Mt.Huangshan is a well-known scenic and historic interest area which is characterized by granite land-forms.Since the approval of membership to the Global Geopark Network,the management committee of Huangshan Scenic A...Mt.Huangshan is a well-known scenic and historic interest area which is characterized by granite land-forms.Since the approval of membership to the Global Geopark Network,the management committee of Huangshan Scenic Area has carried out a series of study and international correlation research of Huangshan granite formation and evolution.Based on the field observation,sampling。展开更多
In evolutionary theory,we generally believe that the evolution of life is from simple to complex,from single to diverse,and from lower to higher.Thus,the idea of evolutionary progress appears obvious.However,in contem...In evolutionary theory,we generally believe that the evolution of life is from simple to complex,from single to diverse,and from lower to higher.Thus,the idea of evolutionary progress appears obvious.However,in contemporary academic circles,some biologists and philosophers challenge this idea.Among them,Gould is the most influential.This paper first describes Gould’s seven arguments against evolutionary progress,i.e.,the human arrogance argument,anthropocentric argument,no inner thrust argument,no biological base argument,extreme contingency argument,statistical error argument,and bacteria(other than human beings)ruling the earth argument.Gould’s arguments against evolutionary progress have great influence in contemporary evolutionary theory.Thus,it is necessary to conduct a careful philosophical analysis of each of Gould’s arguments to reveal his philosophical mistakes.This research contends that Gould’s arguments against evolutionary progress are invalid.展开更多
The challenges brought by broadband wireless access technologies to cellular mobile communication technologies speed up the study and standardization of 3G evolution technologies that support higher data rates. Both t...The challenges brought by broadband wireless access technologies to cellular mobile communication technologies speed up the study and standardization of 3G evolution technologies that support higher data rates. Both the 3GPP and the 3GPP2 have launched research programs on the study and standardization of the emerging 3G evolution technologies. The Long Term Evolution (LTE) program of 3GPP has made progress in key technical indexes of air interface, wireless network architecture and high-level protocols. At the same time, the Air Interface Evolution (AIE) program of 3GPP2 has made study achievements in the formulation of air interface standards for Layer 2 and upper layers, as well as for the physical layer.展开更多
Water is an important material resource for human survival,and with the increasing development of society,the amount of urban industrial wastewater and domestic sewage is gradually increasing.However,wastewater collec...Water is an important material resource for human survival,and with the increasing development of society,the amount of urban industrial wastewater and domestic sewage is gradually increasing.However,wastewater collection and treatment facilities lag behind,so that a large number of wastewater enters urban water,making urban water become gradually black and smelly.In order to provide a good living environment for human beings,a large number of scholars actively explore the treatment technology of black and smelly water.In this paper,the evolution process of black and smelly water was introduced firstly,and then the treatment technology of black and smelly water was summarized.Finally,the prospects for the development of the treatment technology were put forward.展开更多
This paper deals with the development and evolution of modern Yellow River delta and the erosion or deposition rates of its different sections. In June, 1996, Yellow Rivers terminal course was artificially turned east...This paper deals with the development and evolution of modern Yellow River delta and the erosion or deposition rates of its different sections. In June, 1996, Yellow Rivers terminal course was artificially turned eastwards to empty into the sea and then the 11th lobe of the modern Yellow River delta began to form. This course change may mark the beginning of the 3rd subdelta formation. As a result of that, the Yellow River delta advances towards east by north with the 1st, 2nd and 3rd subdeltas arranged in succession. Coast zone in the deltaic area is divided into 7 different sections according to their different erosion or deposition rates: the relatively stable section from Dakou River to Shunjiang Stream, the weakly retreating section from Shunjiang Stream to the Tiaohe River mouth, the strongly retreating section from the Tiaohe River mouth to the station 106, the artificially stable section due to stone dam protection from the station 106 to Gudong Oilfield, the strong deposition section from Gudong Oilfield to Dawenliu Haipu, the weakly deposition section from Dawenliu Haipu to the Zimai Stream mouth, and the stable section from the Zimai Stream mouth to the Jiaolai River mouth. It is predicted that the erosion and deposition situations of the sections will nearly remain the same in 10 years, but the retreating and silting-up rates will tend to become slower gradually. Human activities have an evident influence on the changes of the coastline.展开更多
文章基于Web of Science核心数据库,利用CiteSpace 6.2.R2可视化软件,对与众包物流主题相关的129篇相关文献进行可视化科学计量分析,获得相关文献的发文量、作者图谱、机构图谱、国家图谱及关键词图谱,以探讨该领域的研究热点以及未来...文章基于Web of Science核心数据库,利用CiteSpace 6.2.R2可视化软件,对与众包物流主题相关的129篇相关文献进行可视化科学计量分析,获得相关文献的发文量、作者图谱、机构图谱、国家图谱及关键词图谱,以探讨该领域的研究热点以及未来发展趋势。研究结果表明,目前众包物流发文数量总体呈现出曲折上升的态势;作者以及机构的发文量相差不大且相对较少;最后一公里交付、车辆路线规划、众包运输定价策略以及算法优化等将是众包物流领域未来研究热点。展开更多
对非对称结构形式的变厚度复合材料层合板在准静态压缩载荷下的失效机理进行了试验和数值研究。在ABAQUS/Explicit中建立全新的三维有限元模型(Finite element model, FEM),其中Hashin准则用于复合材料层合板渐进失效分析,内聚力建模用...对非对称结构形式的变厚度复合材料层合板在准静态压缩载荷下的失效机理进行了试验和数值研究。在ABAQUS/Explicit中建立全新的三维有限元模型(Finite element model, FEM),其中Hashin准则用于复合材料层合板渐进失效分析,内聚力建模用于模拟分层的萌生和扩展。根据试验得到的应变数据分析,不连续的中性轴使层合板中产生弯矩,这些弯矩与轴向压缩载荷相互耦合,共同作用在层合板上。有限元结果表明,在薄段和变厚度段的交界处存在明显的应力集中,且薄段的应力大于厚段的应力。在交界处,发生了分层以及纤维和基体的压缩损伤,这与试验的结果一致。FEM预测的极限荷载比试验测得的平均极限荷载小10.7%,证明了模型的可行性和合理性。展开更多
文摘Mt.Huangshan is a well-known scenic and historic interest area which is characterized by granite land-forms.Since the approval of membership to the Global Geopark Network,the management committee of Huangshan Scenic Area has carried out a series of study and international correlation research of Huangshan granite formation and evolution.Based on the field observation,sampling。
文摘In evolutionary theory,we generally believe that the evolution of life is from simple to complex,from single to diverse,and from lower to higher.Thus,the idea of evolutionary progress appears obvious.However,in contemporary academic circles,some biologists and philosophers challenge this idea.Among them,Gould is the most influential.This paper first describes Gould’s seven arguments against evolutionary progress,i.e.,the human arrogance argument,anthropocentric argument,no inner thrust argument,no biological base argument,extreme contingency argument,statistical error argument,and bacteria(other than human beings)ruling the earth argument.Gould’s arguments against evolutionary progress have great influence in contemporary evolutionary theory.Thus,it is necessary to conduct a careful philosophical analysis of each of Gould’s arguments to reveal his philosophical mistakes.This research contends that Gould’s arguments against evolutionary progress are invalid.
基金National "863"Program of China (No. 2005AA123410)
文摘The challenges brought by broadband wireless access technologies to cellular mobile communication technologies speed up the study and standardization of 3G evolution technologies that support higher data rates. Both the 3GPP and the 3GPP2 have launched research programs on the study and standardization of the emerging 3G evolution technologies. The Long Term Evolution (LTE) program of 3GPP has made progress in key technical indexes of air interface, wireless network architecture and high-level protocols. At the same time, the Air Interface Evolution (AIE) program of 3GPP2 has made study achievements in the formulation of air interface standards for Layer 2 and upper layers, as well as for the physical layer.
文摘Water is an important material resource for human survival,and with the increasing development of society,the amount of urban industrial wastewater and domestic sewage is gradually increasing.However,wastewater collection and treatment facilities lag behind,so that a large number of wastewater enters urban water,making urban water become gradually black and smelly.In order to provide a good living environment for human beings,a large number of scholars actively explore the treatment technology of black and smelly water.In this paper,the evolution process of black and smelly water was introduced firstly,and then the treatment technology of black and smelly water was summarized.Finally,the prospects for the development of the treatment technology were put forward.
基金The study is supported by the China National Natural Science Foundation (project No. 49476282)by the Shandong Province Natural Science Foundation (project No. 98E04075).
文摘This paper deals with the development and evolution of modern Yellow River delta and the erosion or deposition rates of its different sections. In June, 1996, Yellow Rivers terminal course was artificially turned eastwards to empty into the sea and then the 11th lobe of the modern Yellow River delta began to form. This course change may mark the beginning of the 3rd subdelta formation. As a result of that, the Yellow River delta advances towards east by north with the 1st, 2nd and 3rd subdeltas arranged in succession. Coast zone in the deltaic area is divided into 7 different sections according to their different erosion or deposition rates: the relatively stable section from Dakou River to Shunjiang Stream, the weakly retreating section from Shunjiang Stream to the Tiaohe River mouth, the strongly retreating section from the Tiaohe River mouth to the station 106, the artificially stable section due to stone dam protection from the station 106 to Gudong Oilfield, the strong deposition section from Gudong Oilfield to Dawenliu Haipu, the weakly deposition section from Dawenliu Haipu to the Zimai Stream mouth, and the stable section from the Zimai Stream mouth to the Jiaolai River mouth. It is predicted that the erosion and deposition situations of the sections will nearly remain the same in 10 years, but the retreating and silting-up rates will tend to become slower gradually. Human activities have an evident influence on the changes of the coastline.
文摘文章基于Web of Science核心数据库,利用CiteSpace 6.2.R2可视化软件,对与众包物流主题相关的129篇相关文献进行可视化科学计量分析,获得相关文献的发文量、作者图谱、机构图谱、国家图谱及关键词图谱,以探讨该领域的研究热点以及未来发展趋势。研究结果表明,目前众包物流发文数量总体呈现出曲折上升的态势;作者以及机构的发文量相差不大且相对较少;最后一公里交付、车辆路线规划、众包运输定价策略以及算法优化等将是众包物流领域未来研究热点。
文摘对非对称结构形式的变厚度复合材料层合板在准静态压缩载荷下的失效机理进行了试验和数值研究。在ABAQUS/Explicit中建立全新的三维有限元模型(Finite element model, FEM),其中Hashin准则用于复合材料层合板渐进失效分析,内聚力建模用于模拟分层的萌生和扩展。根据试验得到的应变数据分析,不连续的中性轴使层合板中产生弯矩,这些弯矩与轴向压缩载荷相互耦合,共同作用在层合板上。有限元结果表明,在薄段和变厚度段的交界处存在明显的应力集中,且薄段的应力大于厚段的应力。在交界处,发生了分层以及纤维和基体的压缩损伤,这与试验的结果一致。FEM预测的极限荷载比试验测得的平均极限荷载小10.7%,证明了模型的可行性和合理性。
