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Coupling changes of soil functional gene abundances and extracellular enzyme activities across the diagnostic horizons of agricultural Isohumosols

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Pedosphere 2024年第3期34卷 540-552页

作者： Zhuxiu liu Haidong GU Xiaojing HU Zhenhua YU Yansheng LI Junjie liu Jian JIN xiaobing liu Guanghua WANG State Key Laboratory of Black Soils Conservation and Utilization Northeast Institute of Geography and AgroecologyChinese Academy of SciencesHarbin 150081(China) University of Chinese Academy of Sciences Beijing 100049(China)

Soil functional microbial taxa and extracellular enzymes are involved in a variety of biogeochemical cycling processes.Although many studies have revealed the vertical change patterns of microbial communities along soil profile,the general understanding of the coupling changes in the functional gene abundances(FGAs)and extracellular enzyme activities(EEAs)in soil profiles is still limited,which hinders us from revealing soil ecosystem processes.Herein,we comparatively investigated the FGAs and EEAs in the diagnostic A,B,and C horizons of soil profiles obtained from two suborders of Isohumosols(Mollisols),Ustic and Udic Isohumosols,in Northeast China based on quantitative real-time polymerase chain reaction and standard fluorometric techniques,respectively.The distribution patterns of both FGAs and EEAs significantly distinguished by the two soil suborders and were also separated from A to C horizon.Additionally,the variations of EEAs and FGAs were greater in Udic Isohumosols compared to Ustic Isohumosols along soil profiles,and greater changes were observed in C horizon than in A horizon.Both FGAs and EEAs correspondently decreased along the soil profiles.However,when normalized by soil organic carbon,the specific EEAs significantly increased in deep soil horizons,suggesting that microorganisms will input more resources to the production of enzymes to ensure microbial nutrient requirements under resource scarcity.More importantly,we revealed that soil microbial nutrient demands were limited by carbon(C)and phosphorus(P),and the C and P limitations significantly increased along soil profiles with a greater C limitation observed in Ustic Isohumosols than in Udic Isohumosols.Overall,our findings provided solid evidence showing the links between FGAs,EEAs,and microbial nutrient limitations,which would be helpful for a better understanding of the ecosystem processes in soil profiles.

关键词： ecoenzymatic stoichiometry microbial nutrient limitation microbial nutrient requirement Mollisols soil ecosystem process soil profile

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Analysis of the world oil and gas exploration situation in 2021

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Petroleum Exploration and Development 2022年第5期49卷 1195-1209页

作者： DOU Lirong WEN Zhixin WANG Jianjun WANG Zhaoming HE Zhengjun liu xiaobing ZHANG Ningning PetroChina Research Institute of Petroleum Exploration&Development Beijing 100083China China National Oil and Gas Exploration and Development Co. LtdBeijing 100034China

The global exploration investment, new oil and gas discoveries, exploration business adjustment strategies of oil companies in 2021, and future favorable exploration domains are systematically analyzed using commercial databases such as IHS and public information of oil companies. It has been found that the world oil and gas exploration situation in 2021 has continued the downturn since the outbreak of COVID-19. The investment and drilling workload decreased slightly, but the success rate of exploration wells, especially deepwater exploration wells, increased significantly, and the newly discovered reserves increased slightly compared with last year. Deep waters of the passive continental margin basins are still the leading sites for discovering conventional large and medium-sized oil and gas fields. The conventional oil and gas exploration in deep formations of onshore petroliferous basins has been keeping a good state, with tight/shale oil and gas discoveries made in Saudi Arabia, Russia, and other countries. While strengthening the exploration and development of local resources, national, international, and independent oil companies have been focusing on major overseas frontiers using their advantages, including risk exploration in deep waters and natural gas. Future favorable exploration directions in the three major frontiers, the global deep waters, deep onshore formations, and unconventional resources, have been clarified. Four suggestions are put forward for the global exploration business of Chinese oil companies: first, a farm in global deepwater frontier basins in advance through bidding at a low cost and adopt the “dual exploration model” after making large-scale discoveries;second, enter new blocks of emerging hot basins in the world through farm-in and other ways, to find large oil and gas fields quickly;third, cooperate with national oil companies of the resource host countries in the form of joint research and actively participate exploration of deep onshore formations of petroliferous basins;four

关键词： exploration investment exploration situation new discoveries favorable exploration areas overseas oil and gas exploration deep water deep formation unconventional resources

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VIBRATION ANALYSIS OF TURBINE BASED ON FLUID-STRUCTURE COUPLING

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Chinese Journal of Mechanical Engineering 2008年第4期21卷 40-43页

作者： liu Demin liu xiaobing School of Energy and Environment Xihua University Chengdu 610039 China Department of Thermal Engineering Tsinghua University Beijing 100084 China

The vibration of a Francis turbine is analyzed with the additional quality matrix method based on fluid-structure coupling （FSC）. Firstly, the vibration frequency and mode of blade and runner in air and water are calculated. Secondly, the influences to runner frequency domain by large flow, small flow and design flow working conditions are compared. Finally the influences to runner modes by centrifugal forces under three rotating speeds of 400 r/rain, 500 r/min and 600 r/rain are compared. The centrifugal force and small flow working condition have greatly influence on the vibration of small runner. With the increase of centrifugal force, the vibration frequency of the runner is sharply increased. Some order frequencies are even close to the runner natural frequency in the air. Because the low frequency vibration will severely damage the stability of the turbine, low frequency vibration of units should be avoided as soon as possible.

关键词： Fluid-structure coupling Additional quality matrix Vibration Mode

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STUDIES　OF　SOLID－LIQUID　TWO－PHASE　TURBULENT　FLOWS　AND　WEAR　IN　HYDRAULIC　TURBOMACHINERY

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Journal of Hydrodynamics 1996年第2期8卷 72-76页

作者： liu, xiaobing Sichuan Inst of Technology Chengdu China

The Lagrangian equation of motion for solid particles in an arbitrary flow field is derived. The linear differential equation form and the general solution of this equation are obtained. Motion of solid particles in dilute solid-liquid turbulent flows is numerically solved and analysed. The K-εtwo-equation turbulence model, the volume fraction turbulence model, the mixed Eulerian-Lagrangian turbulence model, and the dense mixture turbulence model as well as the erosive wear model are developed. Using these models, the turbulent flows and the erosive wear in some hydraulic turbomachinery ducts are numerically predicted. The numerical results show good agreement with the experiments.

关键词： hydraulic turbomachinery solid-liquid two-phase flows turbulence model erosive wear numerical prediction

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Analysis of the world deepwater oil and gas exploration situation

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Petroleum Exploration and Development 2023年第5期50卷 1060-1076页

作者： WEN Zhixin WANG Jianjun WANG Zhaoming HE Zhengjun SONG Chengpeng liu xiaobing ZHANG Ningning JI Tianyu PetroChina Research Institute of Petroleum Exploration&Development Beijing 100083China

The global trends in deepwater oil and gas exploration,characteristics of deepwater oil and gas discovery,and layout of deepwater oil and gas exploration business by seven major international oil companies are systematically analyzed using commercial databases(e.g.S&P Global and Rystad)and public information of oil companies.The deepwater area is currently the most important domain for global oil and gas exploration and discovery,with the most discoveries and reserves in passive continental margin basins.The deepwater discoveries have the greatest contribution to the total newly discovered oil and gas reserves in the sea areas,with an increasing number of lithological reservoirs discovered,and oil and gas discoveries mainly distributed in the Mesozoic–Cenozoic.The seven major international oil companies are widely active in various aspects of deepwater oil and gas exploration and development,and play a leading role.Based on years of theoretical understanding of global oil and gas geology and resource evaluation,it is proposed that favorable deepwater exploration areas in the future will mainly focus on three major areas:the Atlantic coast,the Indian Ocean periphery,and the Arctic Ocean periphery.Six suggestions are put forward for expanding overseas deepwater oil and gas exploration business:first,expand the sources for obtaining multi-user seismic data and improve the scientific selection of deepwater exploration areas;second,increase efforts to obtain deepwater exploration projects in key areas;third,adopt various methods to access into/exit from resource licenses flexibly;fourth,acquire licenses with large equity and operate in“dual-exploration”model;fifth,strengthen cooperation with leading international oil companies in deepwater technology;and sixth,improve business operation capabilities and gradually transform from“non-operators”to“operators”.

关键词： world petroliferous basins deepwater oil and gas exploration situation international oil companies favorable exploration areas

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BOUNDARY LAYER EFFECTS ON SOLID PARTICLE MOTION AND EROSIVE WEAR

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Journal of Hydrodynamics 1996年第4期8卷 9-17页

作者： liu, xiaobing Cheng, Liangjun Sichuan Inst of Technology Chengdu China

Lagrangian motion equation of a solid particle suspended in 2-D turbulent boundary layer flows has been modified. The effects of boundary layer on particle motion were studied. The critical nondimensional incidence velocities and angles to the wall from the edge of a 2-D incompressible turbulent boundary layer were presented for various nondimensional particle sizes and initial velocities. The numerical results clearly show that the effects of boundary layer on particle motion and particle impact erosive wear are very great. The presence of boundary layer decreases particle impact velocity and impact erosive wear.

关键词： Boundary layers Erosion Fluid structure interaction Particles (particulate matter) Suspensions (fluids) Turbulent flow

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线形布置双矩形柱的平均气动力特性试验研究

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振动与冲击 2024年第5期43卷 20-30,81页

作者：姜会民杨群范佳豪刘小兵石家庄铁道大学土木工程学院石家庄050043 河北省风工程和风能利用工程技术创新中心石家庄050043 石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室石家庄050043

为研究线形布置双矩形柱的平均气动力特性,采用刚性模型测压风洞试验测试并分析了宽高比为1∶4的双矩形柱在不同风向角和不同间距比下的平均阻力系数和平均升力系数,并与单矩形柱的试验结果进行了对比分析。在此基础上,通过分析平均风... 详细信息

为研究线形布置双矩形柱的平均气动力特性,采用刚性模型测压风洞试验测试并分析了宽高比为1∶4的双矩形柱在不同风向角和不同间距比下的平均阻力系数和平均升力系数,并与单矩形柱的试验结果进行了对比分析。在此基础上,通过分析平均风压分布进一步揭示了线形布置双矩形柱平均气动力系数的干扰机理。风向角α的变化范围为0°~90°,间距比P/B(双矩形柱的中心距与矩形柱宽度之比)的变化范围为1.2~8.0。研究结果表明:双矩形柱的平均阻力系数可分为0°≤α≤30°和30°<α≤90°两类;上游矩形柱的平均升力系数可分为0°≤α≤75°和75°<α≤90°两类;下游矩形柱的平均升力系数可分为0°≤α≤20°和20°<α≤90°两类。平均气动力系数的放大效应主要体现在上游矩形柱,平均阻力系数最大为单矩形柱的1.5倍,平均升力系数最大为单矩形柱的2.1倍。

关键词：双矩形柱线形布置平均气动力系数平均风压分布风洞试验风向角间距比

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Progress in Overseas Oil and Gas Exploration of Chinese Oil Companies

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China Oil & Gas 2022年第1期29卷 8-13页

作者： Dou Lirong Yuan Shengqiang liu xiaobing Research Institute of Petroleum Exploration and Development PetroChina China National Oil and Gas Exploration and Development Company Ltd

In 1993,responding to the national call,Chinese Oil Companies(COCs)started their“Going global”.In this paper,the overseas oil and gas exploration and development activities carried out by COCs in the past 29 years have been divided into four stages:initiation,growth,expansion,and optimization.Nowadays,COCs are operating(including onshore,deep-water,conventional and unconventional resources)all over the world,especially in six oil and gas cooperation regions,becoming as vital players in the international petroleum sector.During overseas operations,COCs acquired a number of large oil and gas fields through M&As and consolidated China’s reserve base as a response to the Belt and Road Initiative.Overseas oil and gas exploration and development of COCs has become an important safeguard for China’s national energy security in the context of rising dependence on foreign oil and gas.Nevertheless,COCs need to summarize the experience and lessons of“Going global”,and improve their overseas oil and gas operations depending on the latest global situation,so as to realize a longer-term development.

关键词： operations overseas becoming

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Effects of Late Nitrogen Application on Nitrogen Translocation and Protein Fractions of Wheat Genotypes Differing in Protein Content

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Journal of Northeast Agricultural University(English Edition) 1997年第2期4卷 89-94页

作者： liu xiaobing Li Wenxiong Department of Agronomy Northeast Agricultural UniversityHarbin150030 PRC

In order to investigate the effeits of late nitrogen application on nitrogen translocation and protein fractions, three genotypes differing in protein content were studied in pot experiments at low and high fertility regimes with late foliar nitrogen application. At high fertility, late nitrogen application increased N translocation and improved N translocation efficiency greatly, however, cultivar differences were found at low fertility and late nitrogen application increased both leaf and chaff N translocation, and increased culm N translocation only at high fertility. Relative contributions of vegetative components to N translocation efficiency were altered by late nitrogen application. Albumin and gliadin contents at maturity were decreased by late nitrogen application for all cultivars used, and cultivar variations for globulins were also observed. Xin Kehan No. 9, the high yielding, low grain protein content cultivar remained no change for glutenin content to late nitrogen application, Dongnong 7742, the high yielding, high grain protein content, decreased slightly, and Roblin, high grain protein but low yielding cultivar decreased only at hihg fertility. Residual protein contents were significantly increased by late nitrogen application for all cultivars. It was concluded that nitrogen applied at later stage could be used efficiently noly at high fertility, and most of the N translocated were used for the synthesis of residual proteins.

关键词： late N application N translocation grain protein fractions

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Distribution,Properties,Land Use and Management of Mollisols in South America

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Chinese Geographical Science 2011年第5期21卷 511-530页

作者： Artigas Duran Hector Morris Guillermo Studdert liu xiaobing Key Laboratory of Mollisols Agroecology Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Harbin 150081 China Faculty of Agronomy Garzon 780 12900 Montevideo Uruguay Institute of Soils INTA-CIRN CC 25 (1712) Castelar Buenos Aires Argentina Faculty of Agricultural Sciences National University of Mar Del Plata CC 276 (B7620WAP) Balcarce Buenos Aires Argentina

Mollisols are common in South America. They cover about 8.87 × 10 7 ha, 1.3 × 10 7 ha and 4.3 × 10 6 ha in Argentina, Uruguay and Southern Brazil respectively, which is 11.5% of the world total. Most of South American Mol- lisols were developed on Pleistocene and Holocene sediments and lie within the limits of the temperate zone, though the extreme north is bordering subtropical and the extreme south is within a cold-temperate zone. All suborders of Mollisols occur in Argentina, the most extensive being Udolls followed by Ustolls, whereas only Udolls, Aquolls and Albolls occur in Uruguay. Vertisols in Uruguay have many properties similar to Mollisols, and the occurrence of Vertisols is strongly associated with Mollisols. The Pampean Mollisols are a significant component of the global breadbasket of modern times. The main Argentine crops are wheat,corn,sorghum, barley, soybeans and sunflower, while Mollisols in Uruguay remain mostly dedicated to cattle and sheep grazing though crop production has been increasing very rapidly in the last decade. Throughout South America, research has shown that Mollisols are experiencing losses of soil organic matter and nutrients, and degradation of physical properties after long cropping periods, resulting in soil scientists calling for increased conservation practices to reduce future losses and a deterioration of soil quality, and thus a more sustainable agriculture in the region.

关键词：物理性质南美洲松软土地使用土壤有机质管理作物产量可持续农业

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