氟硅酸泵的国产化实践

硅氟酸极具腐蚀性 ,考虑到经济性 ,2 0 #合金、哈氏合金、蒙乃尔等贵金属很少被选为泵材。由于橡胶、塑料等高分子材料具有很好的抗蚀性和一定的机械性能 ,且价格便宜 ,因此一般选用其作为泵体材料。我们通过分析、比较 ,成功选择国产氟硅酸泵替代国外进口泵 ,实现国产化。     

预防液化石油气储罐应力腐蚀的初探

液化石油气储罐在工业和人民生活中有着广泛的应用,探讨液化石油气中所含H2S腐蚀介质对储罐的应力腐蚀及预防措施显得非常重要。     

How to get firms to invest: A simple solution to the hold-up problem in regulation

Abstract. Many governmental programs are effective only if firms make costly investments. The inability of authorities to precommit to a regulatory scheme creates incentives for firms not to invest and to hold-up the regulator. This paper describes a simple subsidy/tax scheme embedded in a four-stage mechanism that solves the hold-up problem. We design a self-financing subsidy/tax scheme which benefits a complying firm at the expense of a non-complying firm. In order to be credible, the subsidy and tax rates must maximize social welfare for any combination of investment decisions. We show that there exists a unique subgame perfect equilibrium in which all firms invest and no actual implementation with subsidies and taxes is required. We discuss in which cases the mechanism can work under incomplete information. Received: 30 December 1998 / Accepted: 12 October 2001     

Central governance or subsidiarity: A property-rights approach to federalism

We consider a model where one region in a federation can realize a public project after undertaking value-increasing investments. While negotiations on the federal level ensure that an efficient project size is implemented in equilibrium, non-contractibility of investments causes the overall outcome to differ across regimes. If the region bears the entire implementation costs of its policies, underinvestment prevails and subsidiarity (centralized governance) is superior when spillovers are weak (strong). Conversely, if linear cost sharing arrangements are feasible, decentralized authority often admits a socially optimal outcome while centralized authority (with majority or unanimity rule) does not.     

A spatial tax harmonization model

Policies to harmonize value-added tax rates are controversial in the European Union. This paper formulates a multi-country model over a one-dimensional space as a non-cooperative Nash game, in which each country aims at maximizing its tax revenue, subject to the constraint that its tax rate lies within a given common band. Then we examine the effects of changes in the common band on tax rates, tax revenues and the number of cross-border shoppers at Nash equilibrium. We also analyze the effects of geographical variation in country size and location.     

The dynamics of moonlighting in Russia1

This paper uses the Russian Longitudinal Monitoring Survey (RLMS) to analyse the dynamics of moonlighting by the working‐age population. We find that moonlighting is transitory and that a desire to switch jobs expressed in the past is positively related to moonlighting in the present and to actual job changes in the future. We also find that workers who moonlighted as self‐employed in the past represent 26.5 percent of the new self‐employed. These results suggest that moonlighting in Russia can be seen as an effective incubator for setting up new self‐employed businesses, thereby providing long‐term benefits for the economy.     

Are stationarity and cointegration restrictions really necessary for the intertemporal budget constraint?

Time series related to fiscal and external deficits are commonly subjected to stationarity and cointegration tests to assess if the deficits are sustainable. Such tests are incapable of rejecting sustainability. The intertemporal budget constraint proves to be satisfied if either the debt series or the revenue and with-interest spending series are integrated of arbitrarily high order, i.e., stationary after differencing arbitrarily often. Revenues and spending do not have to be cointegrated. Rejections of low-order difference-stationarity and of cointegration are thus consistent with the intertemporal budget constraint. Error-correction-type policy reaction functions are suggested as more promising for understanding deficit problems.     

Cr3+-H3PO4光度法测定磷酸体系中的Cr3+

Cr3 与H3PO4生成绿色配合物,其最大吸收峰在660nm,摩尔吸光系数为1.4×102L·mol-1·cm-1,Cr3 在0～0.5mg/30ml范围内符合比尔定律,用加入法直接测定磷酸体系中的Cr3 ,结果满意。     

Trends in British public investment

British public investment has declined sharply both as a share of GDP and as a share of government spending since the 1970s. Only part of this decline is explained by privatisation, which transferred some public investment to the private sector. More important was the very large and permanent reduction in public house‐building between the mid‐1970s and the early 1980s. Between the late 1980s and the early 1990s, the rate of public investment recovered somewhat, but after that time it declined again, reaching a record low in 1999. The most recent decline in public investment has affected a range of central government programmes, and it has not been significantly offset by investment under the Private Finance Initiative. The government now plans to increase investment spending, although levels look set to remain low by historical standards for some time to come.     

The future of social security

We analyze the effect of the projected demographic transition on the political support for social security, and equilibrium outcomes. Embedding a probabilistic-voting setup of electoral competition in the standard OLG model with capital accumulation, we find that intergenerational transfers arise in the absence of altruism, commitment, or trigger strategies. Closed-form solutions predict population ageing to lead to higher social security tax rates, a rising share of pensions in GDP, but eventually lower social security benefits per retiree. The response of equilibrium tax rates to demographic shocks reduces old-age consumption risk. Calibrated to match features of the U.S. economy, the model suggests that, in response to the projected demographic transition, social security tax rates will gradually increase to 16%. Other policies that distort labor supply will become less important; labor supply therefore will rise, in contrast with frequently voiced fears.