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Shear weakening behavior at the surface of structural plane of rock

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Yantu Lixue/Rock and Soil Mechanics 2020年 41卷 19-29页

作者： He, Liu zhao, zhi-ming Wu, Guang Liu, Di-Yi Faculty of Geosciences and Environmental Engineering Southwest Jiaotong University Chengdu 611756 China

Based on a series of direct shear test results of structural planes of similar materials of rock mass, the initial morphology of different structural planes Z2, structural surface wall strength JCS and normal stress σn on the shear weakening and failure of structural surfaces are studied under different shear displacement conditions by applying the three-dimensional scanning identification technique. The results show that the surface damage coefficient (N) of the joint surfaces with higher Z2(initial), JCS and σn increases significantly at different shear displacements with the continuous increase of shear displacement. Structural surfaces with a much higher JCS value are dominated by brittle failure, while structural surfaces with a smaller JCS value are dominated by wear-out failure. During the shear process, the weakening of the structural surface morphology is caused by the "shear effect" of the surface protrusion, and also the "filling effect" of the depressed area of the structural plane. Based on the degradation rate of the morphology factor of structural plane Z2(δ) at different shear displacement, the degradation process of joint surface was classified into three stages with the shear displacement: the initial degradation stage, rapid degradation stage, and constant degradation stage. With the increase of Z2(initial), JCS and σn, the segmentation characteristics of degradation of structural planes become much more obvious, and the transformation process of three stages has an accelerating trend. An empirical model of joint surface morphology degradation under the influence of different factors is proposed through the regression analysis. The results indicate that the accurate tracking on the weakening characteristics of the structural surface morphology during the shearing process is beneficial to study the evolution of mechanical properties of the structural surfaces during the shearing process. © 2020, Science Press. All right reserved.

关键词： Surface morphology

日本滑雪产业助力乡村振兴的经验与启示——基于共生理论的考察

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唐山师范学院学报 2024年第3期46卷 83-88页

作者：周启星赵志明闽南理工学院体育学院福建泉州362000

为促进乡村振兴,日本积极发展滑雪产业,构建了多元主体共生的产业治理模式。研究发现,多元主体协同治理、“六次产业化”、广域DMO合作框架是日本滑雪产业发展的主要实践内容。运用共生理论分析日本滑雪产业共生框架:政府-非政府组织-... 详细信息

为促进乡村振兴,日本积极发展滑雪产业,构建了多元主体共生的产业治理模式。研究发现,多元主体协同治理、“六次产业化”、广域DMO合作框架是日本滑雪产业发展的主要实践内容。运用共生理论分析日本滑雪产业共生框架:政府-非政府组织-企业构成了基本共生单元,政策-区域-市场构成了日本滑雪产业赖以生存的共生环境,关系-价值-治理共同维护了日本滑雪产业共生模式。由此提出我国乡村滑雪产业发展的建议。

关键词：滑雪产业乡村振兴体育产业日本共生理论

UGC模式下著作权保护困境与应对——以二次创作作品为切入点

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山西省政法管理干部学院学报 2024年第2期37卷 50-53页

作者：冯艳艳赵志明山东科技大学文法学院山东青岛266590

为探究全民创造内容背景下著作权保护面临的困境,选取UGC中具有代表性的“二次创作作品”为切入点,对其侵权认定中的合理使用难界定、实质性相似难判定问题进行分析,并通过分析案例指出著作权集体管理组织的缺陷。UGC模式下著作权的保护... 详细信息

为探究全民创造内容背景下著作权保护面临的困境,选取UGC中具有代表性的“二次创作作品”为切入点,对其侵权认定中的合理使用难界定、实质性相似难判定问题进行分析,并通过分析案例指出著作权集体管理组织的缺陷。UGC模式下著作权的保护,应从制度完善和使用新技术等措施寻找解决对策,在立法、司法上优化三步检验法的适用,完善著作权集体管理制度,并以区块链等新技术赋能著作权集体管理。从二次创作作品问题切入,不仅利于UGC模式下的著作权保护,也可促进我国互联网著作权保护进一步发展。

关键词： UGC模式互联网著作权二次创作作品著作权集体管理

Robotic versus laparoscopic surgery for sporadic benign insulinoma:Short-and long-term outcomes

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Hepatobiliary & Pancreatic Diseases International 2024年第4期23卷 399-405页

作者： Zhu-Zeng Yin Yuan-Xing Gao zhi-ming zhao ming-Gen Hu Wen-Bo Tang Rong Liu Faculty of Hepato-Pancreato-Biliary Surgery The First Medical CenterChinese PLA General HospitalBeijing 100853China Institute of Hepatobiliary Surgery of Chinese PLA Beijing 100853China Key Laboratory of Digital Hepatobiliary Surgery of Chinese PLA Beijing 100853China

Background:Minimally invasive surgery is the optimal treatment for insulinoma.The present study aimed to compare short-and long-term outcomes of laparoscopic and robotic surgery for sporadic benign insulinoma.Methods:A retrospective analysis of patients who underwent laparoscopic or robotic surgery for insulinoma at our center between September 2007 and December 2019 was conducted.The demographic,perioperative and postoperative follow-up results were compared between the laparoscopic and robotic groups.Results:A total of 85 patients were enrolled,including 36 with laparoscopic approach and 49 with robotic approach.Enucleation was the preferred surgical procedure.Fifty-nine patients(69.4%)underwent enucleation;among them,26 and 33 patients underwent laparoscopic and robotic surgery,respectively.Robotic enucleation had a lower conversion rate to laparotomy(0 vs.19.2%,P=0.013),shorter operative time(102.0 vs.145.5 min,P=0.008)and shorter postoperative hospital stay(6.0 vs.8.5 d,P=0.002)than laparoscopic enucleation.There were no differences between the groups in terms of intraoperative blood loss,the rates of postoperative pancreatic fistula and complications.After a median follow-up of 65 months,two patients in the laparoscopic group developed a functional recurrence and none of the patients in the robotic group had a recurrence.Conclusions:Robotic enucleation can reduce the conversion rate to laparotomy and shorten operative time,which might lead to a reduction in postoperative hospital stay.

关键词： Robotic surgical procedures Laparoscopy Insulinoma Enucleation Pancreatectomy

Deciphering and integrating invariants for neural operator learning with various physical mechanisms

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National Science Review 2024年第4期11卷 111-122页

作者： Rui Zhang Qi Meng zhi-ming Ma Academy of Mathematics and Systems Science Chinese Academy of Sciences(CAS) Microsoft Research

Neural operators have been explored as surrogate models for simulating physical systems to overcome the limitations of traditional partial differential equation(PDE) solvers. However, most existing operator learning methods assume that the data originate from a single physical mechanism, limiting their applicability and performance in more realistic scenarios. To this end, we propose the physical invariant attention neural operator(PIANO) to decipher and integrate the physical invariants for operator learning from the PDE series with various physical mechanisms. PIANO employs self-supervised learning to extract physical knowledge and attention mechanisms to integrate them into dynamic convolutional layers.Compared to existing techniques, PIANO can reduce the relative error by 13.6%–82.2% on PDE forecasting tasks across varying coefficients, forces or boundary conditions. Additionally, varied downstream tasks reveal that the PI embeddings deciphered by PIANO align well with the underlying invariants in the PDE systems, verifying the physical significance of PIANO.

关键词： neural operator PDE solver contrastive learning physical invariants

Oscillation properties of eigenfunctions for Sturm-Liouville problems with interface conditions via Prufer transformation

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 191-200页

作者： LI zhi-yu LI Kun CAI Jin-ming QIN Jian-fang ZHENG zhao-wen School of Mathematical Sciences Qufu Normal UniversityQufu 273165China College of Mathematics and Systems Science Guangdong Polytechnic Normal UniversityGuangzhou 510665China

A class of Sturm-Liouville problems with discontinuity is studied in this paper.The oscillation properties of eigenfunctions for Sturm-Liouville problems with interface conditions are obtained.The main method used in this paper is based on Prufer transformation,which is different from the classical ones.Moreover,we give two examples to verify our main results.

关键词： Sturm-Liouville problem interface condition oscillatory solution

纳米级钛硅分子筛合成及其催化乙烯制乙二醇性能

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石化技术与应用 2024年第3期42卷 181-185,215页

作者：王漫云刘涛潘志爽吕鹏刚赵鸣芝蔡进军段宏昌何涛中国石油石油化工研究院兰州化工研究中心甘肃兰州730060 中国石油云南石化有限公司生产一部云南安宁650399

以四丙基氢氧化铵为模板剂,钛酸四丁酯为Ti源,硅酸四乙酯(TEOS)、钠型硅溶胶或铵型硅溶胶分别为Si源,通过水热晶化法制备出一系列钛硅分子筛(TS-1),利用X射线衍射仪、自动物理吸附仪、荧光光谱仪、傅里叶红外光谱仪、扫描电子显微镜、... 详细信息

以四丙基氢氧化铵为模板剂,钛酸四丁酯为Ti源,硅酸四乙酯(TEOS)、钠型硅溶胶或铵型硅溶胶分别为Si源,通过水热晶化法制备出一系列钛硅分子筛(TS-1),利用X射线衍射仪、自动物理吸附仪、荧光光谱仪、傅里叶红外光谱仪、扫描电子显微镜、紫外可见分光光度计等仪器对合成的样品进行了表征,考察了Ti源引入温度、Si源种类、晶化时间以及硅钛比[n(Si)/n(Ti),下同]对合成TS-1的影响,并对比评价了系列TS-1催化乙烯制乙二醇(EG)的性能。结果表明:在常温下引入Ti源,选择TEOS作Si源,晶化时间为1 d,硅钛比为50的条件下所合成TE-50 N-1样品的催化性能最优,H_(2)O_(2)转化率为80.04%,EG选择性为97.19%。

关键词：钛硅分子筛硅酸四乙酯催化氧化乙烯乙二醇选择性

P-symmetric Subharmonic Solutions for Nonlinear Hamiltonian Systems

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1388-1408页

作者： Duan zhi ZHANG zhi Hao zhao School of Mathematical Sciences Nankai UniversityTianjin 300071P.R.China

In this paper,we prove that for each positive k≡1 mod m there exists a P-symmetric kmτ-periodic solution xk for asymptotically linear mτ-periodic Hamiltonian systems,which are nonautonomous and endowed with a P-symmetry.If the P-symmetric Hamiltonian function is semi-positive,one can prove,under a new iteration inequality of the Maslov-type P-index,that xk_(1) and xk_(2) are geometrically distinct for k_(1)/k_(2)≥(2n+1)m+1;and xk_(1),xk_(2) are geometrically distinct for k_(1)/k_(2)≥m+1 provided xk_(1) is non-degenerate.

关键词： P-symmetric subharmonic Hamiltonian systems Maslov-type index theory iteration inequality asymptotically linear

Clinical Value of the Quantitative Flow Ratio to Predict Long-term Target Vessel Failure in Patients with In-stent Restenosis after Drug-coated Balloon Angioplasty

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Current Medical Science 2024年第3期44卷 561-567页

作者： Xiang-qi WU Long-bo LI Wei YOU zhi-ming WU Lei zhao zhi-hui WANG Pei-na MENG Bin LIU Fei YE Department of Cardiology Nanjing First HospitalNanjing Medical UniversityNanjing210006China Department of Cardiology The Second Hospital of Jilin UniversityJilin130000China

Objective The study sought to investigate the clinical predictive value of quantitative flow ratio(QFR)for the long-term target vessel failure(TVF)outcome in patients with in-stent restenosis(ISR)by using drug-coated balloon(DCB)treatment after a long-term follow-up.Methods This was a retrospective study.A total of 186 patients who underwent DCB angioplasty for ISR in two hospitals from March 2014 to September 2019 were enrolled.The QFR of the entire target vessel was measured offline.The primary endpoint was TVF,including target vessel-cardiac death(TV-CD),target vessel-myocardial infarction(TV-MI),and clinically driven-target vessel revascularization(CD-TVR).Results The follow-up time was 3.09±1.53 years,and 50 patients had TVF.The QFR immediately after percutaneous coronary intervention(PCI)was significantly lower in the TVF group than in the no-TVF group.Multivariable Cox regression analysis indicated that the QFR immediately after PCI was an excellent predictor for TVF after the long-term follow-up[hazard ratio(HR):5.15×10−5(6.13×10−8−0.043);P<0.01].Receiver-operating characteristic(ROC)curve analysis demonstrated that the optimal cut-off value of the QFR immediately after PCI for predicting the long-term TVF was 0.925(area under the curve:0.886,95%confidence interval:0.834–0.938;sensitivity:83.40%,specificity:88.00;P<0.01).In addition,QFR≤0.925 post-PCI was strongly correlated with the TVF,including TV-MI and CD-TVR(P<0.01).Conclusion The QFR immediately after PCI showed a high predictive value of TVF after a long-term follow-up in ISR patients who underwent DCB angioplasty.A lower QFR immediately after PCI was associated with a worse TVF outcome.

关键词： percutaneous coronary intervention in-stent restenosis target vessel failure quantitative flow ratio