三维各向异性TI介质中的P/S波快速解耦技术及在弹性波逆时偏移中的应用

随着多分量采集技术的发展,弹性波逆时偏移技术在三维各向异性介质复杂地质构造成像中得到了广泛的应用.然而耦合的P波场和S波场,会在传播过程中产生串扰噪声,降低弹性波逆时偏移的成像精度.为了解决这一问题,本研究针对具有倾斜各向异性对称轴的三维横向各向同性(Transverse Isotropy,TI)介质,提出了一种矢量弹性波场快速解耦方法,可以有效提高偏移剖面的成像质量.该方法首先通过坐标转换,将观测系统坐标系的垂直轴旋转到TI介质的对称轴方向,在新坐标系下,根据具有垂直对称轴的三维横向各向同性(Vertical Transverse Isotropy,VTI)介质中的分解算子,推导出三维TI介质解耦算子表达式.接着引入一种在空间域快速计算分解波场的方法,来实现空间域矢量P波场和S波场分离,极大地提高了计算效率.最后,通过点积成像条件,将提出的P/S波分解方法引入到三维TI介质弹性波逆时偏移中,得到高精度的PP和PS成像.与以往的波场分解方法相比,本文方法具有数值稳定和计算效率高的特点.数值算例表明,应用上述三维TI分解算子得到的偏移剖面有效压制了噪声,提高了成像质量.

The Dilemma of Women’s Voices in the Post-Epidemic Era:Misconceptions of Feminism on Digital Media Platforms-The Example of Sina Weibo

Weibo,one of China’s largest digital media platforms,has become a major platform for women’s voices to fight for equality.However,misconceptions of feminism on Weibo have become obstacles to women’s voices,for which the platforms did not post women’s views prominently.From the perspective of women themselves,this paper adopted a questionnaire to study the misunderstanding of feminism and its impact on women’s expression on Weibo.

A Fractal Orifice-Throat Model for Seepage Characteristics of Multiscale Porous Media

The seepage characteristics of multiscale porous media is of considerable significance in many scientific and engineering fields.The Darcy permeability is one of the key macroscopic physical properties to characterize the seepage capacity of porous media.Therefore,based on the statistically fractal scaling law of porous media,fractal geometry is applied to model the multiscale pore structures.And a two-dimensional fractal orifice-throat model with multiscale and tortuous characteristics is proposed for the seepage flow through porous media.The analytical expression for Darcy permeability of porous media is derived,which is validated by comparing with available experimental data.The results show that the Darcy permeability is significantly influenced by porosity,orifice-throat fractal dimension,minimum to maximum diameter ratio,orifice-throat ratio and tortuosity fractal dimension.The present results are helpful for understanding the seepage mechanism of multiscale porous media,and may provide theoretical basis for unconventional oil and gas exploration and development,porous phase transition energy storage composites,CO2 geological sequestration,environmental protection and nuclear waste treatment,etc.

That’s Entertainment! The Cultural Economy

The creative economy is one of the most dynamic sectors of world trade, or so declared UNCTAD’s (United Nations Conference on Trade and Development) Edna dos

Habits on Social Networks at Workplace: A Survey of Motivations and Behaviour

This article explores the use of social networks by workers in Abidjan, Côte d’Ivoire, with particular emphasis on a descriptive or quantitative analysis aimed at understanding motivations and methods of use. More than five hundred and fifty questionnaires were distributed, highlighting workers’ preferred digital channels and platforms. The results indicate that the majority use social media through their mobile phones, with WhatsApp being the most popular app, followed by Facebook and LinkedIn. The study reveals that workers use social media for entertainment purposes and to develop professional and social relationships, with 55% unable to live without social media at work for recreational activities. In addition, 35% spend on average 1 to 2 hours on social networks, mainly between 12 p.m. and 2 p.m. It also appears that 46% believe that social networks moderately improve their productivity. These findings can guide marketing strategies, training, technology development and government policies related to the use of social media in the workplace.

Isolation and Identification of a Taxol-producing Endophytic Fungus Identified from Taxus media

[Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media. [Method] 32 strains of endophytic fungi were identified form the inner bark of T. media,and their fermentation products were detected by high performance liquid chromatography (HPLC). [Result] Through the screening,a strain of taxol-producing endophytic fungi M57 was obtained,which could produce 45-50 μg/L of taxol,and M57 was defined as Rhizopus sp. through morphological observation and 18S rDNA sequence analysis. [Conclusion] The finding of Rhizopus sp. M57 provided a promising strain for producing taxol with taxol-producing fungi fermentation process.

媒介接触下青年群体自主产品消费意愿的形成机理研究——基于S-O-R理论

培养青年群体自主产品消费意愿是实施扩大内需战略与深化供给侧结构性改革有机结合的有力抓手。基于S-O-R(刺激—有机体—反应)这一环境心理学理论,从“爱国情感”和“政府信任”两大路径出发构建媒介接触下的自主产品消费意愿模型,并将媒介细分为主流媒体和非主流媒体展开对比研究。基于结构方程模型的验证发现,主流媒体和社交媒体刺激了消费者的爱国情感和政府信任,最终影响自主产品消费意愿,且爱国情感路径下的作用更为突出。

Baeyer-Villiger oxidation of cyclic ketones utilizing potassium peroxydisulfate(K_2S_2O_8) or sodium perborate(NaBO_3) in acidic media

The efficient, green, facile, mild and straightforward conversion procedure for the oxidation of cyclic ketones to lactones at room temperature utilizing potassium peroxydisulfate （K2S2O8） in acidic media is satisfactory to high yields without using traditional chlorinated solvents is reported. This oxidative reagent is cheap and friendly environmental procedure for industrial purposes than use of organic peracids.

Linear instability of the electrified free interface between two cylindrical shells of viscoelastic fluids through porous media

In this paper, we have discussed the linear stabil- ity analysis of the electrified surface separating two coaxial Oldroyd-B fluid layers confined between two impermeable rigid cylinders in the presence of both interfacial insoluble surfactant and surface charge through porous media. The case of long waves interfacial stability has been studied. The dispersion relation is solved numerically and hence the ef- fects of various parameters are illustrated graphically. Our results reveal that the influence of the physicochemical pa- rameterβ is to shrink the instability region of the surface and reduce the growth rate of the unstable normal modes. Such important effects of the surfactant on the shape of in- terfacial structures are more sensitive to the variation of the βcorresponding to non-Newtonian fluids-model compared with the Newtonian fluids model. In the case of long wave limit, it is demonstrated that increasing r, has a dual role in- fluence （de-stabilizing effects） depending on the viscosity of the core fluid. It has a destabilizing effect at the large values of the core fluid viscosity coefficient, while this role is ex- changed to a regularly stabilizing influence at small values of such coefficient.

Forward modeling of ocean-bottom cable data and wave-mode separation in fluid–solid elastic media with irregular seabed

In marine seismic exploration, ocean-bottom cable techniques accurately record the multicomponent seismic wavefield; however, the seismic wave propagation in fluid–solid media cannot be simulated by a single wave equation. In addition, when the seabed interface is irregular, traditional finite-difference schemes cannot simulate the seismic wave propagation across the irregular seabed interface. Therefore, an acoustic–elastic forward modeling and vector-based P-and S-wave separation method is proposed. In this method, we divide the fluid–solid elastic media with irregular interface into orthogonal grids and map the irregular interface in the Cartesian coordinates system into a horizontal interface in the curvilinear coordinates system of the computational domain using coordinates transformation. The acoustic and elastic wave equations in the curvilinear coordinates system are applied to the fluid and solid medium, respectively. At the irregular interface, the two equations are combined into an acoustic–elastic equation in the curvilinear coordinates system. We next introduce a full staggered-grid scheme to improve the stability of the numerical simulation. Thus, separate P-and S-wave equations in the curvilinear coordinates system are derived to realize the P-and S-wave separation method.

New Media Era: Research on Ideological and Political Education in Universities

The development of new media has brought to the ideological and political education in colleges and universities of the new situation and new problems that are needed to make a new generalization and explanation, which not only endows the new mission of ideological and political education workers, but also brings new opportunities to the innovation and development of ideological and political education theory. This paper argues and interprets the definition, impact analysis, and content &structure optimization of the new media era ideological and political governance education from a new perspective of interdisciplinary study including the sociology, psychology, ethics and Journalism.

Strength criterion of porous media: Application of homogenization techniques

The present paper aims at giving some general ideas concerning the micromechanical approach of the strength of a porous material. It is shown that its determination theoretically amounts to solving a nonlinear boundary value problem defined on a representative elementary volume(REV). The principle of nonlinear homogenization is illustrated based on the case of a solid phase having a Green’s strength criterion. An original refinement of the so-called secant method(based on two reference strains) is also provided. The paper also describes the main feature of the Gurson’s model which implements the principle of limit analysis on a conceptual model of hollow sphere. The last part of the paper gives some ideas concerning poromechanical couplings.

The Role of New Media in Communicating to Beneficiaries of Ngos Working in Kajiado County, Kenya

Organizations serving rural communities in Kenya have found use for media as a tool of replacement for personal interface in the daily communication with the beneficiaries of their programmes in deprived areas. The interactions between two non-governmental organizations （NGOs） and rural beneficiaries in Isinya, Kajiado County, provide case studies of how NGOs modernize their outreach via new media and how beneficiaries respond to the change. The research was not only concerned with the presence of information technology （IT） and online facilities in remote and deprived locations. It also evaluated responses to the replacement of person-to-person contact with technologies, such as social media, the Internet, Compact Disc-Read Only Memory （CD-ROMs）, and Digital Versatile Disc （DVDs）. Conducted in four focus groups, the research evaluated the uptake of new media technologies by beneficiaries following the transition, asked whether beneficiaries engaged with the materials being communicated, and assessed whether this confluence of technology and culture had eased the flow of communication, or unsettled it. Evidence of discomfort among the older （over 50-year-old） beneficiaries stemmed from fear of failure to master the technologies and a desire for a continuation of regular interpersonal interaction with the NGO field officers （whose field trips were scaled back in preference of computer-mediated communication）. However, younger （under 40-year-old） beneficiaries were less insistent on regular interpersonal visits and were appreciative of the use of technology, and of the building of Maarifa Centres to give the beneficiaries free access to internet, DVDs, and hard drive-based information materials. Another demographic, beneficiaries aged between 40 and 50 years old, said they were not comfortable with the change and wanted the interpersonal interaction to continue, but were open to a longer-term transition once the beneficiaries were all conversant with the uses of the new technologies. The study recommends a better managed transition that accommodated the beneficiaries’ fears, misgivings, and cultural preference for verbal, face-to-face consultation.

Motivations of Individuals Participating in Social Media： A Cultural Perspective

Social media is an information technology that allows users to communicate and share information. With steadily rising number of users across the globe, individuals participate in various activities, like connecting with friends and community members, sharing information, posting political messages, disaster recovery activities, reading daily news, learning, and entertainment, each driven by different sets of motivations. Culture has an influence on the kind of motivation―pro-social and personal needs oriented―that drives social media usage by individuals. Using Hofstede’s （1984b） cultural dimensions, the paper suggests that each of the dimensions will have influences on the social media behaviors differently. Such a cultural perspective helps future social media users to plan the kind of activity and information sharing based on the kind of motivation driving the target audience and the platform providers to design and market accordingly.

Motivations of Using Social Media Through Smartphones Among University Students in the United Arab Emirates

The aim of the study was to investigate gratifications of using social media among university students in the United Arab Emirates. Adopting the uses and gratification approach, the study investigates how the students utilize social media to gratify their personal, social, psychological, and educational needs. The study uses a questionnaire to collect data from a sample of 420 students from two universities in the UAE: University of Sharjah and Zayed University. In each university, two colleges were selected to represent art colleges and sciences colleges. The findings of the study show that 69.3% of the students are accessing social media more than five hours daily. 79.0% of the students access the social media through their smartphones. The main social media accessed are WhatsApp, Instagram, and Facebook. The main reasons of using social media are seeking information, communicating with friends, consuming time, and following up public affairs.

A Study of Ba Jin （李尧棠） in Chinese Electronic Media

This paper gives an outline of the core concerns in Chinese Electronic Media, according to the data collection of the webpage about Ba Jin in Chinese, exploring what is happening to Ba Jin on the Chinese Internet in China, including the developments on the introductions to Ba Jin; the biographies of his; the works of his, which takes Turbulent Current Trilogy as an example; as well as politics, especially on anarchism and populism; and images of the female, etc. Besides, it discusses how the criticism and reception of Ba Jin＇s works online in Chinese are different from those in English in the U.S-America. The paper also analyzes the hidden reasons, most of which are owing to the specific historical and theoretical values, expecting to provide necessary reference for a global understanding and appreciation ofBa Jin＇s works, to contribute to promotions to study of Ba home and abroad.

Media Representing Shakespeare： Adaptation, Inter-Textuality, and Gender

Applying the theory of adaptation, Feminism, and Performance Studies, this paper explores the adaptation, inter-textuality, and gender in the three films The Tempest （2010） directed by Julie Taymor, Prospero＇s Books （1991） directed by Peter Greenaway, and Shakespeare in Love （1998） directed by John Madden, referenced to Gnomeo and Juliet （2011）, a cartoon animation. Both films of The Tempest show visual spectacle and technology images by CGI （Computer-Generated Cinematic Graphic Image） effect. The author argues the power struggle between Caliban and Prospero played by actress Helen Mirren, changes from post-colonial discourse in the male domain, to be more about the intellect contest between man and woman, and Taymor＇s adaptation is more focused on maternity than actor John Gielgud＇s on politics. Inter-textuality exists in Shakespeare in Love and Shakespeare＇s Romeo and Juliet, and Twelfth Night. Unlike the tragedy in the films, Gnomeo and Juliet ends happily as we can expect from most musicals and fairy tales. The inter-textuality of literature and art, dramatic plays, historical events, and biographical sketches are delicately intertwined. Media represent Shakespeare applied by Jean Baudrillard＇s ＂simulacra＂ and Richard Schechner＇s ＂simulation＂ to present the liminal threshold between reality, role-playing, and theatricality. Shakespeare represented by media rise to visual narratives.

Kenya and the Emerging Power-Shift in Global Political-Economy: Right-Wing Populism and Social Media Activism

A potential global power transition characterized by emerging economies of BRICS where China is the likely leading contender against the United States as the only global hegemon seems inevitable.The increasingly multipolar world is evidenced by the attention given to right-wing populism in Europe and USA attributed to China’s aggressive approach to international trade through its stealth entry and subsequent investments in global political-economy.China’s presence in Africa and Trump’s America first policy’s attempt to open“new business frontiers”in emerging economies of Asia and Africa in order to contain Chinese influence and threat in global hegemony are interesting happenstances that require closer scrutiny.Kenya,the biggest economy in East Africa,which is among the fastest growing regions globally,is the gateway to the East African Common Market.Historically,Kenya has a policy of non-alignment in international relations making it possible to receive FDI from both China and the US but with highly contested elections.Therefore,Kenya presents a perfect laboratory for examining the emerging power-shift in global political-economy as the country grapples with traditionally chaotic electoral power transitions and the two biggest economies in the world compete for business in Nairobi.The 2017 elections not only betrayed the international community’s commitment to Western values of human rights and democracy,but also revealed the challenges of governance in post-World War II global liberalism characterized by sophisticated media institutional spaces.

Analysis of Vortex Motion in Porous Media

In vortex motion fluid moves in curve path and the stream lines are curved. When the fluid flows between curved stream line, the centrifugal forces are setup which is counter balanced by pressure forces acting in the radial direction. The vortex motion has two types of curved motion. The first type called free vortex type, the fluid moves due to its own natural effect but energy is not added to fluid when moving in curved path. The second type called forced vortex, in which energy is added to fluid. A two dimensional steady laminar free convective flow of viscous incompressible flow in porous media voids is considered. In this paper the motion of fluid is studied while moving in the porous media. It is studied that the motion of the fluid in the porous media is vortex motion at the low Reynolds’s number, where the motion is laminar motion and the fluid obeys the laws of vortex motion.