Studies on the Thermodynamics and Thermal Chemistry Properties for Lithium Salts and Their Aqueous Solution Systems

1 Introduction With the industrial development of lithium battery,nuclear and aerospace industry,the demands of metal lithium and its compounds are increasing significantly.Lithium is called as the energy of the metal in the new century(Zhang et al.2001).The total reserve of lithium resources around the world7

Nuclear geyser model of the origin of life:Driving force to promote the synthesis of building blocks of life

We propose the nuclear geyser model to elucidate an optimal site to bear the first life.Our model overcomes the difficulties that previously proposed models have encountered.Nuclear geyser is a geyser driven by a natural nuclear reactor,which was likely common in the Hadean Earth,because of a much higher abundance of 235U as nuclear fuel.The nuclear geyser supplies the following：（1）high-density ionizing radiation to promote chemical chain reactions that even tar can be used for intermediate material to restart chemical reactions,（2）a system to maintain the circulation of material and energy,which includes cyclic environmental conditions（warm/cool,dry/wet,etc.）to enable to produce complex organic compounds,（3）a lower temperature than 100℃ as not to break down macromolecular organic compounds,（4）a locally reductive environment depending on rock types exposed along the geyser wall,and（5）a container to confine and accumulate volatile chemicals.These five factors are the necessary conditions that the birth place of life must satisfy.Only the nuclear geyser can meet all five,in contrast to the previously proposed birth sites,such as tidal flat,submarine hydrothermal vent,and outer space.The nuclear reactor and associated geyser,which maintain the circulations of material and energy with its surrounding environment,are regarded as the nuclear geyser system that enables numerous kinds of chemical reactions to synthesize complex organic compounds,and where the most primitive metabolism could be generated.

NUMERICAL MODELING OF CUMULUS CLOUD CHEMISTRY—PART Ⅱ:THE IMPACT OF CUMULUS CLOUD PROCESSES ON OZONE CHEMISTRY

Ozone chemistry processes are analyzed during a cumulus cloud process with the model (1CCCM)described in Part Ⅰ.The simulation results show that entire cumulus cloud process can be well described with the development of vertical velocities and liquid water content which are the two most outstanding features of cumulus clouds.Ozone chemistry is strongly influenced by cumulus clouds.NO_x can be transported upwards above 4 km in the first 20 minutes of the convection event and form a relative higher concentration area which enhances the production of ozone.Two areas ap- pear during the convection event:area of net ozone production and area of net ozone depletion.The area of ozone depletion coincides with the area of liquid water within cloud.Results show that the aqueous phase(cloud water and rainwater)can alter gas ozone level through two ways:one is scav- enging free radicals(HO_2)from the gas phase and thereby inhibiting the reactions of transformation to NO_2 from NO,which results in reduction of the gas source of ozone;the other is aqueous phase chemical reactions which consume ozone in the aqueous phase.Calculations reveal that the reaction O_3 +OH→HO_2 is the main pathway of ozone depletion in gas phase during the process of cumulus clouds.

NUMERICAL MODELING OF CUMULUS CLOUD CHEMISTRY—PART Ⅰ.MODEL DEVELOPMENT

A one-dimensional cumulus cloud chemistry model(1CCCM)is developed to simulate cloud physical processes and chemical processes during the evolution of a convective cloud.The cloud physical submodel includes a detailed microphysical parameterized scheme of 20 processes.The chemistry submodel is composed of three parts:gas phase chemistry,aqueous phase chemistry and scavenging of soluble gases.The gas phase reaction mechanism contains 85 reactions among 45 species including 13 organics.The aqueous phase reaction mechanism contains 54 reactions among 40 species and 12 ion equilibria.Mass of 19 gases is transported between the gas phase and the aqueous phase.With this model,studies may be made to analyze the interactions among processes during lifetime of a cumulus cloud.