Evaluation of Well Spacing for Primary Development of Fractured Horizontal Wells in Tight Sandstone Gas Reservoirs

Methods for horizontal well spacing calculation in tight gas reservoirs are still adversely affected by the complexity of related control factors,such as strong reservoir heterogeneity and seepage mechanisms.In this study,the stress sensitivity and threshold pressure gradient of various types of reservoirs are quantitatively evaluated through reservoir seepage experiments.On the basis of these experiments,a numerical simulation model(based on the special seepage mechanism)and an inverse dynamic reserve algorithm(with different equivalent drainage areas)were developed.The well spacing ranges of Classes I,II,and III wells in the Q gas field are determined to be 802–1,000,600–662,and 285–400 m,respectively,with their average ranges as 901,631,and 342.5 m,respectively.By considering both the pairs of parallel well groups and series well groups as examples,the reliability of the calculation results is verified.It is shown that the combination of the two models can reduce errors and provide accurate results.

Gradient effect of road transportation on economic development in different geomorphic regions

The economic benefits of transport infrastructure investment have been widely accepted.However,the varying influence of road transport development across vertical space has rarely been discussed.Taking Sichuan province in China as case study area where the landform is diverse and complex,administrative counties were categorized into 4 main types:plain counties,hill counties,mountain counties,and plateau counties.Using statistical data during 2006-2014,theperformanceofeconomic development and transport construction level in the four types of counties are discussed.Subsequently,the heterogeneous effect of each grade road on economy was calculated by local regression model(GWR).The results indicate that plain counties largely surpassed the other geomorphic counties in economic development level,while the gradient gap among them was on the decline.Similarly,distribution of transport infrastructure presented a decreasing trend from the low plain counties to high plateau counties.Regional imbalances were mainly reflected in the County road and Village road.Regarding the changes of regional gaps,National&Provincial roads and County roads were constantly expanding,whereas the disparity of Village road was slowly narrowing over time.Particularly noteworthy was the non-stationary economic influence of traffic factors across vertical gradients.On average,National&Provincial roads generated higher benefits in the high elevation regions than the lowlands.In contrast,County road and Village road were found to be more effective in promoting economic development in plains.With regard to local estimates of traffic factors,coefficients in mountain counties exhibited larger fluctuation ranges than other geomorphic units.The conclusions provide a basis for government decisionmaking in a more reasonable construction arrangement of road facilities and sustainable economic development.

Reshaping the Cortical Connectivity Gradient by Long-Term Cognitive Training During Development

The organization of the brain follows a topologi-cal hierarchy that changes dynamically during development.However,it remains unknown whether and how cognitive training administered over multiple years during develop-ment can modify this hierarchical topology.By measuring the brain and behavior of school children who had carried out abacus-based mental calculation(AMC)training for five years(starting from 7 years to 12 years old)in pre-training and post-training,we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical topology.We observed the development-induced emergence of the default network,AMC training-promoted shifting,and regional changes in cortical gradi-ents.Moreover,the training-induced gradient changes were located in visual and somatomotor areas in association with the visuospatial/motor-imagery strategy.We found that gradient-based features can predict the math ability within groups.Our findings provide novel insights into the dynamic nature of network recruitment impacted by long-term cognitive training during development.

Effect of Swim-Up and Percoll Treatment on Sperm Quality and In vitro Embryo Development in Yak

This study was designed to determine the effect of different sperm preparation treatments on yak sperm quality and in vitro embryo development.Frozen-thawed semen samples were treated using swim-up or percoll gradient centrifugation methods.Sperm concentration,progressive motility,recovery of motile sperm,membrane integrity,acrosome and chromatin integrity were scored and compared in recovered samples and controls.In addition,the effects of two sperm separation treatments on embryos capable of cleavage and in vitro development to the blastocyst stage were evaluated.Swim-up separated sperm showed a higher motility,while the concentration of spermatozoa recovered and percent recovery of motile sperm were higher with percoll gradient centrifugation separation.According to the optical and electron microscopies,swim-up produced higher percentage of sperm with intact plasma membrane and acrosome than percoll gradient centrifugation separation.However,there was no difference in the percentage of sperm with intact chromatin between two treatment groups.Cell numbers in the blastocysts of two groups were not different.The blastocyst rate was similar in both groups,whereas cleavage rate was higher when swim-up was used.

“以山为名”的高寒生态研究

山地是生物多样性的摇篮,其复杂丰富的生境类型孕育庇护了各种各样的生物物种,许多地区更是特有物种的栖息地。山地具有重要的生态功能与服务价值,易受到气候变化与人类活动干扰的影响。在我国疆域以青藏高原为主体的典型山地生态系统具有极高的环境异质性、物种多样性和特有性,其显著特点是较小的海拔梯度变化能导致巨大的气候差异。利用野外调查、试验研究、文献综述等方法探讨复杂生态系统的变化,特别是在不同时间和空间尺度对全球变化的响应值得我们重点关注。本专辑收录了以中国生态学会高寒生态专业委员会2023年学术年会“高寒生态研究生论坛”报告为主体的多种类型题材的文章,旨在重点展示研究生在高寒生态领域的阶段性研究成果,为未来的深入研究提供重要参考与培养潜在生力军。该专辑不仅深化了对高寒生态系统的科学理解,更为全球环境保护和气候变化应对策略提供了理论支撑,促进了生态系统的适应性管理,最终为可持续发展绘制计划蓝图,制定解决方案。

不同地形梯度下秦巴山区乡村振兴潜力及发展路径

我国山地丘陵地区在空间上相对孤立,乡村发展受到阻碍。开展不同地形梯度下乡村振兴潜力及发展路径研究,旨在为山区因地制宜推进乡村振兴提供理论与科学依据。基于陕南秦巴山区地形差异开展典型村域调研,构建评价指标体系测度乡村振兴潜力,结合相关性与障碍度模型,辨识不同地形梯度下乡村振兴的障碍因素,提出差异化发展建议。结果表明:①各地形梯度下乡村振兴综合潜力由大到小依次为低地形梯度、中低地形梯度、高地形梯度、中高地形梯度,地形梯度与秦巴山区乡村振兴综合潜力及区位条件、基础设施潜力成显著负相关关系;②随着地形梯度的上升,秦巴山区乡村主体、产业发展、人居环境、区位条件、基础设施潜力整体上呈减小趋势,资源禀赋潜力先减小后增大;③不同地形梯度下秦巴山区乡村振兴各维度潜力大小及其障碍因子皆存在明显差异。为优化山区乡村发展模式、全面推进乡村振兴,建议低地形梯度村庄重点防止人口、耕地等农业生产要素流失,中低地形梯度村庄优化基层组织、提升引领能力,中高梯度村庄加强基础设施建设、改善人居环境,高地形梯度村庄充分保护并合理利用林地资源,发展特色产业。

济阳坳陷页岩油储层渗流特征非稳态实验

为形成一种适用于济阳坳陷页岩油储层渗流特征参数的高效而且精确的测试方法,基于一维非稳态渗流模型,建立了非稳态页岩油流动实验方法,分析不同裂缝发育情况下页岩的液测渗透率和启动压力梯度。结果表明:非稳态压力恢复法可准确测试页岩渗透率,测试时间可缩短约90%;由于气液两相间基础物性的巨大差异,液测渗透率约为气测渗透率的0.47%~2.83%;结合数值仿真和压力衰竭测试,可获得页岩液测启动压力梯度(101~102 MPa/m),其随着渗透率的增加呈幂指数递减;层理贯穿缝发育可显著降低页岩的启动压力梯度;相较于稳态法测试,非稳态压力衰竭法测试启动压力梯度数值略小。研究成果可为页岩油储层渗流参数的高效实验测试及开发方案的制定提供技术支撑。

某金矿浮选尾矿综合利用试验研究

为实现矿山经济绿色、可持续发展,以环境效益为前提,本着资源化效益优先、经济效益最大化原则,对某金矿浮选尾矿进行资源综合利用研究。通过分粒级资源利用—充填工艺路线,+0.15 mm粒级制备建筑砂原料,-0.15~+0.038 mm粒级通过磁选除杂制备陶瓷原料(辅料),-0.038 mm细泥及磁性尾矿作为骨料进行井下充填,尾矿综合利用率达100%,创造了良好经济效益,实现了无尾矿山和矿山绿色可持续发展。

共同富裕背景下县域城乡融合发展的理论逻辑与实践进路

共同富裕是中国特色社会主义的本质要求。统筹推进县域城乡融合发展契合共同富裕发展与分配的双重属性,当前,县域城乡融合发展的理论框架与实践路径都处于探索期,文章首先梳理了县域城乡发展的理论共识、分歧与疑问,进而提出县域城乡融合发展的基础性问题,揭示县域城乡融合发展的理论逻辑。从遵循梯度发展原则、走产城融合道路、建立城乡统一的要素市场、加强县域基础设施与公共服务建设四个方面,阐述统筹推进县域城乡融合发展的实践进路。文章将县域城乡融合发展与共同富裕纳入统一的分析框架,为推动以县域为重要载体的新型城镇化建设提供理论依据。

照山白浸膏片的快速多信息梯度薄层鉴别

目的建立照山白浸膏片的快速多信息梯度薄层鉴别方法。方法采用薄层色谱法,分别以不同体积比例的三氯甲烷-乙酸乙酯-甲醇-浓氨水(7.2∶2.2∶3.4∶1,3∶5∶4∶1,2∶3∶5∶1)为梯度展开剂,在紫外光灯(365,254 nm)、暗室透光、日光灯下检视信息斑点。结果共检出信息斑点74个(脂溶性、中极性、水溶性成分斑点分别为27,26,21个),去除因极性间的衔接产生的重复斑点,共归属约26种化学成分。结论该方法简便、效率高,可用于照山白浸膏片的质量控制。

我国产业结构升级与经济高质量发展关系研究

通过搜集2012—2021年的时间序列数据,选取描述产业结构变动和高质量发展的指标采用灰色关联度模型对后疫情时期产业结构变化和高质量发展的关联度进行分析并采用梯度提升回归树方法对接下来我国经济高质量发展水平做出预测。最终得出相关结论:(1)中国经济高质量发展各项指数总体趋好发展,产业结构方面第二产业和第三产业是经济的主要推动力,疫情对第三产业的冲击较为严重;(2)疫情期间的产业结构变化使经济发展稳定性变差,生产效率变低。创新点在于改变现有研究中只用描述性方法测算产业结构和高质量发展关联度的方法,选取模型来定量描述二者之间的关系。

揭开指纹的神秘面纱

以化学指纹显影法为基础,设计了多种不同的科普实验,全面地向科普对象展示化学指纹显影的原理和特点。在科普模式上,项目创新性地将“线上+线下”模式相结合,“居家+实验室”环境相结合,打破了传统科普中受到时间、空间和仪器设备的局限,将科普的范围和广度大大扩大。另外在具体科普项目实施中,注重科普对象的科学和文化素养的提升,开拓公众视野并实现科学有效的辟谣。

近30年福建省土地利用时空演变的海陆梯度分异规律

基于1990、2000、2010、2020年4期福建省土地利用数据集,运用缓冲区梯度带法分析该省海陆梯度下土地利用的时空变化特征及其冷热点的空间分异性,并对原因进行探讨。结果表明:1)从面积变化上看,近30年内主要土地利用类型的面积变化随与海岸线距离的增加具有不同的变化趋势。其中,耕地和城乡建设用地面积变化大致呈持续减少的梯度变化趋势,距海岸线20 km范围二者的面积变化量最大,分别为-1317.12和1799.8 km2;而林地和草地面积变化呈现“减少—增加—减少”的趋势,集中在140~240 km梯度带内。2)从转换类型上看,以耕地、草地转为林地,耕地、林地、草地转为城乡建设用地为主的前10个土地利用变化类型转移变化比例呈现沿海梯度带(44.23%)>过渡梯度带(37.31%)>内陆梯度带(15.03%)的规律;空间分布上,耕地减少和城乡建设用地增加区域主要分布在沿海梯度带;草地减少和林地增加区域主要分布在过渡梯度带、内陆梯度带。3)从综合动态度上看,近30年距海岸线20 km范围的综合动态度最高(0.75%),变化程度最为剧烈;从单一动态度上看,城乡建设用地动态度呈现先升高后降低的梯度变化趋势,其变化速率远远高于其他类型。4)海陆梯度下的土地利用变化具有显著的空间分异性,以2000年为时间分界点,热点区域呈现“由内陆地区向沿海地区转移”、由“北多南少”向“南多北少”转变的空间聚集特征。1990—2020年福建省土地利用变化的海陆梯度分异特征与福建省各阶段的区域发展战略及生态环境建设等政策息息相关。

Development of functional connectome gradients during childhood and adolescence

Connectome mapping studies have documented a principal primary-to-transmodal gradient in the adult brain network,capturing a functional spectrum that ranges from perception and action to abstract cognition.However,how this gradient pattern develops and whether its development is linked to cognitive growth,topological reorganization,and gene expression profiles remain largely unknown.Using longitudinal resting-state functional magnetic resonance imaging data from 305 children(aged 6-14 years),we describe substantial changes in the primary-to-transmodal gradient between childhood and adolescence,including emergence as the principal gradient,expansion of global topography,and focal tuning in primary and default-mode regions.These gradient changes are mediated by developmental changes in network integration and segregation,and are associated with abstract processing functions such as working memory and expression levels of calcium ion regulated exocytosis and synaptic transmission-related genes.Our findings have implications for understanding connectome maturation principles in normal development and developmental disorders.

负密度制约假说的研究进展

负密度制约假说被认为是维持热带森林较高生物多样性的重要机制之一,其主要描述由于资源竞争和有害生物侵害,导致同种个体死亡率增加,从而为其他物种提供生存空间和资源,促进物种共存。通过介绍不同气候带影响负密度制约的驱动因子,以及影响负密度制约强度的生物和非生物因子,本文阐述了最近十余年负密度制约相关研究的进展。其次,通过介绍负密度制约的纬度梯度格局及其存在的争议,讨论了负密度制约的理论意义。最后,利用文献计量学分析方法,探讨了负密度制约近年来的发展趋势以及今后的发展方向。

豫北平原地热资源分区及其开发利用研究

豫北平原地处华北盆地边缘,具有较高的地热流和地温梯度,巨厚的新生界沉积及其覆盖下的下古生界奥陶系、寒武系形成良好的地下水热储层。分析了研究区地温梯度、地温分布、地温异常以及不同深度地温分布,基于此,将研究区划分为8个地热分区:太行拱断束地热分区、汤阴断陷地热分区、内黄凸起地热分区、东明断陷地热分区、济源凹陷地热分区、武陟凸起地热分区、中牟凹陷地热分区、菏泽凸起(河南部分)地热分区。将研究区地热资源开采适宜性划分为最适宜、适宜、差的、不适宜四个等级,针对地热水不同梯级,根据温度、水质确定其不同的开发利用方向,进行综合开发利用。研究为合理开发利用地热资源提供依据。

基于驱替压力梯度的稠油油藏水平井与定向井联合开发策略研究及应用

根据稠油驱替特征采取相应的注采井网对提高开发效果具有重要意义。首先,利用岩心驱替实验与密闭取芯相结合,研究不同原油黏度下驱油效率与驱替压力梯度的关系,建立驱油效率和流度与驱替压力梯度的关系式;根据势的叠加原理,建立以驱替压力梯度和驱油效率为目标、融合井型、井距与井网的注采井网计算模型。结果表明,增大驱替压力梯度有利于提高稠油驱油效率,当原油黏度由60 mPa·s增加到120 mPa·s、180 mPa·s,有效驱替压力梯度由0.002 MPa/m增大至0.005 MPa/m、0.008 MPa/m。在相同井距条件下,水平井网较定向井网提高驱替压力梯度0.8~1.1倍、提高驱油效率8.0%~16.1%,从而大幅度提高水驱采收率6.4%~12.8%。上述认识应用于渤海秦皇岛油田多层砂岩稠油油田高含水后期开发,采取大规模利用水平井联合定向井深度开发策略,由初期定向井反九点井网调整为水平井联合定向井五点井网,采油速度由0.8%提高至1.5%~2.1%,含水上升率控制在0.6%左右,水驱采收率由24.5%提高至39.3%,极大改善开发效果,为类似油田提供经验。

新乡市平原示范区地热资源地质特征及开发利用研究

新乡市平原示范区独特的自然地理条件和地质环境条件,赋存了丰富的地热资源。研究了新乡市平原示范区地热资源地质特征,研究区属于中牟凹陷地热区,主要热储层为新近系明化镇组半固结碎屑岩孔隙裂隙热储层、新近系馆陶组半固结碎屑岩孔隙裂隙热储层、古近系半固结碎屑岩孔隙裂隙热储层,地热类型为层状分布的盆地型地热,地温场类型为地层热传导型,区内断裂无显著导热、导水特征,地温场以地层传导型为主,地温梯度在2.33~3.02℃/hm。并分析了开发利用情况,根据研究区开发利用潜力,为平原示范区建设绿色低碳城市提供地下清洁能源开发利用技术。

Computer-assisted optimization of mobile phase compositions and development distance selectivity in gradient two-step development high-performance thin-layer chromatography

A computer-assisted method is presented for optimization of mobile phase compositions and development distance in gradient two-step development HPTLC. The method is based on a system which can predict the final R(f) values for gradient two-step development from values measured using five preliminary runs. The statistical scanning method is then used for optimization, using R(f) difference as the selection criterion. The method was evaluated using a mixture of eight components. Excellent agreement was obtained between predicted and experimental results.

油藏生产优化理论研究

实现经济高效开发已探明石油资源的途径之一就是立足现有的生产条件,使油藏开发动态实时处于最优状态,这也是智能油田的核心内容之一。将油藏视为一个复杂的动态系统,以油藏开发生产净现值最大化为目标,通过求解描述油藏开发生产的数学模型,实时优化油藏的输入输出控制参数,获取最优的生产方案。鉴于油藏生产优化方法是一个复杂的、大规模优化问题,选用了效率较高的梯度优化算法,利用极大值原理计算所需的梯度,再进行线性搜索,进而优化控制变量。油藏实例进行的分析结果表明,获得的最优生产方案符合油田实际情况,为智能油田体系提供了理论和技术支撑。