全文获取类型
收费全文 | 552篇 |
免费 | 8篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 11篇 |
综合类 | 56篇 |
化学工业 | 36篇 |
金属工艺 | 7篇 |
机械仪表 | 32篇 |
建筑科学 | 121篇 |
矿业工程 | 14篇 |
能源动力 | 23篇 |
轻工业 | 16篇 |
水利工程 | 7篇 |
石油天然气 | 13篇 |
武器工业 | 3篇 |
无线电 | 68篇 |
一般工业技术 | 20篇 |
冶金工业 | 35篇 |
原子能技术 | 2篇 |
自动化技术 | 101篇 |
出版年
2024年 | 1篇 |
2022年 | 5篇 |
2021年 | 16篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 9篇 |
2016年 | 17篇 |
2015年 | 12篇 |
2014年 | 29篇 |
2013年 | 17篇 |
2012年 | 37篇 |
2011年 | 37篇 |
2010年 | 27篇 |
2009年 | 25篇 |
2008年 | 22篇 |
2007年 | 27篇 |
2006年 | 30篇 |
2005年 | 25篇 |
2004年 | 35篇 |
2003年 | 33篇 |
2002年 | 26篇 |
2001年 | 31篇 |
2000年 | 18篇 |
1999年 | 23篇 |
1998年 | 11篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有565条查询结果,搜索用时 0 毫秒
1.
This paper tests the assertion that experienced contractors are more competitive than inexperienced contractors by measuring the effect of experience on bidding competitiveness for building contracts procured by a regular client. Contractors are grouped into experienced and inexperienced contractors, and two levels of contractors’ experience are identified: (1) bidding experience only and (2) bidding plus construction experience. Results of two-sample t tests show that experienced contractors are more competitive than inexperienced contractors. Contractors’ competitiveness in respect of school contracts and other contracts are further compared in evaluating the relationship between the project type and experience effect. Experienced contractors are, on average, more competitive in competing for school contracts. It emerges that the factor of project type familiarity amplifies the experience effect. A comparison of experienced contractors’ competitiveness in bidding for (1) new building works and (2) alteration and extension works shows that the effect of experience would be more significant when contract works packages are highly standardized. 相似文献
2.
随着我国市场的开放,企业面对的竞争日趋激烈,而且企业的竞争优势主要表现为差异化。根据差异化与买方价值的关系,通过技术创新、观念创新实施差异化。 相似文献
3.
90年代初,随着通信向全球化方向发展,发达国家各电信企业纷纷采用联盟的方式,相互联合,发挥各自优势,大举进军全球电信市场。面对这种联盟潮流,想要搭上全球通信的列车,发展中国家应该采取什么措施?坚持什么原则?本文作者对此进行了较深入的分析和研究,并对中国电信的发展提出了建议。 相似文献
4.
与国外大石油公司相比,当前中石油在成品油终端销售方面还存在一些差距,比如管理较落后,流通费用较高,员工素质偏低,技术手段还不够先进,品牌影响力还不够强等等。要提高中石油在成品油市场上的地位,还需要从企业竞争能力、价值链优化整合、市场定位、营销策略等方面进行不断的探索与努力。 相似文献
5.
《Expert systems with applications》2014,41(5):2222-2230
Using competitions to motivate students is a well-known practice that has proved to be successful. Nevertheless, grading students only through their results in the competition could unfairly limit the range of grades that each student can get: regardless of the quality of the different teams participating, one student must necessarily win the tournament, another must be second, and so on until the last place. In fact, player rankings are relative assessments that are conditioned by the performance of every student. In this paper, we propose solving this issue by making students do a code review before betting on the competition. By betting, the grade of students depends both on the performance of their own solution and the one they bet on. This way, grades represent not only coding skills, but also code analysis skills, widening the attainable range of grades and allowing for a fairer grade distribution. As a result, students that are not so proficient in coding are rewarded if they demonstrate they can do a good analysis of the source code written by others, which is a very valuable skill in the professional world. We provide a case study in an undergraduate course, showing positive results. 相似文献
6.
从笔者学校实际情况出发,阐述数学建模课程的特点,探讨数学建模教学及竞赛存在的问题,从开设《数学建模与实验》公共选修课、编写教材或讲义、教学方法改革、成立数学建模竞赛教学团队及考核形式多样化等五个方面提出数学建模课程改革的思路,并给出数学建模教学及竞赛改革的具体建议。 相似文献
7.
机械创新设计大赛是全国大学生重要科技竞赛活动,作为指导教师,通过对指导学生参赛的组织实施过程的体会,阐述了机械创新设计大赛在培养大学生团队合作意识、创新设计能力、理论联系实际的学风、工程实践素质、工程实践训练等综合素质方面的重要作用。 相似文献
8.
针对当前我国铸造材料市场竞争的实际背景,研究某一市场的进入与退出的决策问题,运用静态博弈与动态博弈的原理和方法,讨论企业对于未进入的市场是否可以进入,以及怎样才能进入的问题;同时讨论如何保住已经占领了的市场和进一步扩大已占领的市场份额、击退竞争对手、获得最大市场利润的问题。 相似文献
9.
802.15.4协议中CSMA/CA信道接入方式为了避免再次碰撞使用BEB退避算法,在重负载的情况下网络性能较差。提出一种自适应的退避算法,它用报文的冲突概率来预测节点附近信道的争用状况,在不同的网络状况下,竞争窗口的取值采用相应的退避策略,动态地控制节点的退避范围,以达到改善网络性能的目的。分析与仿真结果表明,新的算法与传统的退避算法BEB算法相比,在网络负载重的情况下,有效地降低了数据包的冲突概率,减少了时延,提高了网络的吞吐量,同时对信道的公平性也有所改善。 相似文献
10.
Some students (base group) played the Circuit Game, a 10-level computer-based learning activity intended to help students learn how electrical circuits work. Other students (competition group) played the same game but with competition features added - including a score bar showing performance on each level, the opportunity to earn one ticket per level if a performance criterion is met, and the opportunity to win a prize based on the number of tickets earned. On a retention test given after the game, the competition group remembered significantly more than the base group (d = 0.47). On an embedded transfer test constituting the final level of the game, the groups did not differ significantly. However, on the transfer test there was a significant gender by group interaction in which men performed worse in the competition group than the base group (d = −0.54) and women performed better in the competition group than the base group (d = 0.24). Overall, adding game-like features to a computer-based learning activity caused students to pay attention to game details but did not motivate students - particularly men - to learn more deeply. 相似文献