Experimental study of enhanced oil recovery by CO2 huff-n-puff in shales and tight sandstones with fractures

The fractures and kerogen,which generally exist in the shale,are significant to the CO2 huff-n-puff in the shale reservoir.It is important to study the effects ...     

瓦斯抽放系统在排放密闭巷道瓦斯过程中的应用

瓦斯抽放的方法有本煤层抽放、邻近层抽放和采空区抽放。传统排放密闭内的瓦斯方法是控制风流排放法,但如何安全、可靠排放密闭巷道内瓦斯问题却有待探索。文章就如何对密闭巷道内的瓦斯进行抽排作浅显论述。     

极端天气下基于时间卷积神经网络的新能源出力评估策略

新能源高渗透率背景下,极端天气造成的出力骤降对电力系统安全运行构成严重挑战,准确评估极端天气下的新能源出力深度是制定电力系统运行方式的重要依据。本文提出一种基于改进的深度时间卷积神经网络(deep temporal convolutional network,DeepTCN)的新能源出力评估方法。通过设计具有动态输入权重的时间卷积神经网络架构,准确量化估计了极端天气对新能源出力的影响,从而为制定极端天气下的电力系统运行方式提供风险程度信息。基于实际电力系统新能源出力数据集的算例结果表明,与常规的时序预测方法相比,所提方法的标准化均方根误差、对称平均绝对百分比误差和平均绝对标度误差3个指标分别最高可提升1.2,0.1和0.22。所提方法能够实现对极端天气下新能源出力的更精准评估。     

一种新的TOC含量拟合方法研究与应用

由于取样的限制,通常在烃源岩评价中往往只能获得十分有限的实测烃源岩的TOC含量数据。但随着我国多数盆地精细勘探的深入,需要更加精细的烃源岩评价,因此,人们对测井数据拟合烃源岩的TOC含量变化越来越重视。目前该技术最先进的是人工神经网络拟合方法,但多种神经网络在拟合高成熟度碳酸盐岩烃源岩地层的TOC含量时相关性均不够高。针对研究区内烃源岩的特点,尝试了一种用图版分类-模糊排队-BP神经网络联合拟合TOC含量的新方法。利用该方法对鄂尔多斯盆地马家沟组的测井资料和实测总有机碳资料进行数据处理,将结果与ΔlogR方法、模糊神经网络方法的结果相比较,证实该方法的结果与实测值有更好的相关性,为系统了解鄂尔多斯盆地下古生界烃源岩发育提供了一定的科学依据。     

Hierarchical Magnetic Network Constructed by CoFe Nanoparticles Suspended Within “Tubes on Rods” Matrix Toward Enhanced Microwave Absorption

Hierarchical magnetic-dielectric composites are promising functional materials with prospective applications in microwave absorption(MA)field.Herein,a three-dimension hierarchical“nanotubes on microrods,”core–shell magnetic metal–carbon composite is rationally constructed for the first time via a fast metal–organic frameworksbased ligand exchange strategy followed by a carbonization treatment with melamine.Abundant magnetic CoFe nanoparticles are embedded within one-dimensional graphitized carbon/carbon nanotubes supported on micro-scale Mo2N rod(Mo2N@CoFe@C/CNT),constructing a special multi-dimension hierarchical MA material.Ligand exchange reaction is found to determine the formation of hierarchical magnetic-dielectric composite,which is assembled by dielectric Mo2N as core and spatially dispersed CoFe nanoparticles within C/CNTs as shell.Mo2N@CoFe@C/CNT composites exhibit superior MA performance with maximum reflection loss of−53.5 dB at 2 mm thickness and show a broad effective absorption bandwidth of 5.0 GHz.The Mo2N@CoFe@C/CNT composites hold the following advantages:(1)hierarchical core–shell structure offers plentiful of heterojunction interfaces and triggers interfacial polarization,(2)unique electronic migration/hop paths in the graphitized C/CNTs and Mo2N rod facilitate conductive loss,(3)highly dispersed magnetic CoFe nanoparticles within“tubes on rods”matrix build multi-scale magnetic coupling network and reinforce magnetic response capability,confirmed by the off-axis electron holography.     

Characterization of a Thermostable and Surfactant-Tolerant Chondroitinase B from a Marine Bacterium Microbulbifer sp. ALW1

Chondroitinase plays an important role in structural and functional studies of chondroitin sulfate (CS). In this study, a new member of chondroitinase B of PL6 family, namely ChSase B6, was cloned from marine bacterium Microbulbifer sp. ALW1 and subjected to enzymatic and structural characterization. The recombinant ChSase B6 showed optimum activity at 40 °C and pH 8.0, with enzyme kinetic parameters of K_m and V_max against chondroitin sulfate B (CSB) to be 7.85 µg/mL and 1.21 U/mg, respectively. ChSase B6 demonstrated thermostability under 60 °C for 2 h with about 50% residual activity and good pH stability under 4.0–10.0 for 1 h with above 60% residual activity. In addition, ChSase B6 displayed excellent stability against the surfactants including Tween-20, Tween-80, Trion X-100, and CTAB. The degradation products of ChSase B6-treated CSB exhibited improved antioxidant ability as a hydroxyl radical scavenger. Structural analysis and site-directed mutagenesis suggested that the conserved residues Lys248 and Arg269 were important for the activity of ChSase B6. Characterization, structure, and molecular dynamics simulation of ChSase B6 provided a guide for further tailoring for its industrial application for chondroitin sulfate bioresource development.     

RC框架梁柱组合件抗震性能试验研究

为提高钢筋混凝土(RC)梁的变形能力,考虑在其塑性铰区采用高延性混凝土(HDC)代替普通混凝土。共设计6个剪跨比为3.6的RC梁试件,包含5个塑性铰区采用HDC的试件和1个RC对比试件。考虑HDC区长度、纵筋配筋率以及配筋方式和梁端配箍率的影响,研究试件在低周反复荷载下的滞回特性、变形能力及耗能能力。结果表明：与RC梁相比,塑性铰区采用HDC后,试件的破坏形态由弯剪破坏向弯曲破坏转变,延性和耗能能力均得到显著提高;纵筋配筋率、配筋方式相同时,在梁端塑性铰区采用HDC,试件的位移延性系数和极限位移角分别提高30%和53%,而同时采用HDC和箍筋时分别相应提高33%和76%;梁端局部采用HDC替换混凝土可减少箍筋用量;梁端塑性铰区的HDC长度对试件延性的影响较小。分别计算塑性铰区采用HDC梁在开裂荷载、屈服荷载、峰值荷载、极限荷载时的顶点位移,其计算值与试验值吻合较好。     

A Novel Human Antibody,HF, against HER2/erb-B2 Obtained by a Computer-Aided Antibody Design Method

Fully human antibodies have minimal immunogenicity and safety profiles. At present, most potential antibody drugs in clinical trials are humanized or fully human. Human antibodies are mostly generated using the phage display method (in vitro) or by transgenic mice (in vivo); other methods include B lymphocyte immortalization, human–human hybridoma, and single-cell polymerase chain reaction. Here, we describe a structure-based computer-aided de novo design technology for human antibody generation. Based on the complex structure of human epidermal growth factor receptor 2 (HER2)/Herceptin, we first designed six short peptides targeting the potential epitope of HER2 recognized by Herceptin. Next, these peptides were set as complementarity determining regions in a suitable immunoglobulin frame, giving birth to a novel anti-HER2 antibody named “HF,” which possessed higher affinity and more effective anti-tumor activity than Herceptin. Our work offers a useful tool for the quick design and selection of novel human antibodies for basic mechanical research as well as for imaging and clinical applications in immune-related diseases, such as cancer and infectious diseases.     

纳米粒子几何结构对膨胀型防火涂料阻燃和抑烟性能的影响

为了研究纳米粒子几何结构对膨胀型防火涂料阻燃和抑烟性能的影响,以聚磷酸铵(APP)-季戊四醇(PER)-三聚氰胺(MEL)-硼酸三聚氰胺(MB)为阻燃体系,硅丙乳液为成膜物质,分别添加球形纳米二氧化硅(Si O2)、经硅烷偶联剂KH560改性的管状碳纳米管(KH560–CNT)和片状水滑石(LDH)制备了3种水性膨胀型防火涂料。采用小室法、隧道法及模拟大板法研究了涂层的防火阻燃性能,再结合热重分析、扫描电镜分析和能谱分析,考察了涂层的热解性能和炭层结构。结果表明,球形Si O2和片状LDH能有效增强防火涂料的阻燃和抑烟性能,表现出较好的协效作用;管状KH560–CNT则会恶化防火涂料的阻燃和抑烟性能,表现出对抗作用。当纳米填料的质量分数为0.5%时,片状LDH表现出最优的协效作用,火焰传播比值为12.5,烟密度等级为14.1%。这是因为它能促进涂层在燃烧过程中形成更多的含磷和含硼交联结构,有效增强了炭层的致密性、连续性和隔热性能。     

坦克对战实景数字游戏的研究与实现

本文简述了实景数字游戏的理念,将我们研制开发的全新模型坦克对战实景数字游戏整体构架和所采用的多项技术作了较为全面地介绍,其中包括计算机无线通信、自动控制、人机智能交互技术等,并对模型坦克对战系统及其各子系统的构成、功能和技术解决方案进行了分析研究。通过对其整体功能检测表明,系统有机融合了各项技术,可靠地构建了一个实景数字游戏环境,游戏参与者利用遥控终端、电子装备以及电子化道具等设备,可进行各种基于真实环境的任务。