We investigate the performance of a class of endoreversible-combined refrigeratkm cycles operating between a low-temperature heat reservoir at TL and a high-temperature heat reservoir at TH, and derive the optimal configuration and the rdation between the optimal coefficient of performance and the rate of refrigeration of these cycles. It is shown that the relation is similar to that of an optimal endoreversible refrigeration cycle. However, it is worth noticing that the overall heat resistace of a combined endoreversible refrigeration cycle is not identical with that of a single one, so that they are somewhat different from each other in performance. Simukaneously, it is pointed out that some performances of an endoreversible refrigeration cycle are quite different from those of an endoreversibIe power cycle.

A detailed study on global oceanic precipitation is carried out using the simultaneous TOPEX and TMR (TOPEX Microwave Radiometer) data. It is motivated by he success of a series of feasibility studies based on a few years of TOPEX TMR data, and the availability of a deeade-Iong new dataset thai spans I992-2002. In this context, a previously proposed rain probability index is improved by taking into account the dirtfference ol the dynamic range of the TOPEX-measured backscatter coefficients at the Ku and C hands and the lalitudinally complementary sensitivities of the TOPEX and TMR rain detections, leading to a refined joint precipitation index, which is generally consistent and quantitatively comparable with existing precipitation ciimatologies from the Global Preelpitation Climatology Project (GPCP) and the Comprehensive Ocean-Atmosphere Data Set (COADS). The new TOPEX-TMR precipitation climatology, on the one hand. confirms the fundamental features of global oceanic rainfall with additional details, and, on the other hand, reveals a number of interesting characteristics that are previously unknown or pnorly defined. 1) The spatial variability of the western Pacific "rain pool" (the atmospheric counterpart of the oceanic warm pool) is characterized by an interannual zonal migration, an annual cycle of meridional seesaw, and a semiannual cycle of expansion and shrinking. 2) The Pacific, Atlantic, and Indian Ocean interropical convergence zones (ITCZs) all have all annual cycle of cross-basin oscillation with east and west slops in JJA and DJE respectively. 31 A well-defined prominent rainy zone is observed in the southeast China Seas sound Taiwan Island, connecting with the Pacific rain pool in the south. 4) Between El Nifio and La Nina years, there is a systematic sign reversal of the geographical distribution of precipitation anomaly, which exists globally rather than in the tropical oceans only. 5) On a global basis, interannual and annual precipitation variabilities are of the same magnitude, bul the interannual (annual) com-ponent is more important for the Southern (Northern) Hemisphere. 6) For the tropical oceans, "season" defined by rainfall usually has a one quarter delay with respect to the coaesponding meteorological season. For the "'marine deserts" in the subtropical oceans, however, the raln-based season is found to be anticorrelated with the meteorological season. In addition, the annual cycle of the Atlantic precipitation is nearly 180 out of phase with respeet to thin of the Pacific and Indian Ocean for the same hemisphere.

In this paper, the equivalent combined systems of three-heat-source heat pumps are studied. It is pointed out that there may be three combined ways for us to conceive a reversible three-heat-source heat pump as a combined system having a reversible Carnot heat pump driven by a reversible Carnot engine. Whereas for an endoreversible three-heat-source heat pump affected by the heat resistances, there is only one combined way for us to conceive it as a combined system having an endoreversible Carnot heat pump driven by an endoreversible Carnot engine. Then, the fundamental optimum formula of a three-heat-source heat pump is derived simply and directly by using those of two-heat-source cycles. The optimal peformance of an endoreversible three-heat-source heat pump is thus discussed. The inherent relation between the two-and the three-heat-source cycles as well as the fundamental distinction between the reversible and the endoreversible three-heat-source cycles is also revealed. These results may enrich the theory of finite time thermodynamics, and provide some new theoretical bases for the exploitation and application of three-heat-source apparatus such as chemical heat pumps, absorption heat pumps, and so on.

The thermostatistic properties of a q-generalized boson system trapped in an n-dimensional harmonic oscillator potential are studied, based on the generalized statistic distribution derived from Tsallis' entropy. The density of states, total number of particles, critical temperature at which Bose-Einstein condensation occurs, internal energy, and heat capacity at constant volume are derived. The characteristics of Bose-Einstein condensation of the system are discussed in detail. It is found from the results obtained here that the thermostatistic properties of such a system depend closely on parameter q, dimensional number of the space, and frequency of the harmonic oscillator; and the external potential has a great influence on the thermostatistic properties of the system.

The thermodynamic properties of a q-generalized ideal boson system with the general energy spectrum ε=aps in a D-dimensional space are investigated, based on the q-generalized statistical distributive function derived by Tsallis entropy. Several important parameters of the system such as the critical temperature tha Bose-Einstein condensation (BEC) occurs, the specifie heat at constant volume, etx. are derived analytically. It is found that the conditions that BEC may occur and the continuity of the specific heat at critical temperature are the same as those of an ordinary boson system. However, the thernodynamic properties of a q-generalized ideal boson system are closely depend on q and D/s and consequently there are some novel results.