GIS-based spatial differentiation of ethnic minority villages in Guizhou Province,China

The protection and development problems in ethnic minority villages have received great attention from the Chinese government.This study aims to systematically identify the spatial differentiation characteristics of ethnic minority villages and their influencing factors in Guizhou Province.Applying ArcGIS and GeoDa,a total of 1,014 ethnic minority villages in the four batches announced by the Ethnic and Religious Affairs Commission of Guizhou Province(272in the first batch,240 in the second batch,255 in the third batch,and 247 in the fourth batch)served as the research objects.Utilizing the economic development data in Guizhou Statistical Yearbook 2018-2020 for analysis,the coupling calculation of the spatial layout and economic development level of ethnic minority villages was conducted.The results indicate that the number of ethnic minority village points varies in spatial distribution with remarkable agglomeration.The spatial equilibrium distribution of ethnic minority villages in the province is imbalanced.The kernel density is characterized by independent single kernel centers with sporadic distributions of subcenters and an echelon distribution whole.The spatial complexity distribution indicates that ethnic minority villages in Guizhou possess unequal characteristics,and the fractal of the system structure is more complicated.The findings reveal that the spatial distribution of ethnic minority characteristic villages in Guizhou is highly consistent with that of ethnic minorities in Guizhou.The distribution is the combined results of geographical factors and socialeconomic factors.Most ethnic minority characteristic villages in Guizhou Province are located in areas with complex terrain,inconvenient transportation,and relatively backward economic development.Based on the current geospatial distribution of ethnic minority villages,the present study will provide remarkable implications for the Chinese government to implement the Rural Revitalization Strategy from several key aspects.The Chinese government should establish a protection and development mechanism in ethnic minority villages and strive to enhance the characteristics of ethnic cultural industries.Meanwhile,the"integration of culture and tourism"should be taken as the development strategy while the industry should support rural economic development and help eliminate poverty.This is of crucial practical significance to national unity and rural revitalization in China.

A decomposition model to analyze effect of SO_2 emission density of China

A decomposition model was applied to study the resource-saving and environment-friendly effects of air pollutant emissions(taking industrial SO2 emission as an example) in China.From the results,it is found that 38.93% and 61.07% are contributed to environment-friendly and resource-saving effects,respectively,by the dramatic decrease in industrial SO2 emission density(nearly 70% from 2001 to 2010).This indicates that China has achieved important progress during the 11th FYP(five-year plan) compared with the 10th FYP.A simultaneous equations model was also employed to analyze the influencing factors by using data from 30 provinces in China.The results imply that the influence of environmental regulation on environment-friendly effect is not obvious during the 10th FYP but obvious during the 11th FYP.Thus,the government should continue promoting the environment-friendly effect by further enhancing environmental regulation and strengthening the role of environmental management.

Dynamic Variation of Land-use Types of the Constructed Wetland before and after Oil-field Water Irrigation Based on 3S Technology

[Objective] The study aimed at analyzing the dynamic variation of land-use types of the constructed wetland before and after oil-field water irrigation based on 3S technology. [Method] At semi-arid and arid areas in the west of Jilin Province, water resource balance between the amount of oil-field water supply and ecological water requirement in the constructed wetland irrigated by oil-field water during 2001-2010 was investigated firstly. Afterwards, based on 3S technology, the partition and dynamic variation of land-use types of the constructed wetland before and after oil-field water irrigation in 2001, 2006, 2008 and 2010 were analyzed. [Result] The annual ecological water requirement of the constructed wetland from 2003 to 2010 varied from 1.62×106 to 2.24×106 m3, and the annual amount of oil-field water supply in the region changed from 2.12×106 to 2.84×106 m3, which showed that the supply amount of oil-field water could meet the basic ecological water requirement of the constructed wetland. Meanwhile, compared with 2001, the areas of water region and paddy field in 2010 increased by 2.3 and 10.0 times, and the areas of forest and marsh rose by 40.15% and 29.5.0% respectively. [Conclusion] Water shortage and ecological environment problem of arid and semi-arid areas had been improved by oil-field water irrigation.

Investigation of the Photosensitized Mechanisms of PCBs in the Presence of Natural Organic Matter

The structures of 26 different congeners of polychlorinated biphenyls（PCBs, including monothrough deca-chlorinated） were optimized using density functional theory（DFT） calculations with the 6-31＋G（d,p） basis set. The activation energies for the dechlorination of these systems were calculated for direct photodegradation and photosensitized degradation reaction pathways in the presence of natural organic matter（NOM）. The dechlorination mechanism of these PCBs and the ring-opening reaction mechanisms（using QST3 method） of the photosensitive degradation products were analyzed. The results showed that（i） the activation energy for the photosensitized degradation of PCBs was much lower than that of direct photodegradation;（ii） the degradation activities（i.e., C–Cl bond cleavage energies） were the same for both degradation pathways and followed the order ortho 〉 meta 〉 para;（iii） the degradation activities of asymmetric PCBs were higher than those of the corresponding symmetrical PCBs for the direct photodegradation and it was completely opposite in the photosensitive degradation;（iv） there was no correlation between the dissociation energy and the number of C–Cl bonds for the direct photodegradation and dechlorination products were all biphenyl;（v） the degradation activity of PCBs decreased as the number of C–Cl bonds increased in the presence of NOM; and（vi） even when the dechlorination reaction was incomplete, it produced chlorophenol. Furthermore, the free radicals of NOM led to the ring-opening reactions of PCBs via an initial addition step. The main site of these ring-opening reactions was the ortho position. Notably, the likelihood of ring-opening reactions occurring involving the degradation products increased as the degradation degree of PCBs increased.

Atmospheric fate of typical liquid crystal monomers in the tropospheric gas,liquid,and granular phases

Mineral aerosol particles significantly impact environmental risk prediction of liquid crystal monomers(LCMs).In this work,we investigated the reaction mechanisms and kinetics of three typical LCMs(4-cyano-3,5-difluorophenyl 4-ethylbenzoate(CEB-2F),4-cyano-3-fluorophenyl 4-ethylbenzoate(CEB-F),and 4-cyanophenyl 4-ethylbenzoate(CEB))with ozone(O_(3))in the atmospheric gas,liquid,and particle phases employing density functional theory(DFT).Here,O_(3)is prone to add to the benzene ring without F atom(s)in the selected LCMs.The ozonolysis products are aldehydes,carboxylic acids,epoxides,and unsaturated hydrocarbons containing aromatic rings.Those products undergo secondary ozonolysis to generate small molecular compounds such as glyoxal,which is beneficial for generating secondary organic aerosol(SOA).Titanium dioxide(TiO_(2)),an essential component of mineral aerosol particles,has good adsorption properties for LCMs;however,it slightly reduces the reactivity with O_(3).At 298 K,the reaction rate constant of the selected LCMs reacting with O_(3)in the gas and atmospheric liquid phases is(2.74–5.53)×10^(-24)cm^(3)/(mol·sec)and 5.58×10^(-3)–39.1 L/(mol·sec),while CEB-2F reacting with O_(3)on(TiO_(2))_(6)cluster is 1.84×10^(-24)cm^(3)/(mol·sec).The existence of TiO_(2)clusters increases the persistence and long-distance transportability of LCMs,which enlarges the contaminated area of LCMs.

Toxic effects of three perfluorinated or polyfluorinated compounds(PFCs)on two strains of freshwater algae:Implications for ecological risk assessments

Perfluorinated or polyfluorinated compounds(PFCs)continue entering to the environmental as individuals or mixtures,but their toxicological information remains largely unknown.Here,we investigated the toxic effects and ecological risks of Perfluorooctane sulfonic acid(PFOS)and its substitutes on prokaryotes(Chlorella vulgaris)and eukaryotes(Microcystis aeruginosa).Based on the calculated EC50 values,the results showed that PFOS was significantly more toxic to both algae than its alternatives including Perfluorobutane sulfonic acid(PFBS)and 6:2 Fluoromodulated sulfonates(6:2 FTS),and the PFOS-PFBS mixture was more toxic to both algae than the other two PFC mixtures.The action mode of binary PFC mixtures on Chlorella vulgaris was mainly shown as antagonistic and on Microcystis aeruginosa as synergistic,by using Combination index(CI)model coupled with Monte Carlo simulation.The mean risk quotient(RQ)value of three individual PFCs and their mixtures were all below the threshold of 10^(−1),but the risk of those binary mixtures were higher than that of PFCs individually because of their synergistic effect.Our findings contribute to enhance the understanding of the toxicological information and ecological risks of emerging PFCs and provide a scientific basis for their pollution control.

Optimization of process parameters for mature landfill leachate pretreatment using MAP precipitation

Chemical precipitation is a useful technology as a pretreatment to treat mature landfill leachate with high concentrations of ammonium-nitrogen （NH＋-N） and refractory organic compounds. Orthogonal experiments and factorial experiments were carried out to determine the optimal conditions enhancing the magnesium ammonium phosphate （MAP） precipitation process, and the experi- mental results demonstrated that the removal rate of NH＋ -N was more than 85% when MgO and NaHEPO4.2H20 were applied as external sources of magnesium and phosphorous under the optimal conditions that molar ratio n（Mg）：n（N）：n（P） = 1.4：1：0.8, reaction time 60 min, original pH of leachate and settling time 30 min. In the precipitation process, pH could be maintained at the optimal range of 8-9.5 because MgO could release hydroxide ions to consume hydrogen ions. Calcium ions and carbonate ions existed in the leachate could affect the precipitation process, which resulted in the decrease of NH＋-N removal efficiency. The residues of MAP sediments decomposed by heating under alkaline condi- tions can be reused as the sources of phosphorous and magnesium for the removal of high concentrations of NH4＋ -N, and up to 90% of ammonium could be released under molar ratio of n[OH]：n[MAP] = 2.5： 1, heating temperature 90℃ and heating time 2h.

Coupled planning of water resources and agricultural land-use based on an inexact-stochastic programming model

Water resources are fundamental for support of regional development. Effective planning can facilitate sustainable management of water resources to balance socioeconomic development and water conservation. In this research, coupled planning of water resources and agricultural land use was undertaken through the develop- ment of an inexact-stochastic programming approach. Such an inexact modeling approach was the integration of interval linear programming and chance-constraint pro- gramming methods. It was employed to successfully tackle uncertainty in the form of interval numbers and probabil- istic distributions existing in water resource systems. Then it was applied to a typical regional water resource system for demonstrating its applicability and validity through generating efficient system solutions. Based on the process of modeling formulation and result analysis, the developed model could be used for helping identify optimal water resource utilization patterns and the corresponding agri- cultural land-use schemes in more, a number of decision three sub-regions. Further- alternatives were generated under multiple water-supply conditions, which could help decision makers identify desired management policies.

A QICAR Model for Metal Ion Toxicity Established via PLS Method

The partial least squares（PLS） method was employed to establish a quantitative ion characteristics-activity relationship（QICAR） model for metal ion toxicity（EC50 of 15 metal ions）. The ion characteristics included AN（the atomic number）, AIP（the change in ionization potential, eV）, Xm（the electronegativity, eV）, AW（the atomic weight）, Xm2r（the covalent index）, △E0（the absolute difference between electrochemical potential of the ion and that of its first stable reduced state, eV）, ｜lgKoH｜ （the absolute value of the lg of the first hydrolysis constant）, AR（the atomic radius, nm）, AR/AW（the ratio between atomic radius and atomic weight） and ap（the softness index） selected based on relative correlation analysis. The simulated and tested（with the other four metals） efficiency coefficients of the model are 0.88 and 0.96, respectively. The information revealed from the QICAR model indicates that the value of the metal ion toxicity was positively correlated with variables AN, AlP, Xm, AW and Xm2r; negatively correlated with variables AE0, ｜IgKoH｜, AR/AW, AR and ap, and ion characteristics △E0, Xm, σp and Xm2r were found to contribute more to the toxicity of metal ions via the accurate analysis method provided by PLS. The model could be used to predict the toxicity of the target metals and preliminary to assess combined pollution and environmental risk for heavy metals in the environments.

Solvent Effect on Characteristic Vibration of IR Spectrum of 4,4＇-Dibromodiphenyl Ether

The optimal geometry, IR spectrum and vibration assignment of 4,4＇-dibromodiphenyl ether（BDE-15） in gas phase were calculated via the density functional theory（DFT） at the level of B3LYP/6-3 l＋G（d）. Based on the vi- bration assignment, the calculation of vibration frequencies and intensities of 5 main vibration types of BDE-15 in 25 kinds of solvents was carried out by means of a self-consistent reaction field（SCRF） theoretical model at the level of B3LYP/6-31＋G（d） to analyze the solvent effect on the vibration of IR spectrum of BDE-15. To study the solvent ef- fect further, C--O asymmetric stretching vibration fluctuating, which is relatively acute in both vibration frequency and intensity, was selected as the characteristic vibration to establish different linear solvation energy relation（LSER） models for solvent categoring. Solvent parameters（a, /3, ~r＊）, acceptable number（AN） and quantitative structure- activity relationship（QSAR） models were established via chemical quantum parameters of solvent moleculer, which were first been introduced to investigate different solvent-solute interaction mechanisms in alcoholic and non-alcoholic solvents on molecular level. At last, a single solvent molecule was embedded in the framework of po- larizable continuum model（PCM） to validate the effect of hydrogen bonding on solvent-solute interaction in alcohol solvents. The obtained results show that 5 main vibration types of BDE-15 in different solvents have small variation range in frequency and intensity and all the vibration frequencies in solvents are lower than those in gas phase, de- creasing along with the increasing of the dielectric Constant（e） of solvents exponentially. In contrast, all the vibration intensities in solvents are greater than those in gas phase and present positive exponential trend. Twenty-five solvents were divided into two categories（non-alcoholic solvents and alcoholic solvents） by LSER. The CmO asymmetric stretching vibration was mainly regulated by non-specific interaction（dipole-dipole and dipole-induced dipole inter- action） and the combination of non-specific interaction and electronic effect in non-alcoholic solvents and alcoholic solvents, respectively, R2 values of the two QSAR models established for different categories are 0.940 and 0.997, both showing good fitness and the decisive parameters for the two models are/~, a= and aye, EHOMO separately, which reflect that the interaction mechanism is coincide with the conclusion obtained by LSER model. The present of hy- drogen bonding in alcoholic solvents improves the differentiation degree of vibration frequency of the two models with the variance increasing from 0.281 to 0.513 and the intensity from 5.263 to 10.382, which is conducive to the identification of polybrominated diphenyl ether（PBDE） homologues, indicating this research would provide theoreti- cal gist for linking the experimental IR spectrum data with the identification of PBDE homologues.

Ultrasonic-assisted Biodegradation of Endocrine DisruptingCompounds in Soil by Pseudomonas putida： the Importance of Rhamnolipid for Intermediate Product Degradation

The present study aimed to completely remove estrogens, including oestrone（E1）, oestradiol（E2）, oes-triol（E3）, 17a-ethinylestradiol（EE2） and bisphenol-A（BPA）, from soil using Pseudomonas putida（P., putida）. A centralcomposite design was developed to determine the optimal conditions of three variables（ultrasonication time, quantityof P. putida, and concentration of added rhamnolipid） for the removal of the estrogens, and the biodegradation ratesof the estrogens were investigated under the optimum conditions. Moreover, a quantitative structure-biedegradationrelationship（QSBR） was used to analyze the effect of the estrogenic physicochemical properties on the enhancementof the biological degradation. The optimal conditions were an ultrasonication time of 3 min, a P. putida quantity of 8mL, and a rhamnolipid concentration of 100 mg/L. These conditions resulted in removal of 100%, 94.86%, 94.90%,96.56% and 94.56% of El, E2, EE2, BPA and E3, respectively after 7 d. The degradations were more rapid and com-plete than those reported in previous studies, indicating the suitability of the adaptation of P. putida to estrogen de-gradation under conditions of ultrasonic-assistance and adding rhamnolipid, improvement was particularly apparentfrom the complete degradation of E3. Based on a Pearson correlation analysis, the estrogen molecule polar surfacearea（PSA） and surface tension were significantly related to the biodegradation effect. An analysis of the QSBR modelwith the estrogen biodegradation rates as a dependent variable and the PSA and surface tension as independent va-riables indicated that larger PSA caused decreased estrogen biodegradation, while the biodegradation progress wasdominated by the surface tension of the estrogens. The interaction of PSA and surface tension had an antagonistic ef-fect on the biodegradation of estrogens. Therefore, rhamnolipid/ultrasonication can significantly improve the biode-gradation rates of oestrogens in soil, while simultaneously adjusting other environmental conditions would influenceand control the biodegradation processes of estrogens.

An uncertain energy planning model under carbon taxes

In this study, an interval fuzzy mixed-integer energy planning model （IFMI-EPM） is developed under considering the carbon tax policy. The developed IFMI- EPM incorporates techniques of interval-parameter programming, fuzzy planning and mixed-integer programming within a general energy planning model. The IFMIEPM can not only be used for quantitatively analyzing a variety of policy scenarios that are associated with different levels of carbon tax policy, but also tackle uncertainties expressed as discrete intervals and fuzzy sets in energy and environment systems. Considering low, medium and high carbon tax rates, the model is applied to an ideal energy and environment system. The results indicate that reasonable solutions have been generated. They can be used for generating decision alternatives and thus help decision makers identify desired carbon tax policy.

Prediction of Stability for Polychlorinated Biphenyls in Transformer Insulation Oil Through Three-dimensional Quantitative Structure-activity Relationship Pharmacophore Model and Full Factor Experimental Design

Based on the obtained data of half-lives（t1/2） for 31 polychlorinated biphenyl congeners（PCBs）, 3D quantitative structure-activity relationship（QSAR） pharmacophore was used to establish a 3D QSAR model to predict the t1/2 values of the remaining 178 PCBs, using the structural parameters as independent variables and lgt1/2 values as the dependent variable. Among this process, the whole data set（31 compounds） was divided into a training set（24 compounds） for model generation and a test set（7 compounds） for model validation. Then, the full factor experimental design was used to research the potential second-order interactional effect between different substituent positions, obtaining the final regulation scheme for PCB. At last, a 3D QSAR pharmacophore model was established to validate the reasonable regulation targeting typical PCB with respect to half-lives and thermostability. As a result, the cross-validation correlation coefficient（q2） obtained by the 3D QSAR model was 0.845（〉0.5） and the coefficient of determination（r2） obtained was 0.936（〉0.9）, indicating that the models were robust and predictive. CoMSIA analyses upon steric, electrostatic and hydrophobic fields were 0.7%, 85.9%, and 13.4%, respectively. The electrostatic field was determined to be a primary factor governing the tt/2. From CoMSIA contour maps, tl/2 increased when substi- tuents possessed electropositive groups at the 2＇-, 3-, Y-, 5- and 5＇- positions and electronegative groups at the 3-, 3＇-, 5-, 6- and 6＇- positions, which could increase the PCB stability in transformer insulation oil. Modification of two typical PCB congeners（PCB-77 and PCB-81） showed that the lgtl/2 for three selected modified compounds increased by 13%（average ratio） compared with that of each congener and the thermostability of them were higher, validating the reasonability of the regulatory scheme obtained from the 3D QSAR model. These results are expected to be beneficial in predicting tl/2 values of PCB homologues and derivatives and in providing a theoretical foundation for further elucidation of the stability of PCBs.

An inexact risk management model for agricultural land-use planning under water shortage

Water resources availability has a significant impact on agricultural land-use planning, especially in a water shortage area such as North China. The random nature of available water resources and other uncertainties in an agricultural system present risk for land-use planning and may lead to undesirable decisions or potential economic loss. In this study, an inexact risk management model （IRM） was developed for supporting agricultural land-use planning and risk analysis under water shortage. The IRM model was formulated through incorporating a conditional value-at-risk （CVaR） constraint into an inexact two-stage stochastic programming （ITSP） framework, and could be used to control uncertainties expressed as not only probability distributions but also as discrete intervals. The measure of risk about the second-stage penalty cost was incorporated into the model so that the trade-off between system benefit and extreme expected loss could be analyzed. The developed model was applied to a case study in the Zhangweinan River Basin, a typical agricultural region facing serious water shortage in North China. Solutions of the IRM model showed that the obtained first-stage land-use target values could be used to reflect decision-makers＇ opinions on the long-term devel- opment plan. The confidence level a and maximum acceptable risk loss fl could be used to reflect decision- makers＇ preference towards system benefit and risk control. The results indicated that the IRM model was useful for reflecting the decision-makers＇ attitudes toward risk aversion and could help seek cost-effective agricul- tural land-use planning strategies under complex uncer- tainties.

Effects of larval size and hydrodynamics on the growth rates of the black fly Simulium tribulatum

Black flies are ubiquitous and important members of lotic ecosystems.Size is known to affect many aspects of their life in the aquatic larval stage,including intraspecific competition for feeding sites.As filter feeders,flow affects their ability to feed and reach sufficiently fast flow.This,in turn,can lead to risky fluid-mediated disper-sal behavior in search of better conditions.It is surprising,therefore,that little information is available regard-ing how physiological and environmental factors combine to affect larval growth rates.The present study deter-mines the relative growth rates of small(0.6 mm)and large(approximately 4 mm)larvae in laboratory flumes designed to produce spatially homogeneous and temporally consistent flow regimes at ecologically relevant ve-locities(44 and 64 cm/s).Our results indicate that size and flow both influence growth rates and that the 2 in-teract significantly.Young larvae exhibit faster growth rates and a greater positive response to increased flow speed.This result might help explain why smaller larvae have a greater propensity to disperse than larger lar-vae:the benefit of increased growth rate that they receive from relocating to faster flow might balance the risks inherent in dispersal.

A review of inexact optimization modeling and its application to integrated water resources management

Water is crucial in supporting people＇s daily life and the continual quest for socio-economic development. It is also a fundamental resource for ecosystems. Due to the associated complexities and uncertainties, as well as intensive competition over limited water resources between human beings and ecosystems, decision makers are facing increased pressure to respond effectively to various water-related issues and conflicts from an integrated point of view. This quandary requires a focused effort to resolve a wide range of issues related to water resources, as well as the associated economic and environmental implications. Effective systems analysis approaches under uncertainty that successfully address interactions, complexities, uncertainties, and changing conditions associated with water resources, human activities, and ecological conditions are desired, which requires a systematic investigation of the previous studies in relevant areas. Systems analysis and optimization modeling for integrated water resources management under uncertainty is thus comprehensively reviewed in this paper. A number of related methodologies and applications related to stochastic, fuzzy, and interval mathematical optimization modeling are examined. Then, their applica- tions to integrated water resources management are presented. Perspectives of effective management schemes are investigated, demonstrating many demanding areas for enhanced research efforts, which include issues of data availability and reliability, concerns over uncertainty, necessity of post-modeling analysis, and the usefulness of the development of simulation techniques.