[Objective] This study aimed to investigate the adsorption and desorption characteristics of cadmium and lead in typical paddy soils of Jiangxi Province. [Method] Gleyed paddy soil and waterloggogenic paddy soil were ...[Objective] This study aimed to investigate the adsorption and desorption characteristics of cadmium and lead in typical paddy soils of Jiangxi Province. [Method] Gleyed paddy soil and waterloggogenic paddy soil were collected from Jiangxi Province and used as experimental materials to investigate single and com- petitive adsorption and desorption behaviors of cadmium and lead by batch equilib- rium method. The environmental risk of the presence of cadmium and lead in paddy soils was assessed using distribution coefficients. [Result] Under equal ratio condi- tions, the adsorption capacity of lead by two types of paddy soils was higher than that of cadmium, and the adsorption rate in waterloggogenic paddy soil was higher than that in gleyed paddy soil. The desorption capacity of cadmium by two types of paddy soils was higher than that of lead, and the desorption rate in gleyed paddy soil was higher than that in waterloggogenic paddy soil. Under competitive condi- tions, the adsorption capacity of cadmium and lead by paddy soils was significantly reduced compared with single ion system, while the desorption rate was remarkably improved. The potential environmental risk of cadmium contamination was greater than that of lead in paddy soils. Moreover, environmental risks of cadmium and lead were reduced with the increase of pH, which increased significantly under the coex- istence state. [Conclusion] In the coexistence of cadmium and lead, cadmium con- tamination should be controlled and avoided compared with lead contamination in paddy soils.展开更多
By using diamond model, the current development status and core competitiveness of the rice seed industry in Guangxi Province were analyzed in detail from the 6 aspects of production factors, demand factors, related i...By using diamond model, the current development status and core competitiveness of the rice seed industry in Guangxi Province were analyzed in detail from the 6 aspects of production factors, demand factors, related industries and support industries, firm strategy, chance factor and government factor, which clarified the advantages of the rice seed industry of Guangxi in the nature and technological factors, firm strategy and government policy, and the disadvantages in demand factors, production cost, infrastructure and related industries. And the corresponding countermeasures were proposed to enhance the competitiveness of the rice seed industry of Guangxi.展开更多
This paper reports the effect of several competing anions on arsenate adsorption with maghemite nanoparticles. Sulphate （as SO4）, nitrate （as NO3-N）, phosphate （as PO4-P） ions and silicate-（as SiO2） were-studi...This paper reports the effect of several competing anions on arsenate adsorption with maghemite nanoparticles. Sulphate （as SO4）, nitrate （as NO3-N）, phosphate （as PO4-P） ions and silicate-（as SiO2） were-studied in dual solution with arsenate. Moreover, the combined effect of ions and other water characteristics were examined with a natural groundwater sample which was spiked with a certain amount of arsenate. Arsenate batch adsorption experiments were carried out with two different kinds of maghemite-a commercially, available one and a homemade one using the sol-gel orocess. Sulohate （≤250 mg.L-1） and nitrate （≤ 12 mg.L-1） had a neglivible effect onthe arsenate （0.5 mg.L-1） adsorption at pH 3. However, both phosphate （42.9 mg·L-1） and silicate （450 mg.L-j） had an adverse impact on arsenate （43 mg.L-1） adsorption at pH 7. Phosphate （41.5 mg.L-1） showed minimal competition with arsenate （0.5 mg.L-1）, while silicate （410 mg.L-1） inhibition was insignificant for all studied As（V） concentrations at p.H 3. The removal of arsenate from the groundwater sample was as efficient as from labo-ratory water tor 0.3 mgL -1 AS（V） botll at pH3 and pH7.展开更多
The main objective of this paper is to analyze the relationships between the productive process and the commercial trade with water resources used by them. For that the goal is to find out, by means of the estimation ...The main objective of this paper is to analyze the relationships between the productive process and the commercial trade with water resources used by them. For that the goal is to find out, by means of the estimation of water embodied in the exported crops which have the highest export competitiveness and lower water consumption. The finding contradicts not only the comparative advantages theory but also the resources sustainability logic. This conclusion is derived from the great exports of water via tomatoes and low profitable vegetables from producers＇ perspective but not economical from social perspectives as shown in domestic resource coefficient. The diversion between financial and economic profitability is due to heavily irrigation water subsidy. The results confirm that Jordan utilizes large amounts of water in its exports, and in turn, it does not export goods with low water requirements. The potential saving would be very significant and agricultural sector need to modify the use of water to a great extent in order to reach significant water savings and an environmental sustainability. Jordan has to implement policies that reduced, or even abandoned, the export and the production of water-intensive crops. Therefore, they have to be replaced with either imports or crops that optimize the water resources.展开更多
[Objective] This study was conducted to investigate the adsorption and desorption characteristics of Cu and Pb in typical paddy soils in Jiangxi Province. [Method] Two kinds of typical paddy soils （Gley type, Waterlo...[Objective] This study was conducted to investigate the adsorption and desorption characteristics of Cu and Pb in typical paddy soils in Jiangxi Province. [Method] Two kinds of typical paddy soils （Gley type, Waterloggogenic type） in Jiangxi Province were chosen as test materials. The single and competitive adsorption behaviors of Cu and Pb in paddy soils were investigated with batch equilibrium method, and the environmental risk under coexistence of Cu and Pb in these soils was estimated with distribution coefficient. The results showed that under equal proportion, the adsorption affinity of Pb was greater than that of Cu in the two paddy soils, and the adsorption capacities in waterloggogenic paddy soil （WPS） were significantly higher than those in gley paddy soil （GTPS）, but the desorption capacities of Cu were greater than those of Pb in the two paddy soils, and the desorption capacities in GTPS were significantly higher than those in the WPS. The adsorption capacities of Cu and Pb ions under competitive condition were obviously lower than those in single system, while the desorption rates significantly increased. The potential environmental risk of Cu pollution was greater than that of Pb in paddy soils, and their environmental risk decreased with the increase of pH, but increased significantly under coexistence of lead and copper. [Conclusion] This research suggests that when Cu and Pb ions coexist in the paddy soils, compared with lead pollution, we should pay attention to the pollution of Cu.展开更多
The Dutch herring trade contributed greatly to Dutch commercial prosperity. The most profitable Dutch fishing grounds, however, were off the coasts of England and Scotland. For centuries, the English allowed the Dutch...The Dutch herring trade contributed greatly to Dutch commercial prosperity. The most profitable Dutch fishing grounds, however, were off the coasts of England and Scotland. For centuries, the English allowed the Dutch to fish these waters. During the reign of James I, however, the changing English perspective of the Dutch led the English Crown to question the right of the Dutch to fish in English waters. In the fishing trade, centuries of cooperation gave way to an emerging commercial rivalry.展开更多
The equilibrium uptake of phenol and lead（II） ions, both singly and in combination, by granular activated carbon was studied in a batch system. The initial pH, temperature, mixing speed and contact time were fixed a...The equilibrium uptake of phenol and lead（II） ions, both singly and in combination, by granular activated carbon was studied in a batch system. The initial pH, temperature, mixing speed and contact time were fixed at 4, 30 ℃, 250 rpm and 6 hrs respectively. Adsorption isotherms were developed for both the single and binary component systems and expressed by ten models for single and four models for binary systems and model parameters were estimated by the non-linear regression method using STATISTICA version-6 and EXCEEL-2007 software. The maximum loading capacity （qm） of the phenol was 66.8234, 60.4823 mg/g and 37.0370, 13.0988 mg/g for lead in single and binary systems respectively. Desorption experiments indicate that the desorption efficiency with 0.1 M NaOH, 0.1 M HCI solution reaches 97.35%, 98% for phenol and lead respectively. There was only 3.58%, 4.93% decrease in removal efficiency for phenol and lead respectively when used regenerated GAC for one cycle.展开更多
Information on weed competitiveness responses to added nitrogen （N） is required to assist with the development of appropriate fertilizer management strategies where weed competition is anticipated. A greenhouse stud...Information on weed competitiveness responses to added nitrogen （N） is required to assist with the development of appropriate fertilizer management strategies where weed competition is anticipated. A greenhouse study was conducted to examine the effects of four N rates on the competitive ability ofEchinochloa colona and Amaranthus viridis grown together with direct-seeded rice. Rice and each weed species were grown in a replacement series design at added N rates of 0, 50, 100, and 150 kg ha1. Replacement series diagrams for relative yield showed that competitive ability ofE. colona increased with added soil N. Values of weed aggressivity index for E. colona also significantly increased with the addition of N in the soil. In the absence of added N, A. viridis was more competitive than rice but this relationship slightly changed as N was added. However, values of weed aggressivity index of were statistically similar at all N rates. The results suggest that the competitiveness ofE. colona increased with added soil N, and A. viridis unchanged by soil N levels. Both weed species were different in their response to higher N levels. Information gained in this study could be used to demonstrate the importance of effective weed and fertilizer management.展开更多
Biliary strictures are caused by a heterogeneous group of benign and malignant conditions, each requiring a specific treatment approach. Management of biliary strictures often involves endoscopy either for definite tr...Biliary strictures are caused by a heterogeneous group of benign and malignant conditions, each requiring a specific treatment approach. Management of biliary strictures often involves endoscopy either for definite treatment, as a bridge to surgery or for palliative purposes. Endoscopic treatment of various types of biliary strictures is not standardized and there are multiple areas of controversy regarding the best treatment options. These controversies are mainly due to lack of well-designed comparative studies to support a specific therapy. This paper reviews three common areas of controversy in the endoscopic management of biliary strictures. The areas discussed in this editorial include the role of biliary drainage in resectable malignant strictures and whether such drainage should be performed routinely prior to surgery, the best endoscopic palliation for unresectable hilar strictures and whether unilateral or bilateral stenting should be attempted, and the optimal endoscopic management for dominant strictures in patients with primary sclerosing cholangitis. The goal of this editorial is twofold. The first is to review the current literature on management of the aforementioned strictures and offer recommendations based on available evidence. The second goal is to highlight the gaps in our knowledge which in turn can encourage future research on these topics.展开更多
China is facing severe problem of water scarcity.Agricultural sector,the main consumer of water resource,has remarkably changed its institutions on water resource deployment,due to heavy environmental pressure.As a ne...China is facing severe problem of water scarcity.Agricultural sector,the main consumer of water resource,has remarkably changed its institutions on water resource deployment,due to heavy environmental pressure.As a new and spontaneous institution,groundwater market has developed rapidly in northern China,and has impacts on waterusing behaviors and benefits of farmers.Using household survey data from Hebei and Henan in 2007,this paper attempts to pin down the development and operating of groundwater market in rural China.We focus on the monopoly and competition in the market.Empirical analysis reveals that Chinese farmers are trying to make rational decision when they compete with others in groundwater market.In general,monopoly is not fierce in Chinese rural groundwater market,with great variations among different villages and even different tubewells within one village.Tubewell costs,regulation and the density of tubewells are the main determinants that affect monopoly level of groundwater market.To make water market benefit more and more farmers of low income,corresponding policies are needed to modify its development in the future.展开更多
The process of constructing hydraulic projects on international rivers is governed by several legal regulations, among the most important of these regulations are： the Principle of no harm, and the Principle of Prior...The process of constructing hydraulic projects on international rivers is governed by several legal regulations, among the most important of these regulations are： the Principle of no harm, and the Principle of Prior Notification, protection of the river＇s environment and the Principle of Settling the International Disputes via Peaceful Means, which is considered one of the most important principles called for by the UN Pact, as it provides for adopting the peaceful means by the member states of the organization to settle international disputes through peaceful means, in addition to an applied study on the Nile Basin＇s projects.展开更多
Plant competition has been recognized as one of the most important factors influencing the soructure and function of lake ecosystems. Competition from plants of dissimilar growth form may have profound effects on shal...Plant competition has been recognized as one of the most important factors influencing the soructure and function of lake ecosystems. Competition from plants of dissimilar growth form may have profound effects on shallow lakes＇. An experiment was conducted to investigate the effects of competitive interactions of submersed plants with dis- similar growth forms on the biomass allocations. Hydrilla verticitlata and Vallisneria natans were selected and were planted in a single-species monoculture and a mixed-species pattern, Results showed that the growth of E natans was＇ significantly affected by the tt, verticillata and caused a sharp reduction of biomass, but the root：shoot ratio of E ha- tans was not affected significantly and there was a minimal increase in mixture： while for H. verticillata, the biomass and the root：shoot ratio were not significantly changed by the competitive interactions ore natans, there was minimal increase of biomass and minimal decrease of the root：shoot ratio. These results may indicate that theplant which can develop a dense mat or canopy at the water surface would be a stronger competitor relative to the plant that depends more on light availability near the sediment.展开更多
The aim of this research is to test to what extent do the classifying variables of company size, technological level and subcontractor nature moderate on the causal relationship between a finn＇s innovative capacities...The aim of this research is to test to what extent do the classifying variables of company size, technological level and subcontractor nature moderate on the causal relationship between a finn＇s innovative capacities and its competitiveness. To this end, we use a random sample of 861 manufactttring f＇Lrms with 10 or more employees from the Basque Autonomous Community （in Spain）, accounting for 26.29% of the population. Maximum sampling error is 2.87% for a 95% confidence interval. We start from a competitiveness general model of the firm, and set out under the resource based view of the finn, which had been previously tested and validated by Martinez （2009） for the whole sample. The model is formed with the constructs of management capabilities, innovative capabilities, marketing capabilities, quality capabilities, current competitiveness and future competitiveness. From this point, we test a set of alternative hierarchical models both for the total sample and for different divisions in sub-samples, according to the intervals of size in number of employees, OECD technological levels and firms＇ subcontractor character. The innovative capabilities construct is reflected in the items of radical product innovation, incremental product innovation, innovation in the production process, innovation in marketing, management innovation and the efforts in company workers＇ training and development. From all these items, previous descriptive data analysis showed that although product radical innovation was the most representative capability for superior innovativeness, it was at the same time the least evident from all the aforementioned items in the case of the analyzed Basque industrial companies. The analysis of results led us to conclude that the factor of innovative capabilities was the most influential on current competitiveness among the whole sample. In particular, as regards the size factor, this positive effect dilutes in the case of smaller companies. In the same manner, whereas in the case of the companies with higher technological level it is verified that the factor of innovative capabilities reveals crucial, in the group of fhans with lower technological level the most relevant factor is quality. Also, the same effect is evidenced for the case of the subcontractor/non-subcontractor nature of the finns： The first ones show quality as the most relevant construct while for the second ones it is the innovative capabilities.展开更多
With today＇s global economic downturn and the increasingly fierce market competition, manufacturing enterprises must guarantee the efficient operation of production system, in order to get ahead in the competition, s...With today＇s global economic downturn and the increasingly fierce market competition, manufacturing enterprises must guarantee the efficient operation of production system, in order to get ahead in the competition, scheduling reasonable flow shop production systems can improve productivity and equipment utilization rate, reduce production costs. So the production system of flow shop scheduling problem has become one of the core problems ofmanufactaring enterprises the use of more and more.展开更多
This paper aims to examine and analyse the level of intra-industry trade on economy of ASEAN. These data obtained from the accurate and reliable source of ASEAN Trade Statistics databases. The importance of intra-indu...This paper aims to examine and analyse the level of intra-industry trade on economy of ASEAN. These data obtained from the accurate and reliable source of ASEAN Trade Statistics databases. The importance of intra-industry and measurement is also described. Moreover, the linkage of intra-industry trade and investment liberalization under the ASEAN Economic Community （AEC） is also explained. The effective enhancement schemed to increase the competitiveness of specific industries had been proposed to enhance ASEAN to be efficient production hub and network of region that lead to the ultimate goal of single market. The further studies can be applied to construct and estimate the econometric model and forecasting technique to confirm the empirical results.展开更多
In order to implement the hierarchical training of core competence in accounting profession, above all we need to establish the positioning for personnel training in intermediate and advanced accounting profession. Ba...In order to implement the hierarchical training of core competence in accounting profession, above all we need to establish the positioning for personnel training in intermediate and advanced accounting profession. Based on the five major targeted vocational positions and its main task of accounting profession, this article has constructed the accounting vocational competence system, analyzed the correspondence between accounting profession＇ s core competencies and educational levels, and raised nine core competencies for the accounting profession, as well as the correspondence between the division of the breadth and depth of core competencies in vocational training and educational levels, with focus on the correspondence between the training breadth and depth of three key core accounting competencies and educational levels in the process of educational convergence.展开更多
Sensory drive predicts that the conditions under which signaling takes place have large effects on signals, sensory systems, and behavior. The coupling of an ecological genetics approach with sen sory drive has been f...Sensory drive predicts that the conditions under which signaling takes place have large effects on signals, sensory systems, and behavior. The coupling of an ecological genetics approach with sen sory drive has been fruitful. An ecological genetics approach compares populations that experi ence different environments and asks whether population differences are adaptive and are the result of genetic and/or environmental variation. The multifaceted effects of signaling environ ments are wellexemplified by the bluefin killifish. In this system, males with blue anal fins are abundant in tanninstained swamps that lack UV/blue light but are absent in clear springs where UV/blue light is abundant. Past work indicates that lighting environments shape genetic and envir onmental variation in color patterns, visual systems, and behavior. Less is known about the select ive forces creating the across population correlations between UV/blue light and the abundance of blue males. Here, we present three new experiments that investigate the roles of lighting environ ments on male competition, female mate choice, and predation. We found strong effects of lighting environments on male competition where blue males were more likely to emerge as dominant in teastained water than in clear water. Our preliminary study on predation indicated that blue males may be less susceptible to predation in teastained water than in clear water. However, there was little evidence for female preferences favoring blue males. The resulting pattern is one where the effects of lighting environments on genetic variation and phenotypic plasticity match the direction of selection and favor the expression of blue males in swamps.展开更多
During adaptation to different habitat types, both morphological and behavioral traits can undergo divergent selection. Males often fight for status in dominance hierarchies and rank positions predict reproductive suc...During adaptation to different habitat types, both morphological and behavioral traits can undergo divergent selection. Males often fight for status in dominance hierarchies and rank positions predict reproductive success. Ecotypes with reduced fighting abilities should have low reproductive success when migrating into habitats that harbor ecotypes with superior fighting abilities. Livebearing fishes in the Poecilia mexicana-species complex inhabit not only regular freshwater environments, but also independently colonized sulfidic （H2S-containing） habitats in three river drainages. In the current study, we found fighting intensities in staged contests to be considerably lower in some but not all sulfidic surface ecotypes and the sulfidic cave ecotype compared with populations from non-sulfidic surface sites. This is perhaps due to selection imposed by H2S, which hampers oxygen uptake and transport, as well as cellular respiration. Furthermore, migrants from sulfidic habitats may lose fights even if they do not show overall reduced aggressiveness, as phys- iological performance is likely to be challenged in the non-sulfidic environment to which they are not adapted. To test this hypothesis, we simulated migration of H2S-adapted males into H2S-free waters, as well as H2S-adapted cave-dwelling males into sulfidic surface waters. We found that intruders established dominance less often than resident males, independent of whether or not they showed reduced aggressiveness overall. Our study shows that divergent evolution of male aggressive behavior may also contribute to the maintenance of genetic differentiation in this system and we call for more careful evaluation of male fighting abilities in studies on ecological speciation.展开更多
基金Supported by Science and Technology Research Project of Jiangxi Education Department(GJJ14289)Science and Technology Research Project of Environmental Protection Department of Jiangxi Province(JXHBKJ2013-4)Special Fund for Visiting Scholars from the Development Program for Middle-aged and Young Teachers in Colleges of Jiangxi Province(GJGH[2014]N0.15)
文摘[Objective] This study aimed to investigate the adsorption and desorption characteristics of cadmium and lead in typical paddy soils of Jiangxi Province. [Method] Gleyed paddy soil and waterloggogenic paddy soil were collected from Jiangxi Province and used as experimental materials to investigate single and com- petitive adsorption and desorption behaviors of cadmium and lead by batch equilib- rium method. The environmental risk of the presence of cadmium and lead in paddy soils was assessed using distribution coefficients. [Result] Under equal ratio condi- tions, the adsorption capacity of lead by two types of paddy soils was higher than that of cadmium, and the adsorption rate in waterloggogenic paddy soil was higher than that in gleyed paddy soil. The desorption capacity of cadmium by two types of paddy soils was higher than that of lead, and the desorption rate in gleyed paddy soil was higher than that in waterloggogenic paddy soil. Under competitive condi- tions, the adsorption capacity of cadmium and lead by paddy soils was significantly reduced compared with single ion system, while the desorption rate was remarkably improved. The potential environmental risk of cadmium contamination was greater than that of lead in paddy soils. Moreover, environmental risks of cadmium and lead were reduced with the increase of pH, which increased significantly under the coex- istence state. [Conclusion] In the coexistence of cadmium and lead, cadmium con- tamination should be controlled and avoided compared with lead contamination in paddy soils.
文摘By using diamond model, the current development status and core competitiveness of the rice seed industry in Guangxi Province were analyzed in detail from the 6 aspects of production factors, demand factors, related industries and support industries, firm strategy, chance factor and government factor, which clarified the advantages of the rice seed industry of Guangxi in the nature and technological factors, firm strategy and government policy, and the disadvantages in demand factors, production cost, infrastructure and related industries. And the corresponding countermeasures were proposed to enhance the competitiveness of the rice seed industry of Guangxi.
文摘This paper reports the effect of several competing anions on arsenate adsorption with maghemite nanoparticles. Sulphate （as SO4）, nitrate （as NO3-N）, phosphate （as PO4-P） ions and silicate-（as SiO2） were-studied in dual solution with arsenate. Moreover, the combined effect of ions and other water characteristics were examined with a natural groundwater sample which was spiked with a certain amount of arsenate. Arsenate batch adsorption experiments were carried out with two different kinds of maghemite-a commercially, available one and a homemade one using the sol-gel orocess. Sulohate （≤250 mg.L-1） and nitrate （≤ 12 mg.L-1） had a neglivible effect onthe arsenate （0.5 mg.L-1） adsorption at pH 3. However, both phosphate （42.9 mg·L-1） and silicate （450 mg.L-j） had an adverse impact on arsenate （43 mg.L-1） adsorption at pH 7. Phosphate （41.5 mg.L-1） showed minimal competition with arsenate （0.5 mg.L-1）, while silicate （410 mg.L-1） inhibition was insignificant for all studied As（V） concentrations at p.H 3. The removal of arsenate from the groundwater sample was as efficient as from labo-ratory water tor 0.3 mgL -1 AS（V） botll at pH3 and pH7.
文摘The main objective of this paper is to analyze the relationships between the productive process and the commercial trade with water resources used by them. For that the goal is to find out, by means of the estimation of water embodied in the exported crops which have the highest export competitiveness and lower water consumption. The finding contradicts not only the comparative advantages theory but also the resources sustainability logic. This conclusion is derived from the great exports of water via tomatoes and low profitable vegetables from producers＇ perspective but not economical from social perspectives as shown in domestic resource coefficient. The diversion between financial and economic profitability is due to heavily irrigation water subsidy. The results confirm that Jordan utilizes large amounts of water in its exports, and in turn, it does not export goods with low water requirements. The potential saving would be very significant and agricultural sector need to modify the use of water to a great extent in order to reach significant water savings and an environmental sustainability. Jordan has to implement policies that reduced, or even abandoned, the export and the production of water-intensive crops. Therefore, they have to be replaced with either imports or crops that optimize the water resources.
基金Supported by the Research Project of Jiangxi Education Department(GJJ14289)the Research Project of Environmental Protection Department of Jiangxi Province(JXHBKJ2013-4)the Special Fund for Visiting Scholar of the Development Plan for Middle-aged and Young Teachers in Colleges of Jiangxi Province(No.GJGH[2014]15)~~
文摘[Objective] This study was conducted to investigate the adsorption and desorption characteristics of Cu and Pb in typical paddy soils in Jiangxi Province. [Method] Two kinds of typical paddy soils （Gley type, Waterloggogenic type） in Jiangxi Province were chosen as test materials. The single and competitive adsorption behaviors of Cu and Pb in paddy soils were investigated with batch equilibrium method, and the environmental risk under coexistence of Cu and Pb in these soils was estimated with distribution coefficient. The results showed that under equal proportion, the adsorption affinity of Pb was greater than that of Cu in the two paddy soils, and the adsorption capacities in waterloggogenic paddy soil （WPS） were significantly higher than those in gley paddy soil （GTPS）, but the desorption capacities of Cu were greater than those of Pb in the two paddy soils, and the desorption capacities in GTPS were significantly higher than those in the WPS. The adsorption capacities of Cu and Pb ions under competitive condition were obviously lower than those in single system, while the desorption rates significantly increased. The potential environmental risk of Cu pollution was greater than that of Pb in paddy soils, and their environmental risk decreased with the increase of pH, but increased significantly under coexistence of lead and copper. [Conclusion] This research suggests that when Cu and Pb ions coexist in the paddy soils, compared with lead pollution, we should pay attention to the pollution of Cu.
文摘The Dutch herring trade contributed greatly to Dutch commercial prosperity. The most profitable Dutch fishing grounds, however, were off the coasts of England and Scotland. For centuries, the English allowed the Dutch to fish these waters. During the reign of James I, however, the changing English perspective of the Dutch led the English Crown to question the right of the Dutch to fish in English waters. In the fishing trade, centuries of cooperation gave way to an emerging commercial rivalry.
文摘The equilibrium uptake of phenol and lead（II） ions, both singly and in combination, by granular activated carbon was studied in a batch system. The initial pH, temperature, mixing speed and contact time were fixed at 4, 30 ℃, 250 rpm and 6 hrs respectively. Adsorption isotherms were developed for both the single and binary component systems and expressed by ten models for single and four models for binary systems and model parameters were estimated by the non-linear regression method using STATISTICA version-6 and EXCEEL-2007 software. The maximum loading capacity （qm） of the phenol was 66.8234, 60.4823 mg/g and 37.0370, 13.0988 mg/g for lead in single and binary systems respectively. Desorption experiments indicate that the desorption efficiency with 0.1 M NaOH, 0.1 M HCI solution reaches 97.35%, 98% for phenol and lead respectively. There was only 3.58%, 4.93% decrease in removal efficiency for phenol and lead respectively when used regenerated GAC for one cycle.
文摘Information on weed competitiveness responses to added nitrogen （N） is required to assist with the development of appropriate fertilizer management strategies where weed competition is anticipated. A greenhouse study was conducted to examine the effects of four N rates on the competitive ability ofEchinochloa colona and Amaranthus viridis grown together with direct-seeded rice. Rice and each weed species were grown in a replacement series design at added N rates of 0, 50, 100, and 150 kg ha1. Replacement series diagrams for relative yield showed that competitive ability ofE. colona increased with added soil N. Values of weed aggressivity index for E. colona also significantly increased with the addition of N in the soil. In the absence of added N, A. viridis was more competitive than rice but this relationship slightly changed as N was added. However, values of weed aggressivity index of were statistically similar at all N rates. The results suggest that the competitiveness ofE. colona increased with added soil N, and A. viridis unchanged by soil N levels. Both weed species were different in their response to higher N levels. Information gained in this study could be used to demonstrate the importance of effective weed and fertilizer management.
文摘Biliary strictures are caused by a heterogeneous group of benign and malignant conditions, each requiring a specific treatment approach. Management of biliary strictures often involves endoscopy either for definite treatment, as a bridge to surgery or for palliative purposes. Endoscopic treatment of various types of biliary strictures is not standardized and there are multiple areas of controversy regarding the best treatment options. These controversies are mainly due to lack of well-designed comparative studies to support a specific therapy. This paper reviews three common areas of controversy in the endoscopic management of biliary strictures. The areas discussed in this editorial include the role of biliary drainage in resectable malignant strictures and whether such drainage should be performed routinely prior to surgery, the best endoscopic palliation for unresectable hilar strictures and whether unilateral or bilateral stenting should be attempted, and the optimal endoscopic management for dominant strictures in patients with primary sclerosing cholangitis. The goal of this editorial is twofold. The first is to review the current literature on management of the aforementioned strictures and offer recommendations based on available evidence. The second goal is to highlight the gaps in our knowledge which in turn can encourage future research on these topics.
基金supported by International Water Management Institute-Groundwater Governance in Asia Program(Grant No.PN-42)
文摘China is facing severe problem of water scarcity.Agricultural sector,the main consumer of water resource,has remarkably changed its institutions on water resource deployment,due to heavy environmental pressure.As a new and spontaneous institution,groundwater market has developed rapidly in northern China,and has impacts on waterusing behaviors and benefits of farmers.Using household survey data from Hebei and Henan in 2007,this paper attempts to pin down the development and operating of groundwater market in rural China.We focus on the monopoly and competition in the market.Empirical analysis reveals that Chinese farmers are trying to make rational decision when they compete with others in groundwater market.In general,monopoly is not fierce in Chinese rural groundwater market,with great variations among different villages and even different tubewells within one village.Tubewell costs,regulation and the density of tubewells are the main determinants that affect monopoly level of groundwater market.To make water market benefit more and more farmers of low income,corresponding policies are needed to modify its development in the future.
文摘The process of constructing hydraulic projects on international rivers is governed by several legal regulations, among the most important of these regulations are： the Principle of no harm, and the Principle of Prior Notification, protection of the river＇s environment and the Principle of Settling the International Disputes via Peaceful Means, which is considered one of the most important principles called for by the UN Pact, as it provides for adopting the peaceful means by the member states of the organization to settle international disputes through peaceful means, in addition to an applied study on the Nile Basin＇s projects.
基金sponsored by China Postdoctoral Science Foundation (Grant No.20090461149)the Postdoctoral Science Foundation of Jiangsu Province (Grant No. 0802029C)the Youth Science Foundation of JINAN Univeristy (Grant No. 51208026)
文摘Plant competition has been recognized as one of the most important factors influencing the soructure and function of lake ecosystems. Competition from plants of dissimilar growth form may have profound effects on shallow lakes＇. An experiment was conducted to investigate the effects of competitive interactions of submersed plants with dis- similar growth forms on the biomass allocations. Hydrilla verticitlata and Vallisneria natans were selected and were planted in a single-species monoculture and a mixed-species pattern, Results showed that the growth of E natans was＇ significantly affected by the tt, verticillata and caused a sharp reduction of biomass, but the root：shoot ratio of E ha- tans was not affected significantly and there was a minimal increase in mixture： while for H. verticillata, the biomass and the root：shoot ratio were not significantly changed by the competitive interactions ore natans, there was minimal increase of biomass and minimal decrease of the root：shoot ratio. These results may indicate that theplant which can develop a dense mat or canopy at the water surface would be a stronger competitor relative to the plant that depends more on light availability near the sediment.
文摘The aim of this research is to test to what extent do the classifying variables of company size, technological level and subcontractor nature moderate on the causal relationship between a finn＇s innovative capacities and its competitiveness. To this end, we use a random sample of 861 manufactttring f＇Lrms with 10 or more employees from the Basque Autonomous Community （in Spain）, accounting for 26.29% of the population. Maximum sampling error is 2.87% for a 95% confidence interval. We start from a competitiveness general model of the firm, and set out under the resource based view of the finn, which had been previously tested and validated by Martinez （2009） for the whole sample. The model is formed with the constructs of management capabilities, innovative capabilities, marketing capabilities, quality capabilities, current competitiveness and future competitiveness. From this point, we test a set of alternative hierarchical models both for the total sample and for different divisions in sub-samples, according to the intervals of size in number of employees, OECD technological levels and firms＇ subcontractor character. The innovative capabilities construct is reflected in the items of radical product innovation, incremental product innovation, innovation in the production process, innovation in marketing, management innovation and the efforts in company workers＇ training and development. From all these items, previous descriptive data analysis showed that although product radical innovation was the most representative capability for superior innovativeness, it was at the same time the least evident from all the aforementioned items in the case of the analyzed Basque industrial companies. The analysis of results led us to conclude that the factor of innovative capabilities was the most influential on current competitiveness among the whole sample. In particular, as regards the size factor, this positive effect dilutes in the case of smaller companies. In the same manner, whereas in the case of the companies with higher technological level it is verified that the factor of innovative capabilities reveals crucial, in the group of fhans with lower technological level the most relevant factor is quality. Also, the same effect is evidenced for the case of the subcontractor/non-subcontractor nature of the finns： The first ones show quality as the most relevant construct while for the second ones it is the innovative capabilities.
文摘With today＇s global economic downturn and the increasingly fierce market competition, manufacturing enterprises must guarantee the efficient operation of production system, in order to get ahead in the competition, scheduling reasonable flow shop production systems can improve productivity and equipment utilization rate, reduce production costs. So the production system of flow shop scheduling problem has become one of the core problems ofmanufactaring enterprises the use of more and more.
文摘This paper aims to examine and analyse the level of intra-industry trade on economy of ASEAN. These data obtained from the accurate and reliable source of ASEAN Trade Statistics databases. The importance of intra-industry and measurement is also described. Moreover, the linkage of intra-industry trade and investment liberalization under the ASEAN Economic Community （AEC） is also explained. The effective enhancement schemed to increase the competitiveness of specific industries had been proposed to enhance ASEAN to be efficient production hub and network of region that lead to the ultimate goal of single market. The further studies can be applied to construct and estimate the econometric model and forecasting technique to confirm the empirical results.
文摘In order to implement the hierarchical training of core competence in accounting profession, above all we need to establish the positioning for personnel training in intermediate and advanced accounting profession. Based on the five major targeted vocational positions and its main task of accounting profession, this article has constructed the accounting vocational competence system, analyzed the correspondence between accounting profession＇ s core competencies and educational levels, and raised nine core competencies for the accounting profession, as well as the correspondence between the division of the breadth and depth of core competencies in vocational training and educational levels, with focus on the correspondence between the training breadth and depth of three key core accounting competencies and educational levels in the process of educational convergence.
文摘Sensory drive predicts that the conditions under which signaling takes place have large effects on signals, sensory systems, and behavior. The coupling of an ecological genetics approach with sen sory drive has been fruitful. An ecological genetics approach compares populations that experi ence different environments and asks whether population differences are adaptive and are the result of genetic and/or environmental variation. The multifaceted effects of signaling environ ments are wellexemplified by the bluefin killifish. In this system, males with blue anal fins are abundant in tanninstained swamps that lack UV/blue light but are absent in clear springs where UV/blue light is abundant. Past work indicates that lighting environments shape genetic and envir onmental variation in color patterns, visual systems, and behavior. Less is known about the select ive forces creating the across population correlations between UV/blue light and the abundance of blue males. Here, we present three new experiments that investigate the roles of lighting environ ments on male competition, female mate choice, and predation. We found strong effects of lighting environments on male competition where blue males were more likely to emerge as dominant in teastained water than in clear water. Our preliminary study on predation indicated that blue males may be less susceptible to predation in teastained water than in clear water. However, there was little evidence for female preferences favoring blue males. The resulting pattern is one where the effects of lighting environments on genetic variation and phenotypic plasticity match the direction of selection and favor the expression of blue males in swamps.
文摘During adaptation to different habitat types, both morphological and behavioral traits can undergo divergent selection. Males often fight for status in dominance hierarchies and rank positions predict reproductive success. Ecotypes with reduced fighting abilities should have low reproductive success when migrating into habitats that harbor ecotypes with superior fighting abilities. Livebearing fishes in the Poecilia mexicana-species complex inhabit not only regular freshwater environments, but also independently colonized sulfidic （H2S-containing） habitats in three river drainages. In the current study, we found fighting intensities in staged contests to be considerably lower in some but not all sulfidic surface ecotypes and the sulfidic cave ecotype compared with populations from non-sulfidic surface sites. This is perhaps due to selection imposed by H2S, which hampers oxygen uptake and transport, as well as cellular respiration. Furthermore, migrants from sulfidic habitats may lose fights even if they do not show overall reduced aggressiveness, as phys- iological performance is likely to be challenged in the non-sulfidic environment to which they are not adapted. To test this hypothesis, we simulated migration of H2S-adapted males into H2S-free waters, as well as H2S-adapted cave-dwelling males into sulfidic surface waters. We found that intruders established dominance less often than resident males, independent of whether or not they showed reduced aggressiveness overall. Our study shows that divergent evolution of male aggressive behavior may also contribute to the maintenance of genetic differentiation in this system and we call for more careful evaluation of male fighting abilities in studies on ecological speciation.
