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THE PHYSICAL ENTROPY OF SINGLE CONSERVATION LAWS

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Journal of Computational Mathematics 1998年第5期16卷 437-444页

作者： (department of Mathematics, peking University, beijing 100871,{3.) beijing Univ Dept Math Beijing 100871 Peoples R China

By means of the comparisons with the formulas in statistical mechanics and thermodynamics, in this paper it is demonstrated that for the single conservation law partial derivative(t)u + partial derivative(x)f(u) = 0, if the flux function f(u) is convex (or concave), then, the physical entropy is S = -f(u); Furthermore, if we assume this result can be generalized to any f(u) with two order continuous derivative, from the thermodynamical principle that the local entropy production must be non-negative, one entropy inequality is derived, by which the O.A. Olejnik's famous E- condition can be explained successfully in physics.

关键词： conservation laws entropy entropy production

Dehydration melting of solid amphibolite at 2.0 GPa: Effects of time and temperature

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Science china Earth sciences 2005年第8期48卷 1120-1133页

作者： ZHOU Wenge1, XIE Hongsen1, LIU Yonggang1, ZHENG Xiaogang1, ZHAO Zhidan2 & ZHOU Hui3.1. Laboratory of Material in the Earth’s Interior, Institute of Geochemistry, Chinese Academy of sciences, Guiyang 550002, china 2. department of Geology, china University of Geosciences, beijing 100083. china 3. department of Geology, peking University, beijing 100871, china 1. Laboratory of Material in the Earth’s Interior Institute of Geochemistry Chinese Academy of Sciences 550002 Guiyang China 2. department of Geology China University of Geosciences 100083 Beijing China 3. department of Geology Peking University 100871 Beijing China

Two sets of dehydration-melting with a natural solid amphibolite, collected from North Himalayan structure zone, Tibet, have been carried out in multi-anvil apparatus at 2.0 GPa and 800―1000℃, for 12―200 h. One is keeping the pressure at 2.0 GPa and the annealing time of 12 h, changing the temperature (800―1000℃). The other is keeping the pressure at 2.0 GPa and temperature at 850℃, varying the annealing time (12―200 h). The products are inspected with microscope and electron probe. The results indicate that at 2.0 GPa, annealing time of 12 h, garnets, melts and clinopyroxenes occur in amphibolite gradually with increasing temperature and the chemical compositions of melt vary from tonalite to granodiorite, and then to tonalite. However, at 2.0 GPa and 850℃, with the annealing time increasing, the garnets, melts and cli-nopyroxenes also occur in amphibolite gradually and the chemical compositions of melt vary from tonalite to granodiorite. In both cases, melts interconnect with each other when the contents of melt are over the 5 vol.%. the viscosities of the melt produced in amphibolite at temperature higher than 850℃ are on a level with 104 Pa·s. The interconnected melt with such a viscosity may segregate from the source rock and form the magma over reasonable geological time. Therefore, it is believed that at the lower part of the overthickened crust, the tonlitic and grano-dioritic magma may be generated through the dehydration melting of amphibolite.

关键词： solid amphibolite, high pressure, high temperature, time, partial melting.

Abrupt climate change and collapse of ancient civilizations at 2200BC-2000BC

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Progress in Natural Science:Materials International 2005年第10期15卷 46-52页

作者： WANG Shaowu (department of atmospheric Science, School of Physics, peking University,{3., china) department of atmospheric Science School of Physics Peking University Beijing 100871 China

Plentiful evidence of historical, archaeological and palaeoclimatic studies proved that an abrupt change from wetter to drier climate occurred over the Nile Valley,the Mesopotamia, the Indus Valley and Huanghe River Valley at 2200BC-2000BC. The abrupt change was developed based on the general lowering of temperature in the middle latitudes, and was a strong cold event since the beginning of the Megathermal (8.5-3.0 kaBP). Collapse of Nile civilization appeared at the First Intermediate Period (2181BC-2040BC). Civilization of Mesopotamia began collapse following the disintegration of Akkadian Empire. This process lasted to the foundation of Babylon Kingdom from 2200BC to 1900BC. Indus civilization abruptly fell off at 1800BC. A widespread alternation of archaeological cultures happened in china at ca. 2000BC except only in its central part. Longsheng culture was replaced by the Erlitou culture, which is now acknowledged in china as Xia Culture. Foundation of Xia Dynasty at 2070BC opened a new chapter in the development of Chinese civilization. Studies indicated that abrupt climate change may be caused by the weakening of the Thermohaline Circulation (THC).

关键词： 2200BC-2000BC abrupt climate change collapse of ancient civilization.

Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

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Science china Earth sciences 2006年第5期49卷 554-560页

作者： FAN Ke1,2,3.& WANG Huijun2 1. Nansen-Zhu International Research Center, Institute of atmospheric Physics, Chinese Academy of sciences, beijing 100029,{3. 2. department of atmospheric Science, Yunnan University, Kunming 650091,{3. 3. Graduate University of the Chinese Academy of sciences, beijing 100049,{3. 1. Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. department of atmospheric Science Yunnan University Kunming 650091 China 3. Graduate University of the Chinese Academy of sciences Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

Characteristics of vertical ozone distribution in the lower troposphere in the Yangtze River Delta at Lin'an in the spring of 2001

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Science china Earth sciences 2005年第9期48卷 1519-1528页

作者： ZHENG Xiangdong1, CHAN Chuenyu2, CUI Hong2, QIN Yu3. CHAN Loyan2, ZHENG Yongguang3.& LEE Yusiang2 1. Chinese Academy of Meteorological sciences, beijing 100081, china 2. {3. of Civil and Structural Engineering, Hong Kong Polytechnic University, Hung Hom, Hong Kong, china 3. department of atmospheric sciences, peking University, beijing 100871, china 1. Chinese Academy of Meteorological sciences 100081 Beijing China 2. department of Civil and Structural Engineering Hong Kong Polytechnic University Hung Hom Hong Kong China 3. department of atmospheric sciences Peking University 100871 Beijing China

We analyzed vertical distributions of ozone (O3. in the lower troposphere (< 5 km above ground) at Lin’an (119.75°E, 3..3.°N), Zhejiang Province using electrochemical concen- tration cell (ECC) ozonesonde data obta... 详细信息

We analyzed vertical distributions of ozone (O3. in the lower troposphere (3..3.°N), Zhejiang Province using electrochemical concen- tration cell (ECC) ozonesonde data obtained from February 21 to April 13. 2001. The results showed that the vertical O3.distributions are controlled by metrological conditions and the char- acteristics of O3.profiles are related to those of wet bulb potential temperature and wind field. O3.below 2 km showed that the strongest variability and enhanced O3.mixing ratios were associated with easterly winds that blow pollutants from the upwind source region of the Yangtze River Delta (YRD) region. Vertical O3.profiles below 5 km can be grouped into 5 categories: (1) peak mixing ratio type, (2) well-mixed type, (3. layered-structure type, (4) episodic pollution type and (5) alti- tudinal increasing type. Vertical distributions of O3.affected by regional transport of polluted air masses were investigated. Transport of polluted air from high latitudes of northern china, ac- companying subsiding motion of air and stagnant atmospheric conditions are important factors that lead to high mixing ratios of O3.at Lin’an. The stagnant atmospheric conditions associated with a continental high pressure system and pollution plume transported from the YRD and cen- tral-eastern china also lead to regional accumulation of O3.and high O3.mixing ratio at Lin’an. Long-range transport of O3.and pollutants from the Pearl River Delta in South china and in-situ O3.formation also resulted in elevated O3.mixing ratios at around 1 km altitudes and layered O3.distribution in the lower troposphere.

关键词： vertical ozone distribution, lower troposphere, Yangtze River Delta, Lin'an.

Petrogenesis of Songshugou dunite body in the Qinling orogenic belt, Central china: Constraints from geochemistry and melt inclusions

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Science china Earth sciences 2005年第8期48卷 1146-1157页

作者： SU Li1,2, SONG Shuguang3.& ZHOU Dingwu1 1. Key Laboratory of Continental Dynamics of the Ministry of Education, department of Geology, Northwestern University, Xi’an 710069, china 2. The Geological Lab Center, china University of Geo{3. (beijing), beijing 100083. china 3. Key Laboratory of Orogenic Belts of the Ministry of Education, department of Geology, peking University, beijing 100871, china 1. Key Laboratory of Continental Dynamics of the Ministry of Education Department of Geology Northwestern University 710069 Xi’an China 2. The Geological Lab Center China University of Geosciences 100083 (Beijing)Beijing China 3. Key Laboratory of Orogenic Belts of the Ministry of Education Department of Geology Peking University 100871 Beijing China

The Songshugou dunite body, which occupies an area of about 20 km2, is the largest ultramafic massif in the eastern Qinling orogenic belt, Central china. The major compo-nent of this body is dunitic rocks including mylonitic dunite and coarse-grained dunite; they oc-cupy about 95 vol% of the total body. Petrography, mineral composition, major and trace ele-ments and primitive melt inclusions have been investigated in this paper; all revealed that this dunite body is the product of melt-rock interaction by porous percolation flow. In comparison with dunite sills or veins in harzburgite from the basal part of Oman ophiolite, this dunite body is characterized by lower contents of Al2O3. CaO and HREE but higher content of highly incom-patible elements and Zr and Hf. The LREE enriched patterns and primitive mantle normalized spidergrams of trace elements are also different from the Oman dunite. Combining with melt in-clusions observed in olivines, we conclude that this dunite body is the product of large- scale porous percolation flow of high-MgO melts within depleted mantle peridotites. The high-MgO magma, in essence, was most probably produced at the hot head of an upwelling mantle plume. The occurrence of the Songshugou dunite body is closely associated with the activity of mantle super-plume in Neo-Proterozoic era in the Yangtze Craton.

关键词： Songshugou dunite body, geochemistry, melt inclusion, mantle plume, Qinling orogenic belt.

Status of study on biological and toxicological effects of nanoscale materials

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Science china Chemistry 2005年第5期48卷 385-394页

作者： WANG Bing1, FENG Weiyue1, ZHAO Yuliang1, XING Gengmei1, CHAI Zhifang1, WANG Haifang2 & JIA Guang3.1. Laboratory for Bio-Environmental Health sciences of Nanoscale Materials (Nanosafety Lab), Institute of High Energy Physics, Chi-nese Academy of sciences, beijing 100049,{3. 2. College of Chemistry and Molecular Engineering, peking University, beijing 100871,{3. 3. department of Occupational and Environmental Health sciences, School of Public Health, peking University, beijing 100083.{3. 1. Laboratory for Bio-Environmental Health sciences of Nanoscale Materials (Nanosafety Lab) Institute of High Energy Physics Chinese Academy of Sciences 100049 Beijing China 2. College of Chemistry and Molecular Engineering Peking University 100871 Beijing China 3. department of Occupational and Environmental Health sciences School of Public Health Peking University 100083 Beijing China

Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the envi-ronment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some ex-clusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new re-search field are also discussed.

关键词： nanomaterials, single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron, biological activity and toxicological effect.

Debating about the climate warming

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Progress in Natural Science:Materials International 2006年第1期16卷 1-6页

作者： WANG Shaowu1, LUO Yong2, ZHAO Zongci2, DONG Wenje2 and YANG Bao3.(1.department of atmospheric sciences, School of Physics, {3. University, beijing 100871, china 2. Laboratory for Climate Studies, china Meteorological Administration, beijing 100081, china 3. Institute of Cold and Arid Regions Environmental and Engineering, Chinese Academy of sciences, Lanzhou 73.000, china) [a] department of atmospheric sciences School of Physics Peking University Beijing China [b] Laboratory for Climate Studies China Meterological Administration Beijing China [c] Institute of Cold and Arid Regions Environmental and Engineering Chinese Academy of Sciences Lanzhou China

Debating about the climate warming is reviewed. Discussions have focused on the validity of the temperature reconstruction for the last millennium made by Mann et al. Arguments against and for the reconstruction are introduced. Temperature reconstructions by other authors are examined, including the one carried out by Wang et al. in 1996. It is concluded that: (1) Ability of reproducing temperature variability of time scale less than 10 a is limited, so no sufficient evidence proves that the 1990s was the warmest decade, and 1998 was the warmest year over the last millennium. (2) All of the temperature reconstructions by different authors demonstrate the occurrence of the MWP (Medieval Warm Period) and LIA (Little Ice Age) in low frequency band of temperature variations, though the peak in the MWP and trough in LIA varies from one reconstruction to the others. Therefore, terms of MWP and LIA can be used in studies of climate change. (3. The warming from 1975 to 2000 was significant, but we do not know if it was the strongest for the last millennium, which needs to be proved by more evidence.

关键词： climate warming MWP LIA the 20th century.

Estimating surface evapotranspiration using combined MODIS and CBERS-02 data

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Science china(Technological sciences) 2005年第S2期48卷 145-160页

作者： XIN Xiaozhou1,2, LIU Qinhuo1, TANG Yong1,3. TIAN Guoliang1, GU Xingfa1, LI Xiaowen1,2, ZHENG Hongsheng4 & CHEN Jiayi4 1. State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of sciences, beijing 100101, china 2. Research Center for Remote Sensing and GIS, {3. of Geography, beijing Normal University, beijing 100875, china 3. Graduate University of Chinese Academy of sciences, beijing 10003., china 4. {3. of atmospheric Physics, peking University,{13., china 1. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China2. Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University 100875 Beijing China3. Graduate University of Chinese Academy of Sciences 100039 Beijing China4. Department of Atmospheric Physics Peking University 100871 Beijing China

Spatial scale error is one of the most serious problems in the estimates of land surface heat fluxes of sensible and latent from satellite-borne data such as MODIS 1km resolution reflectance and emissive data. One of the feasible and economic ways to decrease the spatial scale error is to use high resolution land use class data together with the MODIS data. CBERS-02 data were used to produce land use class of Baiyangdian area, Hebei Province, china in the autumn of 2004. The area ratio of each class in MODIS pixel was calculated, and used to derive the heat fluxes of the mixed pixel. The results showed that the estimated heat fluxes of soil, sensible and latent have been changed remarkably after using the high resolution land class data. It could be concluded from the comparison between simulated and ground-measured fluxes as well as the theoretical analysis that high resolution land class data are useful to diminishing the scale error of heat fluxes estimated from low resolution satellite data.

关键词： surface evapotranspiration spatial scale error MODIS CBERS land class.