A novel method for the preparation of single-phase ammonium dimolybdate with industrial ammonium molybdate was studied. Various in- fluential factors were evaluated in the paper, including reaction temperature, reacti...A novel method for the preparation of single-phase ammonium dimolybdate with industrial ammonium molybdate was studied. Various in- fluential factors were evaluated in the paper, including reaction temperature, reaction time, initial molybdenum concentration, initial NH_3 /Mo molar ratio, and stirring speed. Under the optimum experimental conditions, the crystallization rate of product is 85.23%. The X-ray diffraction (XRD) analysis and chemical analysis show that the product is single-phase ammonium dimolybdate, and no impurity phases exist. The scanning electronic microscope (SEM) image reveals uniform particle size, good particle dispersion, and no agglomeration between particles. Meanwhile, the final pH value of acidification was investigated. The total molybdenum recovery can reach up to 99.40%, and the main phases of acidification product are the same as those of raw material with the final pH value of 1.5. This determines that the acidification product can be used as a raw material to produce single-phase ammonium dimolybdate.展开更多
A job shop scheduling problem with a combination processing in complex production environment is proposed. Based on the defining of ＂non-elastic combination processing relativity＂ and ＂virtual process＂, the proble...A job shop scheduling problem with a combination processing in complex production environment is proposed. Based on the defining of ＂non-elastic combination processing relativity＂ and ＂virtual process＂, the problem can be simplified and transformed to a traditional one. On the basis of the dispatching rules select engine and considered factors of complex production environment, a heuristic method is designed. The algorithm has been applied to a mould enterprise in Shenzhen for half a year. The practice showed that by using the method suggested the number of delayed orders was decreased about 20% and the productivity was increased by 10 to 20%.展开更多
Bananas are highly perishable after harvest,and processing them into dried products is a crucial approach to reducing losses and adding their economic values.To address the inefficiency and prolonged duration of tradi...Bananas are highly perishable after harvest,and processing them into dried products is a crucial approach to reducing losses and adding their economic values.To address the inefficiency and prolonged duration of traditional hot air drying(HAD)and the quality inconsistency associated with single infrared drying(IRD),this study proposed a novel hot air-infrared combined drying(HAD-IRD)strategy.The effects of HAD,IRD,and HAD-IRD on the drying kinetics,color,rehydration capacity,moisture diffusion mechanism,and sensory quality of banana slices were systematically investigated.The parameters of the combined drying process were optimized using an L_(9)(3^(3))orthogonal experimental design.Results indicated that both IRD and HAD-IRD significantly reduced drying time compared to single HAD.While single IRD achieved a rapid drying rate,the lack of effective convective airflow led to potential case-hardening and unstable product quality.In contrast,the HAD-IRD strategy demonstrated a synergistic effect.The optimal parameters were determined as follows:hot air temperature of 70℃,infrared temperature of 60℃,and radiation distance of 16 cm.Under these optimized conditions,HAD-IRD reduced the total drying time by over 70%while simultaneously yielding products with superior color,higher sensory scores,and improved rehydration ratio.This study confirms that HAD-IRD is an efficient and high-quality drying method for banana slices,providing a reliable theoretical foundation and technical solution for the drying of thermosensitive fruits.展开更多
The initial step in the resource utilization of Chinese medicine residues(CMRs)involves dehydration pretreatment,which results in high concentrations of organic wastewater and leads to environmental pollution.Meanwhil...The initial step in the resource utilization of Chinese medicine residues(CMRs)involves dehydration pretreatment,which results in high concentrations of organic wastewater and leads to environmental pollution.Meanwhile,to address the issue of anaerobic systems failing due to acidification under shock loading,a microaerobic expanded granular sludge bed(EGSB)and moving bed sequencing batch reactor(MBSBR)combined process was proposed in this study.Microaeration facilitated hydrolysis,improved the removal of nitrogen and phosphorus pollutants,maintained a low concentration of volatile fatty acids(VFAs),and enhanced system stability.In addition,microaeration promoted microbial richness and diversity,enriching three phyla:Bacteroidota,Synergistota and Firmicutes associated with hydrolytic acidification.Furthermore,aeration intensity in MBSBR was optimized.Elevated levels of dissolved oxygen(DO)impacted biofilm structure,suppressed denitrifying bacteria activity,led to nitrate accumulation,and hindered simultaneous nitrification and denitrification(SND).Maintaining a DO concentration of 2 mg/L enhanced the removal of nitrogen and phosphorus while conserving energy.The combined process achieved removal efficiencies of 98.25%,90.49%,and 98.55%for chemical oxygen demand(COD),total nitrogen(TN),and total phosphorus(TP),respectively.Typical pollutants liquiritin(LQ)and glycyrrhizic acid(GA)were completely degraded.This study presents an innovative approach for the treatment of high-concentration organic wastewater and provides a reliable solution for the pollution control in utilization of CMRs resources.展开更多
First,the analytical hierarchy process(AHP),which stands for the subjective weighting method,and the entropy method,which stands for the objective weighting method,are chosen to calculate the index weights of the cont...First,the analytical hierarchy process(AHP),which stands for the subjective weighting method,and the entropy method,which stands for the objective weighting method,are chosen to calculate the index weights of the contract risks of third party logistics(TPL),respectively.Then,they can determine the combination weights using the combination weighting method.Second,using the combination weights,the contract risks of TPL are evaluated through the fuzzy comprehensive evaluation method.According to the combination weights,the most important risk factor of the contract risks of TPL is choosing sub-contractors.The results are basically consistent with the facts and show that the weights determined by the combination weighting method can avoid the man-made deviations of the subjective weighting method on the one hand,and prevent results opposite to the reality brought about by the objective weighting method on the other hand.Meanwhile,the results of the fuzzy comprehensive evaluation are that the contract risks of TPL are at a high risk level.Roughly this matches real situations,and it indicates that the combination weighting method can generate the comprehensive assessment more scientifically and more reasonably as well.展开更多
This paper introduces and illustrates the concepts of geoecological process combinations and geographical or landscape dimensions by outlining the methodology of a Sino-German cooperative project in Southeast China an...This paper introduces and illustrates the concepts of geoecological process combinations and geographical or landscape dimensions by outlining the methodology of a Sino-German cooperative project in Southeast China and presents the first results of the modelling process for the catchment scale. The project equipped a catchment in subtropical Southeast China from plot scale to catchment scale in order to study the hydrological and soll erosion processes. Distinct spatial differences in principal water and soil material fluxes were quantified. Deep drainage peaks occurred in May, June and July and even in August and November. Measurements in erosion plots as well as sedimentary deposits revealed that there was soil erosion connected with overland flow. Consistent with the results from the regular catenary variations of soil colors, textural stratification and hydrograph analysis, there was also a clear indication of interflow from measured soil moisture data. The experimental set up has the potential to further deepen the understanding of small-scale processes involved in lateral water fluxes and soil erosion. The expected results and interpretations will lead to a further integration of the collected data. In the future, to understand matter transfer in and between landscape ecological units, agricultural influence on nutrient status and flux data will be incorporated.展开更多
Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in undergroun...Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in underground engineering.To reveal the effect of this way,the uniaxial compression experiments with PSC monitoring were conducted on three types of coal-rock combination samples with different strength combinations.The mechanism explanation of PSCs are investigated by resistivity test,atomic force microscopy(AFM)and computed tomography(CT)methods,and a PSC flow model based on progressive failure process is proposed.The influence of strength combinations on PSCs in the progressive failure process are emphasized.The results show the PSC responses between rock part,coal part and the two components are different,which are affected by multi-scale fracture characteristics and electrical properties.As the rock strength decreases,the progressive failure process changes obviously with the influence range of interface constraint effect decreasing,resulting in the different responses of PSC strength and direction in different parts to fracture behaviors.The PSC flow model is initially validated by the relationship between the accumulated charges of different parts.The results are expected to provide a new reference and method for mining design and roadway quality assessment.展开更多
As important emerging contaminants, antibiotics have caused potential hazards to the ecological environment and human health due to their extensive production and consumption. Among various techniques for removing ant...As important emerging contaminants, antibiotics have caused potential hazards to the ecological environment and human health due to their extensive production and consumption. Among various techniques for removing antibiotics from wastewater, H_(2)O_(2)-based advanced oxidation processes(AOPs) have received increasing attention due to their fast reaction rate and strong oxidation capability. Hence this review critically discusses:(i) Recent research progress of AOPs with the addition of H_(2)O_(2) for antibiotics removal through different methods of H_(2)O_(2) activation;(ii) recent advances in AOPs that can in-situ generate and activate H_(2)O_(2) for antibiotics removal;(iii) H_(2)O_(2)-based AOPs as a combination with other techniques for the degradation and mineralization of antibiotics in wastewater. Future perspectives about H_(2)O_(2)-based AOPs are also presented to grasp the future research trend in the area.展开更多
A laboratory scale test was conducted in a combined membrane process （CMP） with a capacity of 2.91 m3/d for 240 d to treat the mixed wastewater of humidity condensate, hygiene wastewater and urine in submarine cabin...A laboratory scale test was conducted in a combined membrane process （CMP） with a capacity of 2.91 m3/d for 240 d to treat the mixed wastewater of humidity condensate, hygiene wastewater and urine in submarine cabin during prolonged voyage. Removal performance of chemical oxygen demand （COD）, ammonia nitrogen （NH4^＋-N）, turbidity and anionic surfactants （LAS） was investigated under different conditions. It was observed that the effluent COD, NH4^＋-N, turbidity and LAS flocculated in ranges of 0.19-0.85 mg/L, 0.03-0.18 mg/L, 0.0-0.15 NTU and 0.0-0.05 mg/L, respectively in spite of considerable fluctuation in corresponding influent of 2120-5350 mg/L, 79.5-129.3 mg/L, 110-181.1NTU and 4.9-5.4 mg/L. The effluent quality of the CMP could meet the requirements of mechanical water and hygiene water according to the class I water quality standards in China （GB3838-2002）. The removal rates of COD, NH4^＋-N, turbidity and LAS removed in the MBR were more than 90%, which indicated that biodegradation is indispensable and plays a major role in the wastewater treatment and reuse. A model, built on the back propagation neural network （BPNN） theory, was developed for the simulation of CMP and produced high reliability. The average error of COD and NH4^＋-N was 5.14% and 6.20%, respectively, and the root mean squared error of turbidity and LAS was 2.76% and 1.41%, respectively. The results indicated that the model well fitted the laboratory data, and was able to simulate the removal of COD, NH4^＋-N, turbidity and LAS. It also suggested that the model proposed could reflect and manage the operation of CMP for the treatment of the mixed wastewaters in submarine.展开更多
District Ghizer is a rugged mountainous territory which experiences several landslides each year. There are 16 major landslide areas and 53 villages that are at high risk to hazards. Keeping in view the severity of na...District Ghizer is a rugged mountainous territory which experiences several landslides each year. There are 16 major landslide areas and 53 villages that are at high risk to hazards. Keeping in view the severity of natural hazards, the present study was designed to generate landslide susceptibility map based on twelve causative factors viz., slope, aspect, elevation, drainage network, Stream Power Index (SPI), Topographic Wetness Index (TWI), lithological units, fault lines, rainfall, road network, land cover and soil texture. Soil texture was determined by particle size analysis and data for other factors were acquired from freely available sources. Analytical Hierarchy Process (AHP) was employed to identify major landslide causative factors in the district Ghizer. Further, a temporal assessment from 1999 till 2015 was generated to assess the impact of land cover change on landslides. It indicated that the barren soil/ exposed rocks and glaciers have reduced while the vegetation and water classes have shown increment. The total area that lies in moderate to very high landslide susceptible zones was 74.38%, while slope is the main landslide causative factor in the district Ghizer. Validation of the susceptibility map showed 88.1% of the landslides in the study area had occurred in the moderate to very high susceptible zones.展开更多
Carbon capture and storage （CCS） technology will play a critical role in reducing anthropogenic carbondioxide （CO2） emission from fossil-fired power plants and other energy-intensive processes. However, theincreme...Carbon capture and storage （CCS） technology will play a critical role in reducing anthropogenic carbondioxide （CO2） emission from fossil-fired power plants and other energy-intensive processes. However, theincrement of energy cost caused by equipping a carbon capture process is the main barrier to its commer-cial deployment. To reduce the capital and operating costs of carbon capture, great efforts have been madeto achieve optimal design and operation through process modeling, simulation, and optimization. Accuratemodels form an essential foundation for this purpose. This paper presents a study on developing a moreaccurate rate-based model in Aspen Plus for the monoethanolamine （MEA）-based carbon capture processby multistage model validations. The modeling framework for this process was established first. The steady-state process model was then developed and validated at three stages, which included a thermodynamicmodel, physical properties calculations, and a process model at the pilot plant scale, covering a wide rangeof pressures, temperatures, and CO2 loadings. The calculation correlations of liquid density and interfacialarea were updated by coding Fortran subroutines in Aspen Plus. The validation results show that the cor-relation combination for the thermodynamic model used in this study has higher accuracy than those ofthree other key publications and the model prediction of the process model has a good agreement with thepilot plant experimental data. A case study was carried out for carbon capture from a 250 MWe combinedcycle gas turbine （CCGT） power plant. Shorter packing height and lower specific duty were achieved usingthis accurate model.展开更多
To resolve the data combination of Phased-array Ground Penetrating Radar (PAGPR), we first build a model of PAGPR and a layered model, and then a new data combination algorithm is presented based on it. This method ca...To resolve the data combination of Phased-array Ground Penetrating Radar (PAGPR), we first build a model of PAGPR and a layered model, and then a new data combination algorithm is presented based on it. This method calculates time delay of multi-receivers, basing on the signal of the nearest receiver, then shifts other signals and adds them up, and gets one signal at last. It has been proved that this method can restrain noise, multiple waves, clutter waves and improve the precision of time location. In the end, an example is given to prove the method's efficiency.展开更多
The selection of a landfill site is considered as a complicated task because this process is based on many factors and restrictions. For Al-Qasim Qadhaa, which is situated in the southern part of the Babylon Governora...The selection of a landfill site is considered as a complicated task because this process is based on many factors and restrictions. For Al-Qasim Qadhaa, which is situated in the southern part of the Babylon Governorate, Iraq, there is no landfill site in that area that conforms to the scientific criteria for selecting sites for landfill. For this reason, 15 criteria were adopted in this study （groundwater depth, rivers, soil types, agriculture lands use, land use, elevation, slope, gas pipelines, oil pipelines, power lines, roads, railways, urban centers, villages and archaeological sites） using GIS （geographic information system）, which has a large ability to manage input data. In addition, the AHP （analytical hierarchy process） method was used to derive the relative weightings for each criterion using pair-wise comparison. To obtain the suitability index for candidate landfill sites, a weighted linear combination method was used. After combining these methods, two suitable candidate landfill sites, with areas of 2.766 km2 and 2.055 km2, respectively, were found to satisfy the scientific and environmental requirements. The area of these sites can accommodate solid waste from 2020 until 2030 based on the required area, which was 0.702 km2.展开更多
Objective:The incidence of distal radius fracture combined with ulnar styloid process fracture is increasing,which seriously affects the quality of life of patients.Small splint therapy of Traditional Chinese Medicine...Objective:The incidence of distal radius fracture combined with ulnar styloid process fracture is increasing,which seriously affects the quality of life of patients.Small splint therapy of Traditional Chinese Medicine is a reliable method for the treatment of such fractures.It not only has good clinical efficacy,but also has fewer complications and high safety.However,the traditional small splint fixation does not cover the styloid process of the ulna,and the fracture of the styloid process of the ulna is closely related to the stability of the wrist joint,which has an important impact on the prognosis of the fracture.Based on this,we believe that the ulnar elongation splint can better improve the wrist function,and further prospects for related issues,in order to guide clinical practice.展开更多
The experiment was carried out in a combined blowing converter.The natural gas was supplied as the cooling medium for the bottom lance.The blow- ing practice of medium P hot metal (0.30-0.85% [P]) indicated that with ...The experiment was carried out in a combined blowing converter.The natural gas was supplied as the cooling medium for the bottom lance.The blow- ing practice of medium P hot metal (0.30-0.85% [P]) indicated that with better stirring at the bottom of the converter and lower P_(CO),this steelmgking process was favorable to reduce the amount of [C] and [O] and increase the (P_2O_5)/[P]. The maximum rate of dephospborization might be high up to 0.0a5%/min and the P content in steel could be reduced to lower than 0.03% by single slag-forming operation.展开更多
基金supported by the National Natural Science Foundation of China(No.51072233)
文摘A novel method for the preparation of single-phase ammonium dimolybdate with industrial ammonium molybdate was studied. Various in- fluential factors were evaluated in the paper, including reaction temperature, reaction time, initial molybdenum concentration, initial NH_3 /Mo molar ratio, and stirring speed. Under the optimum experimental conditions, the crystallization rate of product is 85.23%. The X-ray diffraction (XRD) analysis and chemical analysis show that the product is single-phase ammonium dimolybdate, and no impurity phases exist. The scanning electronic microscope (SEM) image reveals uniform particle size, good particle dispersion, and no agglomeration between particles. Meanwhile, the final pH value of acidification was investigated. The total molybdenum recovery can reach up to 99.40%, and the main phases of acidification product are the same as those of raw material with the final pH value of 1.5. This determines that the acidification product can be used as a raw material to produce single-phase ammonium dimolybdate.
基金Supported by Research Fund for the Doctoral Program of Higher Education of China(20060487072)National Key Technology R&D Program(2006BAF01A43)
文摘A job shop scheduling problem with a combination processing in complex production environment is proposed. Based on the defining of ＂non-elastic combination processing relativity＂ and ＂virtual process＂, the problem can be simplified and transformed to a traditional one. On the basis of the dispatching rules select engine and considered factors of complex production environment, a heuristic method is designed. The algorithm has been applied to a mould enterprise in Shenzhen for half a year. The practice showed that by using the method suggested the number of delayed orders was decreased about 20% and the productivity was increased by 10 to 20%.
基金funded by the National Natural Science Foundation of China,grant number 52306124(received by Dan Huang),URL:https://mp.weixin.qq.com/s/HHNYjgYKAynqYR7ySxYwzQ(accessed on 01 January 2025)the Changsha Municipal Natural Science Foundation,grant number kq2402259(received by Shuai Huang),URL:http://kjj.changsha.gov.cn/zfxxgk/tzgg_27202/202501/t20250122_11726939.html(accessed on 01 January 2025)the Regional Joint Funds of the Natural Science Foundation of Hunan Province,grant num-ber 2025JJ70463(received by Shuai Huang),URL:https://kjt.hunan.gov.cn/kjt/xxgk/tzgg/tzgg_1/202502/t20250212_33585991.html(accessed on 01 January 2025).
文摘Bananas are highly perishable after harvest,and processing them into dried products is a crucial approach to reducing losses and adding their economic values.To address the inefficiency and prolonged duration of traditional hot air drying(HAD)and the quality inconsistency associated with single infrared drying(IRD),this study proposed a novel hot air-infrared combined drying(HAD-IRD)strategy.The effects of HAD,IRD,and HAD-IRD on the drying kinetics,color,rehydration capacity,moisture diffusion mechanism,and sensory quality of banana slices were systematically investigated.The parameters of the combined drying process were optimized using an L_(9)(3^(3))orthogonal experimental design.Results indicated that both IRD and HAD-IRD significantly reduced drying time compared to single HAD.While single IRD achieved a rapid drying rate,the lack of effective convective airflow led to potential case-hardening and unstable product quality.In contrast,the HAD-IRD strategy demonstrated a synergistic effect.The optimal parameters were determined as follows:hot air temperature of 70℃,infrared temperature of 60℃,and radiation distance of 16 cm.Under these optimized conditions,HAD-IRD reduced the total drying time by over 70%while simultaneously yielding products with superior color,higher sensory scores,and improved rehydration ratio.This study confirms that HAD-IRD is an efficient and high-quality drying method for banana slices,providing a reliable theoretical foundation and technical solution for the drying of thermosensitive fruits.
基金funding from the National Key R&D Program of China(No.2019YFC1906600)the National Natural Science Foundation of China(No.52200049)+3 种基金the China Postdoctoral Science Foundation(No.2022TQ0089)the Heilongjiang Province Postdoctoral Science Foundation(No.LBH-Z22181)the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2023DX06)the Fundamental Research Funds for the Central Universities。
文摘The initial step in the resource utilization of Chinese medicine residues(CMRs)involves dehydration pretreatment,which results in high concentrations of organic wastewater and leads to environmental pollution.Meanwhile,to address the issue of anaerobic systems failing due to acidification under shock loading,a microaerobic expanded granular sludge bed(EGSB)and moving bed sequencing batch reactor(MBSBR)combined process was proposed in this study.Microaeration facilitated hydrolysis,improved the removal of nitrogen and phosphorus pollutants,maintained a low concentration of volatile fatty acids(VFAs),and enhanced system stability.In addition,microaeration promoted microbial richness and diversity,enriching three phyla:Bacteroidota,Synergistota and Firmicutes associated with hydrolytic acidification.Furthermore,aeration intensity in MBSBR was optimized.Elevated levels of dissolved oxygen(DO)impacted biofilm structure,suppressed denitrifying bacteria activity,led to nitrate accumulation,and hindered simultaneous nitrification and denitrification(SND).Maintaining a DO concentration of 2 mg/L enhanced the removal of nitrogen and phosphorus while conserving energy.The combined process achieved removal efficiencies of 98.25%,90.49%,and 98.55%for chemical oxygen demand(COD),total nitrogen(TN),and total phosphorus(TP),respectively.Typical pollutants liquiritin(LQ)and glycyrrhizic acid(GA)were completely degraded.This study presents an innovative approach for the treatment of high-concentration organic wastewater and provides a reliable solution for the pollution control in utilization of CMRs resources.
基金The National Key Technology R&D Program of China during the 11th Five-Year Plan Period(No.2006BAH02A06)
文摘First,the analytical hierarchy process(AHP),which stands for the subjective weighting method,and the entropy method,which stands for the objective weighting method,are chosen to calculate the index weights of the contract risks of third party logistics(TPL),respectively.Then,they can determine the combination weights using the combination weighting method.Second,using the combination weights,the contract risks of TPL are evaluated through the fuzzy comprehensive evaluation method.According to the combination weights,the most important risk factor of the contract risks of TPL is choosing sub-contractors.The results are basically consistent with the facts and show that the weights determined by the combination weighting method can avoid the man-made deviations of the subjective weighting method on the one hand,and prevent results opposite to the reality brought about by the objective weighting method on the other hand.Meanwhile,the results of the fuzzy comprehensive evaluation are that the contract risks of TPL are at a high risk level.Roughly this matches real situations,and it indicates that the combination weighting method can generate the comprehensive assessment more scientifically and more reasonably as well.
基金Project supported by the German Research Foundation (DFG) (No. ZE 254/4), the National Natural Science Foundationof China (No. 40071044), and the Chinese Academy of Sciences (No. KZCX2-413-5)
文摘This paper introduces and illustrates the concepts of geoecological process combinations and geographical or landscape dimensions by outlining the methodology of a Sino-German cooperative project in Southeast China and presents the first results of the modelling process for the catchment scale. The project equipped a catchment in subtropical Southeast China from plot scale to catchment scale in order to study the hydrological and soll erosion processes. Distinct spatial differences in principal water and soil material fluxes were quantified. Deep drainage peaks occurred in May, June and July and even in August and November. Measurements in erosion plots as well as sedimentary deposits revealed that there was soil erosion connected with overland flow. Consistent with the results from the regular catenary variations of soil colors, textural stratification and hydrograph analysis, there was also a clear indication of interflow from measured soil moisture data. The experimental set up has the potential to further deepen the understanding of small-scale processes involved in lateral water fluxes and soil erosion. The expected results and interpretations will lead to a further integration of the collected data. In the future, to understand matter transfer in and between landscape ecological units, agricultural influence on nutrient status and flux data will be incorporated.
基金supported by National Key R&D Program of China(No.2022YFC3004705)the National Natural Science Foundation of China(Nos.52074280,52227901 and 52204249)National Natural Science Foundation of China Youth Fund(No.52104230).
文摘Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in underground engineering.To reveal the effect of this way,the uniaxial compression experiments with PSC monitoring were conducted on three types of coal-rock combination samples with different strength combinations.The mechanism explanation of PSCs are investigated by resistivity test,atomic force microscopy(AFM)and computed tomography(CT)methods,and a PSC flow model based on progressive failure process is proposed.The influence of strength combinations on PSCs in the progressive failure process are emphasized.The results show the PSC responses between rock part,coal part and the two components are different,which are affected by multi-scale fracture characteristics and electrical properties.As the rock strength decreases,the progressive failure process changes obviously with the influence range of interface constraint effect decreasing,resulting in the different responses of PSC strength and direction in different parts to fracture behaviors.The PSC flow model is initially validated by the relationship between the accumulated charges of different parts.The results are expected to provide a new reference and method for mining design and roadway quality assessment.
基金financially supported by National Natural Science Foundation of China(Nos.21976096,52170085 and 21773129)Tianjin Development Program for Innovation and Entrepreneurship+2 种基金Key Project of Natural Science Foundation of Tianjin(No.21JCZDJC00320)Tianjin Post-graduate Students Research and Innovation Project(No.2021YJSB013)Fundamental Research Funds for the Central Universities,Nankai University。
文摘As important emerging contaminants, antibiotics have caused potential hazards to the ecological environment and human health due to their extensive production and consumption. Among various techniques for removing antibiotics from wastewater, H_(2)O_(2)-based advanced oxidation processes(AOPs) have received increasing attention due to their fast reaction rate and strong oxidation capability. Hence this review critically discusses:(i) Recent research progress of AOPs with the addition of H_(2)O_(2) for antibiotics removal through different methods of H_(2)O_(2) activation;(ii) recent advances in AOPs that can in-situ generate and activate H_(2)O_(2) for antibiotics removal;(iii) H_(2)O_(2)-based AOPs as a combination with other techniques for the degradation and mineralization of antibiotics in wastewater. Future perspectives about H_(2)O_(2)-based AOPs are also presented to grasp the future research trend in the area.
基金This work was supported by the Heilongjiang Natural Science Foundation(No.E2007-04)the National Natural Science Foundation of China(No.50908062)the State Key Laboratory of Urban Water Resource and Environment(No.HIT-QAK200808).
文摘A laboratory scale test was conducted in a combined membrane process （CMP） with a capacity of 2.91 m3/d for 240 d to treat the mixed wastewater of humidity condensate, hygiene wastewater and urine in submarine cabin during prolonged voyage. Removal performance of chemical oxygen demand （COD）, ammonia nitrogen （NH4^＋-N）, turbidity and anionic surfactants （LAS） was investigated under different conditions. It was observed that the effluent COD, NH4^＋-N, turbidity and LAS flocculated in ranges of 0.19-0.85 mg/L, 0.03-0.18 mg/L, 0.0-0.15 NTU and 0.0-0.05 mg/L, respectively in spite of considerable fluctuation in corresponding influent of 2120-5350 mg/L, 79.5-129.3 mg/L, 110-181.1NTU and 4.9-5.4 mg/L. The effluent quality of the CMP could meet the requirements of mechanical water and hygiene water according to the class I water quality standards in China （GB3838-2002）. The removal rates of COD, NH4^＋-N, turbidity and LAS removed in the MBR were more than 90%, which indicated that biodegradation is indispensable and plays a major role in the wastewater treatment and reuse. A model, built on the back propagation neural network （BPNN） theory, was developed for the simulation of CMP and produced high reliability. The average error of COD and NH4^＋-N was 5.14% and 6.20%, respectively, and the root mean squared error of turbidity and LAS was 2.76% and 1.41%, respectively. The results indicated that the model well fitted the laboratory data, and was able to simulate the removal of COD, NH4^＋-N, turbidity and LAS. It also suggested that the model proposed could reflect and manage the operation of CMP for the treatment of the mixed wastewaters in submarine.
文摘District Ghizer is a rugged mountainous territory which experiences several landslides each year. There are 16 major landslide areas and 53 villages that are at high risk to hazards. Keeping in view the severity of natural hazards, the present study was designed to generate landslide susceptibility map based on twelve causative factors viz., slope, aspect, elevation, drainage network, Stream Power Index (SPI), Topographic Wetness Index (TWI), lithological units, fault lines, rainfall, road network, land cover and soil texture. Soil texture was determined by particle size analysis and data for other factors were acquired from freely available sources. Analytical Hierarchy Process (AHP) was employed to identify major landslide causative factors in the district Ghizer. Further, a temporal assessment from 1999 till 2015 was generated to assess the impact of land cover change on landslides. It indicated that the barren soil/ exposed rocks and glaciers have reduced while the vegetation and water classes have shown increment. The total area that lies in moderate to very high landslide susceptible zones was 74.38%, while slope is the main landslide causative factor in the district Ghizer. Validation of the susceptibility map showed 88.1% of the landslides in the study area had occurred in the moderate to very high susceptible zones.
文摘Carbon capture and storage （CCS） technology will play a critical role in reducing anthropogenic carbondioxide （CO2） emission from fossil-fired power plants and other energy-intensive processes. However, theincrement of energy cost caused by equipping a carbon capture process is the main barrier to its commer-cial deployment. To reduce the capital and operating costs of carbon capture, great efforts have been madeto achieve optimal design and operation through process modeling, simulation, and optimization. Accuratemodels form an essential foundation for this purpose. This paper presents a study on developing a moreaccurate rate-based model in Aspen Plus for the monoethanolamine （MEA）-based carbon capture processby multistage model validations. The modeling framework for this process was established first. The steady-state process model was then developed and validated at three stages, which included a thermodynamicmodel, physical properties calculations, and a process model at the pilot plant scale, covering a wide rangeof pressures, temperatures, and CO2 loadings. The calculation correlations of liquid density and interfacialarea were updated by coding Fortran subroutines in Aspen Plus. The validation results show that the cor-relation combination for the thermodynamic model used in this study has higher accuracy than those ofthree other key publications and the model prediction of the process model has a good agreement with thepilot plant experimental data. A case study was carried out for carbon capture from a 250 MWe combinedcycle gas turbine （CCGT） power plant. Shorter packing height and lower specific duty were achieved usingthis accurate model.
基金Supported by the National Nature Science Founda tion of China(50099620)863 Project(2001AA132050-03)
文摘To resolve the data combination of Phased-array Ground Penetrating Radar (PAGPR), we first build a model of PAGPR and a layered model, and then a new data combination algorithm is presented based on it. This method calculates time delay of multi-receivers, basing on the signal of the nearest receiver, then shifts other signals and adds them up, and gets one signal at last. It has been proved that this method can restrain noise, multiple waves, clutter waves and improve the precision of time location. In the end, an example is given to prove the method's efficiency.
文摘The selection of a landfill site is considered as a complicated task because this process is based on many factors and restrictions. For Al-Qasim Qadhaa, which is situated in the southern part of the Babylon Governorate, Iraq, there is no landfill site in that area that conforms to the scientific criteria for selecting sites for landfill. For this reason, 15 criteria were adopted in this study （groundwater depth, rivers, soil types, agriculture lands use, land use, elevation, slope, gas pipelines, oil pipelines, power lines, roads, railways, urban centers, villages and archaeological sites） using GIS （geographic information system）, which has a large ability to manage input data. In addition, the AHP （analytical hierarchy process） method was used to derive the relative weightings for each criterion using pair-wise comparison. To obtain the suitability index for candidate landfill sites, a weighted linear combination method was used. After combining these methods, two suitable candidate landfill sites, with areas of 2.766 km2 and 2.055 km2, respectively, were found to satisfy the scientific and environmental requirements. The area of these sites can accommodate solid waste from 2020 until 2030 based on the required area, which was 0.702 km2.
基金This study was spoorted by the Project supported by Special Fund for Basic Scientific Research Business Fees of Central Level Public Welfare Scientific Research Institutes"Special Fund for Seedling Cultivation"(ZZ11-084).
文摘Objective:The incidence of distal radius fracture combined with ulnar styloid process fracture is increasing,which seriously affects the quality of life of patients.Small splint therapy of Traditional Chinese Medicine is a reliable method for the treatment of such fractures.It not only has good clinical efficacy,but also has fewer complications and high safety.However,the traditional small splint fixation does not cover the styloid process of the ulna,and the fracture of the styloid process of the ulna is closely related to the stability of the wrist joint,which has an important impact on the prognosis of the fracture.Based on this,we believe that the ulnar elongation splint can better improve the wrist function,and further prospects for related issues,in order to guide clinical practice.
文摘The experiment was carried out in a combined blowing converter.The natural gas was supplied as the cooling medium for the bottom lance.The blow- ing practice of medium P hot metal (0.30-0.85% [P]) indicated that with better stirring at the bottom of the converter and lower P_(CO),this steelmgking process was favorable to reduce the amount of [C] and [O] and increase the (P_2O_5)/[P]. The maximum rate of dephospborization might be high up to 0.0a5%/min and the P content in steel could be reduced to lower than 0.03% by single slag-forming operation.
