首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5294篇
  免费   175篇
财政金融   733篇
工业经济   207篇
计划管理   993篇
经济学   1101篇
综合类   26篇
运输经济   36篇
旅游经济   49篇
贸易经济   1465篇
农业经济   81篇
经济概况   303篇
水利工程   226篇
信息产业经济   1篇
邮电经济   248篇
  2023年   54篇
  2022年   46篇
  2021年   78篇
  2020年   106篇
  2019年   131篇
  2018年   281篇
  2017年   279篇
  2016年   305篇
  2015年   210篇
  2014年   268篇
  2013年   677篇
  2012年   291篇
  2011年   283篇
  2010年   293篇
  2009年   266篇
  2008年   232篇
  2007年   193篇
  2006年   125篇
  2005年   123篇
  2004年   98篇
  2003年   96篇
  2002年   96篇
  2001年   71篇
  2000年   83篇
  1999年   40篇
  1998年   45篇
  1997年   31篇
  1996年   40篇
  1995年   27篇
  1994年   30篇
  1993年   23篇
  1992年   19篇
  1991年   25篇
  1990年   24篇
  1989年   22篇
  1987年   15篇
  1986年   19篇
  1985年   22篇
  1984年   18篇
  1983年   26篇
  1982年   25篇
  1981年   22篇
  1980年   18篇
  1979年   21篇
  1978年   14篇
  1977年   15篇
  1976年   23篇
  1975年   17篇
  1974年   15篇
  1971年   16篇
排序方式: 共有5469条查询结果,搜索用时 0 毫秒
91.
92.
93.
Since the turn of the millennium, stocks of foreign reserves held by central banks in many emerging markets and developing countries have exceeded currency in circulation. To steer money market rates, these central banks have been absorbing liquidity from, rather than providing it to, the banking sector in their regular monetary policy operations. When interest rates in countries with major reserve currencies are low, the yield on foreign reserves is low. A higher interest rate on liquidity‐absorbing operations may expose central banks to losses. Although a central bank is not a profit‐maximizing institution, central bank losses can undermine the independence of the central bank. Using data for a large panel of central banks, this paper provides some evidence that central banks tend to apply low‐remunerated reserve requirements when profitability is at stake.  相似文献   
94.
95.
Trend Assessment by the Innovative-Şen Method   总被引:1,自引:0,他引:1  
Hydro-meteorological time series may include trend components mostly due to climate change since about three to four decades. Trend detection and identification in a better and refined manner are among the major current research topics in water resources domain. Even though different methodologies can be found for trend detection in literature, two well-known procedures are the Mann-Kendall (MK) trend test and recently innovative-?en trend method, which provides different aspects of the trend. The theoretical basis and application of these two methods are completely different. The MK test gives a holistic monotonic trend without any categorization of the time series into a set of clusters, but the innovative-?en method is based on cluster and provides categorical trend behavior in a given time series. The main purpose of this paper is to provide important differences between these two approaches and their possible similarities. The applications of the two approaches are given for hydro-meteorological records including relative humidity, temperature, precipitation and runoff from Ergene drainage basin in the north-western part of Turkey. It is observed that although MK trend test does not show significant trend almost in all the cases, the innovative-?en approach yields trend categorizations as “very low”, “low”, “medium” “high” and “very high”, which should be taken into consideration in future flood (“very high”) and drought (“very low”) studies.  相似文献   
96.
In Turkey, the empirical results on the link between financial development and economic growth are mixed. The existing studies do not take into account the fact that Turkey has experienced endemic political and economic instabilities over extended periods. This study aims to analyse the role of macroeconomic instability and public borrowing on the finance–growth nexus in Turkey by using time series econometric techniques over the 1980–2010 period. In doing so, we attempt to extend the existing literature by taking into account the role of macroeconomic instability as well as public borrowing. Our results reveal that there are additional – albeit indirect – channels between finance and growth via the effects of macro instability and public borrowing on financial development and economic growth. After taking into account the effects of overall instability and public borrowing, we found that growth–financial development relationship is bidirectional and permanent. In other words, in Turkish case, economic growth and financial development are jointly determined. Thus, our results shed some light on the ambiguity of the evidence on the link between financial development and economic growth for Turkey.  相似文献   
97.
The case of German reunification has been subject to extensive research on earnings inequality and labour market integration. However, little is known about the development of equality of opportunity (EOp) in East and West Germany after 1990. Using German micro data, we empirically analyse how circumstances beyond the sphere of individual control relate to inequality in East and West Germany. Our results show that EOp is larger in East than in West Germany. However, despite increasing income inequality, EOp remained surprisingly constant.  相似文献   
98.
Aims: To model direct medical costs associated with reductions in cardiovascular disease (CVD) events in T2DM patients reported in the CANVAS and EMPA-REG trials, which assessed the cardiovascular safety of canagliflozin and empagliflozin, respectively.

Materials and methods: Costs were modeled from a US managed care organization (MCO) perspective for the CVD outcomes included in both trials: three-point major adverse cardiovascular event (MACE) and its components (cardiovascular-related death, nonfatal myocardial infarction, nonfatal stroke), as well as heart failure requiring hospitalization. The rate of CVD events averted (difference between study drug and placebo) was projected to the portion of an MCO T2DM population matching the respective trial’s inclusion criteria. A targeted literature search for paid amounts directly associated with each CVD event provided the unit costs, which were applied to the projected number of events averted, to calculate costs avoided per member per year (PMPY). One-way sensitivity analyses were performed on events averted, unit costs, and percentages of trial-applicable patients.

Results: Based on three-point MACE events averted, costs avoided PMPY of $6.17 (range: $1.27–$10.94) for CANVAS and $2.75 ($0.19–$4.83) for EMPA-REG were estimated. Costs avoided for individual components of MACE ranged from $0.77 to $3.84 PMPY for CANVAS and from -$0.97 (additional costs) to $1.54 for EMPA-REG. PMPY costs avoided for heart failure were $2.72 for CANVAS and $1.32 for EMPA-REG.

Limitations and conclusions: Models assumed independent, non-recurrent outcomes and were restricted to medical costs directly associated with the trial-reported events. The reductions in CVD events in T2DM patients reported for both CANVAS and EMPA-REG project to a positive cost avoidance for these events in an MCO population. The analysis did not include an assessment of the impact on total cost, as the costs associated with adverse events, drug utilization or other clinical outcomes were not examined.  相似文献   

99.
ABSTRACT

Using new technologies in customer interactions is a popular way of trying to increase customer engagement. It is, however, unknown how such efforts by marketers’ affect engagement, and particularly to what that engagement relates to. By analysing interview and observation data, the engagement manifestations of customers of a B2B company using virtual-reality technology were studied. The results show that customer engagement can be targeted at not only brands or firms but also the service the firm offers or the technology that enables the service. It is argued that the different objects of engagement can coexist and support each other but engagement with the firm is less susceptible to fluctuations. Marketers should be aware of what triggers customer engagement and what it is targeted at.  相似文献   
100.
Since combustible wastes usually consist of biogenic (e.g. paper, wood, food waste) and fossil organic matter (plastics), their thermal recovery results in climate neutral and climate relevant CO2 emissions. Moreover, the fraction of biogenic materials in the waste feed is relevant for the amount of renewable energy produced. The latter has to be reported and might be subsidized according to national laws (e.g. based on European directive 2009/28/EG). The present study represents the first comprehensive evaluation of the share of biogenic and fossil materials in the waste feed of waste-to-energy (WTE) plants on a national basis. The Balance Method, which is patented on a European level by TU Wien, was applied to 10 out of 13 Austrian WTE plants (around 2.3 Mio tons of waste corresponding to around 88 % of the overall waste feed in Austrian WTE plants). The method is based on the mathematical reconciliation of the material properties (e.g. mean chemical composition of biogenic and fossil materials) and routinely recorded operating data of WTE plants (e.g. flue gas volume, CO2 and O2-content in the dry flue gas, steam production). The results demonstrate large variations for the share of energy from biogenic sources in the different WTE plants, ranging from 35.7 ± 2.4 % to 61.2 ± 2.7 % (based on annual averages). Additionally, for several WTE plants large temporal variations can be observed based on monthly mean values. Thus, a plant-specific and continuous evaluation of the waste composition in WTE plants (which the Balance Method allows to do at reasonable efforts) can be recommended for a reliable reporting of the renewable share of energy or fossil CO2 emissions from waste incineration. The energy input which stems from fossil and biogenic sources can be estimated to 11,450 ± 120 TJ and 10,730 ± 110 TJ, respectively for the year 2014 (for the 10 WTE plants). In total 1060 ± 24 kt fossil CO2 emissions from the thermal recovery of waste in Austria’s WTE plants in 2014 could be determined (estimation for all 13 WTE plants).  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号