing University of Information Science and TechnologyNanjingChina Hyperspectral Computing Laboratory Escuela PolitecnicaUniversity of ExtremaduraCaceresSpain

Recently,ground coverings change detection(CD)driven by bitemporal hyperspectral images(HSIs)has become a hot topic in the remote sensing *** are two challenges in the HSI‐CD task:(1)attribute feature representation of pixel pairs and(2)feature extraction of attribute patterns of pixel *** solve the above problems,a novel spectral‐spatial sequence characteristics‐based convolutional transformer(S3C‐CT)method is proposed for the HSI‐CD *** the designed method,firstly,an eigenvalue extrema‐based band selection strategy is introduced to pick up spectral information with salient attribute ***,a 3D tensor with spectral‐spatial sequence characteristics is proposed to represent the attribute features of pixel pairs in the bitemporal ***,a fusion framework of the convolutional neural network(CNN)and Transformer encoder(TE)is designed to extract high‐order sequence semantic features,taking into account both local context information and global sequence ***,a spatial‐spectral attention mechanism is employed to prevent information reduction and enhance dimensional interactivity between the CNN and ***,the binary change map is determined according to the fully‐connected *** results on real HSI datasets indicated that the proposed S3C‐CT method outperforms other well‐known and state‐of‐the‐art detection approaches in terms of detection performance.

关键词： change detection imageanalysis

Devonian Bivalve Faunas, Life-habits, and Biodiversity Changes in Guangxi, South China

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Acta Geologica Sinica(English Edition) 2016年第1期90卷 378-379页

作者： YAO Huazhou ZHANG Renjie tu bing YAN Daoping TANG Zhaoyang Wuhan Institute of Geology and Mineral Resources China Geological Survey

Objective The Devonian bivalves are well developed, highly diversified and widely distributed in Guangxi. However, they have not been well studied previously, although several papers have dealt with it. Meanwhile, the biodiversity change of bivalves which is one of the most important benthos during Devonian in South China has not been studied yet. The aim of present project is focused on the study of systematic palaeontology, the life-habits, of Devonian bivalves of Guangxi.

关键词： Devonian Bivalve Faunas Life-habits and Biodiversity Changes in Guangxi South China

New Discovery and Zircon Hf Isotopic Composition of the Early Yanshannian Monzogranite in the Yingyangguan Group of Eastern Guangxi, China

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Acta Geologica Sinica(English Edition) 2018年第4期92卷 1653-1655页

作者： LI Xiang tu bing WANG Lingzhan TIAN Yang XIE Guogang ZHANG Jianyu Wuhan Center of Geological Survey China Geological Survey Research Center of Granitic Diagenesis and Mineralization China Geological Survey School of Earth Sciences China University of Geosciences

Objective The Yingyangguan Group is widely exposed in the southwestern segment of boundary belt between Yangtze and Cathaysian blocks and is mainly composed of a suit of lower-grade metamorphic marine volcanoclastic- sedimentary rocks （Zhou Hanwen et al., 2002）. Its forming age and petrogenesis are critical for better understanding the orogenic process and relationship of the Yangtze and Cathaysian blocks since the Neoproterozoic. However, few zircon U-Pb ages of samples from the Yingyangguan Group have been reported, which are much debated, such as the metamorphic spilite （819±11 Ma）, keratophyre （415.1±2.1 Ma） and ignimbrite （821.3±3.9 Ma）（Tian Yang et al., 2015 and references in）. In this study, we focus on the new discovered Early Yanshannian monzogranite and its mafic enclaves from the Yingyangguan Group, and conducted zircon U-Pb dating and in-situ Hf isotopic analyses to constrain their petrogenesis.

关键词： Hf ICP MS Pb New Discovery and Zircon Hf Isotopic Composition of the Early Yanshannian Monzogranite in the Yingyangguan Group of Eastern Guangxi China

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基于变形和能量的双参数损伤模型

振动与冲击 2016年第11期35卷 196-202页

作者：屠冰冰西安科技大学理学院西安710054

为了弥补既有Park-Ang双参数损伤模型计算工作量大,不便于实际应用,且易产生较大累积误差等方面不足,针对RC框架结构,基于构件位移损伤和耗能损伤关系,提出了一种基于层的半解析半数值双参数损伤模型,并通过与Park-Ang模型计算得到的层... 详细信息

为了弥补既有Park-Ang双参数损伤模型计算工作量大,不便于实际应用,且易产生较大累积误差等方面不足,针对RC框架结构,基于构件位移损伤和耗能损伤关系,提出了一种基于层的半解析半数值双参数损伤模型,并通过与Park-Ang模型计算得到的层间损伤模式对比,验证了所提出模型的有效性。同时,得出以下结论:构件损伤由位移损伤和耗能损伤两部分组成,其中位移损伤起主要作用,且针对各层梁或柱,二者之间有较好的线性关系;RC框架梁、柱层间损伤模式与结构累积塑性变形能分配系数沿楼层的分布趋势相同。

关键词： RC框架累积塑性变形能双参数损伤模型

Investigation on Skidding of Rolling Element Bearing in Loaded Zone

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Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 34-41页

作者： Yi-Min Shao Wen-bing tu Zai-Gang Chen Zhi-Jie Xie Bao-Yu Song State Key Laboratory of Mechanical Transmission Chongqing University School of Mechatronics Engineering Harbin Institute of Technology

Skidding which occurs when rolling element entering into the loaded zone is prone to cause wear and incipient failure to the raceways and rolling elements. This paper presents a dynamic model to investigate the skidding of a rolling element bearing under radial load when the rolling element is entering into the load zone. In this dynamic model, the effects of the contact forces, friction forces on the rolling element-race and rolling element-cage interfaces, gravity, and the centrifugal forces of rolling elements are taken into consideration. The Hertzian contact theory is applied to calculate the non-linear contact forces. The Coulomb friction law is used to calculate the friction forces. The differential equations of rotational motion of the rolling element with regard to its central axis and the central axis of the outer ring are established respectively. The dynamic equations are then solved by using a fourth-order Runge-Kutta algorithm. The skidding characteristics of rolling element at the entry into the loaded zone are exposed, and the effects of the operating parameters on skidding behavior are carefully investigated.

关键词： rolling element bearing skidding loaded zone dynamic model