Discussion on position of China’s north-south transitional zone by comparative analysis of mountain altitudinal belts

The Qinling Mountains has always been regarded as an essential dividing line between the warm temperate zone and the subtropical zone in eastern China and plays a vital role in the geoecological pattern of China.However,there is controversy about the specific location of this geographical boundary in the academic community.As a product of the combined effects of zonal and non-zonal factors,the mountain altitudinal belts(MABs)can reflect both the horizontal zonality and the vertical zonality of vegetation distribution.Using the MAB information,we can not only profoundly understand the complex mountain system of QinlingDaba Mountains but can also judge its nature as a geographical boundary more scientifically.Therefore,based on the comparative analysis of basal belt,dominant belt characteristics and belt structure characteristics of the MABs in Qinling-Daba Mountains,subtropical and temperate mountains,this paper analyzed the MAB differences and similarities among Qinling-Daba Mountains,subtropical and temperate typical mountains,to reveal the vegetation distribution characteristics in the north-south transitional zone.The results show that:(1)The MABs of the southern part of QinlingDaba Mountains(southern slope of the Daba Mountains)are the same or similar to those of the Subtropical Mountains,and the MABs of the northern part of Qinling-Daba Mountains(northern slope of the Qinling Mountains)are similar to those of the temperate mountains.While it shows obvious transitional characteristics in the vast area between the northern slope of the Daba Mountains and the southern slope of the Qinling Mountains:the basal belts gradually transit from the evergreen broadleaved forest belt(basal belt in subtropical mountains)to the evergreen and deciduous broad-leaved mixed forest belt,and the dominant belts also transit from the evergreen broad-leaved forest belt to the evergreen and deciduous broad-leaved mixed forest belt or the deciduous broad-leaved forest belt.(2)The transitional zone between the subtropical zone and the warm temperate zone is located between the northern slope of the Daba Mountains and the southern slope of the Qinling Mountains.The southern boundary of the transitional zone is along the northern slope of Shennongjia Mountain-the northern slope of Micang Mountain-Baishuijiang Nature Reserve,and the northern boundary is along the southern slope of Funiu Mountain-the southern slope of Taibai Mountain-Lianhua Mountain.Additionally,in the transitional zone,the average temperature in January is between-5°C and 1°C,the annual average temperature is between 10°C and 13°C except Hanzhong Basin and Hanshui Valley,and the accumulated temperature above 10°C ranges from 2000°C to 4000°C,the annual rainfall is about 800-1000 mm.The results provide a scientific basis for revealing the characteristics of China’s north-south transitional zone and scientific division of the boundary between the subtropical zone and warm temperate zone in China.

ON THE COMPREHENSIVE DEVELOPMENT AND UTILIZATION OF THE AGRICULTURAL RESOURCES IN YANCHI COUNTY——A TYPICAL TRANSITIONAL BELT BETWEN AGRICULTURE AND ANIMAL HUSBANDRY

1. The natural economic conditions of yanchi county Yanchi County (in Ningxia Province, China) lies between the Muwus Desert and theLoess Plateau, its geographical location is a typical transition belt. The view from south tonorth: the general configuration of the earth’s surface is from the Loess Plateau to Ordos ta-bleland; the climate is from semi arid to arid. The transition of its geogrophical location pro-vides the area such features which are various,complex and fragile in natural conditions.

PRELIMINARY DISCUSSION ON METALLOGENESIS OF LANCANGJIANG RIVER TRANSITIONAL FIELD TECTONIC ZONE IN WESTERN YUNNAN

Applying the crustobody geotectonic theory to geological prospecting at the Lancangjiang river metallogenic belt in western Yunnan province, and on the basis of the basic geological background of western Yunnan and the space-time evolution-movement historical-dynamic features of the Lancangjiang river tectonic belt, the author has discussed firstly the metallogenesis of the Lancangjiang river transitional field tectonic zone, which can provide a new theoretical foundation for exploring the space-time laws of mineralization in this region.

Geochronology,Petrogenesis and Tectonic Setting of the Late Jurassic I-type Granites in the North Qinling Orogenic Belt,Central China

The North Qinling Orogenic Belt(NQOB)is a composite orogenic belt in central China.It started evolving during the Meso-Neoproterozoic period and underwent multiple stages of plate subduction and collision before entering intra-continental orogeny in the Late Triassic.The Meso-Cenozoic intra-continental orogeny and tectonic evolution had different responses in various terranes of the belt,with the tectonic evolution of the middle part of the belt being particularly controversial.The granites distributed in the Dayu and Kuyu areas in the middle part of the NQOB can provide an important window for revealing the geodynamic mechanisms of the NQOB.The main lithology of Dayu and Kuyu granites is biotite monzogranite,and the zircon U-Pb dating yielded intrusive ages of 151.3±3.4 Ma and 147.7±1.5 Ma,respectively.The dates suggest that the biotite monzogranite were formed at the end of the Late Jurassic.The whole-rock geochemistry analysis shows that the granites in the study areas are characterized by slightly high SiO_(2)(64.50-68.88 wt%)and high Al_(2)O_(3)(15.12-16.24 wt%)and Na_(2)O(3.55-3.80 wt%)contents.They are also enriched in light rare earth elements,large ion lithophile elements(e.g.,Ba,K,La,Pb and Sr),and depleted in high field strength elements(HFSEs)(e.g.,Ta,Nb,P and Ti).Additionally,the granites have weakly negative-slightly positive Eu anomalies(δEu=0.91-1.19).Zircon Lu-Hf isotopic analysis showedε_(Hf)(t)=-6.1--3.8,and the two-stage model age is T_(2DM(crust))=1.5-1.6 Ga.The granites in the study areas are analyzed as weak peraluminous high-K calc-alkaline I-type granites.They formed by partial melting of the thickened ancient lower crust,accompanied by the addition of minor mantle-derived materials.During magma ascent,they experienced fractional crystallization,with residual garnet and amphibole for a certain proportion in the magma source region.Comprehensive the geotectonic data suggest that the end of the Late Jurassic granite magmatism in the Dayu and Kuyu areas represents a compression-extension transition regime.It may have been a response to multiple tectonic mechanisms,such as the late Mesozoic intra-continental southward subduction of the North China Craton and the remote effect of the Paleo-Pacific Plate subduction.

渝东南复杂构造区常压页岩气地球物理勘探实践及攻关方向

中国南方常压页岩气资源潜力大,主要分布于四川盆地周缘构造复杂区及盆外褶皱带,具有地表、地下双复杂地质条件,地震采集品质差、成像精度低、甜点参数变化规律不清。本文系统总结了渝东南地区常压页岩气地震采集、成像处理、储层预测等方面的研究成果与技术进展:①形成了变密度三维观测系统设计技术、灰岩地表复杂山地地震激发接收技术,确保复杂地下构造反射波场充分采样,提升采集资料品质,提高施工效率。②完善了复杂山地地震叠前预处理技术、盆缘过渡带复杂构造成像技术、盆外褶皱带向斜构造成像技术,成果剖面信噪比高,有效频带宽,构造成像精度高。③基于岩石物理特征研究,实现优质页岩厚度、地层压力系数、脆性的定量预测;基于统计岩石物理,实现页岩有机碳含量、含气量、孔隙度的定量预测;利用有限元应力场模拟技术,揭示古应力场演化,实现多期构造改造叠加作用形成裂缝的定量预测;采用组合弹簧模型今应力场预测技术,明确今地应力场分布规律。通过攻关研究,有效指导了常压页岩气甜点预测与勘探开发,为南川常压页岩气田的发现提供了依据。下步应重点攻关基于5G无线节点接收的更加科学合理的地震采集技术、复杂山地高陡构造高精度自动化成像处理技术,以及“地质—工程—经济”一体化的甜点地震评价方法。

“一带一路”背景下我国对俄罗斯轨道交通建设的推动机制

“一带一路”倡议背景下,我国深入俄罗斯轨道交通建设并发挥显著推动作用。既有中外文献、报道证实了我国在俄罗斯轨道交通项目中的实践能力,但其推动城市发展的内在机制仍待挖掘。本研究解构现实案例,从城市环境与经济社会效益两个层面系统性剖析我国推动俄罗斯轨道交通建设的具体机制。基于上述机制原理,本文提出应提倡全生命周期节能减碳、推进轨道影响区集约紧凑、加强轨道产业链深度合作、关注站点可达性高效联通等优化建议,为我国在“一带一路”倡议下推进国际轨道交通建设提供参考与指导。

“一带一路”情境下中国城市创新能力的时空演变及驱动机理

采用中国285个地级市2010—2022年面板数据,通过LISA时空跃迁分析、准自然实验等多种分析策略,就“一带一路”和中国城市创新能力增长的驱动机制、区域异质性和政策异质性进行实证分析。结果表明:(1)“一带一路”倡议实施后,中国城市创新要素集聚的时空凝聚度上升,东部地区的局部空间结构、依赖性和变迁方向相对中西部地区稳定;(2)“一带一路”倡议通过双向投资溢出效应、要素自由化流动、基础设施建设、市场需求扩容四大驱动机制促进了中国城市创新能力的提升;(3)东部地区城市创新受“一带一路”倡议的正向影响大,西部地区的创新响应潜力有待提升,中部地区则产生一定挤出效应;(4)以“中欧班列”“友好城市”为代表的“五通”政策子集对中国城市创新具有积极正向的推动作用。基于此,应持续推进“一带一路”倡议,积极推动“软”“硬”通路的建设,提升中西部地区产业筑基能力,深度融入与沿线国家的新合作领域。

中国海外城市轨道交通市场分布与演化特征研究

随着全球范围内人口的快速增加及城市化进程的加速推进,城市轨道交通产品的海外市场需求不断增长,为我国城市轨道交通产品及相关产业“走出去”提供契机。文章聚焦于“一带一路”倡议提出的10年间(2014年—2023年)我国开工建设的海外城市轨道交通建设项目,通过统计梳理此间我国企业在海外承建的城市轨道交通项目建设里程,并将其与“一带一路”倡议提出前的2007年—2013年间数据进行对比,分析出我国海外城市轨道交通市场分布规律、演化特征及所面临的挑战,然后以此为据,从市场定位与进入、产业链延伸及技术输出3方面提出相应的市场开发策略,以期为我国城市轨道交通企业更好地开拓海外市场提供借鉴和参考。

长江经济带耕地空间转型的时空格局及驱动机理研究

研究目的:厘清耕地空间转型的内涵意蕴,识别长江经济带耕地空间转型的时空格局,并揭示其驱动机理,以期为耕地合理利用提供参考。研究方法:熵值法、空间自相关分析、时空地理加权回归模型、中介效应模型。研究结果:(1)长江经济带耕地空间转型指数具有“东西强,中部弱”的空间特征,并在时间上呈增强趋势。(2)人口和经济是影响耕地空间转型的决定性因子。(3)驱动因子对耕地空间转型的影响大多以直接效应为主,而农产品单产和人口城市化率以间接影响为主。(4)耕地空间转型过程中,中介效应以零效应或负效应为主,主要受制于生产技术进步、生产模式升级、基础设施完善等中介机制发展不足;产业结构发展不完善成为制约耕地空间转型的关键瓶颈。研究结论:未来应着重协同提升人口素质、加速农业经济发展和深化产业结构升级,以有效推动长江经济带耕地空间转型,支撑农业现代化进程。

油气安全与能源转型的新趋势

党的二十大报告提出,推动绿色发展,促进人与自然和谐共生,确保能源安全。2023年COP28大会重申既定气候目标,并达成了实现科学净零排放的新共识。全球能源市场格局重塑,油气在能源安全中的地位得到重视,油气企业转型仍聚焦核心竞争优势,但上游投资复苏偏慢。全球二氧化碳捕集与封存(CCS)项目数量爆发式增长,直接空气捕集(DAC)技术受到关注,二氧化碳捕集、利用与封存(CCUS)是实现“双碳”目标的兜底保障技术。针对全球未来发展目标和中国国情,分析了世界油气行业发展趋势和国内油气安全形势,提出了中国油气行业发展趋势及能源转型过程中因势利导和应对挑战的措施,为油气企业转型决策提供参考。中国能源自给率高,能源安全形势总体可控。中国油气产业呈现“三个维度”的发展趋势,勘探深度向万米挺进、油气储集空间尺度拓展到纳米、老油气田开启百年建设新征程,需要从释放“两深一非一老”增储上产潜力、深化“一带一路”重点地区能源合作、扩大油气储备能力,完善管网布局、建立系统化、智能化的风险管理和决策支持体系、大力发展CCUS产业链等方面发力。

“一带一路”沿线国家的生态合作及其路径研究

2023年是共建“一带一路”倡议提出十周年。“一带一路”沿线国家多为发展中国家,从贫穷落后走向发展振兴,从工业文明迈向生态文明是其共同面临的经济社会发展和生态环境挑战,放任生态环境恶化,必将阻碍沿线国家可持续发展,亟待加强生态合作。生态合作是沿线国家共同应对气候变化和经济绿色转型的现实需要,要加强气候领域的合作,建立政策响应机制,将应对气候变化作为实现发展方式转变的重大机遇;加强绿色能源合作,优化能源生产布局和消费结构,加快能源绿色低碳转型;构建绿色金融体系,开展绿色金融国际合作,为沿线国家的绿色发展建设提供资金支持;在绿色技术融资、技术制度管理、技术能力建设、技术知识产权等层面同向发力。沿线国家生态合作面临经济社会发展与生态环境保护、发展结构转型与环境保护制度、内部结构优化与外部发展掣肘之间的矛盾,由此构建生态利益共享机制、建立统一环境协调机构、推动国际绿色标准制定等,成为化解矛盾的重要路径。

推动能源领域科技创新 引领中国新型能源体系建设

全球能源发展环境发生了深刻变化,国际格局动荡变革、极端气候灾害频发、能源行业低碳转型和新一轮科技革命爆发。世界各国持续面临能源供应和需求不平衡问题,能源转型之路并不平坦。协调能源安全性、清洁性和经济性之间的关系,先立后破是建设中国新型能源体系的关键。中国新型能源体系建设分为3个阶段:2035年前新型能源体系筑基期;2036—2050年新型能源体系建设加速期;2051—2060年新型能源体系建成期。油气在中国能源体系中将长期发挥重要作用,天然气在能源转型中将发挥重要的桥梁和伴侣作用。化石能源与新能源融合发展是新型能源体系建设的必由之路。中国要与国际社会共同维护国际能源市场稳定,保障能源产业链供应链安全。与“一带一路”共建国家深入开展低碳技术、碳中和、甲烷控排、碳市场等领域交流合作。能源科技创新进入持续高度活跃期,可再生能源、非常规油气、储能、氢能等一大批新兴能源技术正加快迭代,推动能源产业从资源、资本主导向技术主导转变。新一轮科技革命和产业变革正在重塑全球能源技术和产消结构,成为能源绿色低碳发展的核心驱动力。

中国与中亚五国电力绿色低碳转型机遇挑战分析

中亚国家是中国区域战略和推动“一带一路”倡议的重要合作伙伴。在全球“碳中和”持续推进的背景下,中亚国家能源加速转型,中国与中亚国家的能源合作领域将由传统能源逐渐向可再生能源转变,其中电力的绿色低碳转型将是重点。本文梳理了中亚国家电力行业的基本情况,总结了该区域电力转型的目标和政策,研判绿色低碳转型的发展趋势,并明确了各方合作的基础和重点领域,为中国与中亚地区开展电力转型合作提供参考。

公正能源转型伙伴关系进展、挑战及启示

公正能源转型伙伴关系(JETP)旨在支持对于煤炭等化石燃料依赖程度较高的发展中国家实现能源转型。自2021年启动至今,JETP参与主体已从南非拓展至印尼、越南、塞内加尔共4个国家,筹资渠道从以公共资金为主拓展至兼顾公私资金,支持范围从以脱煤为重点扩大至清洁能源等其他领域,运作过程呈现出多部门协同合作的特点。但在JETP运行过程中,也面临资金总额及优惠融资有限,资金结构不合理且落实难度较大,关键运作程序模糊且多边机构过度参与,用于落实公正原则的资金配置不足且相关工作定位模糊,项目设计缺乏经济性和协同性等问题。JETP相关进展和挑战,对我国推动绿色发展投融资合作伙伴关系(GIFP)具有借鉴作用:在完善“一带一路”绿色项目设计方面要践行绿色可持续原则,坚持多渠道融资,在开展项目准备方面要充分考虑东道国投融资环境等。

矿用圆管带式输送机过渡段的仿真研究

通过仿真分析方法实现矿用圆管带式输送机过渡段仿真分析,根据分析结果介绍过渡段优化设计方案。根据矿用圆管带式输送机过渡段基本结构构建过渡段仿真模型,由此实现矿用圆管带式输送机过渡段有限元仿真分析,根据分析结果介绍过渡段优化设计方案,最终将优化设计方案应用于工程实践,检验优化设计方案可行性。

黄河流域和长江经济带制造业绿色转型效率对比

以黄河流域和长江经济带沿线19个省份为样本,建立超效率SBM(slack-based measure)模型测算分析了2013—2022年黄河流域和长江经济带的制造业绿色转型效率,并利用“泰尔指数”进行转型效率的差异性分析。研究发现,长江经济带绿色转型效率呈上升趋势,相反黄河流域发展相对缓慢;通过差异性分析发现黄河流域的域制造业绿色转型效率低于长江经济带,并且黄河流域中各省份的差异性相差较大。

Gradual Evolution from Fluvial Dominated to Tide Dominated Deltas and Channel Type Transformation: A Case Study of MPE3 Block in the Orinoco Heavy Oil Belt of the Eastern Venezuelan Basin

Based on the data of core description and sporopollen analysis,the gradual evolution of deltas in vertical direction and transition of channel types in the MPE3 block of the eastern Venezuela Basin have been surveyed by seismic phase and well logging facies interpretation.The results show that due to the great sea level rise,the sedimentary system of the Miocene Oficina Formation in the MPE3 block shifted from the distal-source sandy braided river delta to tide-affected delta,and eventually to tide-dominated delta.Vertically,during the early stage of sedimentation of Oficina Formation,the distributary channels of the delta were dominated by braided river channels.While in the later stage,as the tidal effect was gradually intensified,the channel changed from braided channel to meandering channel.On plane,as a result of differential transgression,sedimentary framework and distribution of sand bodies vary across the study area.Compared with the eastern part,the western part has more braided channels,larger channel bars,less developments of distributary bay and higher ratio of sand to mud.Whereas the braided channels in the south are larger than those in the north.It is the first time we pointed out the impact of marine transgression differences on the sedimentary facies distribution and river type transition in the study area.Factors like the structural and paleogeomorphological change,sea level variation,supply of sediments have strong influence on the evolution of sedimentary system and distribution of sandbodies.It is predicted that the major sandbody is more developed in the central south,which can guide the subsequent horizontal well development.

The Geological Significance of the Deformation and Geochronology of the Xiaotian–Mozitan Shear Zone in the Dabie Orogenic Belt(East-Central China)

The Xiaotian–Mozitan Shear Zone(XMSZ)is the boundary of the Dabie High-grade Metamorphic Complex(DHMC)and the North Huaiyang Tectonic Belt.It was deformed in ductile conditions with a top-to-NW/WNW movement.Geothermometers applied to mineral parageneses in mylonites of the shear zone give a temperature range of 623–691°C for the predeformation and 515–568°C for the syndeformation,respectively,which indicates a retrograde process of evolution.A few groups of zircon U-Pb ages were obtained from undeformed granitic veins and different types of deformed rocks in the zone.Zircons from the felsic ultramylonites are all magmatic,producing a weighted mean 206Pb/238U age of 754±8.1 Ma,which indicates the time of magmatic activities caused by rifting in the Neoproterozoic.Zircons from the granitic veins,cutting into the mylonites,are also of magmatic origin,producing a weighted mean 206 Pb/238 U age of 130±2.5 Ma,which represents the time of regional magmatic activity in the Cretaceous.Zircons from the mylonitic gneisses are of anatectic-metamorphic origins and are characterized by a core-mantle interior texture,which yielded several populations of ages including the Neoproterozoic ages with a weighted mean 206 Pb/238 U age of 762±18 Ma,similar to that of the felsic ultramylonites and the Early Cretaceous ages with a weighted mean 206Pb/238U age of 143±1.8 Ma,indicating the anatectic metamorphism in the Dabie Orogenic Belt(DOB).Based on integrated analysis of the structure,thermal conditions of ductile deformation and the contact relations of the dated rocks,the activation time of the Xiaotian–Mozitan Shear Zone is constrained between~143 Ma and 130 Ma,during which the DOB was undergoing a transition in tectonic regime from compression to extension.Therefore,the deformation and evolution of this shear zone plays an instrumental role in fully understanding this process.This research also inclines us to the interpretation of it as an extensional detachment,with regard to the tectonic properties of the shear zone.It may also be part of a continental scale extension in the background of the North China Block’s cratonic destruction,dominated by the subduction and roll-back of the Paleo-Pacific plate,but more detailed work is needed in order to unravel its complicated development.

长江经济带市域生态环境质量空间分异与影响因素分析——基于三生空间的土地利用转型

随着城镇化和工业化进程加快,长江经济带土地利用主导功能发生较大转变,生产、生活、生态空间(“三生空间”)转型对生态环境质量的影响日益增强,从“三生空间”角度研究长江经济带生态环境质量对于推动长江经济带高质量发展意义重大。基于土地利用遥感监测数据,通过生态环境质量指数模型、地理探测器等方法,定量分析长江经济带130个地级市生态环境质量的空间分异及其影响因素。结果表明,(1)2000-2020年长江经济带生态环境质量处于中等以上,其中2000-2010年生态环境质量等级保持不变,主要有中等和较高质量两种类型;2010-2020年生态环境质量等级发生变化,中等质量区和较高质量区面积减少,高质量区面积增加。(2)生态环境质量空间分布存在明显差异。长江经济带生态环境质量整体呈“东北部低、西部、中部和东南部高”。2000-2010年生态环境质量空间分布一致。2010-2020年多数地区的生态环境质量等级上升,主要趋势为中等质量转化为较高质量、较高质量转化为高质量。(3)不同因子对生态环境质量空间分异的影响程度具有显著差异。土地利用程度、人口密度和坡度对生态环境质量的影响占主导地位,对生态环境质量空间分异的解释力q值分别为0.776、0.409、0.406,其他因子对生态环境质量空间分异的影响相对较弱。(4)任意两因子间的交互作用均大于单因子对生态环境质量空间分异的影响,且土地利用程度与其他因子的结合是影响长江经济带生态环境质量空间分异的最主要因素。