National Fire codes,mandated by government authorities to tackle technical challenges in fire prevention and control,establish fundamental standards for construction practices.International collaboration in fire prote...National Fire codes,mandated by government authorities to tackle technical challenges in fire prevention and control,establish fundamental standards for construction practices.International collaboration in fire protection technologies has opened avenues for China to access a wealth of documents and codes,which are crucial in crafting regulations and developing a robust,scientific framework for fire code formulation.However,the translation of these codes into Chinese has been inadequate,thereby diminishing the benefits of technological exchange and collaborative learning.This underscores the necessity for comprehensive research into code translation,striving for higher-quality translations guided by established translation theories.In this study,we translated the initial segment of the NFPA 1 Fire Code into Chinese and examined both the source text and target text through the lens of Translation Shift Theory,a concept introduced by Catford.The conclusion culminated in identifying four key shifts across various linguistic levels:lexis,sentences,and groups,to ensure an accurate and precise translation of fire codes.This study offers a through and lucid explanation of how the translator integrates Catford’s theories to solve technical challenges in NFPA 1 Fire Code translation,and establish essential standards for construction translation practices.展开更多
Based on the discussion of relationships between thinning and wind damage, and published information, a method for estimating risk ratios of wind damage was developed. Estimations of risk-ratio for Pinus thunbergii tr...Based on the discussion of relationships between thinning and wind damage, and published information, a method for estimating risk ratios of wind damage was developed. Estimations of risk-ratio for Pinus thunbergii trees and stands were de-duced from stem bending theory and coefficients characterizing wind profile, distribution of branches and optical stratification po-rosity. The results showed that if the value of constant b in the branch distribution-model equals the attenuation coefficient s in the wind profile model for a single tree crown, then the parameter H/D1.33 (height over stem diameter cubed) can be used to compare and evaluate the risk-ratio of wind damage for individual trees. The same method can be applied to stands using the coefficient of wind profile in a stand, i.e. attenuation coefficient , the coefficient from distributions of optical stratification porosity, i.e. extinction coefficient , and the parameter D1.33. The application of parameter H/D1.33 and the process of determining risk ra-tios of wind damage for stands were also given in the paper.展开更多
Chronic alcohol consumption induces hepatic steatosis, the early stage of alcoholic liver disease （ALD）. The aim ofpresent study is to investigate the protective effect ofPanax notoginseng saponins （PNS） against c...Chronic alcohol consumption induces hepatic steatosis, the early stage of alcoholic liver disease （ALD）. The aim ofpresent study is to investigate the protective effect ofPanax notoginseng saponins （PNS） against chronic ethanol-induced hepaticsteatosis in vivo. Mice were pair-fed a modified Lieber-DeCarli liquid diet containing alcohol or isocaloric maltose dextrin ascontrol diet with or without PNS （200 mg/kg, BW） for 8 weeks. Animals supplemented with PNS were protected against hepaticlipid accumulation induced by chronic ethanol exposure. Accordingly, PNS could significantly decrease the elevation of plasmatriglyceride, plasma enzyme activities, i.e. alanine aminotransferase （ALT） and aspartate aminotransferase （AST）, and hepaticTNF-ct and IL-6 levels which were induced by chronic alcohol exposure. In addition, PNS markedly reduced the lipolysis ofwhite adipose tissue （WAT） that stimulated by alcohol feeding through the inhibiting protein expression of phosphorylation ofhormone-sensitive lipase （p-HSL）, rather than total HSL. Furthermore, alcohol exposure also enhanced fatty acid uptake capacityin liver by elevated hepatic CD36 expression, which could attenuated by PNS treatment. These results demonstrate that PNSsupplementation protects against chronic ethanol-induced hepatic steatosis, which is associated with ameliorating dysfunctionallipid metabolism of WAT and the reduced inflammatory cytokines. Our findings suggested that PNS might be potential to bedeveloped as an effective agent for the treatment of chronic alcoholic steatosis.展开更多
The effluent from the pulping of E. urophylla by alkali sodium sulfite chemi mechanical process(AS-CMP) was characterized for its biodegradability by photosynthetic bacteria (PSB). Chemical coagulation post treat...The effluent from the pulping of E. urophylla by alkali sodium sulfite chemi mechanical process(AS-CMP) was characterized for its biodegradability by photosynthetic bacteria (PSB). Chemical coagulation post treatment of biotreated wastewater was also studied. One month continuous treatment in the laboratory indicated that the COD Cr , BOD 5 and SS removals in biotreatment stages reached 56%, 83% and 89% respectively, and the CH 2Cl 2 extractives decreased from 10.7 mg/L to 7.7 mg/L. In chemical coagulation post treatment stage, the effects of process conditions, such as coagulant dosage, pH value and the coordinated coagulation flocculation treatment of three kinds of coagulants on coagulation effectiveness were discussed. The optimum operating conditions were given.展开更多
In order to study the feasibility of treating petro chemical wastewater by the combination of anaerobic and aerobic biological process, a research of treating wastewater in UASB reactor and aeration basin has been co...In order to study the feasibility of treating petro chemical wastewater by the combination of anaerobic and aerobic biological process, a research of treating wastewater in UASB reactor and aeration basin has been conducted. The test results shows that under moderate temperature, with 5\^2 kgCOD/(m\+3·d) volumetric load of COD Cr in the UASB reactor and 24h of HRT, 85% removal rate of BOD 5 and 83% of COD \{Cr\} and 1\^34 m\+3/(m\+3·d) volumetric gas production rate can be obtained respectively. The aerobic bio degradability can be increased by 20%—30% after the petro chemical wastewater has been treated by anaerobic process. As Ns=0\^45 kgCOD/(kgMLSS·d), HRT=4h in the aeration tank, 94% removal rate of BOD 5, 93% of COD \{Cr\}, 98\^8% total removal rate of COD \{Cr\} and 99% removal rate of BOD 5 can be reached.展开更多
Membrane fouling curtails severely the economical and practical implementation of membrane process. The fundamental principles and mechanisms of membrane fouling as well as factors affecting fouling have been summariz...Membrane fouling curtails severely the economical and practical implementation of membrane process. The fundamental principles and mechanisms of membrane fouling as well as factors affecting fouling have been summarized in this paper. It also has covered three fouling resistance models and four kinds of approaches to improve membrane performance. Membrane cleaning methods are also discussed including physical, chemical, physico\|chemical and biological methods. In the four groups of basic cleaning methods, biological cleaning has considerable advantages and potentials. Extensive research work should be carried out further to explore and develop new ideas and techniques in the field of membrane cleaning and restoration.展开更多
Based upon the deep seismic sounding profile conducted in the Tengchong volcanic-geothermal area, a two-dimensional crustal P velocity structure is obtained by use of the finite-difference inversion and the forward tr...Based upon the deep seismic sounding profile conducted in the Tengchong volcanic-geothermal area, a two-dimensional crustal P velocity structure is obtained by use of the finite-difference inversion and the forward travel-time fitting method. The crustal model shows that there is a low velocity zone in upper crust in the Tengchong area, which may be related to the volcanic-geothermal activities, and two intracrustal faults (the LonglingRuili fault and Tengchong fault) exist on the profile, where the Tengchong fault may extend to the Moho discontinuity. Meanwhile, based on teleseismic data recorded by a temporary seismic network, we obtained the S-wave velocity structures beneath the RehaiRetian region in the Tengchong area, which show the low S-wave velocity anomaly in upper crust. The authors discuss the causes of Tengchong volcanic eruption based on the deep crustal structure. The crustal structure in the Tengchong volcanic-geothermal area is characterized by low P-wave and S-wave velocity, low resistivity, high heat-flow value and low Q value. The P-wave velocity in the upper mantle is also low. For this information, it can be induced that the magma in the crust is derived from the upper mantle, and the low velocity anomaly in upper crust in the Tengchong area may be related to the differentiation of magma. The Tengchong volcanoes are close to an active plate boundary and belong to plate boundary volcanoes.展开更多
Destruction of trichloro ethylene (C 2HCl 3) by pulsed corona discharge reactor packed with alumina pellets and in absence of packing was investigated. Higher conversion of C 2HCl 3 was observed in presence of alu...Destruction of trichloro ethylene (C 2HCl 3) by pulsed corona discharge reactor packed with alumina pellets and in absence of packing was investigated. Higher conversion of C 2HCl 3 was observed in presence of alumina than in absence of packing. Furthermore CO/CO 2 ratio in the by products was found to shift in favor of CO 2 by alumina compared with absence of packing. Influence of catalyst porosity on C 2HCl 3 destruction and on by product ozone generation during the processing was also studied. Both alumina Ⅰ and alumina Ⅱ show similar improvement in C 2HCl 3 destruction. However, more important observation was that alumina Ⅰ produces higher by product ozone, while, alumina Ⅱ produces lower by product ozone, than in the case of no packing. The catalyst porosity effect was also investigated for destruction of toluene and was found to be similar. Intermediates of C 2HCl 3 destruction, as identified by GC MS, were COCl 2, CH 2Cl 2CHCl 3, CCl 4 and C 2HCl 5. In presence of alumina the amount of these intermediates was much reduced, indicating the catalytic function of alumina.展开更多
This paper studied the change in soil animal community in contaminated and irrigated area by organophosphorus pesticide waste water and its mechanism was discussed. The results showed that the species and quantities o...This paper studied the change in soil animal community in contaminated and irrigated area by organophosphorus pesticide waste water and its mechanism was discussed. The results showed that the species and quantities of soil animals decreased with organophosphorus pesticide pollution degree increasing. The species of soil animals decreased with average and rare population mainly decreasing, while the amount change was associated with that of the dominant population of Acarina, Collembola and Nematoda. Toxicity experiment demonstrated that the respiration intensity of soil animal was restrained obviously by pesticide pollution. After observation of SEM, the effect of pesticide pollution on the earthworm (\%Pheretima robusta)\% stomach intestinal mucosa damage has been observed, which showed the pesticide contamination may damage the earthworms bodies. Ulcerous focus and perforation on stomach mucosa were usually seen. The stomach microvilli appeared atrophic and disordered especially in the bodies of these earthworms growing in seriously polluted soil, bad atrophic phenomena were seen not only on the stomach mucosa microvilli but also on the cilia of the intestinal mucosa which appeared swollen as a spheroid. Under TEM, RER and Golgi compound dilatation, chondrisome swell and ridge disappearance were observed on cells of stomach epithelium mucosa of \%P.robusta\% collected from heavy polluted area. By calculation, the safety concentration of earthworm in methamidophos pesticide is 0\^2517 ml/L.展开更多
A series solution for surface motion amplification due to underground group cavities for incident plane P waves is derived by Fourier-Bessel series expansion method. It is shown that underground group cavities signifi...A series solution for surface motion amplification due to underground group cavities for incident plane P waves is derived by Fourier-Bessel series expansion method. It is shown that underground group cavities significantly am-plify the surface ground motion nearby. It is suggested that the effect of subways on ground motion should be con-sidered when the subways are planned and designed.展开更多
In order to decrease the deformation and stress and increase the natural frequency of the fixed table,a method of optimization driven by the sensitivity and topology analyses is proposed.The finite element model of th...In order to decrease the deformation and stress and increase the natural frequency of the fixed table,a method of optimization driven by the sensitivity and topology analyses is proposed.The finite element model of the fixed table is constructed and analyzed by using ANSYS software.Based on the results of static analysis and modal analysis,the maximum deformation,the maximum stress,and natural frequencies are obtained.Then,the sensitivity analysis and topology optimization are carried out to find out the parameters to be optimized.The fixed table is reconstructed according to optimal design scheme.In the comparison of the results between original model and the optimized one,the maximum deformation and stress are decreased by 71.73%and 60.27%respectively.At the same time,the natural frequencies from the first mode to the sixth mode are increased by 30.28%,29.57%,29.51%,31.52%,22.19%,and 21.80%,respectively.The method can provide technology guide for the design and optimization of machining structure.展开更多
Inspired by the idea that bionic non-smooth surfaces(BNSS)can reduce water flow resistance,the application of BNSS resistance reduction method in grooves surface of antiskid tire tread pattern has been investigated fo...Inspired by the idea that bionic non-smooth surfaces(BNSS)can reduce water flow resistance,the application of BNSS resistance reduction method in grooves surface of antiskid tire tread pattern has been investigated for increasing hydroplaning velocity of tire by using computational fluid dynamics(CFD)simulation.Three kinds of BNSS(riblet,convex dome,and dimple concave)are arranged in tire tread grooves to study the water flow resistance effects in grooves with non-smooth characteristics.A tire-water coupled model is established and CFD technique is applied to simulating hydroplaning.The simulation results show that BNSS grooves can reduce water flow resistance and increase mean flow rate by disturbing the eddy movement in boundary layers.The drag forces of riblet and dimple surface are lower and drainage capacity is higher than those of smooth surface under the same void space on tread pattern,but it is not in dome.BNSS is a good way to promote antiskid performance without increasing additional groove space;extra tire-road noise production is therefore avoided due to groove space enlargement.展开更多
Nanometer perovskite LaMnO 3+λ, La 0.6Ce 0.4MnO 3+λ and La 0.6Sr 0.4MnO 3+λ were prepared by citric acid-aid ed sol-gel method. The effects of Ce, Sr on the structure and properties of nan ome...Nanometer perovskite LaMnO 3+λ, La 0.6Ce 0.4MnO 3+λ and La 0.6Sr 0.4MnO 3+λ were prepared by citric acid-aid ed sol-gel method. The effects of Ce, Sr on the structure and properties of nan ometer perovskite were studied through DT-TGA, XRD, TEM and BET analyses. The r esults show that, by sol-gel method, LaMnO 3+λ, La 0.6Ce 0. 4MnO 3+λ and La 0.6Sr 0.4MnO 3+λ were made with average particle size of about 60, 100 and 30 nm, respectively. After partially substituting Sr on La positions in LaMnO 3+λ, it is found that Sr is l ocated at the perovskite lattice so as to reduce the formation temperature of th e perovskite. As a result, the perovskite has a smaller particle size and larger specific surface area. On the contrary, it is difficult for Ce to enter the per ovskite lattice. Ce exists mostly in the form of CeO 2 as partially substitutin g La in LaMnO 3+λ. The formation temperature of the perovskite increas es, and the catalyst containing CeO 2 presents a larger particle size and less specific surface area.展开更多
Ecosystem health is a newly proposed concept that sets new goals for environmental management. Its definition, assessment indicators, and assessment methods are reviewed in this paper. Literature shows that the defini...Ecosystem health is a newly proposed concept that sets new goals for environmental management. Its definition, assessment indicators, and assessment methods are reviewed in this paper. Literature shows that the definitions and the assessment indicators cover a wide range of ecosystem health, and they differ in terms of researchers different scientific background. It is concluded that the concept of ecosystem health cannot be defined or understood simply in biological or ethical or aesthetic or historical terms and the assessment should be based on applying several indicators simultaneously to get overall picture of the health or integrity state of an ecosystem.展开更多
To demonstrate the feasibility of using bioaugmentation to enhance biodegradation of quinoline, four strains capable of using quinoline as sole source of carbon, nitrogen and energy were isolated from different enviro...To demonstrate the feasibility of using bioaugmentation to enhance biodegradation of quinoline, four strains capable of using quinoline as sole source of carbon, nitrogen and energy were isolated from different environmental samples by enrichment technique. Screening for quinoline degrader with the highest quinoline mineralizing rate was carried out in respirometer and one bacterium identified as \%Burkholderia pickettii W2\% was chosen as inoculum in bioaugmentation tests. Quinoline biodegradation experiment results showed that this bacterium degraded quinoline very quickly. 100, 200 and 500 mg/L quinoline can be transformed completely within 1, 2 and 7 hours respectively. A bioaugmentation procedure was proposed and laboratory experiments confirmed that bioaugmentation was an effective way to improve the performance of traditional wastewater treatment facilities for quinoline removal. The effect of inoculum size on bioaugmentation was also investigated in this paper.展开更多
The additives such as phosphoric acid, calcium phosphate, calcium super phosphate, calcium over super phosphate, calcium carbonate, sodium hydrosulphite, etc. were used to produce furfural from the straw by hydrolys...The additives such as phosphoric acid, calcium phosphate, calcium super phosphate, calcium over super phosphate, calcium carbonate, sodium hydrosulphite, etc. were used to produce furfural from the straw by hydrolysis with sulfuric acid. The effect of amount of the additives, the content of the added substance and the conditions of distillation on the acidity of the residues were studied. The experiment results showed that the all residues became neutral complex fertilizer, and the productivity of furfural increases under the following conditions: sulfuric acid concentration is 20% (by weight), the ratio of liquid to solid is 3∶1—4∶1 (by weight), the ratio of the additives to straw is suitable.展开更多
With the rapid economic development and the speeding up of urbanization, the urban environmental problems in China are experiencing a progressive transition, which is characterized by steady transferring to the living...With the rapid economic development and the speeding up of urbanization, the urban environmental problems in China are experiencing a progressive transition, which is characterized by steady transferring to the living (or consumption) oriented pollution pattern from the production oriented pollution pattern. Regarding this transition, the environmental education recognized as an important measure for approaching the objective of sustainable development, should transfer its focus correspondingly in urban area, which is to transfer to the habit cultivating pattern on the basis of the traditional knowledge inputting environmental education pattern. In practice, the urban environmental education should emphasize more on developing or cultivating the sustainable living mode of the urban residents, especially the students in elementary and primary schools and women. By this transform, the environmental education may be guided further towards sustainable development, and to serve the achievement of sustainable cities better in China.展开更多
Polyferric\|silicate\|sulfate(PFSS),as a new type of coagulant,was prepared by using sodium silicate, sulfuric acid and ferric sulfate as materials.The zeta potential of hydrolyzate of PFSS under different pH values w...Polyferric\|silicate\|sulfate(PFSS),as a new type of coagulant,was prepared by using sodium silicate, sulfuric acid and ferric sulfate as materials.The zeta potential of hydrolyzate of PFSS under different pH values was investigated.The effects of Fe/SiO\-2 molar ratio and dosage of PFSS on turbidity removal were studied. The relation between the optimum coagulation pH range and Fe/SiO\-2 molar ratio was found and the coagulation mechanism of PFSS was discussed.The experimental results showed that Fe/SiO\-2 molar ratio has an effect on the zeta potential of hydrolyzate, the coagulation performance and the optimum coagulation pH range of PFSS and that PFSS gives the best turbidity removal effect when its Fe/SiO\-2 molar ratio was 1.5.展开更多
A numerical model has been developed to simulate the transport and fate of oil spilled at sea. The model combines the transport and fate processes of spilled oil with the random walk technique. Oil movement under th...A numerical model has been developed to simulate the transport and fate of oil spilled at sea. The model combines the transport and fate processes of spilled oil with the random walk technique. Oil movement under the influence of tidal currents, wind driven currents, and turbulent eddies is simulated by the PLUME RW dispersion model developed by HR Wallingford. The weathering processes in the model represent physical and chemical changes of soil slicks with time, and comprise mechanical spreading, dispersion, evaporation and emulsification. Shoreline stranding is determined approximately using a capacity method for different shoreline types. This paper presents details of the model, and describe the results of various sensitivity tests. The model is suitable for oil spill contingency planning.展开更多
To understand the earthquake characteristics in Xinfengjiang (XFJ for short) reservoir area, we collected the small earthquakes occurred in the area from 1961 to 1999. We segmented this 40-year period, parted the rese...To understand the earthquake characteristics in Xinfengjiang (XFJ for short) reservoir area, we collected the small earthquakes occurred in the area from 1961 to 1999. We segmented this 40-year period, parted the research region and calculated the composite fault plane solution of each block, disscussed the effect characteristics of stress field of water pressure using Mohrs stress circle. The final result shows that the main rupture pattern was very different before and after the M = 6.1 main shock, changing from strike slip to normal rupture. The maximum principal stress axes of composite fault plane solutions are characterized by synchronous change with water level.展开更多
基金Hangzhou Philosophy and Social Science Planning Program(24JD15)。
文摘National Fire codes,mandated by government authorities to tackle technical challenges in fire prevention and control,establish fundamental standards for construction practices.International collaboration in fire protection technologies has opened avenues for China to access a wealth of documents and codes,which are crucial in crafting regulations and developing a robust,scientific framework for fire code formulation.However,the translation of these codes into Chinese has been inadequate,thereby diminishing the benefits of technological exchange and collaborative learning.This underscores the necessity for comprehensive research into code translation,striving for higher-quality translations guided by established translation theories.In this study,we translated the initial segment of the NFPA 1 Fire Code into Chinese and examined both the source text and target text through the lens of Translation Shift Theory,a concept introduced by Catford.The conclusion culminated in identifying four key shifts across various linguistic levels:lexis,sentences,and groups,to ensure an accurate and precise translation of fire codes.This study offers a through and lucid explanation of how the translator integrates Catford’s theories to solve technical challenges in NFPA 1 Fire Code translation,and establish essential standards for construction translation practices.
基金This study was supported by Innovation Research Project of Chinese Academy of Sciences and the Ministry of Culture and Education Japanese Government.
文摘Based on the discussion of relationships between thinning and wind damage, and published information, a method for estimating risk ratios of wind damage was developed. Estimations of risk-ratio for Pinus thunbergii trees and stands were de-duced from stem bending theory and coefficients characterizing wind profile, distribution of branches and optical stratification po-rosity. The results showed that if the value of constant b in the branch distribution-model equals the attenuation coefficient s in the wind profile model for a single tree crown, then the parameter H/D1.33 (height over stem diameter cubed) can be used to compare and evaluate the risk-ratio of wind damage for individual trees. The same method can be applied to stands using the coefficient of wind profile in a stand, i.e. attenuation coefficient , the coefficient from distributions of optical stratification porosity, i.e. extinction coefficient , and the parameter D1.33. The application of parameter H/D1.33 and the process of determining risk ra-tios of wind damage for stands were also given in the paper.
基金Research Committee of the University of Macao(Grant No.MYRG123-ICMS12 and MYRG111-ICMS13)from Macao Science and Technology Development Fund(Grant No.010/2013/A1)
文摘Chronic alcohol consumption induces hepatic steatosis, the early stage of alcoholic liver disease （ALD）. The aim ofpresent study is to investigate the protective effect ofPanax notoginseng saponins （PNS） against chronic ethanol-induced hepaticsteatosis in vivo. Mice were pair-fed a modified Lieber-DeCarli liquid diet containing alcohol or isocaloric maltose dextrin ascontrol diet with or without PNS （200 mg/kg, BW） for 8 weeks. Animals supplemented with PNS were protected against hepaticlipid accumulation induced by chronic ethanol exposure. Accordingly, PNS could significantly decrease the elevation of plasmatriglyceride, plasma enzyme activities, i.e. alanine aminotransferase （ALT） and aspartate aminotransferase （AST）, and hepaticTNF-ct and IL-6 levels which were induced by chronic alcohol exposure. In addition, PNS markedly reduced the lipolysis ofwhite adipose tissue （WAT） that stimulated by alcohol feeding through the inhibiting protein expression of phosphorylation ofhormone-sensitive lipase （p-HSL）, rather than total HSL. Furthermore, alcohol exposure also enhanced fatty acid uptake capacityin liver by elevated hepatic CD36 expression, which could attenuated by PNS treatment. These results demonstrate that PNSsupplementation protects against chronic ethanol-induced hepatic steatosis, which is associated with ameliorating dysfunctionallipid metabolism of WAT and the reduced inflammatory cytokines. Our findings suggested that PNS might be potential to bedeveloped as an effective agent for the treatment of chronic alcoholic steatosis.
文摘The effluent from the pulping of E. urophylla by alkali sodium sulfite chemi mechanical process(AS-CMP) was characterized for its biodegradability by photosynthetic bacteria (PSB). Chemical coagulation post treatment of biotreated wastewater was also studied. One month continuous treatment in the laboratory indicated that the COD Cr , BOD 5 and SS removals in biotreatment stages reached 56%, 83% and 89% respectively, and the CH 2Cl 2 extractives decreased from 10.7 mg/L to 7.7 mg/L. In chemical coagulation post treatment stage, the effects of process conditions, such as coagulant dosage, pH value and the coordinated coagulation flocculation treatment of three kinds of coagulants on coagulation effectiveness were discussed. The optimum operating conditions were given.
文摘In order to study the feasibility of treating petro chemical wastewater by the combination of anaerobic and aerobic biological process, a research of treating wastewater in UASB reactor and aeration basin has been conducted. The test results shows that under moderate temperature, with 5\^2 kgCOD/(m\+3·d) volumetric load of COD Cr in the UASB reactor and 24h of HRT, 85% removal rate of BOD 5 and 83% of COD \{Cr\} and 1\^34 m\+3/(m\+3·d) volumetric gas production rate can be obtained respectively. The aerobic bio degradability can be increased by 20%—30% after the petro chemical wastewater has been treated by anaerobic process. As Ns=0\^45 kgCOD/(kgMLSS·d), HRT=4h in the aeration tank, 94% removal rate of BOD 5, 93% of COD \{Cr\}, 98\^8% total removal rate of COD \{Cr\} and 99% removal rate of BOD 5 can be reached.
文摘Membrane fouling curtails severely the economical and practical implementation of membrane process. The fundamental principles and mechanisms of membrane fouling as well as factors affecting fouling have been summarized in this paper. It also has covered three fouling resistance models and four kinds of approaches to improve membrane performance. Membrane cleaning methods are also discussed including physical, chemical, physico\|chemical and biological methods. In the four groups of basic cleaning methods, biological cleaning has considerable advantages and potentials. Extensive research work should be carried out further to explore and develop new ideas and techniques in the field of membrane cleaning and restoration.
基金The Climb Program (95-S-05-01) of National Scientific and Technological Ministry of China, the Key Project (95-11-02) from China Seismological Bureau, the State Natural Sciences Foundation of China (49974020) and the Joint Earthquake S
文摘Based upon the deep seismic sounding profile conducted in the Tengchong volcanic-geothermal area, a two-dimensional crustal P velocity structure is obtained by use of the finite-difference inversion and the forward travel-time fitting method. The crustal model shows that there is a low velocity zone in upper crust in the Tengchong area, which may be related to the volcanic-geothermal activities, and two intracrustal faults (the LonglingRuili fault and Tengchong fault) exist on the profile, where the Tengchong fault may extend to the Moho discontinuity. Meanwhile, based on teleseismic data recorded by a temporary seismic network, we obtained the S-wave velocity structures beneath the RehaiRetian region in the Tengchong area, which show the low S-wave velocity anomaly in upper crust. The authors discuss the causes of Tengchong volcanic eruption based on the deep crustal structure. The crustal structure in the Tengchong volcanic-geothermal area is characterized by low P-wave and S-wave velocity, low resistivity, high heat-flow value and low Q value. The P-wave velocity in the upper mantle is also low. For this information, it can be induced that the magma in the crust is derived from the upper mantle, and the low velocity anomaly in upper crust in the Tengchong area may be related to the differentiation of magma. The Tengchong volcanoes are close to an active plate boundary and belong to plate boundary volcanoes.
文摘Destruction of trichloro ethylene (C 2HCl 3) by pulsed corona discharge reactor packed with alumina pellets and in absence of packing was investigated. Higher conversion of C 2HCl 3 was observed in presence of alumina than in absence of packing. Furthermore CO/CO 2 ratio in the by products was found to shift in favor of CO 2 by alumina compared with absence of packing. Influence of catalyst porosity on C 2HCl 3 destruction and on by product ozone generation during the processing was also studied. Both alumina Ⅰ and alumina Ⅱ show similar improvement in C 2HCl 3 destruction. However, more important observation was that alumina Ⅰ produces higher by product ozone, while, alumina Ⅱ produces lower by product ozone, than in the case of no packing. The catalyst porosity effect was also investigated for destruction of toluene and was found to be similar. Intermediates of C 2HCl 3 destruction, as identified by GC MS, were COCl 2, CH 2Cl 2CHCl 3, CCl 4 and C 2HCl 5. In presence of alumina the amount of these intermediates was much reduced, indicating the catalytic function of alumina.
文摘This paper studied the change in soil animal community in contaminated and irrigated area by organophosphorus pesticide waste water and its mechanism was discussed. The results showed that the species and quantities of soil animals decreased with organophosphorus pesticide pollution degree increasing. The species of soil animals decreased with average and rare population mainly decreasing, while the amount change was associated with that of the dominant population of Acarina, Collembola and Nematoda. Toxicity experiment demonstrated that the respiration intensity of soil animal was restrained obviously by pesticide pollution. After observation of SEM, the effect of pesticide pollution on the earthworm (\%Pheretima robusta)\% stomach intestinal mucosa damage has been observed, which showed the pesticide contamination may damage the earthworms bodies. Ulcerous focus and perforation on stomach mucosa were usually seen. The stomach microvilli appeared atrophic and disordered especially in the bodies of these earthworms growing in seriously polluted soil, bad atrophic phenomena were seen not only on the stomach mucosa microvilli but also on the cilia of the intestinal mucosa which appeared swollen as a spheroid. Under TEM, RER and Golgi compound dilatation, chondrisome swell and ridge disappearance were observed on cells of stomach epithelium mucosa of \%P.robusta\% collected from heavy polluted area. By calculation, the safety concentration of earthworm in methamidophos pesticide is 0\^2517 ml/L.
基金Supported by National Natural Science Foundation of China (50378063), Excellent Young Teachers Program of MOE and SRF for ROCS, MOE.
文摘A series solution for surface motion amplification due to underground group cavities for incident plane P waves is derived by Fourier-Bessel series expansion method. It is shown that underground group cavities significantly am-plify the surface ground motion nearby. It is suggested that the effect of subways on ground motion should be con-sidered when the subways are planned and designed.
基金National Major Scientific&Technological Special Program for"High-Grade CNC and Basic Manufacturing Equipment"of China(No.2012ZX04011-031)Science and Technology Programs of Sichuan Province,China(No.2010GZ0250,No.2011GZ0075)
文摘In order to decrease the deformation and stress and increase the natural frequency of the fixed table,a method of optimization driven by the sensitivity and topology analyses is proposed.The finite element model of the fixed table is constructed and analyzed by using ANSYS software.Based on the results of static analysis and modal analysis,the maximum deformation,the maximum stress,and natural frequencies are obtained.Then,the sensitivity analysis and topology optimization are carried out to find out the parameters to be optimized.The fixed table is reconstructed according to optimal design scheme.In the comparison of the results between original model and the optimized one,the maximum deformation and stress are decreased by 71.73%and 60.27%respectively.At the same time,the natural frequencies from the first mode to the sixth mode are increased by 30.28%,29.57%,29.51%,31.52%,22.19%,and 21.80%,respectively.The method can provide technology guide for the design and optimization of machining structure.
基金Colleges and Universities in Jiangsu Province Pans to Graduate Research and Innovation,China(No.CXLX13_676)Jiangsu Province Six Talents Peak Project,China(No.2011A031)
文摘Inspired by the idea that bionic non-smooth surfaces(BNSS)can reduce water flow resistance,the application of BNSS resistance reduction method in grooves surface of antiskid tire tread pattern has been investigated for increasing hydroplaning velocity of tire by using computational fluid dynamics(CFD)simulation.Three kinds of BNSS(riblet,convex dome,and dimple concave)are arranged in tire tread grooves to study the water flow resistance effects in grooves with non-smooth characteristics.A tire-water coupled model is established and CFD technique is applied to simulating hydroplaning.The simulation results show that BNSS grooves can reduce water flow resistance and increase mean flow rate by disturbing the eddy movement in boundary layers.The drag forces of riblet and dimple surface are lower and drainage capacity is higher than those of smooth surface under the same void space on tread pattern,but it is not in dome.BNSS is a good way to promote antiskid performance without increasing additional groove space;extra tire-road noise production is therefore avoided due to groove space enlargement.
文摘Nanometer perovskite LaMnO 3+λ, La 0.6Ce 0.4MnO 3+λ and La 0.6Sr 0.4MnO 3+λ were prepared by citric acid-aid ed sol-gel method. The effects of Ce, Sr on the structure and properties of nan ometer perovskite were studied through DT-TGA, XRD, TEM and BET analyses. The r esults show that, by sol-gel method, LaMnO 3+λ, La 0.6Ce 0. 4MnO 3+λ and La 0.6Sr 0.4MnO 3+λ were made with average particle size of about 60, 100 and 30 nm, respectively. After partially substituting Sr on La positions in LaMnO 3+λ, it is found that Sr is l ocated at the perovskite lattice so as to reduce the formation temperature of th e perovskite. As a result, the perovskite has a smaller particle size and larger specific surface area. On the contrary, it is difficult for Ce to enter the per ovskite lattice. Ce exists mostly in the form of CeO 2 as partially substitutin g La in LaMnO 3+λ. The formation temperature of the perovskite increas es, and the catalyst containing CeO 2 presents a larger particle size and less specific surface area.
文摘Ecosystem health is a newly proposed concept that sets new goals for environmental management. Its definition, assessment indicators, and assessment methods are reviewed in this paper. Literature shows that the definitions and the assessment indicators cover a wide range of ecosystem health, and they differ in terms of researchers different scientific background. It is concluded that the concept of ecosystem health cannot be defined or understood simply in biological or ethical or aesthetic or historical terms and the assessment should be based on applying several indicators simultaneously to get overall picture of the health or integrity state of an ecosystem.
文摘To demonstrate the feasibility of using bioaugmentation to enhance biodegradation of quinoline, four strains capable of using quinoline as sole source of carbon, nitrogen and energy were isolated from different environmental samples by enrichment technique. Screening for quinoline degrader with the highest quinoline mineralizing rate was carried out in respirometer and one bacterium identified as \%Burkholderia pickettii W2\% was chosen as inoculum in bioaugmentation tests. Quinoline biodegradation experiment results showed that this bacterium degraded quinoline very quickly. 100, 200 and 500 mg/L quinoline can be transformed completely within 1, 2 and 7 hours respectively. A bioaugmentation procedure was proposed and laboratory experiments confirmed that bioaugmentation was an effective way to improve the performance of traditional wastewater treatment facilities for quinoline removal. The effect of inoculum size on bioaugmentation was also investigated in this paper.
文摘The additives such as phosphoric acid, calcium phosphate, calcium super phosphate, calcium over super phosphate, calcium carbonate, sodium hydrosulphite, etc. were used to produce furfural from the straw by hydrolysis with sulfuric acid. The effect of amount of the additives, the content of the added substance and the conditions of distillation on the acidity of the residues were studied. The experiment results showed that the all residues became neutral complex fertilizer, and the productivity of furfural increases under the following conditions: sulfuric acid concentration is 20% (by weight), the ratio of liquid to solid is 3∶1—4∶1 (by weight), the ratio of the additives to straw is suitable.
文摘With the rapid economic development and the speeding up of urbanization, the urban environmental problems in China are experiencing a progressive transition, which is characterized by steady transferring to the living (or consumption) oriented pollution pattern from the production oriented pollution pattern. Regarding this transition, the environmental education recognized as an important measure for approaching the objective of sustainable development, should transfer its focus correspondingly in urban area, which is to transfer to the habit cultivating pattern on the basis of the traditional knowledge inputting environmental education pattern. In practice, the urban environmental education should emphasize more on developing or cultivating the sustainable living mode of the urban residents, especially the students in elementary and primary schools and women. By this transform, the environmental education may be guided further towards sustainable development, and to serve the achievement of sustainable cities better in China.
文摘Polyferric\|silicate\|sulfate(PFSS),as a new type of coagulant,was prepared by using sodium silicate, sulfuric acid and ferric sulfate as materials.The zeta potential of hydrolyzate of PFSS under different pH values was investigated.The effects of Fe/SiO\-2 molar ratio and dosage of PFSS on turbidity removal were studied. The relation between the optimum coagulation pH range and Fe/SiO\-2 molar ratio was found and the coagulation mechanism of PFSS was discussed.The experimental results showed that Fe/SiO\-2 molar ratio has an effect on the zeta potential of hydrolyzate, the coagulation performance and the optimum coagulation pH range of PFSS and that PFSS gives the best turbidity removal effect when its Fe/SiO\-2 molar ratio was 1.5.
文摘A numerical model has been developed to simulate the transport and fate of oil spilled at sea. The model combines the transport and fate processes of spilled oil with the random walk technique. Oil movement under the influence of tidal currents, wind driven currents, and turbulent eddies is simulated by the PLUME RW dispersion model developed by HR Wallingford. The weathering processes in the model represent physical and chemical changes of soil slicks with time, and comprise mechanical spreading, dispersion, evaporation and emulsification. Shoreline stranding is determined approximately using a capacity method for different shoreline types. This paper presents details of the model, and describe the results of various sensitivity tests. The model is suitable for oil spill contingency planning.
文摘To understand the earthquake characteristics in Xinfengjiang (XFJ for short) reservoir area, we collected the small earthquakes occurred in the area from 1961 to 1999. We segmented this 40-year period, parted the research region and calculated the composite fault plane solution of each block, disscussed the effect characteristics of stress field of water pressure using Mohrs stress circle. The final result shows that the main rupture pattern was very different before and after the M = 6.1 main shock, changing from strike slip to normal rupture. The maximum principal stress axes of composite fault plane solutions are characterized by synchronous change with water level.
