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11.
本文综述了混合拉曼/掺饵光纤放大器(HFA)的工作原理,结构和特点,介绍了4类HFA基本结构及其实验结果,并通过介绍近年来各类HFA在密集波分复用(DWDM)系统中的应用表明了HFA在带宽,增益和噪声特性方面的优点。  相似文献   
12.
近10年日本宏观经济的理论分析与展望   总被引:3,自引:1,他引:2  
近10年日本经济停滞不前,一方面对外经济状况不佳:日元对美元汇率技术下跌。且不断加剧;出口增长放缓,贸易顺差连续下滑,另一方面国内宏观经济状况严峻;失业率不断上升,内需不振;通货紧缩逐步加深;工业增长持续低迷,工业生产与效益下降,究其原因,用内外均衡模型理论分析得出,日本经济没有达到均衡的0点,内外均衡遭到了破坏,而展望今后的日本经济和日元走势,基于日本财政状况的恶化及货币政策的失效,估计还不会导致资本的大量外流。也不会对资本流动产生重要的影响,而结构改革也将可能引致日元升值。  相似文献   
13.
环保型水性上光油的研制与应用   总被引:1,自引:0,他引:1  
金振华 《化工科技市场》2003,26(3):26-27,23
目前,涂布上光技术已被越来越多的印刷厂家所采用,促使上光油的需求量不断上升。经过近几年的努力,我院研制的环保型水性上光油已取得了突破性的进展,完全能够替代溶剂型水性上光油和油性上光油,由于水性上光油具有无毒、无味、透明感强、无有机挥发物(VOC)的排放,成本低、原材料来源广等特点,在使用中能赋予印刷良好的光泽性、耐折性、耐磨性和化学品性,尤其是它所具有的环保性能特别适合食品、药品和烟草等行业包装印刷材料的加工。  相似文献   
14.
THE SQUARED ORNSTEIN-UHLENBECK MARKET   总被引:2,自引:0,他引:2  
We study a complete market containing J assets, each asset contributing to the production of a single commodity at a rate that is a solution to the squared Ornstein-Uhlenbeck (Cox-Ingersoll-Ross) SDE. The assets are owned by K agents with CRRA utility functions, who follow feasible consumption/investment regimes so as to maximize their expected time-additive utility from consumption. We compute the equilibrium for this economy and determine the state-price density process from market clearing. Reducing to a single (representative) agent, and exploiting the relation between the squared-OU and squared-Bessel SDEs, we obtain closed-form expressions for the values of bonds, assets, and options on the total asset value. Typical model parameters are estimated by fitting bond price data, and we use these parameters to price the assets and options numerically. Implications for the total asset price itself as a diffusion are discussed. We also estimate implied volatility surfaces for options and bond yields.  相似文献   
15.
A survey was conducted in Lilongwe city urban markets in Malawi, to assess the quality of cooking oil used for frying potato chips. Purposive sampling was performed to come up with respondents who were using vegetable oils. A stratified random sampling was used to select the 32 informal food processors who were interviewed using a structured questionnaire. Oil samples were collected from the most commonly used brand of oil. Fifteen respondents were selected and these were divided into three categories of five: those who were not reusing the oil, those who were reusing the oil and those who were preparing potato chips and chicken in the same oil, for chemical analysis. The preliminary results showed that while the majority (59.4%) of the informal food processors discarded the oil after 1 day, 3.1% discarded it after 4 days and another 12.5% after 3 days. A larger proportion of the respondents (40.6%) used the leftover oils at home, 37.5% kept it in oil bottles, 3.1% kept it in plastic papers for reuse the following day. Also, most respondents (57%) indicated dark colour as the sign of oil deterioration, 29% discarded the oil after noticing foam formation while 8.2% and 6.1% said they discarded the oil after noticing a bad smell and food absorbing the oils respectively. A physical observation of the various oils showed that for most of the respondents (34%), the oils were dark brown in colour, in 22%, the oils were slightly dark brown and 16%, the oils were brown. Foam formation was noticed in 13% of the respondents. It was also noted that 91% of the respondents had not been trained or briefed of food quality and safety issues. A chemical analysis of the oils showed high values of free fatty acids (range, 0.84–1.4112 compared with 0.42 in the fresh oil) and peroxide values (range 14.7–16.6 compared with 9.0 in the fresh oil). It may be concluded that the oils being used by the informal food processors in Malawi are of poor quality and so the foods cooked in them may be a health hazard to the consumers and the processors themselves. Although this work in ongoing, it may be recommended at the outset that the health department of the city assemblies should inspect these oils for the good health of the consumers.  相似文献   
16.
17.
Reductions in international interest rates are a major cause of capital flows to emerging economies. Increases in domestic interest rates are a frequent policy response to the resulting price increases. This is often unsuccessful. The paper suggests a theoretical explanation based on distinctive features of emerging financial markets, including imperfect asset substitutability and imperfect capital mobility for some sectors of the economy. It concludes that the appropriate policy response to capital inflows may be lower interest rates.  相似文献   
18.
The oil exporting countries have experienced a relatively continuous fall in GDP per capita over the last 30 years. This is in spite of benefiting from a more than average of the rest of the world investment rate. The findings of this paper, report a lower level of financial development for the oil economies when compared with the rest of the world. We will show in this paper that the higher rate of investment of the oil economies can be explained mainly by the oil revenues and surprisingly, financial development has a net dampening effect on investment for these economies. The paper also shows that the weakness of financial institutions, contributes to the poor performance of economic growth of the oil economies and the weakness of financial institutions might be associated with the dominant role of government in total investment and the weakness of private sector.  相似文献   
19.
Understanding the Large Negative Impact of Oil Shocks   总被引:1,自引:0,他引:1  
This paper offers a plausible explanation for the close link between oil prices and aggregate macroeconomic performance in the 1970s. Although this link has been well documented in the empirical literature, standard economic models are not able to replicate this link when actual oil prices are used to simulate the models. In particular, standard models cannot explain the depth of the recession in 1974–75 and the strong revival in 1976–78 based on the oil price movements in that period. This paper argues that a missing multiplier-accelerator mechanism from standard models may hold the key.  相似文献   
20.
Many regions have experienced long-run economic fluctuations generated by the life cycles of their dominant industrial clusters. During the downswings in the 1970s and 1980s, proactive structural policies were typically launched in German regions to combat job losses in their core clusters and to create new jobs in new industries. With respect to the German State of Bremen, this paper provides empirical evidence of: (1) a long-run regional downswing; (2) the potential job effects of proactive regional industrial policy programmes in terms of increasing regional employment, by safeguarding jobs in the regional core industries and creating new jobs in new growth industries; and (3) a time pattern in the job effects, which are related to the different generations of programmes.  相似文献   
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