三元吸收制冷的研究进展

氨—水和溴化锂—水是目前使用最广泛的两种二元吸收工质对，但各有缺陷，为此人们希望采用三元吸收工质克服这两种二元工质对的不足。国外许多学者对三元吸收制冷尤其是氨—水—溴化锂三元吸收制冷作了大量理论和试验研究，国内未见这方面的文献发表，该文从物性和循环两方面对这些研究作简单介绍，并对三元吸收制冷研究简单展望。     

Linear Algebra Considerations for the Multi-Threaded Simulation of Mechanical Systems

A solution method suitable for the multi-threaded simulation ofmechanical systems represented in Cartesian coordinates isproposed and analyzed. In a state-space framework for thesolution of the Differential Algebraic Equations (DAE) ofMultibody Dynamics, the position/velocity stabilization and theacceleration computation are based on iterative solvers applied toequivalent reduced problems. The most in-depth computationalaspect analyzed is the preconditioning, i.e., the direct solutionof the reduced systems. Provided a topology index reduction is first applied to the model, the effort for the direct solution of the reduced systems is shown to be of order O(N _J ), where N _J is the number of joints in the model. The recurring theme of thepaper is the central role that the topology of the mechanicalsystem plays in the overall performance of the numericalsimulation. Based on the topology of the model, parallelcomputational threads can be established to start in the equationformulation and continue through the iterative numericalalgorithms employed for the numerical solution. Task schedulingthese parallel threads is expected to redeem real-time performancefor certain classes of complex applications.     

如何加强产品质量管理工作的探讨

从人员质量意识、产品设计质量、原材料/元器件的控制、人员操作质量、产品评审力度等方面,分析质量管理工作中存在的难点,并提出相应的解决措施.     

真空钙热还原炉渣的综合利用研究

研究了从真空钙热还原炉渣中回收稀土的工艺条件；采用本工艺得到的合格稀土溶液，其回收率达65．41％；副产品氟化钙用作炼硅铁合金的助熔剂，使钙热还原炉渣得到综合利用。     

An inverse solution methodology for estimating the diffusion coefficient of gases in Athabasca bitumen from pressure-decay data

An inverse solution methodology is developed for the estimation of diffusion coefficient of gases in highly viscous, oil-sands bitumens from isothermal, pressure-decay measurements. The approach involves modeling the rate of change in pressure using the diffusion equation for the liquid phase coupled with a mass balance equation for the gas phase. The inverse solution framework is utilized to arrive at two graphical techniques for estimating the diffusion coefficient. Both techniques involve the determination of the slope of a straight line resulting from plotting the experimental data in accordance with the developed model. An advantage of the proposed techniques is that the diffusion coefficient is estimated directly, i.e. without making it an adjustable parameter. The novelty of the proposed method is in its simplicity as well as its ability to isolate portions of the pressure-decay data affected by experimental fluctuations. The effect of the initial pressure on the predicted diffusion coefficient and pressure-decay profile was also investigated. The diffusion coefficients of CO₂, CH₄, C₂H₆ and N₂ in Athabasca bitumen at 50–90 °C and about 8 MPa were estimated and compared with literature values.     

用模糊综合评判法评估钢制储罐的寿命

针对影响钢制储罐寿命的因素具有复杂性、非确定性以及时变性的特点,提出了用动态二级模糊综合评判的方法对其寿命进行评估,建立了评估的数学模型和评估流程。在对某石油库油罐的寿命分析中,考虑到保留所有评判因素的影响,采用了乘、加型模糊算子,并用层次分析法来确定评价指标权重。计算结果表明,该方法能够解决储罐寿命评估中的一些复杂因素的处理问题,具有一定的实际工程意义。     

开放的ladder型无反转激光系统的稳定性分析

利用开放的ladder型无反转激光系统的密度矩阵运动方程组的定态解和激光场运动方程分析了系统的稳定性。结果表明：如果增益大于激光腔损耗，则零解是不稳定的；如果增益小于激光腔损耗，则零解是稳定的；如果增益大于激光腔损耗，则非零解是稳定的。     

Boundary knot method for 2D and 3D Helmholtz and convection–diffusion problems under complicated geometry

The boundary knot method (BKM) of very recent origin is an inherently meshless, integration‐free, boundary‐type, radial basis function collocation technique for the numerical discretization of general partial differential equation systems. Unlike the method of fundamental solutions, the use of non‐singular general solution in the BKM avoids the unnecessary requirement of constructing a controversial artificial boundary outside the physical domain. The purpose of this paper is to extend the BKM to solve 2D Helmholtz and convection–diffusion problems under rather complicated irregular geometry. The method is also first applied to 3D problems. Numerical experiments validate that the BKM can produce highly accurate solutions using a relatively small number of knots. For inhomogeneous cases, some inner knots are found necessary to guarantee accuracy and stability. The stability and convergence of the BKM are numerically illustrated and the completeness issue is also discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

A new bubble-point-pressure correlation for the binary LiBr/H2O solution

In accord with the increasing concern about the global environmental issues, the absorption refrigeration heat-pump systems are currently being considered very promising and attractive. For the purpose of supporting the advanced R&D technology in this area, we have developed a novel correlation to represent the bubble-point pressures of LiBr H₂O solutions. The developed correlation covers the most extensive range of validity ever proposed: 273–483 K for temperatures, 0.05 kPa to 1.0 MPa for pressures. and 29 76 wt% LiBr for concentrations.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994. Boulder, Colorado, U.S.A.     

Substituted uracils as corrosion inhibitors for copper in 3% NaCl solution

Substituted uracils were tested as corrosion inhibitors of copper in 3% NaCl medium using electrochemical polarisation, impedance measurements and non-electrochemical techniques (weight loss, IR and UV-visible). This study permitted to follow the evolution of the inhibitory effect of the uracil derivatives, according to their substituents, on copper in 3% NaCl medium. Comparison of results showed that dithiouracil (DTUr) was the best inhibitor. The maximum inhibition efficiency reached 98% at 10⁻³ M. DTUr adsorbs on the copper surface according to the Frumkin isotherm model.