High-energy-density(HED)fuels(e.g.JP-10)are of great importance in safeguarding territorial air security,since they can increase the flight range and payload of military aircrafts.To reduce the reliance on limited pet...High-energy-density(HED)fuels(e.g.JP-10)are of great importance in safeguarding territorial air security,since they can increase the flight range and payload of military aircrafts.To reduce the reliance on limited petroleum source,the production of HED fuel with renewable biomass feedstocks is highly appealing.But currently,most of the synthetic biofuels,due to their intrinsic ring structure,are incapable of competing with JP-10 in terms of energy density and freezing point.By emulating the structural characteristic of JP-10,we herein design and prepare a special C16 fused tetracyclic biofuel using renewable cyclopentanone and benzoquinone as feedstocks.Key to success depends on selective dehydration of vicinal diol(dimer of cyclopentanone)over Amberlyst-15 in[Hmim]Cl.The Amberlyst-15/[Hmim]Cl system effectively suppresses the dominant pinacol-type rearrangement pathway and also exhibits good reusability for the dehydration.The hydrogen-bonding interaction between vicinal diol and imidazolium ring,as well as electrostatic force between carbocation intermediate and chloride anion contribute to the high diene selectivity.The compact ring framework gives rise to a density of 0.966 g/mL,combustion heat of 43.1 MJ/L,freezing point of‒67℃,and kinematic viscosity of 12.4 cSt,which are comparable to the properties of JP-10.It is expected that this as-prepared HED biofuel may potentially serve as a renewable alternative to petroleum fuel JP-10.展开更多
The underground water has been contaminated seriously by the leaching water of dumping area or hillock. To determine the pollution limits of underground water, author took samples in the study area, analyzed samples f...The underground water has been contaminated seriously by the leaching water of dumping area or hillock. To determine the pollution limits of underground water, author took samples in the study area, analyzed samples for water quality, assessed the water quality of each monitoring point by the grey associated analysis method, and gave out the classifications of the underground water quality of the study area. Comparing with fuzzy comprehensive appraisal method, it is demonstrated that grey associated analysis method is applied easily, because of its clear concept, simple and convenient calculation and excellently operation.展开更多
Southeast China has comparable stratus cloud to that over the oceans,especially in the cold seasons(winter and spring),and this cloud has a substantial impact on energy and hydrological cycles.However,uncertainties re...Southeast China has comparable stratus cloud to that over the oceans,especially in the cold seasons(winter and spring),and this cloud has a substantial impact on energy and hydrological cycles.However,uncertainties remain across datasets and simulation results about the long-term trend in low-cloud cover in Southeast China,making it difficult to understand climate change and related physical processes.In this study,multiple datasets and numerical simulations were applied to show that low-cloud cover in Southeast China has gone through two stages since 1980—specifically,a decline and then a rise,with the turning point around 2008.The regional moisture transport plays a crucial role in low-cloud cover changes in the cold seasons and is mainly affected by the Hadley Cell in winter and the Walker Circulation in spring,respectively.The moisture transport was not well simulated in CMIP6 climate models,leading to poor simulation of the low-cloud cover trend in these models.This study provides insights into further understanding the regional climate changes in Southeast China.展开更多
Atlantic salmon Salmo salar were reared at four stocking densities--high density D1 (final density -39 kg/m^3), medium densities DE (-29 kg/m^3) and D3 (~19 kg/m^3), and low density D4 (-12 kg/m^3)- for 40 day...Atlantic salmon Salmo salar were reared at four stocking densities--high density D1 (final density -39 kg/m^3), medium densities DE (-29 kg/m^3) and D3 (~19 kg/m^3), and low density D4 (-12 kg/m^3)- for 40 days to investigate the effect of stocking density on their growth performance, body composition and energy budgets. Stocking density did not significantly affect specific growth rate in terms of weight (SGRw) but did affect specific growth rate in terms of energy (SGRe). Stocking density significantly influenced the ration level (RLw and RLe), feed conversion ratio (FCRw and FCRe) and apparent digestibility rate (ADR). Ration level and FCRw tended to increase with increasing density. Fish at the highest density D~ and lowest density D4 showed lower FCRe and higher ADR than at medium densities. Stocking density significantly affected protein and energy contents of the body but did not affect its moisture, lipid, or ash contents. The expenditure of energy for metabolism in the low-density and high-density groups was lower than that in the medium-density groups. Stocking density affected energy utilization from the feces but had no effect on excretion rate. The greater energy allocation to growth at high density and low density may be attributed to reduced metabolic rate and increased apparent digestibility rate. These findings provide information that will assist selection of suitable stocking densities in the Atlantic-salmon-farming industry.展开更多
Religious, occasional and annual fire work festivals worldwide are found to introduce high concentrations of pollutant gases and particulate matter into the atmosphere. These in turn alters the air quality of a region...Religious, occasional and annual fire work festivals worldwide are found to introduce high concentrations of pollutant gases and particulate matter into the atmosphere. These in turn alters the air quality of a region in the short and long time scales and affect human health adversely. The effect of fireworks on short-term variation in air quality of an urban location Dibrugarh, set amidst the rural environment of north-east India, was assessed from the ambient concentrations of 03, SO2, NOx, CO and BC (black carbon) during the Diwali festival during Nov. 13-14, 2012. The firework activity in general peaks during evening to midnight hours. Substantial increase in concentrations of O3, SO2, NOx, CO and BC was observed during the peak hours of firework activity (16:00 h to 22:00 h) in the Day 1 and Day 2 of the Diwali festival. However, the increase in concentrations from the background level was found to be highest on the post-Diwali day due to their accumulation in the atmosphere. The firework activity has not affected the regular diurnal pattern of the measured species during this episode.展开更多
L ethal temperature tolerance was determined for about 8 cm, age 0 Pseudosciaena crocea using both slow heating and rapid transfer protocol. The acclimatization temperature was 28 ℃ with summer season, lethal tempera...L ethal temperature tolerance was determined for about 8 cm, age 0 Pseudosciaena crocea using both slow heating and rapid transfer protocol. The acclimatization temperature was 28 ℃ with summer season, lethal temperature ( LT50 value ) of slow heating protocol ( CTMax ) was 35.0 ℃, and the upper and lower incipient lethal temperatures of rapid transfer protocol were 34.2 ℃ and 17.5 ℃ respectively.展开更多
To study the dynamics of mixed traffic flow consisting of motorized and non-motorized vehicles, a carfollowing model based on the principle of collision free and cautious driving is proposed. Lateral friction and over...To study the dynamics of mixed traffic flow consisting of motorized and non-motorized vehicles, a carfollowing model based on the principle of collision free and cautious driving is proposed. Lateral friction and overlapping driving are introduced to describe the interactions between motorized vehicles and non-motorized vehicles. By numerical simulations, the flux-density relation, the temporal-spatial dynamics, and the velocity evolution are investigated in detail The results indicate non-motorized vehicles have a significant impact on the motorized vehicle flow and cause the maximum flux to decline by about 13%. Non-motorized vehicles can decrease the motorized vehicle velocity and cause velocity oscillation when the motorized vehicle density is low. Moreover, non-motorized vehicles show a significant damping effect on the oscillating velocity when the density is medium and high, and such an effect weakens as motorized vehicle density increases. The results also stress the necessity for separating motorized vehicles from non-motorized vehicles.展开更多
Gracilaria asiatica, being highly efficient in nutrient absorption, is cultivated in sea cucumber ponds to remove nutrients such as nitrogen and phosphate. It was cultured in a laboratory simulating field conditions, ...Gracilaria asiatica, being highly efficient in nutrient absorption, is cultivated in sea cucumber ponds to remove nutrients such as nitrogen and phosphate. It was cultured in a laboratory simulating field conditions, and its nutrient absorption was measured to evaluate effects of environmental conditions. Ammonia nitrogen (AN), nitrate nitrogen (NN), total inorganic nitrogen (TIN), and soluble reactive phosphorus (SRP) uptake rate and removal efficiency were determined in a 4~2 factorial design experiment in water temperatures (T) at 15~C and 25~C, algae biomass (AB) at 0.5 g/L and 1.0 g/L, total inorganic nitrogen (TIN) at 30 ~tmol/L and 60 ~tmol/L, and soluble reactive phosphorus (SRP) at 3 and 6 ~tmol/L. AB and ambient TIN or SRP levels significantly affected uptake rate and removal efficiency of AN, NN, TIN, and SRP (P〈0.001). G. asiatica in AB of 0.5 g/L showed higher uptake rate and lower removal efficiency relative to that with AB of 1.0 g/L. Nitrogen and phosphorus uptake rate rose with increasing ambient nutrient concentrations; nutrient removal efficiency decreased at higher environmental nutrient concentrations. The algae preferred to absorb AN to NN. Uptake rates of AN, NN, and SRP were significantly affected by temperature (P〈0.001); uptake rate was higher for the 25~C group than for the 15~C group at the initial experiment stage. Only the removal efficiency of AN and SRP showed a significant difference between the two temperature groups (P〈0.01). The four factors had significant interactive effects on absorption of N and P, implying that G. asiatica has great bioremedial potential in sea cucumber culture ponds.展开更多
Wetland environment of Assam is fast changing due to encroachments, dumping of solid and liquid wastes, excessive use of wetland water, over exploitation of wetland resources, overgrazing, over fishing, hunting, poach...Wetland environment of Assam is fast changing due to encroachments, dumping of solid and liquid wastes, excessive use of wetland water, over exploitation of wetland resources, overgrazing, over fishing, hunting, poaching, unscientific construction of engineering structures across and along the wetlands, unscientific land use in surrounding areas and various human interferences. On the other hand wetlands play an important role in charging ground water table, sinking of carbon, providing livelihood to thousands of people through fishing, collecting edible plants, agriculture, irrigation and commercial fisheries, besides enrich biodiversity and maintaining environmental quality of a region. The life of wetlands depends on the quantity and quality of water. Any change in water quality and quantity affect the biotic regime of the wetlands. Fish and other aquatic animals and plants found in all levels (floating, rooted, submergent and emergent etc.) are affected by the changes, which are taking place in wetland water. The present study concerns in understanding the environmental quality of the wetlands in Dimoria region of Kamrup (Metro) district, Assam based primarily on the water and soil quality of selected wetlands viz. Jiong, Parkhali, Bomani and Duani.展开更多
We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n...We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n 0f fallen l0gs in the different f0rest c0mmunities and t0 analyze the relati0nships am0ng stand structure, t0p0graphic fact0rs and human disturbance. The v0lume, c0vered area, mean l0g length and number 0f fallen l0gs differed significantly am0ng f0rest types (P 〈 0.05), but mean diameter at breast height sh0wed n0 significant difference (P 〉 0.05). The l0g v0lume and c0vered area in different f0rest types sh0wed the f0ll0wing trend: T. l0ngibracteata pure f0rest 〈 T. l0ngibracteata + Olig0staehyum scabrifl0rur 〈 T. l0ngibraeteata + hardw00d 〈 Rh0d0dendr0n simiarum + T. l0ngibraeteata 〈 T. l0ngibraeteata + Phyll0stachys heter0cycla pubescens. The spatial distributi0n patterns 0f l0gs quantity and quality indicated that l0g v0lume and c0vered area were str0ngly affected by envir0nmental fact0rs in the f0ll0wing 0rder: human disturbance 〉 elevati0n 〉 sl0pe p0siti0n 〉 b0le height 〉 tree height 〉 sl0pe aspect 〉 density 〉 basal area 〉 sl0pe gradient. The relative c0ntributi0n 0f envir0nmental variables 0n the t0tal variance was t0p0graphy (76%) 〉 disturbance (42%) 〉 stand structure (35%). T0p0graphy and disturbance c0mbined explained 8.2% 0f the variance. Fallen l0~s auantitv and aualitvwere negatively related t0 elevati0n and sl0pe p0siti0n, and p0sitively ass0ciated t0 human disturbance. The l0g v0lume decreased fr0m n0rthern t0 s0uthern sl0pes. Envir0nmental fact0rs had the highest impact 0n class I (slightly decayed), and l0west impact 0n class V (highly decayed).展开更多
The objective of the study was to determine the usefulness of measuring maximum temperatures in designated regions of a healthy horse's body surface. Thermographic investigations (Thermovision〉550, FLIR) were carr...The objective of the study was to determine the usefulness of measuring maximum temperatures in designated regions of a healthy horse's body surface. Thermographic investigations (Thermovision〉550, FLIR) were carried out on 35 horses from 6 to 16 years old participating in show jumping competitions. The rectal temperatures of the horses were in the range 37.5-38.2 ℃. The research was performed in a stable, the ambient temperature (Tab) of which was 14℃ with a humidity (φ) of 60%. Thermograms of the left and right side of the horses were obtained. Each thermogram consisted of 36 body surface regions (before the competition) and 25 regions (immediately after the competition). The maximum temperature ranges at rest were 21.8 ℃-31.0℃ and symmetrical regions did not differ statistically (P 〉 0.05). The highest temperatures were on the head, neck and trunk, the lowest-on the limbs. The hind legs were warmer than the front legs in analogous areas, with the exception of the gaskin and forearm. The warmest body areas had the largest surface area, which is indicative of their crucial role in the thermoregulation of the equine organism. The research results may therefore be useful in veterinary diagnosis. The range of maximum temperatures after the competitions was 25.2℃-34.2℃. The highest increment was observed at the breast, elbow, forearm and gaskin, the lowest-at the head, pastern and hoof (foreand hind limbs). Research regarding body surface temperature after exercise does not have diagnostic value for veterinarians because "warming-up" certain parts of body surface masks inflammation.展开更多
We study the influence of the shape of compact a scalar field. We examine both the massive and the massless dimensions to the Casimir energy and Casimir force of scalar field. The total spacetime topology is M^D ×...We study the influence of the shape of compact a scalar field. We examine both the massive and the massless dimensions to the Casimir energy and Casimir force of scalar field. The total spacetime topology is M^D × Tθ2, where M^D) is the D-dimensional Minkowski spacetime and Tθ2 the twisted torus described by R1, R2, and 8. For the case R1 = R2 we found that the massive bulk scalar field Casimir energy is singular for D=even and this singularity is R-dependent and remains even when the force is calculated. Also the massless Casimir energy and force is regular only for D = 4 (!). This is very interesting phenomenologically. We examine the energy and force as a function of 8. Also we address the stabilization problem of the compact space. We also briefly discuss some phenomenological implications.展开更多
In this research, the main purpose is to estimate the variation of PM2.5 mass concentration and study the influence of meteorological characteristics on major components of PM2.5 concentrations in urban Tokyo, Japan. ...In this research, the main purpose is to estimate the variation of PM2.5 mass concentration and study the influence of meteorological characteristics on major components of PM2.5 concentrations in urban Tokyo, Japan. The results shown that the annual mean mass concentration of PM2.5 in urban Tokyo was higher than JEQS (Japanese Environmental Quality Standard) of the MOEJ (Ministry of the Environment Japan) (15 μg/m^3), and 41.1% of the daily PM2.5 mass concentration exceeded the annual JEQS concentration during observation period. The major components of PM2.5 including SO4^2-, NO3^-, NH4^+, OC and EC were tightly related to the meteorological conditions, the correlations results shown that the wind speed and relative humidity had significant correlations with major components of PM2.5 than the other meteorological factors. Higher relative humidity, windless and less rainfall conditions were favorable for elimination of PM2.5 concentration. Higher temperature was beneficial to the formation of SO42", but higher temperature and stronger sunshine duration were not conducive to the formation of NO3^-.展开更多
An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has u...An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has utilized the standard k-ε model and P1 model. The finite-rate/eddy-dissipation (finite-rate/ED) combustion model and non-premixed combustion model were both used to simulate accurately the combustion and the operation status of the steam cracking furnace. Three different surfaces of the steam cracking furnace were obtained from the simulation, namely:the flue gas temperature field of the entrance surface in long flame burners, the central surface location of tubes, and the crossover section surface. Detailed information on the flue gas temperature and the mass concentration fraction of these different surfaces in the steam cracking furnace can also be obtained by the simulation. This paper analyzed and compared the simulation results with the two combustion models, estimated the operation status of the steam cracking furnace, and reported that the finite-rate/ED model is appropriate to simulate the steam cracking furnace by comparing key simulation data with actual test data. This work has also provided a theoretical basis for simulating and operating the steam cracking furnace.展开更多
The characteristics of spring precipitation and water vapor transport in South China were analyzed by using observational data and the National Centers for Environmental Prediction (NCEP) reanalysis data. The results ...The characteristics of spring precipitation and water vapor transport in South China were analyzed by using observational data and the National Centers for Environmental Prediction (NCEP) reanalysis data. The results show that, during the spring, each component of the water cycle (precipitation, wind field, specific humidity, water vapor transport, etc.) in South China exhibits a notable interdecadal variability. An abrupt increase in spring precipitation occurred in the early 1970s. During the dry period from 1958 to 1971, a water vapor flux divergence (positive divQ) existed in South China, which may have led to the deficiency in rainfall. However, during the wet period from 1973 to 1989, there was a remarkable water vapor flux convergence (negative divQ) in South China, which may have resulted in the higher rainfall. The interdecadal variability of water vapor transport is closely related to the interdecadal variability of wind fields, although the interdecadal variability of specific humidity also plays a role to some extent, and the interdecadal variability of the zonal water vapor transport contributes much more to the interdecadal variability of spring precipitation than the meridional water vapor transport.展开更多
The environmental psychology ofa workspace is a rich and diverse field of study that is growing fast and gaining popularity. The indoor environmental factors in workspaces should follow functional as well as behaviora...The environmental psychology ofa workspace is a rich and diverse field of study that is growing fast and gaining popularity. The indoor environmental factors in workspaces should follow functional as well as behavioral requirements as the spaces are designed as per the user's requirements, needs and aspirations. These play a major role in achieving behavioral impact on the user, as sense of well-being in the environment and physical comfort in the space enhances the productivity and efficiency of the user of the space. The slow and gradual importance of this issue in workspace design with Indian context, post occupancy evaluation can be adjudged as a permanent tool for improving indoor environment in buildings. Occupants should be used as a benchmark of evaluation, showing correlation of physical measurements and subjective parameters. It also suggests recommendations to improve quality of indoor environment in office buildings with analytical study, an important step in post occupancy evaluation. The objective of the paper is to inquire how people experience environmental psychology of the workspace as the determinants are efficiency, productivity and comfort. The success of any design depends upon the degree to which it creates an interface between the user and the environment.展开更多
In this article, the authors used the Weather Research and Forecast model to investigate the sensitivity of tropical cyclone Bilis' total precipitation to ambient water vapor content. The tropical cyclone precipit...In this article, the authors used the Weather Research and Forecast model to investigate the sensitivity of tropical cyclone Bilis' total precipitation to ambient water vapor content. The tropical cyclone precipitation decreased dramatically with the reduction of the ambient water vapor content in the atmosphere. The decrease of precipitation can be explained by two mechanisms. First, as the major source of precipitation, moisture conver-gence decreases accordingly with the moisture content. Second, the tropical cyclone (TC) size reduction due to the moisture decrease influences the precipitation area. Both mechanisms were observed in this study.展开更多
文摘High-energy-density(HED)fuels(e.g.JP-10)are of great importance in safeguarding territorial air security,since they can increase the flight range and payload of military aircrafts.To reduce the reliance on limited petroleum source,the production of HED fuel with renewable biomass feedstocks is highly appealing.But currently,most of the synthetic biofuels,due to their intrinsic ring structure,are incapable of competing with JP-10 in terms of energy density and freezing point.By emulating the structural characteristic of JP-10,we herein design and prepare a special C16 fused tetracyclic biofuel using renewable cyclopentanone and benzoquinone as feedstocks.Key to success depends on selective dehydration of vicinal diol(dimer of cyclopentanone)over Amberlyst-15 in[Hmim]Cl.The Amberlyst-15/[Hmim]Cl system effectively suppresses the dominant pinacol-type rearrangement pathway and also exhibits good reusability for the dehydration.The hydrogen-bonding interaction between vicinal diol and imidazolium ring,as well as electrostatic force between carbocation intermediate and chloride anion contribute to the high diene selectivity.The compact ring framework gives rise to a density of 0.966 g/mL,combustion heat of 43.1 MJ/L,freezing point of‒67℃,and kinematic viscosity of 12.4 cSt,which are comparable to the properties of JP-10.It is expected that this as-prepared HED biofuel may potentially serve as a renewable alternative to petroleum fuel JP-10.
文摘The underground water has been contaminated seriously by the leaching water of dumping area or hillock. To determine the pollution limits of underground water, author took samples in the study area, analyzed samples for water quality, assessed the water quality of each monitoring point by the grey associated analysis method, and gave out the classifications of the underground water quality of the study area. Comparing with fuzzy comprehensive appraisal method, it is demonstrated that grey associated analysis method is applied easily, because of its clear concept, simple and convenient calculation and excellently operation.
基金This work was supported by the Ministry of Science and Technology of China[grant number 2017YFA0604002]the National Natural Science Foundation of China[grant numbers 41925023,41575073,41621005,and 91744208]the Collaborative Innovation Center of Climate Change,Jiangsu Province.
文摘Southeast China has comparable stratus cloud to that over the oceans,especially in the cold seasons(winter and spring),and this cloud has a substantial impact on energy and hydrological cycles.However,uncertainties remain across datasets and simulation results about the long-term trend in low-cloud cover in Southeast China,making it difficult to understand climate change and related physical processes.In this study,multiple datasets and numerical simulations were applied to show that low-cloud cover in Southeast China has gone through two stages since 1980—specifically,a decline and then a rise,with the turning point around 2008.The regional moisture transport plays a crucial role in low-cloud cover changes in the cold seasons and is mainly affected by the Hadley Cell in winter and the Walker Circulation in spring,respectively.The moisture transport was not well simulated in CMIP6 climate models,leading to poor simulation of the low-cloud cover trend in these models.This study provides insights into further understanding the regional climate changes in Southeast China.
基金Supported by the National Natural Science Foundation of China(No.31240012)the Earmarked Fund for Modern Agro-industry Technology Research System+2 种基金the Special Foundation for Postdoctoral Innovative Projects of Shandong Province(No.201101009)the National Key Technology R&D Program of China(No.2011BAD13B04)The Key Laboratory of Mariculture(KLM),Ministry of Education,Ocean University of China(OUC)
文摘Atlantic salmon Salmo salar were reared at four stocking densities--high density D1 (final density -39 kg/m^3), medium densities DE (-29 kg/m^3) and D3 (~19 kg/m^3), and low density D4 (-12 kg/m^3)- for 40 days to investigate the effect of stocking density on their growth performance, body composition and energy budgets. Stocking density did not significantly affect specific growth rate in terms of weight (SGRw) but did affect specific growth rate in terms of energy (SGRe). Stocking density significantly influenced the ration level (RLw and RLe), feed conversion ratio (FCRw and FCRe) and apparent digestibility rate (ADR). Ration level and FCRw tended to increase with increasing density. Fish at the highest density D~ and lowest density D4 showed lower FCRe and higher ADR than at medium densities. Stocking density significantly affected protein and energy contents of the body but did not affect its moisture, lipid, or ash contents. The expenditure of energy for metabolism in the low-density and high-density groups was lower than that in the medium-density groups. Stocking density affected energy utilization from the feces but had no effect on excretion rate. The greater energy allocation to growth at high density and low density may be attributed to reduced metabolic rate and increased apparent digestibility rate. These findings provide information that will assist selection of suitable stocking densities in the Atlantic-salmon-farming industry.
文摘Religious, occasional and annual fire work festivals worldwide are found to introduce high concentrations of pollutant gases and particulate matter into the atmosphere. These in turn alters the air quality of a region in the short and long time scales and affect human health adversely. The effect of fireworks on short-term variation in air quality of an urban location Dibrugarh, set amidst the rural environment of north-east India, was assessed from the ambient concentrations of 03, SO2, NOx, CO and BC (black carbon) during the Diwali festival during Nov. 13-14, 2012. The firework activity in general peaks during evening to midnight hours. Substantial increase in concentrations of O3, SO2, NOx, CO and BC was observed during the peak hours of firework activity (16:00 h to 22:00 h) in the Day 1 and Day 2 of the Diwali festival. However, the increase in concentrations from the background level was found to be highest on the post-Diwali day due to their accumulation in the atmosphere. The firework activity has not affected the regular diurnal pattern of the measured species during this episode.
基金supported by the Science and Technology Bureau of Zhejiang Province(No.2003C33064)the Science and Technology Bureau of Ningbo City(No.2003C10002)the Key Laboratory of Marine and Estuarine Fisheries of the Ministry of Agriculture.
文摘L ethal temperature tolerance was determined for about 8 cm, age 0 Pseudosciaena crocea using both slow heating and rapid transfer protocol. The acclimatization temperature was 28 ℃ with summer season, lethal temperature ( LT50 value ) of slow heating protocol ( CTMax ) was 35.0 ℃, and the upper and lower incipient lethal temperatures of rapid transfer protocol were 34.2 ℃ and 17.5 ℃ respectively.
基金Supported by the National Basic Research Program of China under Grant No.2006CB705500the National Natural Science Foundation of China under Grant Nos.70631001 and 70701004
文摘To study the dynamics of mixed traffic flow consisting of motorized and non-motorized vehicles, a carfollowing model based on the principle of collision free and cautious driving is proposed. Lateral friction and overlapping driving are introduced to describe the interactions between motorized vehicles and non-motorized vehicles. By numerical simulations, the flux-density relation, the temporal-spatial dynamics, and the velocity evolution are investigated in detail The results indicate non-motorized vehicles have a significant impact on the motorized vehicle flow and cause the maximum flux to decline by about 13%. Non-motorized vehicles can decrease the motorized vehicle velocity and cause velocity oscillation when the motorized vehicle density is low. Moreover, non-motorized vehicles show a significant damping effect on the oscillating velocity when the density is medium and high, and such an effect weakens as motorized vehicle density increases. The results also stress the necessity for separating motorized vehicles from non-motorized vehicles.
基金Supported by the Science and Technology Project of Tackling Key Problems in Shandong Province(No.2010GHY10505)the National Natural Science Foundation of China(No.31172426)
文摘Gracilaria asiatica, being highly efficient in nutrient absorption, is cultivated in sea cucumber ponds to remove nutrients such as nitrogen and phosphate. It was cultured in a laboratory simulating field conditions, and its nutrient absorption was measured to evaluate effects of environmental conditions. Ammonia nitrogen (AN), nitrate nitrogen (NN), total inorganic nitrogen (TIN), and soluble reactive phosphorus (SRP) uptake rate and removal efficiency were determined in a 4~2 factorial design experiment in water temperatures (T) at 15~C and 25~C, algae biomass (AB) at 0.5 g/L and 1.0 g/L, total inorganic nitrogen (TIN) at 30 ~tmol/L and 60 ~tmol/L, and soluble reactive phosphorus (SRP) at 3 and 6 ~tmol/L. AB and ambient TIN or SRP levels significantly affected uptake rate and removal efficiency of AN, NN, TIN, and SRP (P〈0.001). G. asiatica in AB of 0.5 g/L showed higher uptake rate and lower removal efficiency relative to that with AB of 1.0 g/L. Nitrogen and phosphorus uptake rate rose with increasing ambient nutrient concentrations; nutrient removal efficiency decreased at higher environmental nutrient concentrations. The algae preferred to absorb AN to NN. Uptake rates of AN, NN, and SRP were significantly affected by temperature (P〈0.001); uptake rate was higher for the 25~C group than for the 15~C group at the initial experiment stage. Only the removal efficiency of AN and SRP showed a significant difference between the two temperature groups (P〈0.01). The four factors had significant interactive effects on absorption of N and P, implying that G. asiatica has great bioremedial potential in sea cucumber culture ponds.
文摘Wetland environment of Assam is fast changing due to encroachments, dumping of solid and liquid wastes, excessive use of wetland water, over exploitation of wetland resources, overgrazing, over fishing, hunting, poaching, unscientific construction of engineering structures across and along the wetlands, unscientific land use in surrounding areas and various human interferences. On the other hand wetlands play an important role in charging ground water table, sinking of carbon, providing livelihood to thousands of people through fishing, collecting edible plants, agriculture, irrigation and commercial fisheries, besides enrich biodiversity and maintaining environmental quality of a region. The life of wetlands depends on the quantity and quality of water. Any change in water quality and quantity affect the biotic regime of the wetlands. Fish and other aquatic animals and plants found in all levels (floating, rooted, submergent and emergent etc.) are affected by the changes, which are taking place in wetland water. The present study concerns in understanding the environmental quality of the wetlands in Dimoria region of Kamrup (Metro) district, Assam based primarily on the water and soil quality of selected wetlands viz. Jiong, Parkhali, Bomani and Duani.
基金supported by the National Natural Science Foundation of China (Grant No.31370624)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20103515110005)the Natural Science Foundation of Fujian, China (Grant No. 2011J01071)
文摘We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n 0f fallen l0gs in the different f0rest c0mmunities and t0 analyze the relati0nships am0ng stand structure, t0p0graphic fact0rs and human disturbance. The v0lume, c0vered area, mean l0g length and number 0f fallen l0gs differed significantly am0ng f0rest types (P 〈 0.05), but mean diameter at breast height sh0wed n0 significant difference (P 〉 0.05). The l0g v0lume and c0vered area in different f0rest types sh0wed the f0ll0wing trend: T. l0ngibracteata pure f0rest 〈 T. l0ngibracteata + Olig0staehyum scabrifl0rur 〈 T. l0ngibraeteata + hardw00d 〈 Rh0d0dendr0n simiarum + T. l0ngibraeteata 〈 T. l0ngibraeteata + Phyll0stachys heter0cycla pubescens. The spatial distributi0n patterns 0f l0gs quantity and quality indicated that l0g v0lume and c0vered area were str0ngly affected by envir0nmental fact0rs in the f0ll0wing 0rder: human disturbance 〉 elevati0n 〉 sl0pe p0siti0n 〉 b0le height 〉 tree height 〉 sl0pe aspect 〉 density 〉 basal area 〉 sl0pe gradient. The relative c0ntributi0n 0f envir0nmental variables 0n the t0tal variance was t0p0graphy (76%) 〉 disturbance (42%) 〉 stand structure (35%). T0p0graphy and disturbance c0mbined explained 8.2% 0f the variance. Fallen l0~s auantitv and aualitvwere negatively related t0 elevati0n and sl0pe p0siti0n, and p0sitively ass0ciated t0 human disturbance. The l0g v0lume decreased fr0m n0rthern t0 s0uthern sl0pes. Envir0nmental fact0rs had the highest impact 0n class I (slightly decayed), and l0west impact 0n class V (highly decayed).
文摘The objective of the study was to determine the usefulness of measuring maximum temperatures in designated regions of a healthy horse's body surface. Thermographic investigations (Thermovision〉550, FLIR) were carried out on 35 horses from 6 to 16 years old participating in show jumping competitions. The rectal temperatures of the horses were in the range 37.5-38.2 ℃. The research was performed in a stable, the ambient temperature (Tab) of which was 14℃ with a humidity (φ) of 60%. Thermograms of the left and right side of the horses were obtained. Each thermogram consisted of 36 body surface regions (before the competition) and 25 regions (immediately after the competition). The maximum temperature ranges at rest were 21.8 ℃-31.0℃ and symmetrical regions did not differ statistically (P 〉 0.05). The highest temperatures were on the head, neck and trunk, the lowest-on the limbs. The hind legs were warmer than the front legs in analogous areas, with the exception of the gaskin and forearm. The warmest body areas had the largest surface area, which is indicative of their crucial role in the thermoregulation of the equine organism. The research results may therefore be useful in veterinary diagnosis. The range of maximum temperatures after the competitions was 25.2℃-34.2℃. The highest increment was observed at the breast, elbow, forearm and gaskin, the lowest-at the head, pastern and hoof (foreand hind limbs). Research regarding body surface temperature after exercise does not have diagnostic value for veterinarians because "warming-up" certain parts of body surface masks inflammation.
文摘We study the influence of the shape of compact a scalar field. We examine both the massive and the massless dimensions to the Casimir energy and Casimir force of scalar field. The total spacetime topology is M^D × Tθ2, where M^D) is the D-dimensional Minkowski spacetime and Tθ2 the twisted torus described by R1, R2, and 8. For the case R1 = R2 we found that the massive bulk scalar field Casimir energy is singular for D=even and this singularity is R-dependent and remains even when the force is calculated. Also the massless Casimir energy and force is regular only for D = 4 (!). This is very interesting phenomenologically. We examine the energy and force as a function of 8. Also we address the stabilization problem of the compact space. We also briefly discuss some phenomenological implications.
文摘In this research, the main purpose is to estimate the variation of PM2.5 mass concentration and study the influence of meteorological characteristics on major components of PM2.5 concentrations in urban Tokyo, Japan. The results shown that the annual mean mass concentration of PM2.5 in urban Tokyo was higher than JEQS (Japanese Environmental Quality Standard) of the MOEJ (Ministry of the Environment Japan) (15 μg/m^3), and 41.1% of the daily PM2.5 mass concentration exceeded the annual JEQS concentration during observation period. The major components of PM2.5 including SO4^2-, NO3^-, NH4^+, OC and EC were tightly related to the meteorological conditions, the correlations results shown that the wind speed and relative humidity had significant correlations with major components of PM2.5 than the other meteorological factors. Higher relative humidity, windless and less rainfall conditions were favorable for elimination of PM2.5 concentration. Higher temperature was beneficial to the formation of SO42", but higher temperature and stronger sunshine duration were not conducive to the formation of NO3^-.
基金supported by the technology development fund of China Petroleum & Chemical Corporation (Sinopec 409045)
文摘An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has utilized the standard k-ε model and P1 model. The finite-rate/eddy-dissipation (finite-rate/ED) combustion model and non-premixed combustion model were both used to simulate accurately the combustion and the operation status of the steam cracking furnace. Three different surfaces of the steam cracking furnace were obtained from the simulation, namely:the flue gas temperature field of the entrance surface in long flame burners, the central surface location of tubes, and the crossover section surface. Detailed information on the flue gas temperature and the mass concentration fraction of these different surfaces in the steam cracking furnace can also be obtained by the simulation. This paper analyzed and compared the simulation results with the two combustion models, estimated the operation status of the steam cracking furnace, and reported that the finite-rate/ED model is appropriate to simulate the steam cracking furnace by comparing key simulation data with actual test data. This work has also provided a theoretical basis for simulating and operating the steam cracking furnace.
基金supported by the National Basic Research Program of China (Grant No. 2009CB421406)the National Key Technologies R&D Program of China (Grant No. 2007BAC03A00)
文摘The characteristics of spring precipitation and water vapor transport in South China were analyzed by using observational data and the National Centers for Environmental Prediction (NCEP) reanalysis data. The results show that, during the spring, each component of the water cycle (precipitation, wind field, specific humidity, water vapor transport, etc.) in South China exhibits a notable interdecadal variability. An abrupt increase in spring precipitation occurred in the early 1970s. During the dry period from 1958 to 1971, a water vapor flux divergence (positive divQ) existed in South China, which may have led to the deficiency in rainfall. However, during the wet period from 1973 to 1989, there was a remarkable water vapor flux convergence (negative divQ) in South China, which may have resulted in the higher rainfall. The interdecadal variability of water vapor transport is closely related to the interdecadal variability of wind fields, although the interdecadal variability of specific humidity also plays a role to some extent, and the interdecadal variability of the zonal water vapor transport contributes much more to the interdecadal variability of spring precipitation than the meridional water vapor transport.
文摘The environmental psychology ofa workspace is a rich and diverse field of study that is growing fast and gaining popularity. The indoor environmental factors in workspaces should follow functional as well as behavioral requirements as the spaces are designed as per the user's requirements, needs and aspirations. These play a major role in achieving behavioral impact on the user, as sense of well-being in the environment and physical comfort in the space enhances the productivity and efficiency of the user of the space. The slow and gradual importance of this issue in workspace design with Indian context, post occupancy evaluation can be adjudged as a permanent tool for improving indoor environment in buildings. Occupants should be used as a benchmark of evaluation, showing correlation of physical measurements and subjective parameters. It also suggests recommendations to improve quality of indoor environment in office buildings with analytical study, an important step in post occupancy evaluation. The objective of the paper is to inquire how people experience environmental psychology of the workspace as the determinants are efficiency, productivity and comfort. The success of any design depends upon the degree to which it creates an interface between the user and the environment.
基金supported by the National Basic Research Program of China (2009CB421405)the Special Scientific Research Project for Public Interest(GYHY201006021)the National Natural Science Foundation of China (40975046 and 40921160379)
文摘In this article, the authors used the Weather Research and Forecast model to investigate the sensitivity of tropical cyclone Bilis' total precipitation to ambient water vapor content. The tropical cyclone precipitation decreased dramatically with the reduction of the ambient water vapor content in the atmosphere. The decrease of precipitation can be explained by two mechanisms. First, as the major source of precipitation, moisture conver-gence decreases accordingly with the moisture content. Second, the tropical cyclone (TC) size reduction due to the moisture decrease influences the precipitation area. Both mechanisms were observed in this study.