全文获取类型
收费全文 | 40407篇 |
免费 | 822篇 |
国内免费 | 1篇 |
专业分类
财政金融 | 7358篇 |
工业经济 | 3115篇 |
计划管理 | 6826篇 |
经济学 | 9040篇 |
综合类 | 466篇 |
运输经济 | 258篇 |
旅游经济 | 641篇 |
贸易经济 | 6381篇 |
农业经济 | 1970篇 |
经济概况 | 5098篇 |
信息产业经济 | 1篇 |
邮电经济 | 76篇 |
出版年
2021年 | 233篇 |
2020年 | 398篇 |
2019年 | 537篇 |
2018年 | 714篇 |
2017年 | 728篇 |
2016年 | 700篇 |
2015年 | 515篇 |
2014年 | 790篇 |
2013年 | 3859篇 |
2012年 | 1107篇 |
2011年 | 1204篇 |
2010年 | 990篇 |
2009年 | 1170篇 |
2008年 | 1135篇 |
2007年 | 1111篇 |
2006年 | 993篇 |
2005年 | 877篇 |
2004年 | 888篇 |
2003年 | 857篇 |
2002年 | 849篇 |
2001年 | 806篇 |
2000年 | 840篇 |
1999年 | 709篇 |
1998年 | 736篇 |
1997年 | 708篇 |
1996年 | 700篇 |
1995年 | 629篇 |
1994年 | 682篇 |
1993年 | 686篇 |
1992年 | 688篇 |
1991年 | 702篇 |
1990年 | 611篇 |
1989年 | 510篇 |
1988年 | 525篇 |
1987年 | 552篇 |
1986年 | 566篇 |
1985年 | 788篇 |
1984年 | 784篇 |
1983年 | 761篇 |
1982年 | 721篇 |
1981年 | 652篇 |
1980年 | 632篇 |
1979年 | 649篇 |
1978年 | 512篇 |
1977年 | 462篇 |
1976年 | 358篇 |
1975年 | 380篇 |
1974年 | 328篇 |
1973年 | 321篇 |
1972年 | 257篇 |
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
951.
Richard J. Cebula 《Metroeconomica》1992,43(3):397-402
This paper empirically investigates the impact of central government budget deficits upon interest rates in Italy. The period studied runs from 1955 to 1989, and annual data are used. The interest rate measure is the ex ante real rate of interest. It is found, using an instrumental variables technique to control for the endogeneity of the budget deficit, that the budget deficit raises the ex ante real interest rate in Italy. 相似文献
952.
953.
JAGDISH AGRAWAL PAMELA E. GRIMM NARASIMHAN SRINIVASAN 《The Journal of consumer affairs》1993,27(2):335-356
A quantity surcharge exists when the unit cost of a given brand is higher for a large package than for a small one. This paper examines some product and household characteristics that influence observed quantity surcharging practices. Results indicate that the propensity to buy a large package of a product is positively influenced by the extent of a household's usage of that product, procurement cost, and carrying capacity and is negatively influenced by the propensity to price search. A retailer's decision to levy a quantity surcharge is, in turn, influenced by demand for the product, the propensity to buy large packages, and to some extent the product's carrying cost. 相似文献
954.
Michael J. Gootzeit 《Metroeconomica》1993,44(2):146-166
The credit cycle implicit in Wicksell's upward cumulative process (UCP) is described. UCP may be interpreted as a stable cycle with two phases and an upper turning point corresponding to the maximum 2-rate-differential. The volume of credit and the rate of inflation is shown to expand in phase 1 and to contract in phase 2. The role of velocity increasing in causing a higher inflation rate is also described. This cycle has not been noticed in the literature because Lectures(2) was unclear about how long it would take to reach an upper turning point. But, Interest and Prices emphasized that the continuous return of the inflation rate to zero equilibrium would begin after a relatively short period. 相似文献
955.
Metallic structured packings have found increasing use in the cryogenic distillation of air. An experimental program was performed to test the flammability of selected metal packings under simulated high oxygen concentration operating conditions. Aluminum flammability in gaseous oxygen has been shown to be very dependent upon argon dilution, and in the presence of liquid oxygen, strong energy releases have been observed. Brass packing exhibited an unexpectedly high relative flammability whereas copper has been found to be non-flammable in all tested oxygen purities. These findings suggest the use of copper structured packing in higher purity GOX/LOX regions of an air separation distillation column and aluminum structured packing in the remainder of the column. 相似文献
956.
While the magnitude of potential consequences might vary, most hazards encountered in pilot plant operations are the same as those experienced in full scale commercial facilities. For example, safeguarding hazardous chemicals storage and transfer, protecting reaction vessels against catastrophic failure or runaways, all require careful consideration regardless of scale. We, however, want to address some aspects of pilot plants which can introduce hazards unique or more common to their operation. To illustrate, we present some case histories from our own pilot plant experience in BASF's Chemical Engineering Department, and include a brief discussion of some corresponding safeguards to mitigate these situations. 相似文献
957.
CHETAH, which stands for the Chemical Thermodynamic and Energy Release Program, was introduced in 1974. Since then, the CHETAH program has been widely used in the chemical industry for hazard evaluation. Although its chief aim is to predict deflagration/detonation potential from molecular structure, it can also be used to estimate heats of reaction, heat capacities, and entropies. One of the limitations of the original program was its rigid, punched card oriented format for data input and the lack of an overall hazard rating derived from the several hazard criteria. A new release of this program alleviates these shortcomings and includes other improvements. The main features of the new release are: 1) a totally interactive front end, 2) an interpreter subroutine which uses sophisticated pattern recognition techniques to combine the four hazard criteria into an overall hazard rating, 3) recognition of certain atomic groupings which are known to be sensitive, 4) correct handling of the symmetry number, and 5) an updated data bank. One of the most important features of this release is its availability in an IBM PC compatible version, making the program accessible to more users. 相似文献
958.
959.
960.
An Incident Investigation system based on a combination of Fault Tree Analysis logic and the Deming Principles of Systems and Quality was developed during a three-year period. The system was given an excellent test in the investigation of the explosion of a tank car filled with methacrylic acid. In this case, the Event Tree constructed during the investigation was easily converted into a Fault Tree. The Fault Tree so constructed was then used to evaluate the effectiveness of proposed corrective changes to the production, loading, and analytical systems before the changes were actually implemented. By making use of these tools to guide the addition of feedback loops (“And” Gates in fault Tree terminology), the intrinsic safety of the methacrylic acid production and shipping system was greatly enhanced at a relatively low cost. 相似文献