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1Quantitative characterization of reservoir space in the Lower Silurian Longmaxi Shale,southern Sichuan,China显示文摘Based on the drilling data of the Upper Ordovician Wufeng Shale and the Lower Silurian Longmaxi Shale in southern Sichuan Basin,the construction of matrix pores and the development condition of fractures in a marine organic-rich shale are quantitatively evaluated through the establishment of the reservoir petrophysical models and porosity mathematical models.Our studies show that there are four major characteristics of the Longmaxi Shale confirmed by the quantitative characterization:(1)the pore volume of per unit mass is the highest in organic matter,followed in clay minerals,finally in brittle minerals;(2)the porosity of the effective shale reservoir is moderate and equal to that of the Barnett Shale,and the main parts of the shale reservoir spaces are interlayer pores of clay minerals and organic pores;(3)the porosity of the organic-rich shale is closely related to TOC and brittle mineral/clay mineral ratio,and mainly increases with TOC and clay mineral content;(4)fractures are developed in this black shale,and are mainly micro ones and medium-large ones.In the Longmaxi Shale,the fracture density increases from top to bottom,reflecting the characteristics with high brittle mineral content,high Young’s modulus,low Poisson's ratio and high brittleness at its bottom.WANG YuMan DONG DaZhong YANG Hua HE Ling WANG ShiQian HUANG JinLiang PU BoLing WANG ShuFang 2014Science China Earth Sciences2014,57,2:36
2Progress in China's Unconventional Oil & Gas Exploration and Development and Theoretical Technologies显示文摘The new century has witnessed a strategic breakthrough in unconventional oil & gas.Hydrocarbon accumulated in micro-/nano-scale pore throat shale systems has become an important domain that could replace current oil & gas resources.Unconventional oil & gas plays an increasingly important role in our energy demand.Tight gas,CBM,heavy oil and asphaltic sand have served as a key domain of exploration & development,with tight oil becoming a 'bright spot' domain and shale gas becoming a 'hotspot' domain.China has made great breakthroughs in unconventional oil & gas resources,such as tight gas,shale gas,tight oil and CBM,and great progress in oil shale,gas hydrate,heavy oil and oil sand.China has an estimated(223-263)×10~8t of unconventional oil resources and(890-1260)×l0^(12)m^3 of gas resources.China has made a breakthrough for progress in unconventional oil & gas study.New progress achieved in fine-grained sedimentary studies related to continental open lacustrine basin large-scale shallow-water delta sand bodies,lacustrine basin central sandy clastic flow sediments and marine-continental fine-grained sediments provide a theoretical basis for the formation and distribution of basin central reservoir bodies.Great breakthroughs have been made in unconventional reservoir geology in respect of research methodology & technology,multi-scale data merging and physical simulation of formation conditions.Overall characterization of unconventional reservoirs via multi-method and multi-scale becomes increasingly popular and facilitates the rapid development of unconventional oil & gas geological theory,method and technology.The formation of innovative,continuous hydrocarbon accumulation theory,the establishment of the framework of the unconventional oil & gas geological theory system,and the determination of the implications,geological feature,formation mechanism,distribution rule and core technology of unconventional oil& gas geological study lays a theoretical foundation for extensive unconventional oil & gas exploration and development.Theories and technologies of unconventional oil & gas exploration and development developed rapidly,including some key evaluation techniques such as 'sweet spot zone' integrated evaluation and a six-property evaluation technique that uses hydrocarbon source,lithology,physical property,brittleness,hydrocarbon potential and stress anisotropy,and some key development &engineering technologies including micro-seismic monitoring,horizontal drilling & completion and 'factory-like' operation pattern, 'man-made reservoir' development,which have facilitated the innovative development of unconventional oil & gas.These breakthroughs define a new understanding in four aspects:①theoretical innovation;② key technologies;③ complete market mechanism and national policy support;and ④ well-developed ground infrastructure,which are significant for prolonging the life cycle of petroleum industry,accelerating the upgrade and development of theories and technologies and altering the global traditional energy structure.ZOU Caineng YANG Zhi ZHU Rukai ZHANG Guosheng HOU Lianhua WU Songtao TAO Shizhen YUAN Xuanjun DONG Dazhong WANG Yuman WANG Lan HUANG Jinliang WANG Shufang 2015Acta Geologica Sinica(English Edition)2015,89,3:27
3Spatial heterogeneity of DTPA-extractable zinc in cultivated soils induced by city pollution and land use显示文摘The spatial heterogeneity of DTPA-extractable zinc in the cultivated soils of Shenyang suburbs in Liaoning Province of China was investigated, and its map was drawn by the methods of geostatistics combined with geographic information system. The data of soil DTPA-extractable zinc fitted normal distribution after logarithm transformation, and its semivariogram fitted a spherical model. The semivariogram indicated that the spatial dependence of soil DTPA-extractable zinc content was moderate, with the spatial dependence range of 1.69 km and the fractal dimension of 1.96. Stochastic factors contributed to 49.9% of the spatial variability, while structural factors contributed to 50.1% of it. The spatial heterogeneity of soil DTPA-extractable zinc shown by a kriged interpolation map was deeply influenced by stochastic factors such as city pollution, land use pattern and crop distributions. For example, the average content of Zn in vegetable garden soils was 2.5-4 times as much as in their originated soils, and was lower in paddy soils than in their originated soils. The areas with a higher content of soil DTPA-extractable zinc appeared in the near suburbs and the riverside along Hunhe River and the wastewater drainage of Xihe River, and the extremely high values in the near suburb of the city's residential area were a striking feature, indicating the key role of city pollution in the spatial heterogeneity of soil DTPA-extractable zinc. When recorded in the form of a soil pollution map,the results of such a survey make it possible to identify the unusually polluted areas, and to provide more information for precise agriculture and environmental control.JIANG Yong, LIANG Wenju, WEN Dazhong, ZHANG Yuge & CHEN Wenbo Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, Shenyang 110016, China College of Land and Environment, Shenyang Agricultural University, Shenyang 110161, China 2005Science China(Life Sciences)2005,48,z1:13
4The Change of the Inlet Geometry of a Centrifugal Compressor Stage and its Influence on the Compressor Performance显示文摘The impact on the compressor performance is important for designing the inlet pipe of the centrifugal compressor of a vehicle turbocharger with different inlet pipes. First, an experiment was performed to determine the compressor performance from three cases: a straight inlet pipe, a long bent inlet pipe and a short bent inlet pipe. Next, dynamic sensors were installed in key positions to collect the sign of the unsteady pressure of the centrifugal compressor. Combined with the results of numerical simulations, the total pressure distortion in the pipes, the pressure distributions on the blades and the pressure variability in the diffuser are studied in detail. The results can be summarized as follows: a bent pipe results in an inlet distortion to the compressor, which leads to performance degradation, and the effect is more apparent as the mass flow rate increases. The distortion induced by the bent inlet is not only influenced by the distance between the outlet of the bent section and the leading edge of the impeller but also by the impeller rotation. The flow fields in the centrifugal impeller and the diffuser are influenced by a coupling effect produced by the upstream inlet distortion and the downstream blocking effect from the volute tongue. If the inlet geometry is changed, the distributions and the fluctuation intensities of the static pressure on the main blade surface of the centrifugal impeller and in the diffuser are changed accordingly.WANG Leilei YANG Ce ZHAO Ben LAO Dazhong MA Chaochen LI Du 2013Journal of Thermal Science2013,22,3:13
5Advances in fabrication of ceramic corundum abrasives based on sol–gel process显示文摘Corundum abrasives with good chemical stability can be fabricated into various free abrasives and bonded abrasive tools that are widely used in the precision machining of various parts.However,these abrasives cannot satisfy the machining requirements of difficult-to-machine materials with high hardness,high strength,and strong wearing resistance.Although superhard abrasives can machine the above-mentioned materials,their dressing and manufacturing costs are high.By contrast,ceramic corundum abrasives fabricated by sol–gel method is a costeffective product between conventional and superhard abrasives.Ceramic corundum abrasives exhibit self-sharpening and high toughness.In this review,the optimization methods of ceramic corundum abrasive properties are introduced from three aspects:precursor synthesis,particle shaping,and sintering.Firstly,the functional mechanism of seeds and additives on the microstructural and mechanical properties of abrasives is analyzed.Specifically,seeds can reduce the phase transition temperature and improve fracture toughness.The grain size and uniformly dense structure can be controlled by applying an appropriate amount of multicomponent additives.Then,the urgent need of engineering application and machinability of special shape ceramic corundum abrasives is reviewed,and three methods of abrasive shaping are summarized.The micromold replication technique is highly advanced and can be used to prepare functional abrasives.Additionally,the influence of a new sintering method,namely,two-step sintering technique,on the microstructural and mechanical performance of ceramic corundum abrasives is summarized.Finally,the challenge and developmental trend of the optimization of ceramic corundum abrasives are prospected.Baoteng HUANG Changhe LI Yanbin ZHANG Wenfeng DING Min YANG Yuying YANG Han ZHAI Xuefeng XU Dazhong WANG Sujan DEBNATH Muhammad JAMIL Hao Nan Li Hafiz Muhammad ALI Munish Kumar GUPTA Zafar SAID 2021Chinese Journal of Aeronautics2021,34,6:11
6Precambrian Geochronology, Chronotectonic Framework and Model of Chronocrustal Structure of the Zhongtiao Mountains显示文摘The Zhongtiao Mountains, a typical exposure area of Precambrian rocks, are a concentration area of vari-ous types of copper deposit. The rocks were dated using several dating methods. Based on the age data ob-tained by means of three methods, several aspects are dealt with: (1) the dating results obtained by differentmethods and their geological implications have been compared; (2) a chronotectonic framework has been con-structed by means of these reliable ages, which indicates that the ages of the rocks of the Proterozoic mobilebelt fall in a time span of 2400 to 2000 Ma during which global magmatic records are lacking and reflects theages of important events in the mobile belt; (3) according to the ages of inherited zircons, neodymium modelage of the depleted mantle sources (TDM) and geochemical and geological data, a model of Precambrianchronocrustal structure has been constructed, representing a typical for the North China craton.Sun Dazhong Li Huimin Lin Yuanxian Zhou Huifang Zhao Fengqing Tang Min Tianjin Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, Tianjin Fei Zhenbi 1992Acta Geologica Sinica(English Edition)1992,66,1:10
7Effects of heavy metal pollution of highway origin on soil nematode guilds in North Shenyang, China显示文摘Soil samples were collected with distance at 5,20,40,80,160,and 320 m from the Shen-Ha(Shenyang-Harbin) Highway,Northeast China,to investigate the effect of heavy metals of highway origin on soil nematode guilds.The contents of soil Pb,Cu,Zn,and the nematode community structure were analyzed.The results showed that the contents of total and available Pb,Cu,Zn varied significantly with the different distances from the highway.Pb was the main pollutant in the soils in the vicinity of Shen-Ha Highway.The zone from 20 to 40 m away from the highway was the most polluted area.The highest abundance of soil nematodes was found at 5 m while the lowest at 20 m away from the highway.Thirty six genera of nematodes belonging to 23 families were identified.Nematode guilds having different responses to soil heavy metals were classified into four types.Soil nematode guilds may act as a prominent indicator to heavy metal pollution of highway origin.HAN Dechang ZHANG Xiaoke TOMAR Vijay Vikram Singh LI Qi WEN Dazhong LIANG Wenju 2009Journal of Environmental Sciences2009,21,2:10
8Methods for Shale Gas Play Assessment: A Comparison between Silurian Longmaxi Shale and Mississippian Barnett Shale显示文摘Based on field work, organic geochemical analyses and experimental testing, a six-property assessment method for shale gas is proposed. These six properties include organic matter properies, lithofacies, petrophysical properties, gas content, brittleness and local stress field. Due to the features of continuous distribution over a large area and low resource abundance in shale plays, a sweet spot should have these following properties:(a) TOC>2%;(b) brittle minerals content(>40%) and clay minerals(<30%);(c) Ro(>1.1%);(d) porosity(>2%) and permeability(>0.000 1 m D), and(e) effective thickness(30–50 m). Applying these criteria in the Sichuan Basin, the Silurian Longmaxi shale consists of four prospecting sweet spots, including blocks of Changning, Weiyuan, Zhaotong and Fushun-Yongchuan. Although these four blocks have some similarities, different features were usually observed. After comprehensive analyses using the six-property assessment method, the Fushun-Yongan Block ranks the most favorable sweet spot, followed by the Weiyuan Block. For the other two blocks, the Changning Block is better than the Zhaotong Block. By comparing with the Mississippian Barnett shale, characteristics that are crucial for a high-yielding in the Sichuan Basin include a high content of organic matter(TOC>2.5%), a moderate thermal maturity(Ro=0.4%–2%), a high content of brittle minerals(quartz: 30%–45%), a high gas content(>2.5 m3?t-1), and types I and II1 kerogen.Songqi Pan Caineng Zou Zhi Yang Dazhong Dong Yuman Wang Shufang Wang Songtao Wu Jinliang Huang Qun Liu Dule Wang Ziyuan Wang 2015Journal of Earth Science2015,26,2:10
9Shale Gas Formation and Occurrence in China: An Overview of the Current Status and Future Potential显示文摘Shale gas is one of the most promising unconventional resources both in China and abroad. It is known as a form of self-contained source-reservoir system with large and continuous dimensions. Through years of considerable exploration efforts, China has identified three large shale gas fields in the Fuling, Changning and Weiyuan areas of the Sichuan Basin, and has announced more than 540 billion m^3 of proven shale gas reserves in marine shale systems. The geological theories for shale gas development have progressed rapidly in China as well. For example, the new depositional patterns have been introduced for deciphering the paleogeography and sedimentary systems of the Wufeng shale and Longmaxi shale in the Sichuan Basin. The shale gas storage mechanism has been widely accepted as differing from conventional natural gas in that it is adsorbed on organic matter or a mineral surface or occurs as free gas trapped in pores and fractures of the shale. Significant advances in the techniques of microstructural characterization have provided new insights on how gas molecules are stored in micro- and nano-scale porous shales. Furthermore, newly-developed concepts and practices in the petroleum industry, such as hydraulic fracturing, microseismic monitoring and multiwell horizontal drilling, have made the production of this unevenly distributed but promising unconventional natural gas a reality. China has 10–36 trillion m^3 of promising shale gas among the world's whole predicted technically recoverable reserves of 206.6 trillion m^3. China is on the way to achieving its goal of an annual yield of 30–50 billion m^3 by launching more trials within shale gas projects.ZOU Caineng YANG Zhi PAN Songqi CHEN Yanyan LIN Senhu HUANG Jinliang WU Songtao DONG Dazhong WANG Shufang LIANG Feng SUN Shasha HUANG Yong WENG Dingwei 2016Acta Geologica Sinica(English Edition)2016,90,4:9
10Non-axisymmetric Flow Characteristics in Centrifugal Compressor显示文摘The flow field distribution in centrifugal compressor is significantly affected by the non-axisymmetric geometry structure of the volute.The experimental and numerical simulation methods were adopted in this work to study the compressor flow field distribution with different flow conditions.The results show that the pressure distribution in volute is characterized by the circumferential non-uniform phenomenon and the pressure fluctuation on the high static pressure zone propagates reversely to upstream,which results in the non-axisymmetric flow inside the compressor.The non-uniform level of pressure distribution in large flow condition is higher than that in small flow condition,its effect on the upstream flow field is also stronger.Additionally,the non-uniform circumferential pressure distribution in volute brings the non-axisymmetric flow at impeller outlet.In different flow conditions,the circumferential variation of the absolute flow angle at impeller outlet is also different.Meanwhile,the non-axisymmetric flow characteristics in internal impeller can be also reflected by the distribution of the mass flow.The high static pressure region of the volute corresponds to the decrease of mass flow in upstream blade channel,while the low static pressure zone of the volute corresponds to the increase of the mass flow.In small flow condition,the mass flow difference in the blade channel is bigger than that in the large flow condition.WANG Leilei LAO Dazhong LIU Yixiong YANG Ce 2015Journal of Thermal Science2015,24,4:7
11Milling Force Model for Aviation Aluminum Alloy: Academic Insight and Perspective Analysis显示文摘Aluminum alloy is the main structural material of aircraft,launch vehicle,spaceship,and space station and is processed by milling.However,tool wear and vibration are the bottlenecks in the milling process of aviation aluminum alloy.The machining accuracy and surface quality of aluminum alloy milling depend on the cutting parameters,material mechanical properties,machine tools,and other parameters.In particular,milling force is the crucial factor to determine material removal and workpiece surface integrity.However,establishing the prediction model of milling force is important and difficult because milling force is the result of multiparameter coupling of process system.The research progress of cutting force model is reviewed from three modeling methods:empirical model,finite element simulation,and instantaneous milling force model.The problems of cutting force modeling are also determined.In view of these problems,the future work direction is proposed in the following four aspects:(1)high-speed milling is adopted for the thin-walled structure of large aviation with large cutting depth,which easily produces high residual stress.The residual stress should be analyzed under this particular condition.(2)Multiple factors(e.g.,eccentric swing milling parameters,lubrication conditions,tools,tool and workpiece deformation,and size effect)should be considered comprehensively when modeling instantaneous milling forces,especially for micro milling and complex surface machining.(3)The database of milling force model,including the corresponding workpiece materials,working condition,cutting tools(geometric figures and coatings),and other parameters,should be established.(4)The effect of chatter on the prediction accuracy of milling force cannot be ignored in thin-walled workpiece milling.(5)The cutting force of aviation aluminum alloy milling under the condition of minimum quantity lubrication(mql)and nanofluid mql should be predicted.Zhenjing Duan Changhe Li Wenfeng Ding Yanbin Zhang Min Yang Teng Gao Huajun Cao Xuefeng Xu Dazhong Wang Cong Mao Hao Nan Li Gupta Munish Kumar Zafar Said Sujan Debnath Muhammad Jamil Hafiz Muhammad Ali 2021Chinese Journal of Mechanical Engineering2021,34,1:7
12Effects of slow-release urea fertilizers on urease activity, microbial biomass, and nematode communities in an aquic brown soil显示文摘A field experiment was carried out at the Shenyang Experimental Station of Ecology (CAS) in order to study the effects of slow-release urea fertilizers high polymer-coated urea (SRU1), SRU1 mixed with dicyandiamide DCD (SRU2), and SRU1 mixed with calcium carbide CaC2 (SRU3) on urease activity, microbial biomass C and N, and nematode communities in an aquic brown soil during the maize growth period. The results demonstrated that the application of slow-release urea fertilizers inhibits soil urease activity and increases the soil NH4+-N content.Soil available N increment could promote its immobilization by microorganisms. Determination of soil microbial biomass N indicated that a combined application of coated urea and nitrification inhibitors increased the soil active N pool. The population of predators/omnivores indicated that treatment with SRU2 could provide enough soil NH4+-N to promote maize growth and increased the food resource for the soil fauna compared with the other treatments.JIAO Xiaoguang, LIANG Wenju, CHEN Lijun, ZHANG Haijun, LI Qi, WANG Peng & WEN Dazhong Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Shenyang Experimental Station of Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China Graduate School of Chinese Academy of Sciences, Beijing 100039, China 2005Science China(Life Sciences)2005,48,z1:5
13What's So Special about China's Producer Services?An Input–output Analysis显示文摘In the present study,five stylized facts about China's producer services are established through international,intersectoral and intertemporal comparisons based on input –output tables.First,the overall service input ratio is the lowest in all the sample economies.Second,most producer services are supplied by the traditional labor-intensive sectors.Third,manufacturing is the biggest user of producer services,and service industry is the second,while the opposite is true for most of the other sample economies.Fourth,unlike other economies,China's 'R&D' is characterized more by consumer services than producer services.Fifth,China has fairly lower service input ratios in almost all the industries.The backward and forward linkages coefficients are both smaller for 'real estate activities'and 'finance and insurance.' Policy reform should focus not only on specific producer services but also on reducing obstacles that are inhibiting the balanced development of diverse producer services that will help China to optimize its economic structure.Dazhong Cheng Peter W.Daniels 2014China & World Economy2014,22,1:5
14Differences between Marine and Terrestrial Shale Gas Accumulation:Taking Longmaxi Shale Sichuan Basin and Yanchang Shale Ordos Basin as Examples显示文摘1 Introduction With the rapid development of theory and practice,shale gas has gradually become an important part in diversified energy structure.Though a lot of research have been done mainly for shale gas exploration prospects,geological conditions and shale gas accumulation have been analyzed and summarized,prospective resources have been preliminarily predicted,and favorable explorationPU Boling DONG Dazhong ZHAO Jingzhou ER Chuang HUANG Jinliang 2015Acta Geologica Sinica(English Edition)2015,89,A01:3
15Environmental risks of shale gas exploitation and solutions for clean shale gas production in China显示文摘Shale gas is a relatively clean-burning fossil fuel,produced by hydraulic fracturing.This technology may be harmful to the environment;therefore,environmentally friendly methods to extract shale gas have attracted considerable attention from researchers.Unlike previous studies,this study is a comprehensive investigation that uses systematic analyses and detailed field data.The environmental challenges associated with shale gas extraction,as well as measures to mitigate environmental impacts from the source to end point are detailed,using data and experience from China’s shale gas production sites.Environmental concerns are among the biggest challenges in practice,mainly including seasonal water shortages,requisition of primary farmland,leakage of drilling fluid and infiltration of flowback fluid,oil-based drill cuttings getting buried underground,and induced seismicity.China’s shale gas companies have attempted to improve methods,as well as invent new materials and devices to implement cleaner processes for the sake of protecting the environment.Through more than 10-year summary,China’s clean production model for shale gas focuses on source pollution prevention,process control,and end treatment,which yield significant results in terms of resource as well as environmental protection,and can have practical implications for shale gas production in other countries,that can be duplicated elsewhere.Shikui GAO Quanzhong GUAN Dazhong DONG Fang HUANG 2021Frontiers of Earth Science2021,15,2:3
16Forced Responses on a Radial Turbine with Nozzle Guide Vanes显示文摘Radial turbines with nozzle guide vanes are widely used in various size turbochargers.However,due to the interferences with guide vanes,the blades of impellers are exposed to intense unsteady aerodynamic excitations,which cause blade vibrations and lead to high cycle failures(HCF).Moreover,the harmonic resonance in some frequency regions are unavoidable due to the wide operation conditions.Aiming to achieve a detail insight into vibration characteristics of radial flow turbine,a numerical method based on fluid structure interaction(FSI) is presented.Firstly,the unsteady aerodynamic loads are determined by computational fluid dynamics(CFD).And the fluctuating pressures are transformed from time domain to frequency domain by fast Fourier-transform(FFT).Then,the entire rotor model is adopted to analyze frequencies and mode shapes considering mistuning in finite element(FE) method.Meanwhile,harmonic analyses,applying the pressure fluctuation from CFD,are conducted to investigate the impeller vibration behavior and blade forced response in frequency domain.The prediction of the vibration dynamic stress shows acceptable agreement to the blade actual damage in consistent tendency.LIU Yixiong YANG Ce MA Chaochen LAO DaZhong 2014Journal of Thermal Science2014,23,2:3
17The Arabidopsis catalase triple mutant reveals important roles of catalases and peroxisome-derived signaling in plant development显示文摘Hydrogen peroxide(H_2O_2)is generated in many metabolic processes.As a signaling molecule,H_2O_2plays important roles in plant growth and development,as well as environmental stress response.In Arabidopsis,there are three catalase genes,CAT1,CAT2,and CAT3.The encoded catalases are predominately peroxisomal proteins and are critical for scavenging H_2O_2.Since CAT1 and CAT3 are linked on chromosome 1,it has been almost impossible to generate cat1/3 and cat1/2/3 mutants by traditional genetic tools.In this study,we constructed cat1/3 double mutants and cat1/2/3 triple mutants by CRISPR/Cas9 to investigate the role of catalases.The cat1/2/3 triple mutants displayed severe redox disturbance and growth defects under physiological conditions compared with wild-type and the cat2/3 double mutants.Transcriptome analysis showed a more profound transcriptional response in the cat1/2/3 triple mutants compared to the cat2/3 mutants.These differentially expressed genes are involved in plant growth regulation as well as abiotic and biotic stress responses.In addition,expression of OXI1(OXIDATIVE SIGNAL INDUCIBLE 1)and several MAPK cascade genes were changed dramatically in the catalase triple mutant,suggesting that H_2O_2produced in peroxisomes could serve as a peroxisomal retrograde signal.Tong Su Pingping Wang Huijuan Li Yiwu Zhao Yao Lu Peng Dai Tianqi Ren Xiaofeng Wang Xuezhi Li Qun Shao Dazhong Zhao Yanxiu Zhao Changle Ma 2018Journal of Integrative Plant Biology2018,60,7:3
18Minimum quantity lubrication machining of aeronautical materials using carbon group nanolubricant: From mechanisms to application显示文摘It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL)technology.Nevertheless,for aeronautical difficult-tomachine materials,MQL couldn’t meet the high demand of cooling and lubrication due to high heat generation during machining.Nano-biolubricants,especially non-toxic carbon group nano-enhancers(CGNs)are used,can solve this technical bottleneck.However,the machining mechanisms under lubrication of CGNs are unclear at complex interface between tool and workpiece,which characterized by high temperature,pressure,and speed,limited its application in factories and necessitates in-depth understanding.To fill this gap,this study concentrates on the comprehensive quantitative assessment of tribological characteristics based on force,tool wear,chip,and surface integrity in titanium alloy and nickel alloy machining and attempts to answer mechanisms systematically.First,to establish evaluation standard,the cutting mechanisms and performance improvement behavior covering antifriction,antiwear,tool failure,material removal,and surface formation of MQL were revealed.Second,the unique film formation and lubrication behaviors of CGNs in MQL turning,milling,and grinding are concluded.The influence law of molecular structure and micromorphology of CGNs was also answered and optimized options were recommended by considering diverse boundary conditions.Finally,in view of CGNs limitations in MQL,the future development direction is proposed,which needs to be improved in thermal stability of lubricant,activity of CGNs,controllable atomization and transportation methods,and intelligent formation of processing technology solutions.Xin CUI Changhe LI Wenfeng Ding Yun CHEN Cong MAO Xuefeng XU Bo LIU Dazhong WANG Hao Nan LI Yanbin ZHANG Zafar SAID Sujan DEBNATH Muhammad JAMIL Hafiz Muhammad ALI Shubham SHARMA 2022Chinese Journal of Aeronautics2022,35,11:3
19Lower limit of thermal maturity for the carbonization of organic matter in marine shale and its exploration risk显示文摘Based on the drilling data of the Silurian Longmaxi Formation in the Sichuan Basin and periphery, SW China, the Ro lower limits and essential features of the carbonization of organic matter in over-high maturity marine shale were examined using laser Raman, electrical and physical property characterization techniques. Three preliminary conclusions are drawn:(1) The lower limit of Ro for the carbonization of Type I-II1 organic matter in marine shale is 3.5%; when the Ro is less than 3.4%, carbonization of organic matter won't happen in general; when the Ro ranges from 3.4% to 3.5%, non-carbonization and weak carbonization of organic matter may coexist; when the Ro is higher than 3.5%, the carbonization of organic matter is highly likely to take place.(2) Organic-rich shale entering carbonization phase have three basic characteristics: log resistivity curve showing a general 'slender neck' with low-ultralow resistance response, Raman spectra showing a higher graphite peak, and poor physical property(with matrix porosity of only less than 1/2 of the normal level).(3) The quality damage of shale reservoir caused by the carbonization of organic matter is almost fatal, which primarily manifests in depletion of hydrocarbon generation capacity, reduction or disappearance of organic pores and intercrystalline pores of clay minerals, and drop of adsorption capacity to natural gas. Therefore, the lower limit of Ro for the carbonization of Type I-II1 organic matter should be regarded as the theoretically impassable red line of shale gas exploration in the ancient marine shale formations. The organic-rich shale with low-ultralow resistance should be evaluated effectively in area selection to exclude the high risk areas caused by the carbonization of organic matter. The target organic-rich shale layers with low-ultralow resistance drilled during exploration and development should be evaluated on carbonization level of organic matter, and the deployment plan should be adjusted according to the evaluation results in time.WANG Yuman LI Xinjing CHEN Bo WU Wei DONG Dazhong ZHANG Jian HAN Jing MA Jie DAI Bing WANG Hao JIANG Shan 2018Petroleum Exploration and Development2018,45,3:2
20Is the Chinese Economy Moving in the Direction of Tertiarization?显示文摘利用输出,雇用,消费和贸易数据,这篇文章检验是否在中国的经济有一个经济 tertiarization 趋势并且评估驾驶当前的趋势的普通因素。它证明 tertiarization 趋势以服务为全面经济和大多数区域是明显的名字的增值比率和服务雇用和消费。然而, tertiarization 趋势不以服务是重要的真实增值比率,并且因为服务的减少的比例,有甚至某并发的“ detertiarization ”。确实,中国的 tertiarization 趋势在它的工业化趋势后面是远的。在服务的相对价格的上升解释家庭服务消费开销并且进一步的升起的比例照亮为什么真实增值比率没种的服务。为服务雇用的成长百分比的主要原因是在在和服务需求的价格无弹力的相互作用的服务劳动生产率生长的 lag。“费用疾病”出现在服务消费。Dazhong Cheng Jean-Marc Blanchard 2009China & World Economy2009,17,6:2
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