Located in the eastern part of the Tarim basin, Xinjiang, the Lop Nur was an ultimate water catchment area of the Tarim basin during the Quaternary. Through nearly ten years of investigation and research, the authors ...Located in the eastern part of the Tarim basin, Xinjiang, the Lop Nur was an ultimate water catchment area of the Tarim basin during the Quaternary. Through nearly ten years of investigation and research, the authors have found a superlarge brine potash deposit in the Luobei subbasin—a secondary basin of the Lop Nur depression. The deposit has been mined now. On that basis, the authors propose new theories on the genesis of the potash rock deposit. In the tectonic and geomorphologic contexts, the Tarim basin lies in a 'high mountain-deep basin' environment. At the beginning of the Quaternary, influenced by the neotectonic movement, the Lop Nur evolved into a 'deep basin' in the Tarim basin. At the end of the middle Pleistocene, neotectonic migration began to take place in the interior of the Lop Nur and a new secondary deep basin—the Luobei subbasin—formed gradually. Despite its small area, it is actually the deepest subbasin in the Lop Nur depression, where brines of the Lop Nur Salt Lake gather and evaporate, thus providing materials for the formation of a superlarge brine potash rock deposit. With respect to the phenomenon of brine concentration and change with deepening of the lake, the authors propose a model of 'high mountain-deep basin' tectonic migration for potash concentration. In the sedimentological context, the honeycomb-shaped voids developed in glauberite rock in the subbasin are good space for potash-rich brine accumulation. Study indicates that the deposition of glauberite requires recharge of calcium-rich water. In the Tarim area the calcium-rich water might come from deep formation water or oilfield water, and the river water recharging the Lop Nur Salt Lake was rich in sulfate radicals and other components; in addition, the climate in the area was very dry and the brine evaporated steadily, thus resulting in deposition of substantial amount of glauberite, potash accumulation in intercrystal brine and final formation of the potash deposit. Generally, potash formation in a salt lake undergoes a three-stage process of 'carbonates—?sulfates (gypsum and glauberite)—^chlorides (halite etc.)', but in the study area there only occurred a two-stage process of 'carbonates—>sulfates (gypsum and glauberite)'. The authors call this new geological phenomenon the 'two-stage potash formation' model. In conclusion, the superlarge Lop Nur potash deposit is the result of combined 'high mountain-deep basin' tectonism and 'two-stage potash formation'.展开更多
Environmental risk(ER) factors come from ER source and they are controlled by the primary control mechanism(PCM) of environmental risk, due to the self failures or the effects of external environment risk trigger mech...Environmental risk(ER) factors come from ER source and they are controlled by the primary control mechanism(PCM) of environmental risk, due to the self failures or the effects of external environment risk trigger mechanism, the PCM could not work regularly any more, then, the ER factors will release environmental space, and an ER field is formed up. The forming of ER field does not mean that any environmental pollution accident(EPA) will break out; only the ER receptors are exposed in the ER field and damaged seriously, the potential ER really turns into an actual EPA. Researching on the general laws of evolving from environmental risk to EPA, this paper bring forwards a relevant concept model of risk forecasting and evaluating of EPA. This model provides some scientific methods for risk evaluation, prevention and emergency response of EPA. This model not only enriches and develops the theory system of environment safety and emergency response, but also acts as an instruction for public safety, enterprise's safety management and emergency response of the accident.展开更多
One of the difficulties frequently encountered in water quality assessment is that there are many factors and they cannot be assessed according to one factor, all the effect factors associated with water quality must ...One of the difficulties frequently encountered in water quality assessment is that there are many factors and they cannot be assessed according to one factor, all the effect factors associated with water quality must be used. In order to overcome this issues the projection pursuit principle is introduced into water quality assessment, and projection pursuit cluster(PPC) model is developed in this study. The PPC model makes the transition from high dimension to one-dimension. In other words, based on the PPC model, multifactor problem can be converted to one factor problem. The application of PPC model can be divided into four parts: (1) to estimate projection index function Q(); (2) to find the right projection direction ; (3) to calculate projection characteristic value of the i th sample z-i, and (4) to draw comprehensive analysis on the basis of z-i. On the other hand, the empirical formula of cutoff radius R is developed, which is benefit for the model to be used in practice. Finally, a case study of water quality assessment is proposed in this paper. The results showed that the PPC model is reasonable, and it is more objective and less subjective in water quality assessment. It is a new method for multivariate problem comprehensive analysis.展开更多
This paper shows the dynamic process of regional disparity of economic development in China in the past 50 years from a new insight by using the rescaled range statistic (R/S) analysis and wavelet analysis of the Thei...This paper shows the dynamic process of regional disparity of economic development in China in the past 50 years from a new insight by using the rescaled range statistic (R/S) analysis and wavelet analysis of the Theil index sequence with different time scales. The main conclusions are: 1) The regional disparity of economic development in China, including the inter-provincial disparity, inter-regional disparity and intra-regional disparity, has existed for many years. Theil index by the comparative price has revealed the true trend for comparative disparity of regional economic development from 1952 to 2000. 2) Decomposition of Theil index indicates that the dynamic trend of comparative inter-provincial disparity in the coastal region is in line with dynamic trend of inter-provincial disparity in the whole China. 3) The R/S analysis results tell us that during 1966-1978, the Hurst exponent H=0.504 approximate to 0.5, which indicates that in that period the evolution of comparative inter-provincial disparity of economic development showed a random characteristic, and in the other periods, i.e. 1952-1965, 1979-1990 and 1991-2000, the Hurst exponent H>0.5, which indicates that in those periods the evolution of the comparative inter-provincial disparity of economic development in China had a long-enduring characteristic. 4) By using wavelet analysis at different time scale, we arrived at a conclusion that the evolutionary process of the disparity of economic development of China is not a simple inverted U shape but a compound of several U shapes. The result tells us that the evolutionary plot of inter-provincial disparity in China follows the inverted U on the whole at the higher scale, 24 ( 16 years). That is to say, the disparity tends to rise in the first stage of economic development, and fall slowly over the peak in the second stage of economic development. However, if we shorten the time scale to 23 ( 8 years), then a link of several U shapes will appear.展开更多
Growth and uptake of exogenous phosphate by Microcystis aeruginosa in batch culture under different temperature, photoperiod, and turbulence were studied by the method of phosphate isotope tracer. Relatively high temp...Growth and uptake of exogenous phosphate by Microcystis aeruginosa in batch culture under different temperature, photoperiod, and turbulence were studied by the method of phosphate isotope tracer. Relatively high temperature, long photoperiod and strong turbulence increased the cell density of M. aeruginosa in these batch cultures. The initial rapid uptake of phosphate by M. aeruginosa was independent of the temperature, photoperiod, and turbulence. Similarly, maximum exogenous phosphate uptake was not related to these environmental factors. However, elevated temperature and turbulence shortened the time, required to obtain maximum P accumulation. The growth of M. aeruginosa could alleviate the phosphorous leakage. Total amounts of exogenous phosphate uptake to M. aeruginosa and the phosphorus leakage of M. aeruginosa were significantly influenced by the growth state of M. aeruginosa closely correlated with the environmental factors. The maximum volume of exogenous phosphate uptake to M. aeruginosa was 46% of added exogenous phosphate in water with 16 hours of photoperiod. Thus, total amounts of exogenous phosphate uptake to M. aeruginosa were more strongly affected by the photoperiod length than temperature and turbulence.展开更多
The adsorption of two phenols, namely, phenol and salicylic acid(SA) onto a water-compatible hypercrosslinked polymeric resin(NJ-8) were studied in terms of pseudo-second-order and first order mechanisms for chemical ...The adsorption of two phenols, namely, phenol and salicylic acid(SA) onto a water-compatible hypercrosslinked polymeric resin(NJ-8) were studied in terms of pseudo-second-order and first order mechanisms for chemical sorption as well as an intraparticle diffusion mechanism process. Kinetic analysis showed that the intraparticle diffusion process was the essential rate-controlling step. The activation energies of sorption have also been evaluated with the pseudo-second-order and intraparticle diffusion constants, respectively. Adsorption equilibrium data were well fitted by the Langmuir, Freundlich and Redlich-Peterson isotherms. Adsorption was exothermic and basically of a type of transition between physical and chemical character. The sorption capacity was higher for SA due to its more hydrophobic. Phenol has a higher adsorption enthalpy since it could form stronger hydrogen bonding on NJ-8.展开更多
The nitrogen transformation in maize soil after application of different organic manure was studied. The nitrogen mineralization in surface soil, NO - 3-N dynamics and distribution in soil profile, and N 2O emissio...The nitrogen transformation in maize soil after application of different organic manure was studied. The nitrogen mineralization in surface soil, NO - 3-N dynamics and distribution in soil profile, and N 2O emission were investigated. Eight treatments were laid out randomizing with three replications in 24 plots: maize plantation without fertilizer(CK1), bare soil without maize plantation and fertilization(CK2), swine manure(S1, S2), poultry manure(P1, P2), and cattle manure(C1, C2). Three manures were applied at two application levels(15 t/hm 2 and 30 t/hm 2). The results indicated that NH + 4-N in surface soil showed the same temporal pattern without much variation among different treatments. But NO - 3-N in the same layer exhibited large temporal pattern in all treatments, which was mainly due to its easy eluviations of NO - 3-N in soil, its transformation to N 2O and the influence of precipitation. The distribution of NO - 3-N in the soil profile during maize growing season showed the leaching tendency from surface soil to subsoil, which was different among the treatments. The poultry treatments showed the largest leaching tendency. The study also revealed that the emissions of N 2O were affected by the application of organic manures in the order of P2>S2>C2>P1>S1>C1>CK1>CK2. All these results showed that organic manure applications significantly affect nitrogen transformation and distribution in maize soil. Considering N 2O emission and NO - 3-N leaching, the management of organic manure in the agriculture needs further studies.展开更多
The influence of the Haizhou Open Pit Mine on the atmospheric flow in nearby Fuxin City in China was analyzed with the aid of the steady-state Navier-Stokes equations. The finite element method was used to obtain nume...The influence of the Haizhou Open Pit Mine on the atmospheric flow in nearby Fuxin City in China was analyzed with the aid of the steady-state Navier-Stokes equations. The finite element method was used to obtain numerical solutions to these equations. The results showed that the Haizhou Open Pit Coal Mine contributes to the turbulent flow in the Fuxin City and its surroundings. However, when compared with the climatic effects, the open pit mine has a relatively small impact on the atmospheric flow over Fuxin.展开更多
One of the most suitable ways under study for the disposal of high-level radioactive waste (HLW) is isolation in deep geological repositories. It is very important to research the thermo-hydro- mechanical (THM) coupl...One of the most suitable ways under study for the disposal of high-level radioactive waste (HLW) is isolation in deep geological repositories. It is very important to research the thermo-hydro- mechanical (THM) coupled processes associated with an HLW disposal repository. Non-linear coupled equations, which are used to describe the THM coupled process and are suited to saturated-unsaturated porous media, are presented in this paper. A numerical method to solve these equations is put forward, and a finite element code is developed. This code is suited to the plane strain or axis-symmetry problem. Then this code is used to simulate the THM coupled process in the near field of an ideal disposal repository. The temperature vs. time, hydraulic head vs. time and stress vs. time results show that, in this assumed condition, the impact of temperature is very long (over 10 000 a) and the impact of the water head is short (about 90 d). Since the stress is induced by temperature and hydraulic head in this condition, the impact time of stress is the same as that of temperature. The results show that THM coupled processes are very important in the safety analysis of an HLW deep geological disposal repository.展开更多
A new molecular representation, molecular hologram, is employed to investigate the quantitative rela- tionships between gas chromatographic retention indices (GC-RI) and molecular structures of polychlorinated diben- ...A new molecular representation, molecular hologram, is employed to investigate the quantitative rela- tionships between gas chromatographic retention indices (GC-RI) and molecular structures of polychlorinated diben- zofurans (PCDFs). Together with application of partial least squares (PLS) regression, the quantitative structure-reten- tion relationship (QSRR) model is constructed for GC-RI of 135 PCDFs. This new QSRR model presents high statistical quality and predictive value with crossvalidation correlation coefficient q2LOO values of 0.998, and non-crossvalidation correlation coefficient r2 of 0.998. 100 PCDFs are selected randomly as training set and the rest as testing set. The re- sult of PLS regressive analysis of training set yields r2 of 0.998 and q2LOO of 0.997. The GC-RIs of testing set are pre- dicted, and the correlation equation indicates that the model based on training set has excellent ability to predict the GC-RIs of PCDFs in testing set.展开更多
基金the Oriented Foundation Proiect (DKD 95—22) the form er Ministry of Geology and Mineral Resources,State 305 Project(96-915—08—05)+2 种基金 the Ministry of Science Technology and Project 992025 the Ministry of Land and Resources.
文摘Located in the eastern part of the Tarim basin, Xinjiang, the Lop Nur was an ultimate water catchment area of the Tarim basin during the Quaternary. Through nearly ten years of investigation and research, the authors have found a superlarge brine potash deposit in the Luobei subbasin—a secondary basin of the Lop Nur depression. The deposit has been mined now. On that basis, the authors propose new theories on the genesis of the potash rock deposit. In the tectonic and geomorphologic contexts, the Tarim basin lies in a 'high mountain-deep basin' environment. At the beginning of the Quaternary, influenced by the neotectonic movement, the Lop Nur evolved into a 'deep basin' in the Tarim basin. At the end of the middle Pleistocene, neotectonic migration began to take place in the interior of the Lop Nur and a new secondary deep basin—the Luobei subbasin—formed gradually. Despite its small area, it is actually the deepest subbasin in the Lop Nur depression, where brines of the Lop Nur Salt Lake gather and evaporate, thus providing materials for the formation of a superlarge brine potash rock deposit. With respect to the phenomenon of brine concentration and change with deepening of the lake, the authors propose a model of 'high mountain-deep basin' tectonic migration for potash concentration. In the sedimentological context, the honeycomb-shaped voids developed in glauberite rock in the subbasin are good space for potash-rich brine accumulation. Study indicates that the deposition of glauberite requires recharge of calcium-rich water. In the Tarim area the calcium-rich water might come from deep formation water or oilfield water, and the river water recharging the Lop Nur Salt Lake was rich in sulfate radicals and other components; in addition, the climate in the area was very dry and the brine evaporated steadily, thus resulting in deposition of substantial amount of glauberite, potash accumulation in intercrystal brine and final formation of the potash deposit. Generally, potash formation in a salt lake undergoes a three-stage process of 'carbonates—?sulfates (gypsum and glauberite)—^chlorides (halite etc.)', but in the study area there only occurred a two-stage process of 'carbonates—>sulfates (gypsum and glauberite)'. The authors call this new geological phenomenon the 'two-stage potash formation' model. In conclusion, the superlarge Lop Nur potash deposit is the result of combined 'high mountain-deep basin' tectonism and 'two-stage potash formation'.
文摘Environmental risk(ER) factors come from ER source and they are controlled by the primary control mechanism(PCM) of environmental risk, due to the self failures or the effects of external environment risk trigger mechanism, the PCM could not work regularly any more, then, the ER factors will release environmental space, and an ER field is formed up. The forming of ER field does not mean that any environmental pollution accident(EPA) will break out; only the ER receptors are exposed in the ER field and damaged seriously, the potential ER really turns into an actual EPA. Researching on the general laws of evolving from environmental risk to EPA, this paper bring forwards a relevant concept model of risk forecasting and evaluating of EPA. This model provides some scientific methods for risk evaluation, prevention and emergency response of EPA. This model not only enriches and develops the theory system of environment safety and emergency response, but also acts as an instruction for public safety, enterprise's safety management and emergency response of the accident.
文摘One of the difficulties frequently encountered in water quality assessment is that there are many factors and they cannot be assessed according to one factor, all the effect factors associated with water quality must be used. In order to overcome this issues the projection pursuit principle is introduced into water quality assessment, and projection pursuit cluster(PPC) model is developed in this study. The PPC model makes the transition from high dimension to one-dimension. In other words, based on the PPC model, multifactor problem can be converted to one factor problem. The application of PPC model can be divided into four parts: (1) to estimate projection index function Q(); (2) to find the right projection direction ; (3) to calculate projection characteristic value of the i th sample z-i, and (4) to draw comprehensive analysis on the basis of z-i. On the other hand, the empirical formula of cutoff radius R is developed, which is benefit for the model to be used in practice. Finally, a case study of water quality assessment is proposed in this paper. The results showed that the PPC model is reasonable, and it is more objective and less subjective in water quality assessment. It is a new method for multivariate problem comprehensive analysis.
基金Under the auspices of National Philosophy and Social Sciences Foundation of China (No. 00BJL051 03BJL027)
文摘This paper shows the dynamic process of regional disparity of economic development in China in the past 50 years from a new insight by using the rescaled range statistic (R/S) analysis and wavelet analysis of the Theil index sequence with different time scales. The main conclusions are: 1) The regional disparity of economic development in China, including the inter-provincial disparity, inter-regional disparity and intra-regional disparity, has existed for many years. Theil index by the comparative price has revealed the true trend for comparative disparity of regional economic development from 1952 to 2000. 2) Decomposition of Theil index indicates that the dynamic trend of comparative inter-provincial disparity in the coastal region is in line with dynamic trend of inter-provincial disparity in the whole China. 3) The R/S analysis results tell us that during 1966-1978, the Hurst exponent H=0.504 approximate to 0.5, which indicates that in that period the evolution of comparative inter-provincial disparity of economic development showed a random characteristic, and in the other periods, i.e. 1952-1965, 1979-1990 and 1991-2000, the Hurst exponent H>0.5, which indicates that in those periods the evolution of the comparative inter-provincial disparity of economic development in China had a long-enduring characteristic. 4) By using wavelet analysis at different time scale, we arrived at a conclusion that the evolutionary process of the disparity of economic development of China is not a simple inverted U shape but a compound of several U shapes. The result tells us that the evolutionary plot of inter-provincial disparity in China follows the inverted U on the whole at the higher scale, 24 ( 16 years). That is to say, the disparity tends to rise in the first stage of economic development, and fall slowly over the peak in the second stage of economic development. However, if we shorten the time scale to 23 ( 8 years), then a link of several U shapes will appear.
文摘Growth and uptake of exogenous phosphate by Microcystis aeruginosa in batch culture under different temperature, photoperiod, and turbulence were studied by the method of phosphate isotope tracer. Relatively high temperature, long photoperiod and strong turbulence increased the cell density of M. aeruginosa in these batch cultures. The initial rapid uptake of phosphate by M. aeruginosa was independent of the temperature, photoperiod, and turbulence. Similarly, maximum exogenous phosphate uptake was not related to these environmental factors. However, elevated temperature and turbulence shortened the time, required to obtain maximum P accumulation. The growth of M. aeruginosa could alleviate the phosphorous leakage. Total amounts of exogenous phosphate uptake to M. aeruginosa and the phosphorus leakage of M. aeruginosa were significantly influenced by the growth state of M. aeruginosa closely correlated with the environmental factors. The maximum volume of exogenous phosphate uptake to M. aeruginosa was 46% of added exogenous phosphate in water with 16 hours of photoperiod. Thus, total amounts of exogenous phosphate uptake to M. aeruginosa were more strongly affected by the photoperiod length than temperature and turbulence.
文摘The adsorption of two phenols, namely, phenol and salicylic acid(SA) onto a water-compatible hypercrosslinked polymeric resin(NJ-8) were studied in terms of pseudo-second-order and first order mechanisms for chemical sorption as well as an intraparticle diffusion mechanism process. Kinetic analysis showed that the intraparticle diffusion process was the essential rate-controlling step. The activation energies of sorption have also been evaluated with the pseudo-second-order and intraparticle diffusion constants, respectively. Adsorption equilibrium data were well fitted by the Langmuir, Freundlich and Redlich-Peterson isotherms. Adsorption was exothermic and basically of a type of transition between physical and chemical character. The sorption capacity was higher for SA due to its more hydrophobic. Phenol has a higher adsorption enthalpy since it could form stronger hydrogen bonding on NJ-8.
文摘The nitrogen transformation in maize soil after application of different organic manure was studied. The nitrogen mineralization in surface soil, NO - 3-N dynamics and distribution in soil profile, and N 2O emission were investigated. Eight treatments were laid out randomizing with three replications in 24 plots: maize plantation without fertilizer(CK1), bare soil without maize plantation and fertilization(CK2), swine manure(S1, S2), poultry manure(P1, P2), and cattle manure(C1, C2). Three manures were applied at two application levels(15 t/hm 2 and 30 t/hm 2). The results indicated that NH + 4-N in surface soil showed the same temporal pattern without much variation among different treatments. But NO - 3-N in the same layer exhibited large temporal pattern in all treatments, which was mainly due to its easy eluviations of NO - 3-N in soil, its transformation to N 2O and the influence of precipitation. The distribution of NO - 3-N in the soil profile during maize growing season showed the leaching tendency from surface soil to subsoil, which was different among the treatments. The poultry treatments showed the largest leaching tendency. The study also revealed that the emissions of N 2O were affected by the application of organic manures in the order of P2>S2>C2>P1>S1>C1>CK1>CK2. All these results showed that organic manure applications significantly affect nitrogen transformation and distribution in maize soil. Considering N 2O emission and NO - 3-N leaching, the management of organic manure in the agriculture needs further studies.
文摘The influence of the Haizhou Open Pit Mine on the atmospheric flow in nearby Fuxin City in China was analyzed with the aid of the steady-state Navier-Stokes equations. The finite element method was used to obtain numerical solutions to these equations. The results showed that the Haizhou Open Pit Coal Mine contributes to the turbulent flow in the Fuxin City and its surroundings. However, when compared with the climatic effects, the open pit mine has a relatively small impact on the atmospheric flow over Fuxin.
文摘One of the most suitable ways under study for the disposal of high-level radioactive waste (HLW) is isolation in deep geological repositories. It is very important to research the thermo-hydro- mechanical (THM) coupled processes associated with an HLW disposal repository. Non-linear coupled equations, which are used to describe the THM coupled process and are suited to saturated-unsaturated porous media, are presented in this paper. A numerical method to solve these equations is put forward, and a finite element code is developed. This code is suited to the plane strain or axis-symmetry problem. Then this code is used to simulate the THM coupled process in the near field of an ideal disposal repository. The temperature vs. time, hydraulic head vs. time and stress vs. time results show that, in this assumed condition, the impact of temperature is very long (over 10 000 a) and the impact of the water head is short (about 90 d). Since the stress is induced by temperature and hydraulic head in this condition, the impact time of stress is the same as that of temperature. The results show that THM coupled processes are very important in the safety analysis of an HLW deep geological disposal repository.
基金supported by the National Natural Science Foundation of China(Grant No.50278041)supported by the Key Invite Public Bidding Project for Social Development of Jiangsu Province(Grant No.BS2002049)+1 种基金the Key Laboratory Foundation of Environmental Engineering of Jiangsu Province(Grant No.KF040002)funded by the US National Science Foundation(USA,NSF,Grant No.BES-0201849).
基金This work was supported by the National Basic Research Program of China(Grant No.2003CB4 l5001)the National Natural Science Foundation of China(Grant No.20477018)+1 种基金European Commission International Scientific Cooperation Project(Grant No.ICA4-CT-2001-10039)the Doctoral Program of Higher Education of China and the Core University Program.
文摘A new molecular representation, molecular hologram, is employed to investigate the quantitative rela- tionships between gas chromatographic retention indices (GC-RI) and molecular structures of polychlorinated diben- zofurans (PCDFs). Together with application of partial least squares (PLS) regression, the quantitative structure-reten- tion relationship (QSRR) model is constructed for GC-RI of 135 PCDFs. This new QSRR model presents high statistical quality and predictive value with crossvalidation correlation coefficient q2LOO values of 0.998, and non-crossvalidation correlation coefficient r2 of 0.998. 100 PCDFs are selected randomly as training set and the rest as testing set. The re- sult of PLS regressive analysis of training set yields r2 of 0.998 and q2LOO of 0.997. The GC-RIs of testing set are pre- dicted, and the correlation equation indicates that the model based on training set has excellent ability to predict the GC-RIs of PCDFs in testing set.
