Experimental Study on the Characteristics of CO_2 Hydrate Formation in Porous Media below Freezing Point

Porous medium has an obvious effect on the formation of carbon dioxide hydrate. In order to study the characteristics of CO2 hydrate formation in porous medium below the freezing point, the experiment of CO2 hydrate formation was conducted in a high-pressure 1.8-L cell in the presence of porous media with a particle size of 380 μm, 500 μm and 700 μm, respectively. The test results showed that the porous medium had an important influence on the process of CO2 hydrate formation below the freezing point. Compared with porous media with a particle size of 500 μm and 700 μm, respectively, the average hydrate formation rate and gas storage capacity of carbon dioxide hydrate in the porous medium with a particle size of 380 μm attained 0.016 14 mol/h and 65.094 L/L, respectively. The results also indicated that, within a certain range of particle sizes, the smaller the particle size of porous medium was, the larger the average hydrate formation rate and the gas storage capacity of CO2 hydrate during the process of hydrate formation would be.

Vesicle Formation from Equimolar Cationic-anionic Surfactant Mixture in Non-aqueous Media

Unilamellar vesicles from the mixtures of 1:1 sodium 10-undecenoate and trimethyl[2-(10-undecenoyloxy)ethyl]ammonium iodide in the mixed solvents of ethanol and heptane can be formed spontaneously or by sonication. They can exist in the variation of concentrations and volume ratios of ethanol to heptane, which indicates to some extent the high capability of vesicle formation in such mixed systems.

TRANSFORMATION OF EFFUSION AND FORMATION OF GRANULATION TISSUE IN PATHOLOGIC PROCESS OF OTITIS MEDIA WITH EFFUSION

Objective To explore the diversity of stagnant effusions and the pathologic processes leading to granulation tissue formation in otitis media with effusion(OME). Methods Temporal bone slides from 306 ears with OME were studied histopathologically under the light microscope. Results Results of this study revealed a pathologic process in witch the type and the condition of stagnant effusion in the middle ear cleft was a variable in the dynamics of OME progression from an early stage to an advanced stage. The location of granulation tissue and retentive effusion were found to be closely related. Conclusion Early stage granulation tissue formation exhibited a pathologic process in which granulation tissue formation occurred only in areas where effusion had stagnated or was absorbed. The incidence of the retentive effusion and formation of granulation tissue was much higher and the pathologic changes most extensive in the area around the ossicular chain.

支持或反对:社交媒体用户观点的形成机理

探究社交媒体用户观点形成机理,揭示影响网民观点形成的重要因素,可深入理解网络用户的行为模式,洞察网络舆论本质。文章以“双减”话题微博数据为数据源,基于主题模型和机器学习的情感分析方法挖掘用户观点;从意见氛围、社交关系、前期行为特征和用户属性等维度构造特征变量,基于LightGBM建立不同主题下的情感预测模型,采用SHapley Additive exPlanations(SHAP)对特征重要性进行排序,发现影响网民观点形成的重要因素。研究发现:前期行为特征对用户观点形成的影响最大,意见氛围次之,社交关系即好友关系影响较弱;个体在情感倾向上更易跟随规模较大的传播主体,而不是崇拜权威。

MediaInfo工具在视频文件管理中的应用

云转码产品在开发与运营阶段都涉及到视频文件库管理,仅依靠视频文件的扩展名进行分类管理不能满足要求,需要按照视频文件特定重点参数进行文件的分类管理,并不断更新视频文件库的索引文件。Media Info是通用的多媒体文件参数信息提取的开源软件工具,支持目前各类主流格式的图像、音频、视频文件参数信息获取。Media Info工具根据用户的不同需求有三种形式的工具,包括图形界面工具、命令行工具和动态库工具。结合实例详细叙述了三种形式Media Info工具的使用方法,归纳分析了三种工具的特点。最后介绍了Media Info工具在云转码视频文件库管理中的应用,叙述了视频文件库的管理方式,详细叙述了一个典型案例的处理方法。灵活运用Media Info工具,可以解决视频文件库管理中遇到的各种问题,极大地提升管理工作效率。

对抗速朽:对当代数字视听文化的批判性反思

基于对当下代表性数字视听内容样态的分析,文章探讨数字视听文化迭进的规律,并立足于媒介文化的历史与社会角色展开反思。通过对网络综艺、网络微短剧、剧场化平台和虚拟现实项目四种样态的考察,提出当代数字视听文化在演进过程中体现出丰富多元的态势,呈现出结构化和展演性的新特征,并以智能化为未来向度。据此,可从五个方面展开对数字视听文化的速朽性的批判性反思。数字视听文化发展的基本矛盾是其艺术属性与媒介属性关于传播效能问题的分歧,应以对抗速朽为价值目标检视数字技术加诸文化的消极影响。通过回归马克思主义经典文化理论的方式,探索以坚持历史标准和公共旨趣的“活文化”来对抗速朽的可能路径。

社交机器人对社会舆论的影响因素研究

近年来,社交机器人已经成为人工智能领域的一个最新的研究方向。由于新冠疫情、俄乌冲突、英国脱欧等一系列重大事件中,社交机器人对公众舆论产生了重要影响,学界对社交机器人的关注度日渐升高。本文提出了基于社交机器人的社会舆论形成过程模型,分为舆论出现、争夺影响力、舆论形成3个阶段,社交机器人可以在3个阶段介入和影响。研究了社交机器人的级联效应、工作原理、影响因素,指出媒体类型、事件模糊性和争议性、受众群体等均是影响社会舆论的主要因素。调查问卷实验与案例分析表明:社交机器人对信息传播速度、网民意见/倾向的形成等具有显著影响,实验数据对今后研究具有重要参考意义。

以“耕织图像”为核心的知识图谱设计及应用研究

耕织图像是艺术领域重要的图像资源,在人工智能技术与网络技术的驱动下,提出一种面向耕织图像的数字资源开发,实现多种载体形式的耕织图像资源数据知识图谱构建、主题性检索功能设计,以满足知识服务需求。构建耕织图像知识图谱与数据关联,选取各种载体形式的耕织图像资料为数据来源,搭建图文资料图数据库,并在此基础上构建本体知识图谱,以充分挖掘利用图像知识。基于关联数据构建作品的知识图谱模型,能够揭示耕织图像的语义信息,为各种载体形式的耕织图像资料的数据化转换提供新方法和新思路,既能揭示耕织图像之间隐藏的关系,又能比较分析耕织图像中未知图像的内涵,以及耕织图像中所涵盖的关于耕作和纺织图像技术、工具、动能等的发展演变。

基于Windows Media技术的网络教学系统的应用研究与实现

介绍了W indow s m ed ia技术的功能、组成以及工作方式,给出了W indow s m ed ia技术在网络教学中的系统组成模型,详细介绍了客户端播放媒体流的实现过程。

Methane hydrate formation and dissociation behaviors in montmorillonite

The methane hydrate formation and the methane hydrate dissociation behaviors in montmorillonite are experimentally studied. Through the analyses of the microstructure characteristic, the study obtains the porous characteristic of montmorillonite. It is indicated that methane hydrate in montmorillonite forms the structure I (si) crystal. Meanwhile, molecular dynamics simulation is carried out to study the processes of the methane hydrate formation and the methane hydrate dissociation in montmorillonite. The microstructure and microscopic properties are analyzed. The methane hydrate formation and methane hydrate dissociation mechanisms in the montmorillonite nanopore and on the montmorillonite surface are expounded. Combining the experimental and simulating analyses, the results indicate the methane hydrate formation and methane hydrate dissociation processes have little influence upon the crystal structure of porous media from either micro- or macro-analysis. It is beneficial to the fundamental researches on the exploitation and security control technologies of natural gas hydrate in deep-sea sediments.

Simulations of THM processes in buffer-rock barriers of high-level waste disposal in an argillaceous formation

The main objective of this paper is to investigate and analyse the thermo-hydro-mechanical（THM） coupling phenomena and their influences on the repository safety.In this paper,the high-level waste（HLW） disposal concept in drifts in clay formation with backfilled bentonite buffer is represented numerically using the CODE BRIGHT developed by the Technical University of Catalonia in Barcelona.The parameters of clay and bentonite used in the simulation are determined by laboratory and in situ experiments.The calculation results are presented to show the hydro-mechanical（HM） processes during the operation phase and the THM processes in the after-closure phase.According to the simulation results,the most probable critical processes for the disposal project have been represented and analyzed.The work also provides an input for additional development regarding the design,assessment and validation of the HLW disposal concept.

Experimental study on geochemical characteristic of methane hydrate formed in porous media

The natural occurrence of methane hydrates in marine sediments has been intensively studied over the past decades, and geochemical charac-teristic of hydrate is one of the most attractive research fields. In this paper, we discussed the geochemical anomaly during hydrate formation in porous media. By doing so, we also investigated the temperature influence on hydrate formation under isobaric condition. It turns out that sub-cooling is an important factor to dominate hydrate formation. Larger subcooling provides more powerful driving force for hydrate formation. During the geochemical anomaly research, six kinds of ions and the total dissolved salt （TDS） were measured before and after the experiment in different porous media. The result is that all kinds of ionic concentration increased after hydrate formation which can be defined as salting out effect mainly affected by gas consumption. But the variation ratio of different ions is not equal. Ca^2＋ seems to be the most significantly influenced one, and its variation ratio is up to 80%. Finally, we theoretically made a model to calculate the TDS variation, the result is in good accordance with measured one, especially when gas consumption is large.

Electro-oxidation of mixed reactants of ethanol and formate on Pd/C in alkaline fuel cells

Direct ethanol fuel cells have attracted attention as an alternative energy technology due to several advantages such as high theoretical energy density and abundant supply of ethanol.In spite of the advantages,commercialization of direct ethanol fuel cells is hampered by the relatively low performance caused by its slow oxidation kinetics and difficulty of complete oxidation.In this study,formate,which has relatively faster oxidation kinetics,was mixed with ethanol to compensate the latter’s sluggish kinetics.Effects of p H,concentration,scan rate,and temperature on the mixed reactants oxidation on Pd were investigated by electrochemical experiments such as potential sweep and potentiostatic methods.Furthermore,the potential of the mixed reactants as fuel was evaluated by single cell experiments.As a result,we demonstrate that mixing formate with ethanol results in enhanced power performance in a single cell system.

Water transfer characteristics during methane hydrate formation and dissociation processes inside saturated sand

Gas hydrates formation and dissociation processes inside porous media are always accompanied by water transfer behavior, which is similar to the water behavior of ice freezing and thawing processes. These processes have been studied by many researchers, but all the studies are so far on the water transfer characteristics outside porous media and the water transfer characteristics inside porous media have been little known. In this study, in order to study the water transfer characteristics inside porous media during methane hydrate formation and dissociation processes, a novel apparatus with three pF-meter sensors which can detect water content changes inside porous media was applied. It was experimentally observed that methane hydrate formation processes were accompanied by water transfer from bottom to top inside porous media, however, the water behavior during hydrate dissociation processes was abnormal, for which more studies are needed to find out the real reason in our future work.

海域水合物藏样品实验室制备及生成特性

实际海域水合物藏样品不易获取,其资源化开采仍需大量室内基础实验作为支撑。为实现代表性水合物藏样品的精确制备,实验室研制了一套天然气水合物三维模拟装置,采用多次注水的方式对目标样品中气、水和水合物饱和度及生成后体系的温压条件进行控制,分析了甲烷水合物生成过程中系统内压力、温度及电阻率等参数的变化特性。结果表明,多次注水的方式可有效控制样品中各相饱和度;驱动压力及过冷度较大时难以观察到水合物生成诱导期的存在;在周围水浴良好的传热作用下,水合物生成放热引起的温升现象可能会被消除;电阻率的变化显示水合物在多孔介质中生成可能存在“爬壁效应”,而影响电阻率的因素较多,或难以用于准确评估多孔介质中水合物的生成过程。此外,初始气液比增大可促进水合物生成速率增大。

不同氧浓度进行培养液的平衡对辅助生殖临床结局的影响

目的探讨不同氧浓度进行培养液的平衡对辅助生殖临床结局的影响。方法回顾性分析2020年3月至2021年9月在福建省妇幼保健院生殖医学中心进行辅助生殖的患者资料,符合纳入标准的周期数共401个取卵周期,根据使用不同氧气浓度的培养箱分为大气氧平衡组和5%氧平衡组,其中大气氧平衡组有201个周期,5%氧平衡组有200个周期,比较分析两组患者的体外胚胎发育情况和临床结局。结果两组患者的基线资料比较,差异无统计学意义(P>0.05)。大气氧平衡组正常受精率、优质囊胚形成率均高于5%氧平衡组,差异有统计学意义(P<0.05)。两组患者多精受精率、D3优质胚胎率、囊胚形成率、临床妊娠率、种植率、流产率、新生儿妊娠天数、新生儿出生体重和新生儿出生身长比较,差异无统计学意义(P>0.05)。结论在常规体外授精和胚胎移植的周期中,使用大气氧浓度的普通培养箱进行培养液的平衡,可能有利于患者的正常受精和优质囊胚形成。

合肥地铁商业发展现状及对策研究

合肥地铁的发展不仅提升了城市交通运输能力,也对沿线商业产生了深远影响,主要表现在汇聚大量消费群体、促进商业业态布局优化与升级等方面。由于合肥地铁处于发展初期,地铁商业发展存在诸多问题,如商业规划不足、商业氛围缺乏、商业体差异化优势不明显、商业经营管理水平不高等。文章围绕上述问题,从科学编制发展规划、优化业态布局与商业空间设计、实施整合营销策略、培养商业经营管理人才等方面提出对策建议。

深层碳酸盐岩缝洞介质应力敏感特性研究

深层缝洞型碳酸盐岩油藏具有埋藏环境复杂、作用机制复杂、储集空间复杂3大特征,这使得这类油藏难以有效动用和高效开发。为了揭示深层高温、高压和高应力条件下碳酸盐岩缝洞储层的应力敏感特征,本文基于改进的储层应力敏感性流动实验方法,构建了具有不同裂缝发育程度、不同裂缝粗糙度、不同孔洞类型以及不同充填类型的碳酸盐岩缝洞介质模型,深入探究了不同缝洞发育特征对碳酸盐岩介质应力敏感性的影响规律。研究结果表明:(1)深层条件下碳酸盐岩缝洞介质普遍存在“应力敏感滞后效应”,孔隙压力恢复阶段的实测绝对渗透率均小于孔隙压力降低阶段的绝对渗透率;(2)具有相同发育特征的碳酸盐岩缝洞介质的最大渗透率损害率与不可逆渗透率损害率之间存在较好的相关性,即最大渗透率损害率越大,相应的不可逆渗透率损害率也越大;(3)不同充填型碳酸盐岩缝洞介质的应力敏感效应表现出明显的孔隙型介质特征,孔隙压力降低和恢复阶段的渗透率损害率普遍偏小;(4)裂缝是影响碳酸盐岩复合介质应力敏感程度的主控发育结构,裂缝型介质的应力敏感效应明显强于孔洞型介质;(5)随着裂缝数量和形态展布复杂性的增加,深层条件下碳酸盐岩缝洞介质的应力敏感性明显减弱,而溶蚀孔洞和溶洞的存在进一步减弱了复合介质的应力敏感效应。本研究阐明了深层条件下不同发育特征碳酸盐岩缝洞介质的应力敏感特性及其存在的显著差异,为深层碳酸盐岩缝洞型油藏开发技术政策的制定提供了理论依据。

液化条件对多孔介质中CO_(2)水合物生成过程的影响

为了研究液化条件对多孔介质中CO_(2)水合物生成过程的影响机制及其规律,在初始压力为3.9、4.2、4.5、4.8和5.1 MPa,温度为273.5、274.5和275.5 K条件下研究粒径为700μm的石英砂介质中CO_(2)水合物的生成过程。结果表明:在相同条件下,随着初始压力的增加,多孔介质中CO_(2)水合物的生成速率逐渐增大;当压力低于液化压力时,随着初始压力的增加,CO_(2)水合物的生成速率逐渐增大,且温度越高,水合物生成速率增加的趋势越明显;当CO_(2)气体压力达到液化压力时,随着初始压力的不断升高,CO_(2)水合物的生成速率明显增大;多孔介质中CO_(2)水合物的最大生成速率达到了9.297×10^(-3)mol·s^(-1)。研究结果进一步表明:液化可有效强化多孔介质中CO_(2)水合物的生成过程,提高CO_(2)水合物的生成速率。