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On s*-Completions of Maximal Subgroups of Finite Groups 被引量:1
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作者 高辉 高胜哲 尹丽 《Chinese Quarterly Journal of Mathematics》 2015年第3期381-388,共8页
Given a maximal subgroup M of a group G, a θ*-completion C of M is called an s*-completion if either C = G or there exists a subgroup D of G which is not a θ*-completion of M such that D contains C as a maximal subg... Given a maximal subgroup M of a group G, a θ*-completion C of M is called an s*-completion if either C = G or there exists a subgroup D of G which is not a θ*-completion of M such that D contains C as a maximal subgroup. In this paper, we obtain several results on s*-completions which imply G to be solvable or supersolvable. 展开更多
关键词 MAXIMAL sUBgroups θ*-completions s*-completions sOLVABLE groups super-solvable groups
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Influence of group B streptococcus and vaginal cleanliness on the vaginal microbiome of pregnant women 被引量:2
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作者 Qi Liao Xiao-Fen Zhang +3 位作者 Xin Mi Feng Jin Hong-Min Sun Qing-Xuan Wang 《World Journal of Clinical Cases》 SCIE 2022年第34期12578-12586,共9页
BACKGROUND The vaginal microbiome plays a critical role in the health of pregnant women and their newborns.Group B Streptococcus(GBS)and vaginal cleanliness significantly affect the vaginal microecosystem and are clos... BACKGROUND The vaginal microbiome plays a critical role in the health of pregnant women and their newborns.Group B Streptococcus(GBS)and vaginal cleanliness significantly affect the vaginal microecosystem and are closely associated with vaginal diseases.AIM To explore the effects of GBS status and vaginal cleanliness on vaginal microecosystems.METHODS We collected 160 vaginal swabs from pregnant women and divided them into the following four groups based on GBS status and vaginal cleanliness:GBS-positive+vaginal cleanliness I–II degree,GBS-negative+vaginal cleanliness I–II degree,GBS-positive+vaginal cleanliness III–IV degree,and GBS-negative+vaginal cleanliness III–IV degree.Samples were subjected to 16S rRNA gene amplicon sequencing.RESULTS Alpha diversity analysis showed that the Shannon index did not significantly differ between the four groups.We identified significant variation in taxa abundance between the GBS-positive and GBS-negative groups and between the vaginal cleanliness I–II degree and III–IV degree groups.Principal coordinate analysis and non-metric multidimensional scaling analysis further confirmed the microbial diversity of the four groups.Moreover,the linear discriminant analysis demonstrated that Lactobacillus jensenii and Actinobacteria were strongly associated with GBS-positive status,and Lactobacillus iners,Lactobacillaceae,Lactobacillus,Lactobacillales,Bacilli and Firmicutes were closely correlated with GBS-negative status.CONCLUSION GBS status and vaginal cleanliness significantly affect vaginal microbiome differences in pregnant women.Our findings provide instructional information for clinical antibiotic treatment in pregnant women with different GBS statuses and vaginal cleanliness degrees. 展开更多
关键词 Vaginal microbiome Pregnant women 16s rRNA gene amplicon sequencing group B streptococcus Vaginal cleanliness
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ON CRITICAL CASES OF SOBOLEV'S INEQUALITIES FOR HEISENBERG GROUPS 被引量:1
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作者 杨乔华 《Acta Mathematica Scientia》 SCIE CSCD 2012年第4期1584-1592,共9页
We prove some Trudinger-type inequalities and Brezis-Gallouet-Wainger inequality on the Heisenberg group, extending to this context the Euclidean results by T. Ozawa.
关键词 sobolev's inequality Brezis-Gallouet-Wainger inequality Heisenberg group
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Symmetry Groups and New Exact Solutions to (2+1)-Dimensional Variable Coefficient Canonical Generalized KP Equation 被引量:7
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作者 ZHANG Li-Hua LIU Xi-Qiang BAI Cheng-Lin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第3X期405-410,共6页
In this paper, the modified CK's direct method to find symmetry groups of nonlinear partial differential equation is extended to (2+1)-dimensional variable coeffficient canonical generalized KP (VCCGKP) equation... In this paper, the modified CK's direct method to find symmetry groups of nonlinear partial differential equation is extended to (2+1)-dimensional variable coeffficient canonical generalized KP (VCCGKP) equation. As a result, symmetry groups, Lie point symmetry group and Lie symmetry for the VCCGKP equation are obtained. In fact, the Lie point symmetry group coincides with that obtained by the standard Lie group approach. Applying the given Lie symmetry, we obtain five types of similarity reductions and a lot of new exact solutions, including hyperbolic function solutions, triangular periodic solutions, Jacobi elliptic function solutions and rational solutions, for the VCCGKP equation. 展开更多
关键词 (2+1)-dimensional variable coefficient canonical generalized KP (VCCGKP) equation modified CK's'direct method symmetry groups Lie symmetry similarity reductions new exact solutions
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Synthesis and mesomorphic properties of fluorinated Schiff's base liquid crystals containing vinyl end groups 被引量:1
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作者 Qiang Wei Siquan Zhu +4 位作者 Lin Shi Lipei Zhang Xiaotao Yuan Hui Cao Huai Yang 《Journal of University of Science and Technology Beijing》 CSCD 2007年第4期373-377,共5页
Three kinds of fluorinated Schiff's base esters, 4-allyloxy-2-X-6-X-benzoic acid 4-[(2, 3, 4-trifluorophenylimino)methyl]phenyl ester, where X=H or F, were synthesized and characterized. Their chemical structures w... Three kinds of fluorinated Schiff's base esters, 4-allyloxy-2-X-6-X-benzoic acid 4-[(2, 3, 4-trifluorophenylimino)methyl]phenyl ester, where X=H or F, were synthesized and characterized. Their chemical structures were identified by Fourier transform infrared spectroscopy (FTIR) and ^1H nuclear magnetic resonance (^1H NMR). Their mesomorphic properties were studied by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). It was found that all the three compounds exhibited enantiotropic nematic phases only. And their cleating point temperature and thermal range of mesophase decreased with the number of fluorine atoms on the rigid core of the compounds; while their melting point temperature showed no distinct regularity. 展开更多
关键词 sYNTHEsIs schiff's base fluorinated liquid crystal vinyl end group
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Entanglement of E8E8 Exceptional Lie Symmetry Group Dark Energy, Einstein’s Maximal Total Energy and the Hartle-Hawking No Boundary Proposal as the Explanation for Dark Energy 被引量:7
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作者 Mohamed S. El Naschie 《World Journal of Condensed Matter Physics》 2014年第2期74-77,共4页
The present note is concerned with two connected and highly important fundamental questions of physics and cosmology, namely if E8E8 Lie symmetry group describes the universe and where cosmic dark energy comes from. F... The present note is concerned with two connected and highly important fundamental questions of physics and cosmology, namely if E8E8 Lie symmetry group describes the universe and where cosmic dark energy comes from. Furthermore, we reason following Wheeler, Hartle and Hawking that since the boundary of a boundary is an empty set which models the quantum wave of the cosmos, then it follows that dark energy is a fundamental physical phenomenon associated with the boundary of the holographic boundary. This leads directly to a clopen universe which is its own Penrose tiling-like multiverse with energy density in full agreement with COBE, WMAP and Type 1a supernova cosmic measurements. 展开更多
关键词 E8 Exceptional Lie symmetry group Dark Energy Einstein’s Relativity E-INFINITY Theory Wheeler BOUNDARY of a BOUNDARY Hartle-Hawking NO BOUNDARY PROPOsAL Penrose Tiling Multiverse
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Lie Symmetry Groups of(2+1)-Dimensional BKP Equation and Its New Solutions 被引量:1
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作者 MA Hong-Cai LOU Sen-Yue DENG Ai-Ping 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第9期685-688,共4页
A modified direct method is developed to find finite symmetry groups of nonlinear mathematical physicssystems.Applying the modified direct method to the well-known (2+1)-dimensional BKP equation we get its symmetry.Fu... A modified direct method is developed to find finite symmetry groups of nonlinear mathematical physicssystems.Applying the modified direct method to the well-known (2+1)-dimensional BKP equation we get its symmetry.Furthermore,the exact solutions of (2+1)-dimensional BKP equation are obtained through symmetry analysis. 展开更多
关键词 (2+1)-dimensional BKP equation Lie symmetry group CK's direct method exact solution
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Synthesis and properties of soluble poly(aryl ether sulfone ether ketone)s copolymers containing pendant methyl groups 被引量:1
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作者 ZHONG Ming YU Wen-wen SONG Cheng LIU Yong-jun SONG Cai-sheng 《Journal of Chemistry and Chemical Engineering》 2009年第4期26-31,38,共7页
A series of Poly(arly ether sulfone ether ketone)s containing pendant methyl groups were synthesized by the reaction of 4,4'-[sulfonylbis (1,4-phenylene)dioxy] dibenzoyl chloride (SODBC) with 4,4'- diphenoxy d... A series of Poly(arly ether sulfone ether ketone)s containing pendant methyl groups were synthesized by the reaction of 4,4'-[sulfonylbis (1,4-phenylene)dioxy] dibenzoyl chloride (SODBC) with 4,4'- diphenoxy diphenylsulfone (DPODPS), 4,4'- di(2-methylphenoxy) diphenylsulfone (o-Me-DPODPS), 4,4'- di(3-methylphenoxy) diphenylsulfone (m-Me-DPODPS), 4,4'- di (2,6-bimethylphenoxy) biphenylsulfone(o-Me2-DPODPS) respectively, in a mixture of 1,2-dichloroethane (DCE) and N-methylpyrrolidone (NMP). These reactions were catalyzed by anhydrous aluminum chloride (AlCl). The characteristic of copolymers were studied by means of advanced analytical techniques such as FT-IR,1H-NMR, DSC, TGA and WAXD. The results show glass transition temperature (Tg) in the range of 193-206℃, thermally stable in excess of 434℃ and excellent solubility in polar solvents. Methyl-substituted Poly(aryl ether sulfone ketone)s had higher glass transition temperatures, lower initial decomposition temperatures than the unsubstituted ones. 展开更多
关键词 poly (aryl ether sulfone ether ketone)s characterization sOLUBLE pendent methyl groups
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A Framework for Exploring the Dynamics of Autonomous Work Groups in Manufacturing Organizations
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作者 Joseph W K Chan W B Lee 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期211-212,共2页
Nowadays, new paradigm of enterprise organization i s constantly changing due to the emergence of the global marketplace, the rise of information technology, and the emphasis of the social developments. This re quires... Nowadays, new paradigm of enterprise organization i s constantly changing due to the emergence of the global marketplace, the rise of information technology, and the emphasis of the social developments. This re quires a more flexible form of organization that are more adaptable to rapid cha nges in business environment such as autonomous work groups (AWGs) in order to achieve higher productivity and effectiveness. AWGs are work units responsib le for the production of goods and the provision of services. They involve team members in making decisions that are traditionally the responsibility of the sup ervisors and managers (Cohen & Bailey, 1997). Team members of AWGs are allowed t o self-regulate their behavior on jobs such as task assignments, methods for ca rrying out the work, and scheduling of activities etc. (Cohen & Ledford, 1994). For example, Motorola achieved a high organizational performance due to the succ essful implementation of AWGs in quality management (Piczak & Hauser, 1996). Xer ox also reported their operational successes based on the team-oriented work gr oups (Wageman, 1997). In recent years many organizations have replaced the traditional layers of manag ement with autonomous team-based work arrangements. Surveys indicated that the adoption of AWGs has soared in responding to the competitive business challenges . Many enterprises are making a deliberate effort to use AWGs to carry out work and operational processes as an alternative for hierarchical approaches (Lawler et al., 1995). There is a growing body of evidence that AWGs are more effective than traditionally managed groups and they contributes to organizational perform ance, such as improvement in operational performance, productivity, quality, cos t savings, employee attitude and behavior, and employee satisfaction (e.g. Pears on, 1992; Cohen & Ledford, 1994; Seers et al. 1995). Given the complexity and cognitive nature of team-based organizations, the mech anisms that the enterprises use in the development of the increasingly sophistic ated models, which can contribute to the effective functioning of AWGs, are extr emely important. The process of developing effective AWGs enables enterprises to inherent built-in intelligence of the organizations so that they will be more able to accommodate to external pressures and changes. The context of this paper is the construction of a dynamics framework and a stra tegic path for autonomous work groups in the technology-oriented manufacturing organization re-design. The framework is a conceptual one drawn from the litera ture survey. The importance of studying autonomous work groups for today’s manuf acturing organizations is claimed. Based on the General System Theory (GST), the characterization of AWGs is addressed. Three-dimensional domains such as t echnical content, service content, and relationship content are identified. A st rategic path is proposed to guide the organizations how the development of AWGs progresses at different levels of maturity that are associated with organization al effectiveness and performance. The utility of the model for AWGs is expected to provide technology-oriented organizations with a strategic path to achieve h igher organizational performance. 展开更多
关键词 autonomous work group three-dimensional dynamic s model general systems theory EFFECTIVENEss maturity level
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Future Development Strategies for S Group Based on SWOT Analysis
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作者 Guohui QI Ligen CHEN 《Asian Agricultural Research》 2014年第4期129-132,共4页
In recent years,the real estate development enterprises are facing the gradually increased government's macro-control,and the increasingly fierce market competition,so it is very imperative to timely adjust and ch... In recent years,the real estate development enterprises are facing the gradually increased government's macro-control,and the increasingly fierce market competition,so it is very imperative to timely adjust and change the enterprises' development strategies to adapt to the new development situation.With S Group as the study object,we use SWOT analysis to analyze the company's internal and external environment,study the current situation of the company and the existing problems,and clearly point out the opportunities and challenges facing the company.Finally we put forth some targeted strategic recommendations,in order to provide a reference for the development of S Group. 展开更多
关键词 REAL EsTATE sWOT analysis s group DEVELOPMENT stra
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Synthesis and characterization functionalized poly(ether ether ketone)s with carboxylic groups
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作者 王冬 高鸿 姜振华 《Journal of Beijing Institute of Technology》 EI CAS 2012年第1期118-121,共4页
A novel type of aromatic poly( ether ether ketone) s with carboxyl groups were prepared by polycondensation of 4,4-bis(4-hydroxyphenyl)pentanoic acid with difluoro-monomers. Their mo- lecular structures were deter... A novel type of aromatic poly( ether ether ketone) s with carboxyl groups were prepared by polycondensation of 4,4-bis(4-hydroxyphenyl)pentanoic acid with difluoro-monomers. Their mo- lecular structures were determined by ^1H-NMR and IR, respectively. Their molecular weights were measured by gel permeation chromatography ( GPC ), which showed that all the polymers had high molecule weights ( 〉 42 000). Due to the long side chains of polymers, all the polymers had good solubility (soluble in NMP, DMAc, THF, etc. ). The differential scanning calorimeter (DSC) detected their excellent glass transition temperatures ( Tg ) up to 195 ℃. The Tg increased with the content of carboxylic units in the polymer chains, because the interactions of H bonds increased with increasing content of carboxylic. The polymers could form transparent and flexible films, which make them a candidate for membrane materials. 展开更多
关键词 poly( ether ether ketone) s carboxylic groups high Tg
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Group Purchasing Organizations (GPOs) in the U.S.: Development and Reform 被引量:1
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作者 Jin Jing Xiong Jiamei +1 位作者 Yang Yue Huang Zhe 《Asian Journal of Social Pharmacy》 2019年第3期100-109,共10页
Objective To study the characteristics, specific functions and policy improvement process of the Group Purchasing Organizations (GPOs) in the U.S. and to provide references for drug group purchasing practices in China... Objective To study the characteristics, specific functions and policy improvement process of the Group Purchasing Organizations (GPOs) in the U.S. and to provide references for drug group purchasing practices in China. Methods Domestic and foreign relevant literatures, websites were reviewed or searched to analyze the functions and policy improvement process of the GPOs in the U.S. so as to provide references for drug group purchasing practices in China. Results and Conclusion As a third party in the U.S. GPOs has formed a relatively integrated business process and projects service system after long-term development. Supported by corresponding policies and industrial regulations, GPOs have made a great contribution to control the growth of medical and healthcare expenses and improve the efficiency of medical institutions, and its development experience can enlighten the practices in China. 展开更多
关键词 group PURCHAsING ORGANIZATION (GPO) drug PURCHAsE the U.s.
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Kantorovich’s theorem for Newton’s method on Lie groups
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作者 WANG Jin-hua LI Chong 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第6期978-986,共9页
The convergence criterion of Newton’s method to find the zeros of a map f from a Lie group to its corresponding Lie algebra is established under the assumption that f satisfies the classical Lipschitz condition, and ... The convergence criterion of Newton’s method to find the zeros of a map f from a Lie group to its corresponding Lie algebra is established under the assumption that f satisfies the classical Lipschitz condition, and that the radius of convergence ball is also obtained. Furthermore, the radii of the uniqueness balls of the zeros of f are estimated. Owren and Welfert (2000) stated that if the initial point is close sufficiently to a zero of f, then Newton’s method on Lie group converges to the zero; while this paper provides a Kantorovich’s criterion for the convergence of Newton’s method, not requiring the existence of a zero as a priori. 展开更多
关键词 Newton's method Lie group Kantorovich's theorem Lipschitz condition
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HEAT KERNELS AND HARDY'S UNCERTAINTY PRINCIPLE ON H-TYPE GROUPS
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作者 朱赋鎏 杨乔华 《Acta Mathematica Scientia》 SCIE CSCD 2008年第1期171-178,共8页
This article obtains an explicit expression of the heat kernels on H-type groups and then follow the estimate of heat kernels to deduce the Hardy's uncertainty principle on the nilpotent Lie groups.
关键词 H-type groups heat kernel Hardy's uncertainty principle
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THE WREATH PRODUCT GROUP FOR NMR SPECTRA ANALYSES OF MOLECULA WITH S_4[S_2]SYMMETRY
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作者 Wei Liang ZHOU Xiao Chun HE Yong Ren HUANG East China Normal University,Shanghai,200062 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第4期325-328,共4页
This paper presents a character table of S_4 wr S_2 wreath product group.Using this character table,~1H or ^(13)C NMR spectra analysis of molecula with S_4[S_2]symmetry,especially simplification of the secular determi... This paper presents a character table of S_4 wr S_2 wreath product group.Using this character table,~1H or ^(13)C NMR spectra analysis of molecula with S_4[S_2]symmetry,especially simplification of the secular determinant equation will be easy to carry out. Molecules with S_4[S_2]symmetry,are exemplified by octaphenylcyclo- tetrasiloxane and 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine chromium (Ⅲ)chloride. 展开更多
关键词 NMR UC this THE WREATH PRODUCT group FOR NMR sPECTRA ANALYsEs OF MOLECULA WITH s4[s2]sYMMETRY 公寸
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Nikodým-Type Theorems for Lattice Group-Valued Measures with Respect to Filter Convergence
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作者 Antonio Boccuto Xenofon Dimitriou 《Advances in Pure Mathematics》 2014年第5期213-221,共9页
We present some convergence and boundedness theorems with respect to filter convergence for lattice group-valued measures. We give a direct proof, based on the sliding hump argument. Furthermore we pose some open prob... We present some convergence and boundedness theorems with respect to filter convergence for lattice group-valued measures. We give a direct proof, based on the sliding hump argument. Furthermore we pose some open problems. 展开更多
关键词 LATTICE group (Free) FILTER (s)-Bounded MEAsURE σ-Additive MEAsURE Diagonal FILTER Block-Respecting FILTER Limit THEOREM Nikodym Boundedness THEOREM
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The Power of Group Generators and Relations: An Examination of the Concept and Its Applications
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作者 Tiancheng Zhou 《Journal of Applied Mathematics and Physics》 2018年第11期2425-2444,共20页
This paper investigates the approach of presenting groups by generators and relations from an original angle. It starts by interpreting this familiar concept with the novel notion of “formal words” created by juxtap... This paper investigates the approach of presenting groups by generators and relations from an original angle. It starts by interpreting this familiar concept with the novel notion of “formal words” created by juxtaposing letters in a set. Taking that as basis, several fundamental results related to free groups, such as Dyck’s Theorem, are proven. Then, the paper highlights three creative applications of the concept in classifying finite groups of a fixed order, representing all dihedral groups geometrically, and analyzing knots topologically. All three applications are of considerable significance in their respective topic areas and serve to illustrate the advantages and certain limitations of the approach flexibly and comprehensively. 展开更多
关键词 Generators and RELATIONs Free group Dyck’s Theorem Dihedral group Presentation Classification of Finite groups (Application) Realizing Dihedral groups Geometrically (Application) KNOT group (Application)
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Group Psychological Intervention for Children with Hyperactivity Disorder
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作者 Ying Xu 《International Journal of Mental Health Promotion》 2023年第1期81-97,共17页
ADHD is a broad psychiatric disorder that affects children of normal or near-normal intelligence.It is character-ized by inattention,hyperactivity,and age-inappropriate impulsivity,and it is often accompanied by learn... ADHD is a broad psychiatric disorder that affects children of normal or near-normal intelligence.It is character-ized by inattention,hyperactivity,and age-inappropriate impulsivity,and it is often accompanied by learning dif-ficulties,behavioral,emotional,and interpersonal problems.On the other hand,hyperactive tendencies in children with ADHD exhibit ADHD-like behaviors such as lack of self-control,inattention,hyperactivity,and emotional impulsivity.However,because their symptoms are less severe,they do not meet the diagnostic criteria for ADHD but are ADHD or at risk of developing ADHD.The purpose of this study is to alleviate and reduce children’s hyperactivity symptoms by investigating the current situation of the children studied,and systemati-cally intervening and educating children with ADHD through psychological group intervention.Research data shows that ADHD is most commonly diagnosed in school-age children,and in 70%–80%of children with ADHD,symptoms persist into adolescence and 30%into adulthood.Through the use of group psychological intervention in the experiment,the prevalence rate of children with hyperactivity disorder tendency has been effectively reduced.This shows that group psychological intervention training has a significant effect on improving hyper-activity symptoms in children with ADHD tendency. 展开更多
关键词 Attention deficit hyperactivity disorder children’s group psychological intervention
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From Rhode Island to Bavaria:Launch and Sinking of the Group 47’s Founders
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作者 Francesca Somenzari 《International Relations and Diplomacy》 2019年第5期224-229,共6页
In 1946,after a two-year imprisonment in Rhode Island,Alfred Andersch and Werner Richter(Group 47’s future founders)came back to Germany as selected German citizens as a result of their cooperation with the American ... In 1946,after a two-year imprisonment in Rhode Island,Alfred Andersch and Werner Richter(Group 47’s future founders)came back to Germany as selected German citizens as a result of their cooperation with the American military authorities.In a short time,Andersch and Richter obtained a publishing license for their newspaper and so they started to act as journalists and writers within the U.S.zone of occupation.Nevertheless,American consideration and support for both of them vanished when they assumed autonomous stances concerning the future of Germany. 展开更多
关键词 group 47 Germany U.s.occupation POsTWAR culture
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Concentration of Platinum Group Elements during the Early Earth Evolution: A Review
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作者 Arkady Pilchin Lev Eppelbaum 《Natural Resources》 2017年第3期172-233,共62页
Numerous unique geological processes [1] took place during the early Earth evolution;several of them, especially those occurring in the Hadean—Early Archean and later, are reflected in the modern geological (geophysi... Numerous unique geological processes [1] took place during the early Earth evolution;several of them, especially those occurring in the Hadean—Early Archean and later, are reflected in the modern geological (geophysical, geochemical, etc.) pattern. One such significant enigmatic feature is the preservation of extremely dense and heavy platinum group elements (PGEs): Pt, Pd, Rh, Ru, Ir, Os. Concentration of PGEs during this period could have taken place in two ways: 1) presence of particular matter capable of preserving PGEs near the earth's surface, 2) transportation of PGEs by magma flows from deep lithospheric (asthenospheric) layers (slabs) to the subsurface. Clearly, much of the dense and heavy PGEs did not sink through to the Earth’s mantle (core) at the time of the magma-ocean, and occur near Earth’s surface in abundances for formation of ore deposits with PGE concentrations found to be 2 - 3 orders of magnitude greater than those in their host media. Their enrichments are associated in numerous cases with such enigmatic phenomena as formation of anorthosites and anorthosite-bearing layered magmatic intrusions. PGE deposits and mineralization zones are also found in associations with chromitites, dunites and serpentinites. In this review, problems related to the initial concentration and preservation of PGEs, their association with anorthosites, and formation of layered intrusions are discussed in detail. The main aim of this article is analysis of the requirements—initial concentration and preservation of PGE and PGM (Platinum Group Minerals) during the early Earth evolution, as well as examination of the distribution behavior of some PGEs in different ore deposits and meteorites. It is supposed that meteoritic bombardment of Earth has played a significant role in formation of PGEs deposits. Some conclusions made in this article may be useful for developing and enhancing strategies of prospecting for PGEs deposits. 展开更多
关键词 PLATINUM group Elements Early Earth EVOLUTION Magma-Ocean Earth’s BOMBARDMENT PGE DEPOsIT Formation
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