四川盆地中三叠统雷口坡组天然气来源及勘探方向

四川盆地中三叠统雷口坡组天然气勘探近年来取得重要突破后继而成为业内关注的热点，但对气源的认识存在较大的分歧。基于天然气地球化学特征开展的成因鉴别和气源对比研究表明，雷口坡组天然气既有主要来自下伏上二叠统龙潭组/吴家坪组烃源岩（磨溪雷一段气藏），断裂下盘须一段烃源岩有一定贡献（中坝雷三段气藏）或供烃条件（川西雷四段气藏），也有主要来自须家河组烃源岩，雷口坡组自身烃源岩有一定贡献（元坝和龙岗雷四段气藏）。雷口坡组气藏具有3种不同的源储组合，其天然气勘探方向具有差异。上二叠统龙潭组烃源岩作为主力烃源岩构成下生上储型，切穿龙潭组至雷口坡组的深断裂周缘的正向构造是寻找雷口坡组规模性气藏的最有利区。上三叠统须家河组底部烃源岩和雷口坡组顶部储层可以构成旁生侧储型，岩溶残丘或岩溶斜坡局部构造高点是这类组合较有利的发育部位。雷口坡组自身构成自生自储型，这类组合往往作为辅助参与气藏形成。     

Can lanthanum doping enhance catalytic performance of silver in direct propylene epoxidation over NaMoAg/SiO_2?

In the attempt to reduce surface free energy of silica to improve interaction of silica with silver, silica was doped by different amounts of low surface energy lanthanum, La_2O_3, through impregnation. The doped and undoped silica were used as supports for preparation of Na/Ag/Mo/La_2O_3-SiO_2 catalysts. Catalytic performances of the catalysts were evaluated in direct epoxidation of propylene(DPO) using molecular oxygen under atmospheric pressure and without adding hydrogen. Adding 5 wt%La to the Na/Ag/Mo/SiO_2 catalyst improves both the catalysts electivity in DPO and its stability over 20h of time-on-stream.The characterization results show that La_2O_3 species interact strongly with silver particles on the silica surface which result in significant improvement in the dispersion profile of silver and marked decrease in the size of silver nanoparticles(AgNPs). The estimated mean diameter of AgNPs is ca. 4.0 nm in Na/Ag/Mo/5 wt%La_2O_3-SiO_2, which is smaller than that(53.9 nm) found in Na/Ag/SiO_2. The presence of subnanometer AgNPs on Ag/La_2O_3-SiO_2 prior addition of MoO_3 and NaCl to the sample can enhance the mutual electronic synergism between Ag, MoO_3 and Na for selective production of propylene oxide.     

Thermal conductivity of natural rubber nanocomposites with hybrid fillers

Natural rubber nanocomposites filled with hybrid fillers of multi-walled carbon nanotubes(CNTs) and carbon black(CB) were prepared. CNTs were ultrasonically modified in mixture of hydrogen peroxide(H_2O_2) and distilled water(H_2O). The functional groups on the surface of CNTs, changes in nanotube structure and morphology were characterized by Fourier transform infrared spectroscopy(FT-IR), Raman Spectroscopy, and transmission electron microscopy(TEM). It shows that hydroxyl(OH·) is successfully introduced. The surface defects of modified CNTs were obviously higher than those of original CNTs, and the degree of agglomeration was greatly reduced. Thermal conductivity of the composites was tested by protection heat flow meter method. Compared with unmodified CNTs/CB filling system, the thermal conductivity of hybrid composites is improved by an average of 5.8% with 1.5 phr(phr is parts per hundred rubber) of hydroxyl CNTs and 40 phr of CB filled. A three-dimensional heat conduction network composed of hydroxyl CNTs and CB, as observed by TEM, contributes to the good properties. Thermal conductivity of the hybrid composites increases as temperature rises. The mechanical properties of hybrid composites are also good with hydroxyl CNTs filled nanocomposites; the tensile strength, 100% and 300% tensile stress are improved by 10.1%, 22.4% and 26.2% respectively.     

Influence of lanthanum on enhancement of mechanical and electrical properties of Cu-Al_2O_3 composites

Two kinds of Cu-Al_2O_3 composites(with and without La) were prepared via mechanical alloying-spark plasma sintering(MA-SPS) method. Microstructure, mechanical properties and electrical resistivity were investigated systematically using metallography, scanning electron microscopy, transmission electron microscopy, mechanical and electrical properties testing. The results indicate that an appropriate amount of La can homogenize the distribution of Al_2O_3. As such, yield strength, ultimate tensile strength and elongation of Cu-Al_2O_3-La are greatly increased. Some semi-coherent interface between Cu and Al_2O_3 is found, which means a low interface energy. The grain shape of Cu changes to irregular band with the addition of La. This change results in a density decrease of grain boundary and reduces electrical resistance. Lanthanum may exist in the form of La_2O_3.     

Prediction methods and applications in the science of science: A survey

Science of science has become a popular topic that attracts great attentions from the research community. The development of data analytics technologies and the readily available scholarly data enable the exploration of data-driven prediction, which plays a pivotal role in finding the trend of scientific impact. In this paper, we analyse methods and applications in data-driven prediction in the science of science, and discuss their significance. First, we introduce the background and review the current state of the science of science. Second, we review data-driven prediction based on paper citation count, and investigate research issues in this area. Then, we discuss methods to predict scholar impact, and we analyse different approaches to promote the scholarly collaboration in the collaboration network. This paper also discusses open issues and existing challenges, and suggests potential research directions.     

川东南回龙场地区小河坝组砂岩元素特征及古环境意义

川东南志留系小河坝组具有良好的生储盖组合，勘探前景较好，但小河坝组的沉积学和地球化学等基础研究薄弱，制约了目的层系的油气勘探。以川东南回龙场地区为例，系统采集了研究区小河坝组101个样品，利用常量及微量元素分析了小河坝组古沉积环境及其演化特征。结果表明，小河坝组主要形成于淡水—微咸水、温暖潮湿、弱氧化—弱还原的浅水三角洲沉积环境；纵向上，海平面变化表现为2个海侵—海退旋回，自下而上划分为X1、X2、X3和X4共4段。X1、X3段为海侵体系域（TST），气候温暖湿润，古盐度较低，水体还原性强，古水深较深；X2、X4段为高水位体系域(HST)，气候干燥炎热，古盐度较高，水体还原性弱，古水深较浅。     

致密砂岩气藏井网加密优化

采用物理模拟实验与数学评价方法相结合，系统研究了井控范围从500 m逐步加密至100 m(相当于井距从1 000 m加密至200 m）过程中不同渗透率砂岩储层在不同含水饱和度条件时的储量采出程度，揭示了井网加密对提高储量采出程度作用，以采出程度提高5%~10%和大于10%为依据，建立井网加密可行性判识图表，为气藏井网部署和加密方案优化提供了参考依据。实验岩心常规空气渗透率分别为1.63×10^-3 μm²、0.58×10^-3 μm²、0.175×10^-3 μm²、0.063×10^-3 μm²，含水饱和度介于30.3%~71.1%之间。研究结果表明：渗透率为1.63×10^-3 μm²的储层，采出程度总体均较高，除了在含水饱和度高达69.9%时的采出程度与井控范围有关外，其余含水饱和度条件下，采出程度与井控范围关系不大，可以采用大井距开发；渗透率为0.58×10^-3 μm²的储层，采出程度与含水饱和度和井控范围关系密切，随含水饱和度降低、井控范围加密而增加；渗透率为0.175×10^-3 μm²的储层，采出程度受含水饱和度的影响十分显著，只有在含水饱和度≤52.3%时，井网加密优化可提高储量采出程度，当含水饱和度>52.3%时，储量采出程度均较低，一般≤10%，即使井控范围加密至100 m，也难以得到提高；渗透率为0.063×10^-3 μm²的储层，总体上采出程度非常低，即使含水饱和度仅有31.6%，井控范围加密至100 m，其采出程度最高也只有2.3%，因此，该类储层依靠井网加密难以得到有效动用。     

典型碳酸盐岩渗透力学行为特征及其对储、盖性质的判定

目前对碳酸盐岩的研究主要关注其油气的储集空间，针对含油气盆地中碳酸盐岩的勘探也主要是为了寻找优质的油气储集体。然而，随着油气勘探向深层更古老的地层拓展，有效的碳酸盐岩储—盖配置显得至关重要。勘探证实，深埋条件下碳酸盐岩有利相带仍然发育高孔渗的优质储集体，然而是否发育与之配置的碳酸盐岩盖层就成为了制约深层碳酸盐岩油气勘探的关键因素。首次系统全面地通过对典型碳酸盐岩开展不同温度条件下三轴应力加载全过程渗透力学试验，得出了碳酸盐岩在破坏变形过程中渗透率随温度、围压的演化过程。试验分析结果显示，典型白云岩和典型灰岩在深埋应力作用过程中渗透力学行为特征具有明显差异，白云岩更多地显示出储集性能的特征，表现为脆—塑转换临界围压较大，岩石更容易形成裂缝，渗透率随温度的增加而增大等；而灰岩则表现出盖层的属性，体现在脆—塑转换临界围压小于白云岩，岩石相对容易形成密闭，渗透率随温度的增大逐渐减小。综合分析认为，白云岩和灰岩的纵向叠置能够形成有效的油气藏储—盖组合。     

新城市科学背景下的城市设计新可能

本文面对智慧城市和新城市科学 迅速发展的背景，立足新时期城市设计转型 需求，针对新近涌现出的以机器学习、虚拟 现实、计算机可视化等为代表的多种新技术 和以街景数据、兴趣点数据、位置服务数据 等为代表的多源城市数据开展讨论。继而对 其所带来的城市设计新可能进行了探讨和展 望，并对于相关典型工具和代表性案例进行 了介绍。这些伴随新城市科学涌现的数据和 技术不仅能够为城市设计在场地分析、设计 开展和方案评估上带来工作方式的革新，而 且有望进一步明确城市设计的专属技术体 系，并以此推动城市设计的领域构建。