全文获取类型
收费全文 | 416篇 |
免费 | 32篇 |
国内免费 | 2篇 |
专业分类
财政金融 | 10篇 |
工业经济 | 55篇 |
计划管理 | 227篇 |
经济学 | 25篇 |
综合类 | 33篇 |
运输经济 | 11篇 |
旅游经济 | 3篇 |
贸易经济 | 36篇 |
农业经济 | 13篇 |
经济概况 | 37篇 |
出版年
2023年 | 7篇 |
2022年 | 5篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 10篇 |
2018年 | 3篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 22篇 |
2014年 | 40篇 |
2013年 | 25篇 |
2012年 | 53篇 |
2011年 | 68篇 |
2010年 | 50篇 |
2009年 | 29篇 |
2008年 | 15篇 |
2007年 | 14篇 |
2006年 | 14篇 |
2005年 | 15篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有450条查询结果,搜索用时 15 毫秒
1.
To address the challenge of global tourism resources being overloaded or underutilization, there requires an adequate method for assessing the tourism resource carrying capacity (TRCC). However, the majority of previous evaluation perspectives on TRCC are limited by thresholds. This paper develops an innovative approach for assessing TRCC from the “load-carrier” perspective. TRCC is assessed by exploring the interaction between the carriers and loads of tourism resources. Chongqing city in China is employed as the case city to demonstrate the application of the established TRCC method. The conclusions are as follows: 1) This study elaborates the new connotation of TRCC from the perspective of “load-carrier”, and establishes the TRCC evaluation system based on the dynamic relationship between the carrier and load of tourism resources. 2) The proposed TRCC evaluation method is proved effective through an empirical study of Chongqing. 3) Chongqing's case unveils that the overload performance of TRCC can be dynamically monitored and predicted. By applying the TRCC evaluation methodology developed in this study, tourism managers and policymakers can identify whether it is the load or the carrier of tourism resources that affect the performance of TRCC, thereby taking targeted policy measures to eliminate potential risks of overload or underutilization. 相似文献
2.
《International Journal of Forecasting》2019,35(4):1460-1468
Team QUINKAN competed in the GEFCom2017 final match of hierarchical probabilistic load forecasting by adopting the quantile regression method using the R package quantreg. The weather stations were clustered into 11 groups, from which an optimal one was chosen for each load meter using the boosting method. The load meter records were cleaned and/or supplemented by various methods in order to secure robust quantile predictions. The variation in the regression formulas was kept as small as possible by introducing measures for suppressing prediction instability, although special formulas were employed for loading meters that were of an industrial nature. Several procedures were applied to help improve the accuracy, such as the smoothing of season transitions, coarse graining of the relative humidity, the use of load-oriented day-type definition, the averaging of weather data, and outlier removal. 相似文献
3.
本文运用有限元分析软件Midas civil和ANSYS分别建立了栈桥钢管桩的整体及局部有限元模型,分析了在浮冰冲击荷载作用下钢管柱的受力情况,为栈桥检算提供理论依据,同时优化设计方案,保证了栈桥在使用中的安全可靠。 相似文献
4.
本文对内爆荷载作用下钢筋混凝土板进行数值模拟,并对不同炸药量和爆炸距离作用下产生的爆炸峰值压力及脉冲压力大小进行数值模拟计算,然后分析板破坏过程及破坏形式,给出安全等级评估,从而为板的防爆设计加固提供一些有益的参考。 相似文献
5.
文中采用理论分析与模型构建相结合的方式,研究货运车辆的燃油消耗与运输效率之间的关系,基于调研数据,采用回归分析的方法构建模型,得到了不同车型车辆的百吨公里燃油消耗量与实载率的倒数关系模型,为企业提高车辆运输效率,降低燃油消耗提供数据参考。 相似文献
6.
吊桶是立井井筒开凿时期提升矸石和运送材料及升降人员的主要容器,吊桶的卸矸目前多采用挂钩式或座钩式卸料方式;但是随着矿井的开凿深度不断延伸,在过透水层时,由于探放水不及时或涌出水比较大,超出了井筒的排水量,或者是由于冷冻井在解冻后,井筒的井筒质量不过关,各别井壁也会发生透水事故;这就会出现淹井事故,有时淹井深度达二三百米。对于处理这种淹井事故,往往只有一个办法,那就是用沙或混凝土对井筒回填;这就需要吊桶在下到几百米下的水底自动把料卸掉,但现在矿井常用的挂钩式吊桶和座钩式吊桶已经不能满足这个需要了。 相似文献
7.
New virtual reality technology presents hotels with wide-ranging marketing, training, and customer service opportunities. The purpose of this study was to explore both the immediate and delayed effects of hotel VR commercials as compared to traditional video commercials. Based on the perceptual load theory and elaboration likelihood model, this study designed and conducted a 2 × 2 laboratory experiment with two stages of data collection. The study demonstrated that VR commercials produced better immediate effects than the traditional commercials, especially for participants with high elaboration likelihood levels. However, the findings also revealed significant decreases in purchase intention among participants watching VR commercials and a significant improvement in attitudes among participants watching traditional commercials. Both theoretical and practical implications were discussed to leverage the power of VR in marketing. 相似文献
8.
地理信息系统(Geographic Information System,GIS)和多目标算法为异构网络基站部署问题带来新的突破。ArcGIS系列是GIS专业化的管理软件,采用ArcGIS软件对包含学校、医院等场景的中国某市密集城区进行建模分析,并且提出基于目标权重因子的多目标离散粒子群算法(Multi-objective Discrete Particle Swarm Optimization algorithm based on Target Weight Factor,MDPSO/TWF),基于多个目标函数整体最优研究异构网络基站部署问题。仿真结果表明,所提的MDPSO/TWF算法具有可行性和先进性,可以综合考虑网络负载和网络能效多个优化目标,将业务需求与实际基站选址相结合,在满足业务需求的基础上尽可能达到节能的目的。 相似文献
9.
施工组织设计能有效地把施工生产合理地组织起来,使工程的设计和施工、技术和经济、前方和后方有机结合起来,它有着重要的指导作用。文章以该车站工程的施工环境、特殊条件为基础,对施工组织设计进行深入研究,并结合实际工程概况制定了有效的解决措施;该工程又将"四新"技术切实有效地融入了施工组织设计中,从而保证了建设项目优质、高产、经济和安全。 相似文献
10.
结合武汉市二七长江大桥上跨铁路工程施工过程,采用模拟计算墩梁固结临时墩的受力,结合监控资料,得出其荷载的合理取值,并总结归纳墩梁固结的多种形式,分析优缺点,提出各种形式的适用范围。 相似文献