The experimental performance of small-sized ground-coupled heat pump (GCHP) is researched intensively. However, there are little data documenting the operation performance of existing large-sized GCHP system. We prese...The experimental performance of small-sized ground-coupled heat pump (GCHP) is researched intensively. However, there are little data documenting the operation performance of existing large-sized GCHP system. We presented the actual performance measurement of a GCHP installed for apartment buildings in Wuhan, Hubei province, P. R. China. The system was constructed with a closed vertical typed ground heat exchanger with a total pipe length of 32 000 m. During one year, various operating parameters were monitored, including the outdoor temperature, the flow rate, the electrical consumption, and the water temperature. The seasonal coefficients of performances of the heat pumps and the system based on the measured data were found to be 4.01 and 2.96 in the cooling season, and 3.54 and 2.86 in the heating season, respectively. The GCHP system was more economical than the air-source room air conditioner in the energy efficiency which was increased by 29% in cooling mode and 50% in heating mode. There was an obvious heat imbalance of soil between the injection rate and the extraction rate in the residential GCHP system operation.展开更多
It has previously been shown that tryptophan, the biosynthesis precursor ofPeganum harmala alkaloids, and its derivatives have anti-TMV activity bothin vitro and in vivo. Further exploration of this led to the identif...It has previously been shown that tryptophan, the biosynthesis precursor ofPeganum harmala alkaloids, and its derivatives have anti-TMV activity bothin vitro and in vivo. Further exploration of this led to the identification of NK0238as a highly effective agent for the prevention and control of diseases caused byplant viruses, but the existing routes are unsuitable for its large-scale synthesis.This study optimized a route for two-step synthesis of this virucide candidate viareaction of L-tryptophan with triphosgene to produce L-tryptophan-N-carboxylicanhydride, which then reacts with n-octylamine to give NK0238 at up to 94%yield and nearly 97% HPLC purity. In addition, the route was used for thepreparation of NK0238 on a > 40 g scale permitting further assessment of itsantivirus activity in the greenhouse and field experiments, and toxicity tests.NK0238 exhibited useful antiviral activities against a variety of viruses both ingreenhouse and field experiments. The toxicity tests showed that NK0238 wasnot acutely toxic to birds, fish, honey bees and silkworms. The optimized routeprovides a solid foundation for its large-scale synthesis and subsequent efficacyand toxicity studies, its excellent activity and safety make NK0238 a promisingdrug candidate for further development.展开更多
This paper presents the applications of digital image correlation technique to the mesoscopic damage and fracture study of some granular based composite materials including steel- fiber reinforced concrete,sandstone a...This paper presents the applications of digital image correlation technique to the mesoscopic damage and fracture study of some granular based composite materials including steel- fiber reinforced concrete,sandstone and crystal-polymer composite.The deformation fields of the composite materials resulted from stress localization were obtained by the correlation computation of the surface images with loading steps and thus the related damage prediction and fracture parameters were evaluated.The correlation searching could be performed either directly based on the gray levels of the digital images or from the wavelet transform(WT)coefficients of the transform spectrum.The latter was developed by the authors and showed higher resolution and sensitivity to the singularity detection. Because the displacement components came from the rough surfaces of the composite materials without any coats of gratings or fringes of optical interferometry,both surface profiles and the deformation fields of the composites were visualized which was helpful to compare each other to analyze the damage of those heterogeneous materials.展开更多
For a special use a new modelling method of evaluating external disturbing potential is presented in this paper.Being different from classical methods in physical geodesy this method is grounded upon the theory of uni...For a special use a new modelling method of evaluating external disturbing potential is presented in this paper.Being different from classical methods in physical geodesy this method is grounded upon the theory of unified representation of gravitational field.The models created in this way are particularly satisfactory for a high_speed computation of gravitational field in low altitude because they take account of topographic effects and have their kernel functions with simple structure and weak singularity.展开更多
Integrating fertility control techniques using steroid hormones after lethal control can help reduce post control rebuildup of rodent populations.The current study is thefirst to assess the antifertility effects of qu...Integrating fertility control techniques using steroid hormones after lethal control can help reduce post control rebuildup of rodent populations.The current study is thefirst to assess the antifertility effects of quinestrol in male lesser bandicoot rat,Bandicota bengalensis which is the predominant rodent pest species in Southeast Asia.Rats in different groups were fed bait containing 0.00%,0.01%,0.02%,and 0.03%quinestrol for 10 days in laboratory and evaluated immediately,and 15,30,and 60 days after treatment discontinuation for effect on reproduction and other antifertility parameters.Effect of 0.03%quinestrol treatment for 15 days was also observed in managing rodent populations in groundnut cropfields.Treatment resulted in average consumption of 19.53±1.80,67.63±5.50,and 246.67±1.78 mg/kg bwt active ingredient by three treated groups of rats,respectively.No reproduction was observed in female rats mated with male rats treated with 0.03%quinestrol,even 30 days after cessation of treatment.Post-mortem examination showed a significant(P<0.0001)effect of treatment on organ weights(testis,cauda epididymis,seminal vesicles,and prostate gland)and different sperm parameters(sperm motility,sperm viability,sperm count,and sperm abnormality)in the cauda epididymalfluid with partial reversibility after 60 days.A significant(P<0.0001)effect of quinestrol on the histomorphology of testis and cauda epididymis was observed,suggesting its effect on spermatogenesis.Affected cell association and cell count in seminiferous tubules did not fully recover within 60 days of stopping treatment.Evaluation of the effects of quinestrol treatment in groundnutfields showed greater reductions in rodent activity infields treated with 2%zinc phosphide followed by 0.03%quinestrol treatment as compared tofields treated with 2%zinc phosphide alone.Research concludes that quinestrol has the potential to reduce fecundity and post control rebuildup of B.bengalensis populations,but long-term studies of the effectiveness of quinestrol under large-scalefield conditions are needed to use it as part of an integrated pest control program for rodents.展开更多
Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment and competing for survival space with weeds.However,whether the expression of the Bacillus thuringiensi...Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment and competing for survival space with weeds.However,whether the expression of the Bacillus thuringiensis(Bt)gene in rice will alter the relationship between transgene plants and weeds and induce undesirable environmental consequences are poorly understood.Thus,field experiments were conducted to investigate the weed competitiveness and assess the ecological risk of transgenic Bt rice under herbicide-free and lepidopterous pest-controlled environments.Results showed that weed–rice competition in the direct-sowing(DS)field was earlier and more severe than that in the transplanting(TP)field,which resulted in a significant decrease in biomass and yield in DS.However,conventional Bt and non-Bt rice yield was not significantly different.The weed number,weed coverage ratio,and weed diversity of conventional Bt rice were significantly higher than those of non-Bt rice at the early growth and mature stages,especially in DS plots,suggesting that Bt traits did not increase the weed competitiveness of transgenic rice and had no negative effect on weed diversity.Grain yield and weed number varied between different hybrid rice lines,but those differences were insignificant between Bt and non-Bt rice.The number of insects increased with the increase of weeds in hybrid rice plots,whereas the insect number and diversity did not display a significant difference between Bt and non-Bt rice.Therefore,the ecological risk of transgenic Bt rice is comparable to non-Bt rice.展开更多
Acoustic Barkhausen Emission (ABE) and Electromagnetic Barkhausen Emission (EBE) have been measured. Explanations of the response of nickel to an applied magnetic field are considered using energy density diagrams and...Acoustic Barkhausen Emission (ABE) and Electromagnetic Barkhausen Emission (EBE) have been measured. Explanations of the response of nickel to an applied magnetic field are considered using energy density diagrams and critical fields deduced using Kersten's modified theory. These theoretical models are correlated with ABE and EBE measurements, providing further confirmation of the origins of ABE being non-180° domain wall motion. This paper also shows that the motion of domain walls, on increasing the magnetising fields from saturation to satu -ration, follows the sequence of 71°-180° - 109°. Values of critical fields correponding to 71°, 180° and 109° wall motions in nickel are determined using these techniques .展开更多
A new method to obtain numerical solution of Acoustic Transfer Function (ATF) by BEM is presented. For a simply supported panel backed by a rectangular cavity at low frequency band (0-200 Hz), the frequency property o...A new method to obtain numerical solution of Acoustic Transfer Function (ATF) by BEM is presented. For a simply supported panel backed by a rectangular cavity at low frequency band (0-200 Hz), the frequency property of ATF is analyzed. The relation between the accuracy of the rapid evaluation of sound field and the discretization schemes of the vibrational panel is discussed. The result shows that the method to obtain ATF and the rapid evaluation of sound field using the ATF is suitable to low frequency band. If an appropriate discretization scheme is choosed based on the frequency involved and the effort to obtain ATF, the accuracy of the rapid evaluation of sound field is acceptable.展开更多
Background:Health personnel face challenges in diagnosing vector-borne and other diseases of poverty in urban settings.There is a need to know what rapid diagnostic technologies are available,have been properly assess...Background:Health personnel face challenges in diagnosing vector-borne and other diseases of poverty in urban settings.There is a need to know what rapid diagnostic technologies are available,have been properly assessed,and are being implemented to improve control of these diseases in the urban context.This paper characterizes evidence on the field validation and implementation in urban areas of rapid diagnostics for vector-borne diseases and other diseases of poverty.Main body:A scoping review was conducted.Peer-reviewed and grey literature were searched using terms describing the targeted infectious diseases,diagnostics evaluations,rapid tests,and urban setting.The review was limited to studies published between 2000 and 2016 in English,Spanish,French,and Portuguese.Inclusion and exclusion criteria were refined post hoc to identify relevant literature regardless of study design and geography.A total of 179 documents of the 7806 initially screened were included in the analysis.Malaria(n=100)and tuberculosis(n=47)accounted for the majority of studies that reported diagnostics performance,impact,and implementation outcomes.Fewer studies,assessing mainly performance,were identified for visceral leishmaniasis(n=9),filariasis and leptospirosis(each n=5),enteric fever and schistosomiasis(each n=3),dengue and leprosy(each n=2),and Chagas disease,human African trypanosomiasis,and cholera(each n=1).Reported sensitivity of rapid tests was variable depending on several factors.Overall,specificities were high(>80%),except for schistosomiasis and cholera.Impact and implementation outcomes,mainly acceptability and cost,followed by adoption,feasibility,and sustainability of rapid tests are being evaluated in the field.Challenges to implementing rapid tests range from cultural to technical and administrative issues.Conclusions:Rapid diagnostic tests for vector-borne and other diseases of poverty are being used in the urban context with demonstrated impact on case detection.However,most evidence comes from malaria rapid diagnostics,with variable results.While rapid tests for tuberculosis and visceral leishmaniasis require further implementation studies,more evidence on performance of current tests or development of new alternatives is needed for dengue,Chagas disease,filariasis,leptospirosis,enteric fever,human African trypanosomiasis,schistosomiasis and cholera.展开更多
The large number of environmental problems faced by society in recent years has driven researchers to collect and study massive amounts of data in order to understand the complex relations that exist between people an...The large number of environmental problems faced by society in recent years has driven researchers to collect and study massive amounts of data in order to understand the complex relations that exist between people and the environment in which we live.Such datasets are often high dimensional and heterogeneous in nature,with complex geospatial relations.Analysing such data can be challenging,especially when there is a need to maintain spatial awareness as the non-spatial attributes are studied.Geo-Coordinated Parallel Coordinates(GCPC)is a geovisual analytics approach designed to support exploration and analysis within complex geospatial environmental data.Parallel coordinates are tightly coupled with a geospatial representation and an investigative scatterplot,all of which can be used to show,reorganize,filter,and highlight the high dimensional,heterogeneous,and geospatial aspects of the data.Two sets of field trials were conducted with expert data analysts to validate the real-world benefits of the approach for studying environmental data.The results of these evaluations were positive,providing real-world evidence and new insights regarding the value of using GCPC to explore among environmental datasets when there is a need to remain aware of the geospatial aspects of the data as the non-spatial elements are studied.展开更多
基金Funded by National Natural Science Foundation of China (Grant No. 51078160)
文摘The experimental performance of small-sized ground-coupled heat pump (GCHP) is researched intensively. However, there are little data documenting the operation performance of existing large-sized GCHP system. We presented the actual performance measurement of a GCHP installed for apartment buildings in Wuhan, Hubei province, P. R. China. The system was constructed with a closed vertical typed ground heat exchanger with a total pipe length of 32 000 m. During one year, various operating parameters were monitored, including the outdoor temperature, the flow rate, the electrical consumption, and the water temperature. The seasonal coefficients of performances of the heat pumps and the system based on the measured data were found to be 4.01 and 2.96 in the cooling season, and 3.54 and 2.86 in the heating season, respectively. The GCHP system was more economical than the air-source room air conditioner in the energy efficiency which was increased by 29% in cooling mode and 50% in heating mode. There was an obvious heat imbalance of soil between the injection rate and the extraction rate in the residential GCHP system operation.
基金The authors are grateful to the National Natural Science Foundation of China(21977056,21732002)the Fundamental Research Funds for the Central Universities,Nankai University(63201043)for generous financial support for their programs.
文摘It has previously been shown that tryptophan, the biosynthesis precursor ofPeganum harmala alkaloids, and its derivatives have anti-TMV activity bothin vitro and in vivo. Further exploration of this led to the identification of NK0238as a highly effective agent for the prevention and control of diseases caused byplant viruses, but the existing routes are unsuitable for its large-scale synthesis.This study optimized a route for two-step synthesis of this virucide candidate viareaction of L-tryptophan with triphosgene to produce L-tryptophan-N-carboxylicanhydride, which then reacts with n-octylamine to give NK0238 at up to 94%yield and nearly 97% HPLC purity. In addition, the route was used for thepreparation of NK0238 on a > 40 g scale permitting further assessment of itsantivirus activity in the greenhouse and field experiments, and toxicity tests.NK0238 exhibited useful antiviral activities against a variety of viruses both ingreenhouse and field experiments. The toxicity tests showed that NK0238 wasnot acutely toxic to birds, fish, honey bees and silkworms. The optimized routeprovides a solid foundation for its large-scale synthesis and subsequent efficacyand toxicity studies, its excellent activity and safety make NK0238 a promisingdrug candidate for further development.
基金The project supported by the National Natural Science Foundation of China (10125211 and 10072002),the Scientific Committee of Yunnan Province for the Program of Steel Fiber Reinforced Concrete,and the Institute of Chemical Materials,CAEP at Mianyang
文摘This paper presents the applications of digital image correlation technique to the mesoscopic damage and fracture study of some granular based composite materials including steel- fiber reinforced concrete,sandstone and crystal-polymer composite.The deformation fields of the composite materials resulted from stress localization were obtained by the correlation computation of the surface images with loading steps and thus the related damage prediction and fracture parameters were evaluated.The correlation searching could be performed either directly based on the gray levels of the digital images or from the wavelet transform(WT)coefficients of the transform spectrum.The latter was developed by the authors and showed higher resolution and sensitivity to the singularity detection. Because the displacement components came from the rough surfaces of the composite materials without any coats of gratings or fringes of optical interferometry,both surface profiles and the deformation fields of the composites were visualized which was helpful to compare each other to analyze the damage of those heterogeneous materials.
文摘For a special use a new modelling method of evaluating external disturbing potential is presented in this paper.Being different from classical methods in physical geodesy this method is grounded upon the theory of unified representation of gravitational field.The models created in this way are particularly satisfactory for a high_speed computation of gravitational field in low altitude because they take account of topographic effects and have their kernel functions with simple structure and weak singularity.
文摘Integrating fertility control techniques using steroid hormones after lethal control can help reduce post control rebuildup of rodent populations.The current study is thefirst to assess the antifertility effects of quinestrol in male lesser bandicoot rat,Bandicota bengalensis which is the predominant rodent pest species in Southeast Asia.Rats in different groups were fed bait containing 0.00%,0.01%,0.02%,and 0.03%quinestrol for 10 days in laboratory and evaluated immediately,and 15,30,and 60 days after treatment discontinuation for effect on reproduction and other antifertility parameters.Effect of 0.03%quinestrol treatment for 15 days was also observed in managing rodent populations in groundnut cropfields.Treatment resulted in average consumption of 19.53±1.80,67.63±5.50,and 246.67±1.78 mg/kg bwt active ingredient by three treated groups of rats,respectively.No reproduction was observed in female rats mated with male rats treated with 0.03%quinestrol,even 30 days after cessation of treatment.Post-mortem examination showed a significant(P<0.0001)effect of treatment on organ weights(testis,cauda epididymis,seminal vesicles,and prostate gland)and different sperm parameters(sperm motility,sperm viability,sperm count,and sperm abnormality)in the cauda epididymalfluid with partial reversibility after 60 days.A significant(P<0.0001)effect of quinestrol on the histomorphology of testis and cauda epididymis was observed,suggesting its effect on spermatogenesis.Affected cell association and cell count in seminiferous tubules did not fully recover within 60 days of stopping treatment.Evaluation of the effects of quinestrol treatment in groundnutfields showed greater reductions in rodent activity infields treated with 2%zinc phosphide followed by 0.03%quinestrol treatment as compared tofields treated with 2%zinc phosphide alone.Research concludes that quinestrol has the potential to reduce fecundity and post control rebuildup of B.bengalensis populations,but long-term studies of the effectiveness of quinestrol under large-scalefield conditions are needed to use it as part of an integrated pest control program for rodents.
基金funded by the National Program of Transgenic Variety Development of China(2016ZX08001001)。
文摘Transgene escape could lead to genetically modified rice establishing wild populations in the natural environment and competing for survival space with weeds.However,whether the expression of the Bacillus thuringiensis(Bt)gene in rice will alter the relationship between transgene plants and weeds and induce undesirable environmental consequences are poorly understood.Thus,field experiments were conducted to investigate the weed competitiveness and assess the ecological risk of transgenic Bt rice under herbicide-free and lepidopterous pest-controlled environments.Results showed that weed–rice competition in the direct-sowing(DS)field was earlier and more severe than that in the transplanting(TP)field,which resulted in a significant decrease in biomass and yield in DS.However,conventional Bt and non-Bt rice yield was not significantly different.The weed number,weed coverage ratio,and weed diversity of conventional Bt rice were significantly higher than those of non-Bt rice at the early growth and mature stages,especially in DS plots,suggesting that Bt traits did not increase the weed competitiveness of transgenic rice and had no negative effect on weed diversity.Grain yield and weed number varied between different hybrid rice lines,but those differences were insignificant between Bt and non-Bt rice.The number of insects increased with the increase of weeds in hybrid rice plots,whereas the insect number and diversity did not display a significant difference between Bt and non-Bt rice.Therefore,the ecological risk of transgenic Bt rice is comparable to non-Bt rice.
文摘Acoustic Barkhausen Emission (ABE) and Electromagnetic Barkhausen Emission (EBE) have been measured. Explanations of the response of nickel to an applied magnetic field are considered using energy density diagrams and critical fields deduced using Kersten's modified theory. These theoretical models are correlated with ABE and EBE measurements, providing further confirmation of the origins of ABE being non-180° domain wall motion. This paper also shows that the motion of domain walls, on increasing the magnetising fields from saturation to satu -ration, follows the sequence of 71°-180° - 109°. Values of critical fields correponding to 71°, 180° and 109° wall motions in nickel are determined using these techniques .
基金This work is supported by the National Natural Science Foundation of China (No.59875069).
文摘A new method to obtain numerical solution of Acoustic Transfer Function (ATF) by BEM is presented. For a simply supported panel backed by a rectangular cavity at low frequency band (0-200 Hz), the frequency property of ATF is analyzed. The relation between the accuracy of the rapid evaluation of sound field and the discretization schemes of the vibrational panel is discussed. The result shows that the method to obtain ATF and the rapid evaluation of sound field using the ATF is suitable to low frequency band. If an appropriate discretization scheme is choosed based on the frequency involved and the effort to obtain ATF, the accuracy of the rapid evaluation of sound field is acceptable.
基金This study was funded by WHO/TDR Special program for Research and Training in Tropical Diseases and by Universidad del Valle,Cali-Colombia.
文摘Background:Health personnel face challenges in diagnosing vector-borne and other diseases of poverty in urban settings.There is a need to know what rapid diagnostic technologies are available,have been properly assessed,and are being implemented to improve control of these diseases in the urban context.This paper characterizes evidence on the field validation and implementation in urban areas of rapid diagnostics for vector-borne diseases and other diseases of poverty.Main body:A scoping review was conducted.Peer-reviewed and grey literature were searched using terms describing the targeted infectious diseases,diagnostics evaluations,rapid tests,and urban setting.The review was limited to studies published between 2000 and 2016 in English,Spanish,French,and Portuguese.Inclusion and exclusion criteria were refined post hoc to identify relevant literature regardless of study design and geography.A total of 179 documents of the 7806 initially screened were included in the analysis.Malaria(n=100)and tuberculosis(n=47)accounted for the majority of studies that reported diagnostics performance,impact,and implementation outcomes.Fewer studies,assessing mainly performance,were identified for visceral leishmaniasis(n=9),filariasis and leptospirosis(each n=5),enteric fever and schistosomiasis(each n=3),dengue and leprosy(each n=2),and Chagas disease,human African trypanosomiasis,and cholera(each n=1).Reported sensitivity of rapid tests was variable depending on several factors.Overall,specificities were high(>80%),except for schistosomiasis and cholera.Impact and implementation outcomes,mainly acceptability and cost,followed by adoption,feasibility,and sustainability of rapid tests are being evaluated in the field.Challenges to implementing rapid tests range from cultural to technical and administrative issues.Conclusions:Rapid diagnostic tests for vector-borne and other diseases of poverty are being used in the urban context with demonstrated impact on case detection.However,most evidence comes from malaria rapid diagnostics,with variable results.While rapid tests for tuberculosis and visceral leishmaniasis require further implementation studies,more evidence on performance of current tests or development of new alternatives is needed for dengue,Chagas disease,filariasis,leptospirosis,enteric fever,human African trypanosomiasis,schistosomiasis and cholera.
基金This work was supported in part by grant from Social Sciences and Humanities Research Council of Canada(SSHRC)(895-2011-1011)held by the second author.
文摘The large number of environmental problems faced by society in recent years has driven researchers to collect and study massive amounts of data in order to understand the complex relations that exist between people and the environment in which we live.Such datasets are often high dimensional and heterogeneous in nature,with complex geospatial relations.Analysing such data can be challenging,especially when there is a need to maintain spatial awareness as the non-spatial attributes are studied.Geo-Coordinated Parallel Coordinates(GCPC)is a geovisual analytics approach designed to support exploration and analysis within complex geospatial environmental data.Parallel coordinates are tightly coupled with a geospatial representation and an investigative scatterplot,all of which can be used to show,reorganize,filter,and highlight the high dimensional,heterogeneous,and geospatial aspects of the data.Two sets of field trials were conducted with expert data analysts to validate the real-world benefits of the approach for studying environmental data.The results of these evaluations were positive,providing real-world evidence and new insights regarding the value of using GCPC to explore among environmental datasets when there is a need to remain aware of the geospatial aspects of the data as the non-spatial elements are studied.