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Belt or network?The spatial structure and shaping mechanism of the Great Wall cultural belt in Beijing

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Journal of Mountain Science 2018年第9期15卷 2027-2042页

作者： WANG Fang XU Yi-yi ZHAO Ye zhu Xiao-hua NSFC-DFGSino-German Cooperation Group on Urbanization and Locality(UAL) College of Architecture and Landscape ArchitecturePeking UniversityBeijing 100871China Key Laboratory for Earth Surface Processes Ministry of EducationPeking UniversityBeijing 100871China College of Urban and Environmental Sciences Peking UniversityBeijing 100871China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

The relationship between cross-regional cultural landscapes does not currently receive enough attention in cultural landscape conservation. Cultural landscapes in China are faced with the crisis of fragmentation and islanding, which makes it necessary to strengthen the idea of integrated conservation. The Great Wall cultural belt in Beijing is a cross-regional linear cultural landscape in the northwest mountainous area of Beijing. With the Great Wall as a link connecting the surrounding natural, social, and cultural resources to form a banded structure, it has the typical and practical significance of integrated conservation. Based on the theory of the cultural landscape security pattern and its ‘node – setting – connection' model, this research studies the spatial structure and shaping mechanism of the Great Wall cultural belt in Beijing from the perspective of tourist flow, using Flickr geo-tagged photos and Wikiloc tracks. The results identify the core nodes and intermediate nodes of the Great Wall cultural belt in Beijing and show that it has a multicore, multi-group hierarchical nesting structure differing from the geographic space, which has groups following the evolution orbit of ‘linear string – circumnuclear star – complete network.' To explain the differences between the cultural association network(CAN) and the geospatial network(GSN), we find that the cultural associations between nodes rely on geophysical channels, including heritage corridors and traffic passages, as physical carriers, but the nodes' attraction and their setting elements, containing natural geography environments, settlements, administrative divisions, etc., change the channel resistance, so CAN and GSN present different characteristics. From the perspective of systematic and spatial network thoughts, this study has made an attempt to adopt new analysis and research methods to achieve the integrated conservation and inheritance of linear cultural landscapes in mountainous areas.

关键词： Network analysis belt Cultural landscape securityMountainous landscapeGreat Wall culturalpattern Geotagging

Micro-macro fracture mechanism of heterogeneous granite in percussive drilling

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Petroleum Science 2023年第5期20卷 3131-3142页

作者： Wei-Ji Liu Yan-Fei Wang Zhao-Wang Dan Xiao-hua zhu School of Mechatronic Engineering Southwest Petroleum UniversityChengdu610500SichuanChina Geothermal Energy Research Center Southwest Petroleum UniversityChengdu610500SichuanChina Powerchina Sinohydro Bureau 7 Co. LTDChengdu610500SichuanChina

The conventional rotary rock breaking method faces a technical bottleneck in improving the rate of penetration(ROP)in deep hard *** drilling is the most potential approach to increase rock-breaking efficiency and ***,the rock-breaking mechanism of percussive drilling is still unclear enough,especially the micro-fracture mechanism of rock under confining pressure(under lateral pressure and hydraulic pressure).In this paper,the impact rock breaking experiments by four kinds of Polycrystalline Diamond Compact(PDC)cutters are carried out using a drop-weight impact testing machine and an acoustic emission(AE)recording system,the influence of parameters such as cutter shape,rake angle,and impact energy on rock-breaking are systematically *** study includes a numerical simulation to examine the process of crack initiation,propagation,and cuttings formation during the impact process with the consideration of confining *** results show the conicalshaped cutter is the most aggressive with high breaking *** penetration depth of the cutter is mainly influenced by the impact energy and cutter shape than the rake angle of the *** exists critical impact energy makes the rock breaking efficiency the *** critical impact energy is about 40 J when using the conical-shaped cutter with a rake angle of 15°.The rock mainly failed in tensile mode,and the inter-grain crack is the main *** pressure can inhibit the formation of horizontal cracks,while lateral pressure can inhibit the formation of vertical cracks and reduce the proportion of tensile *** research results can provide some reference and basis for improving the rock-breaking efficiency in deep hard formations.

关键词： Percussive drilling PFC Rock fragmentation characteristics Rock breaking efficiency

Chaotic characteristics and attractor evolution of friction noise during friction process

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Friction 2018年第1期6卷 47-61页

作者： Cong DING hua zhu Guodong SUN Yuankai ZHOU Xue ZUO School of Mechatronic Engineering China University of Mining and Technology School of Mechanical Engineering Jiangsu University of Science and Technology Jiangsu Provincial Key Laboratory of Advanced Manufacturing for Marine Mechanical Equipment Jiangsu University of Science and Technology

Friction experiments are conducted on a ring-on-disk tribometer, and friction noise produced during the friction process is extracted by a microphone. The phase trajectory and chaotic parameters of friction noise are obtained by phase-space reconstruction, and its attractor evolution is analyzed. The results indicate that the friction noise is chaotic because the largest Lyapunov exponent is positive. The phase trajectory of the friction noise follows a "convergence-stability-divergence" pattern during the friction process. The friction noise attractor begins forming in the running-in process, and the correlation dimension D increases gradually. In the stable process, the attractor remains steady, and D is stable. In the last step of the process, the attractor gradually disappears, and D decreases. The friction noise attractor is a chaotic attractor. Knowledge of the dynamic evolution of this attractor can help identify wear state changes from the running-in process to the steady and increasing friction processes.

关键词： friction noise phase trajectory chaotic parameters Lyapunov exponent chaotic attractor

Experimental research on charging characteristics of a pressure-controlled VRLA battery in high-temperature environments

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第3期10卷 418-422页

作者： hua zhu Jin-jun TAN Zhang-lu XU Ji-sen XU Institute of Thermal Science and Power Systems Zhejiang University Hangzhou 310027 China

Valve-regulated-lead-acid (VRLA) battery charging performed in high-temperature environments is extremely risky under overcharge conditions, and may lead to a subsequent thermal runaway. A new pressure-controlled charging method was adopted and the charging characteristics of the pressure-controlled VRLA battery in high-temperature environments were ex-perimentally studied. The concept was tested in a large temperature gradient to obtain more details about the effects of users' accustomed charging and discharging modes on battery capacity. The premature capacity loss (PCL) phenomenon under high temperature exposure was analyzed. The results showed that the capacity loss could be recovered by charging using a large current.

关键词： Valve-regulated-lead-acid (VRLA) battery Pressure-controlled charging method High-temperature environments Charging and discharging characteristics

The Influence of Normal Load and Sliding Speed on Frictional Properties of Skin

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Journal of Bionic Engineering 2008年第1期5卷 33-38页

作者： Wei Tang Shi-rong Ge hua zhu Xi-chuan Cao Ning Li Institute of Tribology and Reliability Engineering School of Mechanical and Electrical Engineering China University of Mining and Technology Xuzhou 221116 P. R. China Biotribology Center of the State Key Laboratory of Tribology China University of Mining and Technology Xuzhou 221116 P. R. China

The study of frictional properties of human skin is important for medical research, skin care products and textile exploi- tation. In order to investigate the influence of normal load and sliding speed on the frictional properties of skin and its possible mechanism, tests were carded out on a multi-specimen friction tester. When the normal load increases from 0.1 N to 0.9 N, normal displacement and the friction coefficient of skin increase. The friction coefficient is dependent on the load, indicating that both adhesion and deformation contribute to the friction behaviour. The deformation friction was interpreted using the plough model of friction. When sliding speed increases from 0.5 mm·s^-1 to 4 mm·s^-1, the friction coefficient increases and ＂stick-slip＂ phenomena increase, indicating that hysteretic friction contributes to the friction. The hysteretic friction was in- terpreted using schematic of energy translation during the rigid spherical probe sliding on the soft skin surface, which provides an explanation for the influence of the sliding speed on the frictional characteristics of the skin.

关键词： normal load sliding speed friction coefficient skin

Formation and Destiny of White Dwarf and Be Star Binaries

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Research in Astronomy and Astrophysics 2023年第2期23卷 262-274页

作者： Chun-hua zhu Guo-Liang Lü Xi-Zhen Lu Jie He School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

The binary systems consisting of a Be star and a white dwarf(Be WDs) are very *** can originate from the binaries composed of a Be star and a subdwarf O or B star(Besd OBs),and they can merge into red giants via luminous red nova or can evolve into double WD potentially detected by the LISA *** the method of population synthesis,we investigate the formation and the destiny of Be WDs,and discuss the effects of the metallicity(Z) and the common envelope evolution *** find that Besd OBs are significant progenitors of Be *** 30%(Z = 0.0001)-50%(Z = 0.02) of Be WDs come from Besd *** 60%(Z = 0.0001)-70%(Z = 0.02) of Be WDs turn into red giants via a merger between a WD and a non-degenerated *** 30%(Z = 0.0001)-40%(Z = 0.02) of Be WDs evolve into double WDs which are potential gravitational waves of the LISA mission at a frequency band between about 3 × 10^(-3)and 3 × 10^(-2)*** common envelope evolution parameter introduces an uncertainty with a factor of about 1.3 on Be WD populations in our simulations.

关键词： (stars:)binaries(including multiple) close-stars evolution-stars rotation-(stars:)white dwarfs

Tuning electronic structure of Pt to enhance ethanol electrooxidation performance of SnO_(2) patched ultrathin PtRhNi nanowires

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Rare Metals 2023年第11期42卷 3614-3621页

作者： Xiao-Kun Fan Wen Chen Yun-hua zhu Wen-Hui Wang Bay Area Center for Electron Microscopy Songshan Lake Materials LaboratoryDongguan523808China School of Civil and Environmental Engineering Harbin Institute of TechnologyShenzhen518055China State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and EngineeringTongji UniversityShanghai200092China

Developing highly active and stable Pt-based nanocatalysts towards the ethanol oxidation reaction(EOR)is still a challenge for the commercialization of direct ethanol fuel ***,SnO_(2) patched ultrathin PtRhM(M=Ni or C... 详细信息

关键词： nanowires electronic structure

Cycloastragenol induces apoptosis and protective autophagy through AMPK/ULK1/mTOR axis in human non-small cell lung cancer cell lines

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Journal of Integrative Medicine 2024年第4期22卷 503-514页

作者： Li-hua zhu Yu-pei Liang Lian Yang Feng zhu Li-jun Jia He-gen Li Department of Oncology Longhua HospitalShanghai University of Traditional Chinese MedicineShanghai 200032China Cancer Institute of Traditional Chinese Medicine Longhua HospitalShanghai University of Traditional Chinese MedicineShanghai 200032China Department of Laboratory Medicine Huadong HospitalFudan UniversityShanghai 200237China

Objective:Studies have demonstrated that cycloastragenol induces antitumor effects in prostate,colorectal and gastric cancers;however,its efficacy for inhibiting the proliferation of lung cancer cells is largely *** study explores the efficacy of cycloastragenol for inhibiting non-small cell lung cancer(NSCLC)and elucidates the underlying molecular ***:The effects of cycloastragenol on lung cancer cell proliferation were assessed using an adenosine triphosphate monitoring system based on firefly luciferase and clonogenic formation ***-induced apoptosis in lung cancer cells was evaluated using dual staining flow cytometry with an annexin V-fluorescein isothiocyanate/propidium iodide *** elucidate the role of cycloastragenol in the induction of apoptosis,apoptosis-related proteins were examined using Western *** and Western blotting were used to determine whether cycloastragenol could induce autophagy in lung cancer *** techniques,including small interfering RNA technology,were used to investigate the underlying *** effects against lung cancer and biosafety of cycloastragenol were evaluated using a mouse subcutaneous tumor ***:Cycloastragenol triggered both autophagy and ***,cycloastragenol promoted apoptosis by facilitating the accumulation of phorbol-12-myristate-13-acetate-induced protein 1(NOXA),a critical apoptosis-related ***,cycloastragenol induced a protective autophagy response through modulation of the adenosine 5'-monophosphate-activated protein kinase(AMPK)/unc-51-like autophagy-activating kinase(ULK1)/mammalian target of rapamycin(mTOR)***:Our study sheds new light on the antitumor efficacy and mechanism of action of cycloastragenol in *** insight provides a scientific basis for exploring combination therapies that use cycloastragenol and inhibiting the AMPK/ULK1/mTOR pathway as a promising approach to

关键词： Non-small cell lung cancer Cycloastragenol Autophagy Apoptosis

Experimental study of debris flow caused by domino failures of landslide dams

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International Journal of Sediment Research 2014年第3期29卷 414-422页

作者： hua-Yong CHEN Peng CUI Gordon G.D.ZHOU Xing-hua zhu Jin-Bo TANG Key Laboratory of Mountain Hazards and Earth Surface Process CAS Institute of Mountain Hazards and Environment CAS

The formation of landslide dams is often induced by earthquakes in mountainous *** failure of a landslide dam typically results in catastrophic flash floods or debris flows *** attention has been given to the processes and mechanisms involved in the failure of individual landslide ***,the processes leading to domino failures of multiple landslide dams remain *** this study,experimental tests were carried out to investigate the domino failure of landslide dams and the consequent enlargement of downstream debris *** blockage conditions were considered,including complete blockage,partial blockage and erodible bed(no blockage).The mean velocity of the flow front was estimated by *** stress transducers(TSTs)and Laser range finders(LRFs) were employed to measure the total stress and the depth of the flow front,*** a complete blockage pattern,a portion of the debris flow was trapped in front of each retained landslide dam before the latter collapsed *** was accompanied by a dramatic decrease in the mean velocity of the flow ***,under both partial blockage and erodible bed conditions,the mean velocity of the flow front increased gradually downward along the sloping *** failures of the landslide dams were triggered when a series of dams(complete blockage and partial blockage) were distributed along the ***,not all of these domino failures led to enlarged debris *** modes of dam failures have significant impacts on the enlargement of debris ***,further research is necessary to understand the mechanisms of domino failures of landslide dams and their effects on the enlargement of debris flows.

关键词： Debris flow Landslide dams Domino failures Enlargement of debris flow Mean velocity