West Pacific and North Indian Ocean Seafloor and Their Ocean-Continent Connection Zones: Evolution and Debates

The Indian Ocean and the West Pacific Ocean and their ocean-continent connection zones are the core area of ＂the Belt and Road＂. Scientific and in-depth recognition to the natural environment, disaster distribution, resources, energy potential of ＂the Belt and Road＂ development, is the cut-in point of the current Earth science community to serve urgent national needs. This paper mainly discusses the following key tectonic problems in the West Pacific and North Indian oceans and their ocean-continent connection zones （OCCZs）： 1. modern marine geodynamic problems related to the two oceans. Based on the research and development needs to the two oceans and the ocean-continent transition zones, this item includes the following questions. （1） Plate origin, growth, death and evolution in the two oceans, for example, 1） The initial origin and process of the triangle Pacific Plate including causes and difference of the Galapagos and West Shatsky microplates; 2） spatial and temporal process, present status and trends of the plates within the Paleo- or Present-day Pacific Ocean to the evolution of the East Asian Continental Domain; 3） origin and evolution of the Indian Ocean and assembly and dispersal of supercontinents. （2） Latest research progress and problems of mid-oceanic ridges： 1） the ridge-hot spot interaction and ridge accretion, how to think about the relationship between vertical accretion behavior of thousands years or tens of thousands years and lateral spreading of millions years at 0 Ma mid- oceanic ridges; 2） the difference of formation mechanisms between the back-arc basin extension and the normal mid-oceanic ridge spreading; 3） the differentials between ultra-slow Indian Ocean and the rapid Pacific spreading, whether there are active and passive spreading, and a push force in the mid-oceanic ridge; 4） mid-oceanic ridge jumping and termination： causes of the intra-oceanic plate reorganization, termination, and spatial jumps; 5） interaction of mantle plume and mid-oceanic ridge. （3） On the intra- oceanic subduetion and tectonics： 1） the origin ofintra-oceanic arc and subduction, ridge subduction and slab window on continental margins, transform faults and transform-type continental margin; 2） causes of the large igneous provinces, oceanic plateaus and seamount chains. （4） The oceanic core complex and rheology of oceanic crust in the Indian Ocean. （5） Advances on the driving force within oceanic plates, including mantle convection, negative buoyancy, trench suction and mid-oceanic ridge push, is reviewed and discussed. 2. The ocean-continent connection zones near the two oceans, including： （1） Property of continental margin basement： the crusts of the Okinawa Trough, the Okhotsk Sea, and east of New Zealand are the continental crusts or oceanic crusts, and origin of micro-continent within the oceans; （2） the ocean-continent transition and coupling process, revealing from the comparison of the major events between the West Pacific Ocean seamount chains and the continental margins, mantle exhumation and the ocean-continent transition zones, causes of transform fault within back-arc basin, formation and subduction of transform-type continental margin; （3） strike-slip faulting between the West Pacific Ocean and the East Asian Continent and its temporal and spatial range and scale; （4） connection between deep and surface processes within the two ocean and their connection zones, namely the assembly among the Eurasian, Pacific and India-Australia plates and the related effect from the deep mantle, lithosphere, to crust and surface Earth system, and some related issues within the connection zones of the two oceans under the super-convergent background. 3. On the relationship, especially their present relations and evolutionary trends, between the Paleo- or Present-day Pacific plates and the Tethyan Belt, the Eurasian Plate or the plates within the Indian Ocean. At last, this paper makes a perspective of the related marine geology, ocean-continent connection zone and in-depth geology for the two oceans and one zone.

Response Mechanism of Water Ecosystem under the Influence of Urbanization: A Case Study of the Connection Zone between Shenyang and Fushun

Taking the connection zone between Shenyang and Fushun as an example,urbanization indicator system was established from the aspects of population,economy,space and society,and the comprehensive evaluation indicator system of water ecological environment was also established from the aspects of water ecological environmental pressure,state and response. Based on the evaluation of comprehensive level of urbanization and the comprehensive quality of water ecological environment,their changing trends during 2000-2014 were analyzed,and the response model between them was established. The composite index of urbanization in the connection zone between Shenyang and Fushun always increased from 2000 to 2014,and urbanization developed rapidly after 2004. The comprehensive quality of water ecological environment decreased firstly and then increased during 2000-2014. The response relationship between urbanization comprehensive index and water ecological comprehensive index during 2000-2014 could be expressed by a cubic curve.

A Novel Method for Node Connectivity with Adaptive Dragonfly Algorithm and Graph-Based m-Connection Establishment in MANET

Maximizing network lifetime is measured as the primary issue in Mobile Ad-hoc Networks(MANETs).In geographically routing based models,packet transmission seems to be more appropriate in dense circumstances.The involvement of the Heuristic model directly is not appropriate to offer an effectual solution as it becomes NP-hard issues;therefore investigators concentrate on using Meta-heuristic approaches.Dragonfly Optimization(DFO)is an effective meta-heuristic approach to resolve these problems by providing optimal solutions.Moreover,Meta-heuristic approaches(DFO)turn to be slower in convergence problems and need proper computational time while expanding network size.Thus,DFO is adaptively improved as Adaptive Dragonfly Optimization(ADFO)to fit this model and re-formulated using graph-based m-connection establishment(G-𝑚𝑚CE)to overcome computational time and DFO’s convergence based problems,considerably enhancing DFO performance.In(G-𝑚𝑚CE),Connectivity Zone(CZ)is chosen among source to destination in which optimality should be under those connected regions and ADFO is used for effective route establishment in CZ indeed of complete networking model.To measure complementary features of ADFO and(G-𝑚𝑚CE),hybridization of DFO-(G-𝑚𝑚CE)is anticipated over dense circumstances with reduced energy consumption and delay to enhance network lifetime.The simulation was performed in MATLAB environment.

Study on Landscape Pattern Index-based Connectivity Analysis of the Primary Farmland Protection Zones

Farmland and primary farmland protection are important contents of land management and land use planning of China. In the new round of land use planning and database construction, primary farmland protection zones are required to have high integrity and connectivity. Using landscape pattern indexes, the integrity and connectivity of primary farmland protection zones was studied in Licheng District of Jinan City. The results showed that, except patch area standard deviation, the other indexes including average patch area, patch area variation coefficient, patch edge density, largest patch index, and mean euclidean nearest-neighbor, all indicate high connectivity of primary farmland protection zones after layout adjustment. A simple and convenient method for identifying the integrity and connectivity of primary farmland protection zones was supplied.

Using Anonymous Connected Vehicle Data to Evaluate Impact of Speed Feedback Displays, Speed Limit Signs and Roadway Features on Interstate Work Zones Speeds

Annually, there are over 120,000 crashes in work zones in the United States. High speeds in construction zones are a well-documented risk factor that increases the frequency and severity of crashes. This study used connected vehicle data to evaluate the spatial and temporal impact that regulatory signs, speed feedback displays, and construction site geometry had on vehicle speed. Over 27,000 unique trips over 2 weeks on a 15-mile interstate construction work zone near Lebanon, IN were analyzed. Spatial analysis over a 0.2-mi segment before and after the posted speed limit signs showed that the regulatory signs had no statistical impact on reducing speeds. A before/after analysis was also conducted to study the impact of radar-based speed feedback that displays the motorists’ speed on a sign below a regulatory speed limit sign. Results showed a maximum drop in median speeds of approximately 5 mph. Speeds greater than 15 mph above the speed limit dropped by 10% - 15%. The reduction in speeds began approximately 1000 feet ahead of the sign and results were found to be statistically significant. The analysis also revealed that larger speed drops inside the work zone were due to geometric constraints that required additional driver workloads, especially during shoulder width changes and lane shifts. The results from this study will be helpful for agencies to understand driver behavior in the work zones and to identify proper speed limit compliance techniques that significantly reduce driver speeds in and around work zones.

考虑智能网联车辆影响的八车道高速公路施工区可变限速控制方法

为提升车联网环境下高速公路施工区交通运行效率及安全水平,提出了一种基于强化学习的可变限速控制方法.选取智能驾驶模型和真车试验模型,分别对传统人工车辆和智能网联车辆的跟驰行为进行建模,构建了以瓶颈下游路段交通流量为效率指标、瓶颈路段速度标准差为安全指标的复合奖励值,利用深度确定性策略梯度算法,分车道动态求解最佳限速值.仿真结果表明,所提可变限速控制方法在不同智能网联车辆渗漏率条件下均能有效提升交通流运行效率和安全水平,且在智能网联车辆渗漏率较低时,提升效果更加显著.当智能网联车辆渗漏率为1.0时,瓶颈下游路段交通流量提升10.1%,瓶颈路段速度标准差均值下降68.9%;当智能网联车辆渗漏率为0时,瓶颈下游路段交通流量提升20.7%,瓶颈路段速度标准差均值下降78.1%.智能网联车辆的引入能够提升至多52.0%的瓶颈下游路段交通流量.

直连绳索取心钻杆分区热处理技术研究

为了提高绳索取心钻杆的性能,对直连绳索取心钻杆的受力情况、结构特点以及传统处理工艺进行分析,提出了分区热处理的工艺。通过对两端进行热加工处理,使钻杆中间管体区域和两端热处理螺纹区域性能出现差异,提高两端综合强度的同时改善螺纹部分的受力状态,可使钻杆柱既具有高强度又兼具柔性,大幅提高钻杆机械性能以及耐磨性。其中调质硬度HRC33~38能在保证管体延伸率与正火、回火基本一致的情况下,强度提高37.7%,硬度提高40%,抗冲击性提高46.7%。调质硬度HRC38~42时,材料的耐磨性提高9.1%。更适合全液压钻机施工及深孔钻进,为钻探施工提供了钻机、钻杆配套性的优选方案。

寒区混凝土构件连接螺栓张紧力的松弛行为

螺栓连接具有施工快速、连接可靠的技术优势,已成为混凝土结构连接的主要方式之一。寒区环境下螺栓连接部位的混凝土会受到冻融循环的影响,分析混凝土材料冻融损伤对螺栓张紧力的影响具有工程意义。基于光纤传感技术对螺栓连接部位冻融过程进行了螺栓张紧力的全过程监测。研究结果表明:抗冻性能差的混凝土会引起预紧力大幅降低,并且由于孔内结冰膨胀的原因,螺栓和混凝土之间若存在4 mm间隙,则螺栓连接部位经历3次~6次冻融循环后出现脆性破坏。研究结果对冻融环境下装配式结构螺栓连接部位的耐久性和安全性设计提供了科学依据。

城市海岸带沿线规划设计提升策略研究——以烟台市蓬莱区段为例

在海洋文明发展的时代背景下,城市海岸带沿线区域不仅是连结陆海的重要纽带,也是空间联动的重要载体。而现今,我国海岸带沿线的发展仍在功能串联、价值转化、韧性生态等方面面临着极大挑战。文章将以烟台市蓬莱区段为例,研究分析规划策略,重点突出陆海统筹布局、全域联动升级的规划路径,以期为城市海岸带沿线区域现阶段的提升发展提供具有实践意义的策略思考。

上海临空园区接驳轨道交通站点共享班车方案研究

为优化轨道交通站点“最后一公里”接驳方式,提出共享班车模式实现资源利用最大化。首先,借助交通大数据及调研数据,深入分析上海临空园区的交通出行特征;其次,提出整合共享、分期实施的策略方案,构建多方参与、权责明确的联合模式,进一步规划5条班车线路,实现园区轨道交通接驳全覆盖。研究结果显示,共享班车方案可减少2%的小汽车出行,降低30%的乘客等待时间,同时具有可观的经济效益。

Effect of the Entrained Air Void on Strength and Interfacial Transition Zone of Air-Entrained Mortar

In order to facilitate the development and application of air entraining agents (AEA) in the high performance concrete, entrained air void structure parameters (air void size range from 10 to 1 600 mu m) of 28 d sifted mortar were measured by image analysis method. The relationship between the air void size distribution and strength of mortar was studied by methods of grey connection analysis and multiple linear regression analysis. The multiple linear regression equation was established with a correlation coefficient of 0.966. The weight of the affection of hierarchical porosity on the compressive strength ratio was also obtained. In addition, the effect of air voids on the paste-aggregate interfacial transition zone (ITZ) was analyzed by microhardness. The results show that the correlation between different pore size range and the compressive strength is negative. The effect of air void size distribution on 28 days compressive strength is different: under the condition of similar total porosity, with the increase of the porosity of the air void size, ranging from 10 to 200 mu m, and the decrease of the porosity, ranging from 200 to 1 600 mu m, the average air void diameter and mean free spacing are decreased; as well as the width of ITZ. On the contrary, the microhardness of the ITZ is increased while the compressive strength loss is decreased.

Migration and speciation transformation mechanisms of mercury in undercurrent zones of the Tongguan gold mining area, Shaanxi Loess Plateau and impact on the environment

In order to study the migration and transformation mechanism of Hg content and occurrence form in subsurface flow zone of gold mining area in Loess Plateau and its influence on water environment,the field in-situ infiltration test and laboratory test were carried out in three typical sections of river-side loess,alluvial and proluvial strata in Tongguan gold mining area of Shaanxi Province,and the following results were obtained:(1)The source of Hg in subsurface flow zone is mainly caused by mineral processing activities;(2)the subsurface flow zone in the study area is in alkaline environment,and the residual state,iron and manganese oxidation state,strong organic state and humic acid state of mercury in loess are equally divided in dry and oxidizing environment;mercury in river alluvial or diluvial strata is mainly concentrated in silt,tailings and clayey silt soil layer,and mercury has certain stability,and the form of mercury in loess is easier to transform than the other two media;(3)under the flooding condition,most of mercury is trapped in the silt layer in the undercurrent zone where the sand and silt layers alternate with each other and the river water and groundwater are disjointed,and the migration capacity of mercury is far less than that of loess layer and alluvial layer with close hydraulic connection;(4)infiltration at the flood level accelerates the migration of pollutants to the ground;(5)the soil in the undercurrent zone is overloaded and has seriously exceeded the standard.Although the groundwater monitoring results are safe this time,relevant enterprises or departments should continue to pay attention to improving the gold extraction process,especially vigorously rectify the small workshops for illegal gold extraction and the substandard discharge of the three wastes,and intensify efforts to solve the geological environmental problems of mines left over from history.At present,the occurrence form of mercury in the undercurrent zone is relatively stable,but the water and soil layers have been polluted.The risk of disjointed groundwater pollution can not be ignored while giving priority to the treatment of loess and river alluvial landform areas with close hydraulic links.The research results will provide a scientific basis for water conservancy departments to groundwater prevention and control in water-deficient areas of the Loess Plateau.

基于社会网络分析的京津冀地区碳排放空间关联与碳平衡分区

基于2005、2010、2015和2017年的碳排放/碳汇数据,利用社会网络分析和探索性空间数据分析对京津冀县级尺度的碳排/碳汇的空间关联作用进行实证分析并进行碳平衡分区划分,提供了在县级空间尺度上划分碳平衡区的路径.研究结果表明:(1)京津冀地区碳排放年均增长率由2005-2010年间的10.05%放缓至2010-2017年间的1.25%,碳汇总量先降后增,2010-2017年间增长15%,但2017年净碳排放量达到了6亿t,反映了当前碳中和压力仍然巨大,京津冀北部和西部是主要的碳补偿率高值区,京津唐、石家庄和邯郸-邢台及其周边地区是主要的碳补偿率低值区;(2)京津冀碳排放空间网络格局逐渐清晰,形成了京津碳排放区、石家庄碳排放区、邯郸碳排放区三个主要的碳排放空间联动区,分别占整个区域面积的36.65%、9.64%、6.76%;(3)根据实证结果,京津冀区域被划分为集中碳汇区、局部调节区、核心-联动碳排区、分散-联动碳排区、分散-孤岛碳排区、一般-联动碳排区、一般-孤岛碳排区7个碳平衡功能区,分别占整个区域面积的22.07%、32.62%、12.81%、0.45%、1.14%、22.55%、8.36%,且有19个关键县域被识别并定义为核心县域、行动县域或桥梁县域.

LCL型并网逆变器新型电容电压有源阻尼策略

在弱电网条件下,数字控制延时会导致虚拟阻抗呈现负阻性,无法起到阻尼效果,因此并网逆变器在电网阻抗变化情况下不能稳定运行,鲁棒性受到严重威胁。针对上述问题,提出一种双线性正反馈有源阻尼策略,以扩大系统的有效阻尼区。为了节省传感器成本,将其优化为电容电压正反馈有源阻尼策略,在电容电压两端添加合适的正反馈阻尼环节,使得系统的有效阻尼区扩大为(0,0.477f3)。分析结果表明该策略使得并网逆变器在弱电网条件下始终具有良好的鲁棒性,即使谐振频率等于1/6采样频率时,系统也具有较好的稳定性。最后,以三相LCL型并网逆变器为例进行实验验证,实验结果验证了该策略的正确性。

塔里木盆地顺北1号断裂带走滑分段特征与控储控藏作用

塔里木盆地顺北地区沿走滑断裂带展布的特深层断控缝洞型油气藏具有明显的分段性。通过三维地震断裂精细解释,综合钻井、测井、试采等资料对顺北1号断裂带走滑分段特征及分段内部储集体结构差异性及成因进行了研究,优选出有利的储集体类型。研究结果表明:(1)顺北1号断裂带由8个几何分段斜列叠置而成,每个几何分段形成一套独立的储集单元,单个储集单元的内部缝洞结构基本一致,但相邻储集单元的内部缝洞结构差异明显,且彼此间油气藏不连通。(2)几何分段的内部缝洞结构由走滑构造的活动强度控制,据此可以划分出内洞外缝结构、双重洞-缝结构与大型“均质”储集体等内部储集体结构类型,其中大型“均质”储集体发育多套缝洞体,缝洞尺寸大、数量多、内部连通性强,有利于油气富集。

顺北油田顺北4号断裂带中段断控储集体连通性评价

顺北4号走滑断裂带断控储集体类型多样,各储集层空间位置,影响储集体连通能力,制约不同部位油井产量。通过探讨一种在钻前评价目标储集体连通能力的方法,对顺北4号走滑断裂带中段断控储集体连通性展开评价。结果表明,顺北4号走滑断裂带中段断控储集体共划分为4个分隔单元,各分隔单元内部洞穴连通率均超过50%,高角度裂缝延伸,垂向洞穴累计厚度大,连通能力较强,分隔单元3与分隔单元4内部的有利目标获取高产概率较大。

基于水资源分区的中国水系发育度与连通度相关性

为了探究大型水系发育水平和连通程度之间的联系,以中国水资源区为基本单元,采用分形理论计算各水资源一级区的水系盒维数,并选用支流发育系数等多指标综合表征水系的发育水平;基于图论方法计算在流域单元分解、大型湖泊优化和大型调水工程连通等工况下各水资源一级区的水系连通度,并选用水系环度等多项指标来表征水系的连通程度;采用统计学方法分析各水资源一级区水系发育度指标和连通度指标的内在联系。结果表明:中国十大水资源区的水系盒维数在1.1~1.6之间,分为成熟、较成熟、不成熟3级;通过对各水资源分区的图模型改进,能更好地反映出水系的复杂性和细节特征,提高水系连通度的计算精度;通过相关分析显示,水系发育度和水系连通度指标之间整体呈正相关关系。该研究结果有助于定量描述水资源区的水系特征和连通程度,为水资源优化配置和管理调度提供借鉴。

基于MSPA模型的新型城市热景观连通性分析

基于土地利用景观格局对城市热岛效应的影响研究较多,但准确识别对城市热岛效应具有重要影响的关键斑块和节点方面的研究亟待开展。以新型中小城市株洲云龙示范区为例,以城市热岛网络构建为切入点,应用形态学空间格局分析(Morphological Spatial Pattern Analysis,MSPA)与景观连通性模型识别城市发展进程中核心热景观斑块和关键节点,并分析其时空演变特征。研究结果表明:(1)2007—2018年云龙示范区热岛斑块趋于集中,热岛面积较研究初期有明显增加,从地表温度空间分布上体现为城区与周边农村的温度对比更加鲜明,表明城市化进程中建设用地呈聚集扩散趋势。(2)研究期间热岛核心区占热景观面积比最大,且比例有明显上升趋势。而边缘、支线、孤岛、桥接、环线以及孔隙形态类型面积占比均呈现出不同程度的下降趋势,表明热岛斑块之间聚集程度不断提高。(3)识别出景观连通度重要性值较高的前20热景观斑块,其中前3斑块的重要性值和面积占比较大,属于极重要与重要两个热岛核心斑块重要性等级,值得重点关注与优化。(4)对重要性值高的热岛核心区域可优先采取降温措施,可以打断节点之间连接减缓整个区域的热岛效应。本研究结果对我国中小城市规划和可持续发展具有重要的实践指导意义。

引入耕地生态价值的咸阳市基本农田划定

为了探索科学客观的基本农田划定方法,实现将集中连片和优质稳定的耕地划为基本农田的目标,有效保护耕地和保障国家农业生产安全。该研究以陕西省咸阳市为例,引入耕地生态价值和政策条件多维度评价耕地质量,结合耕地质量空间集聚类型划定耕地保护分区;采用缓冲区分析法识别耕地连片性,耦合耕地保护分区和耕地连片等级,尝试探索“连片优先、质量优良、数量约束”的基本农田划定流程。结果表明:1)咸阳市耕地质量划分为高、较高、一般、较低、低5个等级,全市超过一半面积的耕地质量等级为低和较低等级(35.81%和29.67%),一般和较高等级的耕地面积占比也均超过了10%;不同耕地质量等级在空间分布上的差异受地形和区域经济发展影响较大,耕地质量等级总体上呈现出“南高北低”的空间分布格局;咸阳市耕地质量在空间上呈现出明显的集聚特征,以高-高值集聚型和低-低值集聚型耕地为主;2)将全市耕地划为优先保护区、适宜保护区、重点整治区和全面治理区4个保护分区并提出一些保护建议。全面治理区内耕地面积最多,占全市耕地总面积的35.50%,适宜保护区内耕地面积最少,仅占11.81%;3)咸阳市共得到49713个耕地连片地块,面积289033.61 hm^(2),占全市耕地总面积的95.10%。将连片耕地划为6个等级,五级连片耕地面积最多,达到92432.08 hm^(2),一级连片耕地面积最少,为20927.65 hm^(2);4)咸阳市最终划定基本农田面积266420.85 hm^(2),占全市耕地总面积的87.66%,乾县、泾阳县、彬州市和永寿县是重点划定区域,累计划定面积占全市基本农田划定总面积的51.64%。研究方法可为优化耕地布局提供新思路,研究结果在一定程度上可为咸阳市下一阶段的基本农田调整与划定提供借鉴。

陇山杂岩早古生代变质事件的厘定及其地质意义

长期以来,陇山杂岩的归属问题一直存在争议。本文对出露于秦岭-祁连山结合部位的陇山杂岩中石榴黑云斜长片麻岩和石榴斜长角闪岩进行了详细的岩石学、P-T温压计算、独居石和榍石U-Pb年代学研究。通过详细的岩相学观察,石榴黑云斜长片麻岩的变质峰期矿物组合为石榴子石+黑云母+斜长石+石英;石榴斜长角闪岩中则识别出了以石榴子石+单斜辉石+角闪石+斜长石+石英为峰期的变质矿物组合。通过传统温压计计算,石榴黑云斜长片麻岩(样品21LS40)和石榴斜长角闪岩样品(样品21LS42-1)的峰期变质P-T条件分别为700℃、0.72GPa和710℃、0.74GPa。激光剥蚀电感耦合等离子体质谱(LA-ICP-MS) U-Pb数据表明,石榴黑云斜长片麻岩中独居石的206Pb/238U的加权平均年龄为407~435Ma。石榴斜长角闪岩中榍石的下交点年龄分别为410±7Ma、409±5Ma和426±10Ma,榍石中Zr含量温度计的计算结果分别为750℃、751℃和748℃(假定压力为0.7GPa)。本文从变质作用的角度出发,将陇山杂岩与秦岭杂岩进行温压条件和变质时代对比研究,认为陇山杂岩与东秦岭杂岩高压-超高压岩石的最后一期退变质作用和西秦岭天水地区的秦岭杂岩麻粒岩相变质作用类似,可能为北秦岭造山带的西延。