Archaeopteryx： Dinosaur or Bird？

An Archaeopteryx-like theropod dinosaur newly found from western Liaoning Province in northeastern China would make an unusual, if not unwelcome, gift for the 150th birthday of Archaeopteryx, the oldest bird as long-believed by paleontologists: Named as Xiaotingia zhengiis, the new species carries some critical traits suggesting that Archaeopteryx might have actually been a dinosaur. Naturally this breaking news stirred     

Dinosaurs of a Feather

<正>From the earliest days of paleontological research, the origin of birds was an area of special interest. Largely thanks to the work of Thomas Huxley and the     

所有的恐龙都披羽毛

恐龙长羽毛也许是普遍规律,而不是个别现象。自1996年震惊世界的中华龙鸟被发现以来,人们开始接受,兽脚类恐龙是披羽毛的,这类恐龙后来进化成了鸟类。     

单用亚砷酸对儿童M3型白血病具有高效低毒特点

一个由我国科学家领导的国际联合古生物学考察队在内蒙古发现一件保存完整的小型兽脚类恐龙化石。这件被命名为“精美临河盗龙”的化石被确定为驰龙类的一个新属种,也是世界上保存最为完好的白垩纪晚期小型肉食龙类标本之一。科学家表示,对这一类群的深入研究将有助于对鸟类起源的理解。     

鸟类不认恐龙做祖宗了

鸟类起源于恐龙?一些科学家说:\"不,一些恐龙起源于鸟类!\"在飞机发明之前,人类只能站在地面,羡慕地看着鸟类自由自在地翱翔于蓝天之上,心中充满了疑惑:\"这些长着翅膀的家伙是怎么出现的呢?\"鸟类起源,众说纷纭这个问题其实困扰了人类几千年。在科学发展起来后,关于鸟类的起源,逐渐形成了两大派别。一派是恐龙派,认为鸟类起     

Origin of Birds: Decade-Long Efforts and Evidence from China

<正>In its 2014 version of top 10 ground-breaking discoveries and achievements released on December 19,Science,the world-leading journal included the transition from dinosaurs to birds in its annual selection,noting that a series of papers detailed how certain dinosaurian lineages developed small,lightweight body features,which have enabled them to evolve into birds and gain the ability to fly.The dinosaur-bird transition,now evaluated as one of     

提高科研创新水平建设研究型大学

本文通过分析国内外一流研究型大学的科研现状,提出我国需通过增加科研经费投入、加强人才培养、重视基础性交叉学科创新性研究等环节,以提高科研创新水平,加快建设研究型大学的步伐。     

超越能力峡从“本土”吸收到“当地”吸收

随着全球经济一体化程度的加深,吸收和利用跨国知识溢出逐渐成为发展中国家能力形成和提升的重要途径。本文在全球生产网络的框架下,围绕我国能力的形成和提升,系统讨论了知识吸收的地理区位与我国能力演变的关系。分析显示,通过基于“本土”的知识吸收活动,我国形成了世界级的生产能力,并出现向创新能力跨越的趋势,不过,在创新能力赶上发达国家的过程中,从“当地”吸收外部知识的重要性正在不断增强。     

经济体制和结构变化:基于中国收入不平等总量的实证分析

本文在考虑经济结构变化的基础上,利用LM(最小拉格朗日乘数)单位根检验方法,对我国1952-2000年间的全国基尼系数、GE、城乡基尼系数和内陆一沿海基尼系数等时间序列的数据生成过程的动态特征进行了研究.本文的研究结果表明,4个时间序列均为服从一个断点或两个断点的趋势平稳过程,结构断点出现的时间与我国经济体制改革的时间相吻合.这说明了以政府为导向的经济体制结构的改革对我国收入平等有长期持续效应.     

树立先进的社会管理理念加快电子政务发展

阐述了网络环境下社会管理的特点，提出树立先进的社会管理理念，加快电子政务发展的对策建议。     

分化到融合——改革开放30年教师与课程关系考察

改革开放30年来,我国课程与教师的关系一直处于变化之中,课程改革与教师之间在不同的阶段呈现出不同的关系,大体来说分为三个时期,即课程与教师关系的分化时期、互渗时期、融合时期。考察教师与课程之间的关系,是为了对目前教师与课程关系的整合进行一些前瞻性的反思。     

Temporal Issues in Information and Communication Technology-Enabled Organizational Change: Evidence From an Enterprise Systems Implementation

In this article we highlight temporal effects in information and communication technology-enabled organizational change. Examples of temporal effects are explored in the context of one organization's efforts to implement an enterprise-wide information system. Temporality is presented as having two aspects, with the first being the well-recognized, linear and measured clock time. The second aspect of time is that which is perceived--often as nonlinear--and socially defined. We find that temporal effects arise both in changes to the structure of work and in differences among groups in how time is perceived. Evidence suggests that both specific characteristics of the implementation and of the enterprise systems' technologies further exacerbate these temporal effects. We conclude with suggestions for how to incorporate a temporally reflective perspective into analysis of technology-enabled organizational change and how a temporal perspective provides insight into both the social and technical aspects of the sociotechnical nature of enterprise systems.     

From Findings to Theories: Institutionalizing Social Informatics

We focus here on the history, status, and future of social informatics. In doing this we build on the visionary work of the late Rob Kling. Social informatics research contributes insights and perspectives to the study of computing in our society that other approaches do not. We make the case that social informatics is on its way to becoming a scholarly institution: accepted as one of the several approaches to study computing, and in particular, the approach best suited to engage on computerization. In making this case, we highlight the value of social informatics, summarize its principles and common findings, point to current work and issues, illustrate the three perspectives through which to pursue this scholarship, and identify several current activities remaining for social informatics to institutionalize.