Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and...Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination planning.This paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the destination.The results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism networks.The macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high value.The mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of clusters.The pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four different periods has a very similar importance profile structure suggesting that the attraction network has the same construction rules and evolution mechanism,which aids in understanding the attraction network pattern at both macro and micro scales.Important approaches and practical implications for planners and managers are presented.展开更多
The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has...The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has been no mechanistic explanation that reveals what causes the charged particles to accelerate, either towards or away from each other. This paper gives a detailed explanation of the phenomena of electrical attraction and repulsion based on my previous work that determined the exact wave-function solutions for both the Electron and the Positron. It is revealed that the effects are caused by wave interactions between the wave functions that result in Electromagnetic reflections of parts of the particle’s wave functions, causing a change in their momenta.展开更多
Attracting foreign capital is a key pillar of China’s reform and opening up policy,and foreign-funded enterprises are an important component of China’s economy.Currently,China is taking steps to further boost its at...Attracting foreign capital is a key pillar of China’s reform and opening up policy,and foreign-funded enterprises are an important component of China’s economy.Currently,China is taking steps to further boost its attractiveness as a foreign direct investment(FDI)destination in order to seek more foreign capital.展开更多
[Objective] The paper aims to study the attractive effects of 12 Chinese medicinal herbs on Scophthalmus maximus juvenile.[Method] We took 200 Scophthalmus maximus with the average body length of 3 cm,average weight o...[Objective] The paper aims to study the attractive effects of 12 Chinese medicinal herbs on Scophthalmus maximus juvenile.[Method] We took 200 Scophthalmus maximus with the average body length of 3 cm,average weight of 1 g and 60 days of age as the research object,and 12 Chinese medicinal herbs as feed attractants were selected,including Cloves,Cinnamon,Star anise,Kaempferol,Mint,Coptis,Phellodendron,skullcap,Gardenia,Sophora flavescens,Mume,Myrobalan meat were selected.The amount added to the basic diet was 2‰..The times of turbot juveniles going into each inducing room and the times of turbot juveniles biting the feed ball were recorded by maze experiments.Inducing effects of the Chinese herbal medicines were analyzed.[Result] The results showed that the attractant effect of Mume,Gardenia,Scutellaria and kaempferol had the significantly inducing effect on Scophthalmus maximus juvenile.And 2‰ Gardenia,5‰ Matrine,5‰ Scutellaria and 2‰ Kaempferol have the best attractant effects.In compound experients,the attractive effect of mixture of 2‰ matrine and gardenia on Scophthalmus maximus was the best.[Conclusion] The attractive effect on Scophthalmus maximus has something to do with the kind and concentration of Chinese medicinal herbs.展开更多
The tea geometridEctropis obliquais one of the most serious leaf-feeding insect pests in tea (Camelia sinensis) in East Asia. Although several volatile chemicals emitted from tea plants have been reported to be attr...The tea geometridEctropis obliquais one of the most serious leaf-feeding insect pests in tea (Camelia sinensis) in East Asia. Although several volatile chemicals emitted from tea plants have been reported to be attractive toE. obliqua moths, no synthetic attractants for E. obliqua moths have been developed. By measuring the behavioral responses of the moth to a series of chemicals in the lab, we found that a blend containing a ternary mixture containing (Z)-3-hexenal, (Z)-3-hexenyl hexanoate and benzyl alcohol clearly attracted toE. obliqua moths of both sex and that (Z)-3-hexenyl acetate could enhance the attractiveness of the ternary blend. Moreover, we found that the volatiles emitted from the plant-E. obliqua larva com-plex have the same attractiveness as: 1) the blend of volatiles containing the ternary mixture and 2) the blend containing (Z)-3-hexenyl acetate plus the ternary mixture to both male and female moths. In a ifeld bioassay, more male moths were observed on traps that were baited with the blend containing (Z)-3-hexenyl acetate plus the ternary mixture than on control traps. Our study raises the tantalizing possibility that synthetic blends could be deployed as attractants for pests in the ifeld.展开更多
Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals...Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals, such as Pb, Cu, Ag, and Cr, would result in severe defects of chemotaxis to water-soluble attractants of NaCl, cAMP, and biotin. Moreover, the morphology of ASE neuron structures as observed by relative fluorescent intensities and relative size of fluorescent puncta of cell bodies, relative lengths of sensory endings in ASE neurons, and the expression patterns of che-1 were obviously altered in metal exposed animals when they meanwhile exhibited obvious chemotaxis defects to water-soluble attractants. In addition, the dendrite morphology could be noticeably changed in animals exposed to 150 μmol/L of Pb, Cu, and Ag. Furthermore, we observed significant decreases of chemotaxis to water-soluble attractants in Pb exposed che-1 mutant at concentrations more than 2.5 μmol/L, and in Cu, Ag, and Cr exposed che-1 mutant at concentrations more than 50 μmol/L. Therefore, impairment of the ASE neuron structures and functions may largely contribute to the appearance of chemotaxis defects to water-soluble attractants in metal exposed nematodes.展开更多
[ Objective] The aim was to study the effects of four feeding attractants(dimethyl-15-propiothetin, trimethylamine oxide, betaine, sodium- 5'-inosinate) on feed intake, growth performance, body composition, digesti...[ Objective] The aim was to study the effects of four feeding attractants(dimethyl-15-propiothetin, trimethylamine oxide, betaine, sodium- 5'-inosinate) on feed intake, growth performance, body composition, digestive enzyme activities and serum indices of Hucho taimen with initial body weight 9.39 ±0.26 g. [ Method] The Hucho taimen was raised in water flow system. There was one control group and four process group. Each diet was randomly assigned to triplicates of 50 fish for 56 days. During the experiment, the water temperature fluctuated from 9.3℃ to 14.2℃ and the dissolved oxygen was above 8.0 mg/L. [ Result ] The weight gain rate and specific growth rate increased significantly by adding 0.2% dimethyl- 13-propiothetin, 0.2% trimethylamine oxide, 0.2% betaine, but there were no changes with 0.05% sodium-5'-inosinate supplementation ( P 〉 0.05). The body crude protein increased significantly by supplementing 0.2% dimethyl-15-propiothetin( P 〈0.05), and body crude lipid decreased signifi- cantly by adding 0.2% trimethylamine oxide and 0.2% betaine( P 〈0.05), but body composition had no changes by supplementing 0.05% sodium- 5'-inosinate( P 〉0.05). The digestive enzyme activities increased significantly by adding 0.2% dimethyl-13-propiothetin and 0.2% trimethylamine oxide( P 〈0.05), and the lipase increased significantly by supplementing 0.2% betaine( P 〈 0.05), but digestive enzyme activities had no changes supplemented 0.05% sodium-5'-inosinate( P 〉 0.05). The serum total protein, albumin and globulin increased significantly added 0.2% dimethyl-15- propiothetin( P 〈0.05), and the high density lipoprotein content increased while cholesterol, triglycedde and low density lipoprotein decreased sig- nificantly added 0.2% trimethylamine oxide and 0.2% betaine( P 〈 0.05), and serum complement 3 and complement 4 increased significantly sup- plemented 0.05% sodium-5'-inosinate ( P 〈 0.05). [ Conclusion] The food intake, growth performance, body composition and digestive ability of taimen were improved supplemented with 0.2% dimethyl-15-propiothetin, 0.2% trimethylamine oxide and 0.2% betaine, respectively( P 〈 0.05), but not 0.05% sodium-5'-inosinate. The immunity of body was improved by adding 0.05% sodium-5'-inosinate.展开更多
In the present study,we isolated the lactic acid bacterium strain SC-01 from Pacific white shrimp(Litopenaeus vannamei)intestine.Using conventional and molecular methods,we identified the bacterium as Enterococcus fae...In the present study,we isolated the lactic acid bacterium strain SC-01 from Pacific white shrimp(Litopenaeus vannamei)intestine.Using conventional and molecular methods,we identified the bacterium as Enterococcus faecium,and found it had the function of feeding attractant and could inhibit the development of Vibrio parahaemolyticus(zone of inhibition:14 mm).The attractant effect of its fermentation broth is significantly better than that of the chemical attractant trimethylamine oxide(TMAO)(P<0.05),and is equivalent to that of dimethyl-beta-propiothetin(DMPT)based on the feeding behavior of shrimp.High performance liquid chromatography(HPLC)analysis suggested that inosine-5’-monophosphate(IMP)may be a component of the attractant.A biosecurity evaluation revealed a negative result in hemolytic assays,and no shrimp mortality was resulted from SC-01 fermentation broth challenge.Feeding trials(60 days)indicated that the SC-01 fermentation broth(viable counts:5.7×109 cfu mL−1)could improve feed intake,weight gain rate(WGR)and specific growth rate(SGR),and decrease the count of Vibrio sp.in the intestine of shrimp.展开更多
The Tianji brand highly effective nitrogen-phosphate compound fertilizer is produced by the Shanxi Cheyenne Fertilizer Plant, one of the main compound fertilizer producers in the country. The fertilizer is made throug...The Tianji brand highly effective nitrogen-phosphate compound fertilizer is produced by the Shanxi Cheyenne Fertilizer Plant, one of the main compound fertilizer producers in the country. The fertilizer is made through the chemical reaction between the nitric acid and the fine phosphate ore and a series of purifying and condensing processes. It contains nitrogen, phosphate, calcium, magnesium, zinc, copper and iron. It has high and lasting fertility展开更多
[Objective]The paper was to explore the comprehensive sexual attraction control technology of main pests in broccoli,and to improve the green control technology of main pests in broccoli.[Method]The comprehensive cont...[Objective]The paper was to explore the comprehensive sexual attraction control technology of main pests in broccoli,and to improve the green control technology of main pests in broccoli.[Method]The comprehensive control technology of sex attractants against major pests in broccoli was studied by using special sex attractants,lures and traps.[Result]The mixed quantities of Spodoptera litura,Spodoptera exigua and Plutella xylostella were fluctuated in a"W"shape in broccoli growing season in coastal area of Taizhou,central Zhejiang province,including seedling growth period(July to August),rosette and bud growth period(late September to early November),late harvest period of late-ripening broccoli(after early march).S.exigua and S.litura occurred severely at seedling stage;S.litura,S.exigua and P.xylostella occurred simultaneously at rosette and bud growth period;P.xylostella damaged florets of lateral branches in late harvest period.The trapping effects of combination A and E against S.litura,S.exigua and P.xylostella were the best;more than 1260 individuals of S.litura,S.exigua and P.xylostella were daily trapped per hectare,and the occurrence and damage of the three insect pests could be basically controlled.With the sex attract produced in Ningbo as an example,the combination of S.litura S type∶S.exigua S type∶P.xylostella blue type=1∶1∶4 distributed in five stars of clubs(space 10-20 cm)showed good comprehensive trapping effect in large area demonstration;traps were hung at the height of 0.5 m(0.2 m for P.xylostella),and lures were replaced once every 30-40 d.[Conclusion]Using special sex attractants,the comprehensive effects on S.litura,S.exigua and P.xylostella were determined at rosette and bud growth period of broccoli through combination modes,and supporting application technology were put forward,making great progress in exploring and improving sex attractant combination against insect pests.展开更多
Contemporary villages of the mountain region are subject to uncontrolled structural and spatial transformations,which cause deformation of centuries-old spatial systems of high cultural and natural value.The aim of th...Contemporary villages of the mountain region are subject to uncontrolled structural and spatial transformations,which cause deformation of centuries-old spatial systems of high cultural and natural value.The aim of the study is to confront the opinions of the inhabitants and experts regarding the condition of the cultural landscape of the villages in south-eastern Poland.This area belongs to the Carpathian region of Central Europe.The historical and economic conditions of the studied region,related to the functioning in the post-war period,and then its breakdown and the development of the free market economy,constitute an interesting background for the proposed research.Local communities still remembering the period of difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,many difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,which is also expressed in a completely new,previously unknown way of managing the landscape.Investments implemented in villages are associated by the inhabitants with the improvement of the standards and quality of life.They assess them rather positively.An expert assessment of these landscape transformations indicates their negative dimension and the risk of losing timeless values.The discrepancy in the assessment of experts and local residents creates difficulties in the protection of the rural landscape.Therefore,high-quality visual landscape features among rural residents is necessary from the point of view of its multi-faceted and effective protection.Local initiatives and actions in the field of industry policy should play a significant role in this respect by consolidating the images of a harmonious landscape in the public awareness.展开更多
The persistent challenges in attracting and retaining a diverse healthcare workforce, with a specific focus on nurses, have become increasingly pronounced in recent years. These hurdles have been exacerbated by a grow...The persistent challenges in attracting and retaining a diverse healthcare workforce, with a specific focus on nurses, have become increasingly pronounced in recent years. These hurdles have been exacerbated by a growing difficulty in retaining young nurses, thereby exacerbating labor shortages driven by demographic shifts and the retirement of experienced nursing professionals. While most research efforts have concentrated on the broader issue of nurse retention, our study is centered on a specific demographic—young nurses. Our research endeavors to shed light on the unique challenges faced by young nurses through a qualitative survey involving nursing students who are simultaneously employed. We seek to discern the multifaceted obstacles they encounter in both their academic environment and the healthcare organizations where they work. While certain challenges are linked to course organization, examinations, and the time required for studying, our respondents overwhelmingly emphasize the pivotal role of the work environment in facilitating the harmonization of work, family, and educational commitments. This reconciliation is achieved through measures such as flexible working arrangements and the efficient organization of nursing duties. The primary objective of our research is to provide insights into how these diverse challenges can be effectively addressed and how a range of measures can significantly contribute to the attraction and retention of nursing students, as well as the long-term retention of nurses within the healthcare system. Our recommendations are intended to be of practical use to a wide array of stakeholders, including academic institutions, particularly colleges and universities offering nursing programs, as well as hospitals, clinics, and other healthcare institutions that hire nurses. By collaboratively addressing these challenges and implementing the recommended measures, we aim to fortify the healthcare workforce and ensure the continued provision of quality care to patients. .展开更多
With the penetration of the Internet, virtual groups have become more and more popular. The reliability and accuracy of interpersonal perception in the virtual environment is an intriguing issue. Using the Social rela...With the penetration of the Internet, virtual groups have become more and more popular. The reliability and accuracy of interpersonal perception in the virtual environment is an intriguing issue. Using the Social relations model (SRM) [1], this paper investigates interpersonal perception in virtual groups from a multilevel perspective. In particular, it examines the following three areas: homophily, identification, and individual attraction, and explores how much of these directional and dyadic relational evaluations can be attributed to the effect of the actor, the partner, and the relationship.展开更多
This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link,and propose a new six-dimensional system,which exhibits some hidden attractors.The param...This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link,and propose a new six-dimensional system,which exhibits some hidden attractors.The parameter switching algorithm is used to numerically study the dynamic behaviors of the system.Moreover,it is investigated that for some parameters the system with a stable equilibrium point can generate strange hidden attractors.A self-excited attractor with the change of its parameters is also recognized.In addition,numerical simulations are carried out to analyze the dynamic behaviors of the proposed system by using the Lyapunov exponent spectra,Lyapunov dimensions,bifurcation diagrams,phase space orbits,and basins of attraction.Consequently,the findings in this work show that the basins of hidden attractors are tiny for which the standard computational procedure for localization is unavailable.These simulation results are conducive to better understanding of hidden chaotic attractors in higher-dimensional dynamical systems,and are also of great significance in revealing chaotic oscillations such as uncontrolled speed adjustment in the operation of hydropower station due to small changes of initial values.展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.41971202)the National Natural Science Foundation of China(No.42201181)the Fundamental research funding targets for central universities(No.2412022QD002)。
文摘Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination planning.This paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the destination.The results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism networks.The macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high value.The mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of clusters.The pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four different periods has a very similar importance profile structure suggesting that the attraction network has the same construction rules and evolution mechanism,which aids in understanding the attraction network pattern at both macro and micro scales.Important approaches and practical implications for planners and managers are presented.
文摘The phenomenon of electrical attraction and repulsion between charged particles is well known, and described mathematically by Coulomb’s Law, yet until now there has been no explanation for why this occurs. There has been no mechanistic explanation that reveals what causes the charged particles to accelerate, either towards or away from each other. This paper gives a detailed explanation of the phenomena of electrical attraction and repulsion based on my previous work that determined the exact wave-function solutions for both the Electron and the Positron. It is revealed that the effects are caused by wave interactions between the wave functions that result in Electromagnetic reflections of parts of the particle’s wave functions, causing a change in their momenta.
文摘Attracting foreign capital is a key pillar of China’s reform and opening up policy,and foreign-funded enterprises are an important component of China’s economy.Currently,China is taking steps to further boost its attractiveness as a foreign direct investment(FDI)destination in order to seek more foreign capital.
文摘[Objective] The paper aims to study the attractive effects of 12 Chinese medicinal herbs on Scophthalmus maximus juvenile.[Method] We took 200 Scophthalmus maximus with the average body length of 3 cm,average weight of 1 g and 60 days of age as the research object,and 12 Chinese medicinal herbs as feed attractants were selected,including Cloves,Cinnamon,Star anise,Kaempferol,Mint,Coptis,Phellodendron,skullcap,Gardenia,Sophora flavescens,Mume,Myrobalan meat were selected.The amount added to the basic diet was 2‰..The times of turbot juveniles going into each inducing room and the times of turbot juveniles biting the feed ball were recorded by maze experiments.Inducing effects of the Chinese herbal medicines were analyzed.[Result] The results showed that the attractant effect of Mume,Gardenia,Scutellaria and kaempferol had the significantly inducing effect on Scophthalmus maximus juvenile.And 2‰ Gardenia,5‰ Matrine,5‰ Scutellaria and 2‰ Kaempferol have the best attractant effects.In compound experients,the attractive effect of mixture of 2‰ matrine and gardenia on Scophthalmus maximus was the best.[Conclusion] The attractive effect on Scophthalmus maximus has something to do with the kind and concentration of Chinese medicinal herbs.
基金sponsored by the Special Fund for Agro-scientific Research in the Public Interest, China (201403030)the National Basic Research Program of China (2012CB114104)+1 种基金the National Natural Science Foundation of China (31272053)the Division of Science and Technology of Zhejiang Province, China (2015C32081)
文摘The tea geometridEctropis obliquais one of the most serious leaf-feeding insect pests in tea (Camelia sinensis) in East Asia. Although several volatile chemicals emitted from tea plants have been reported to be attractive toE. obliqua moths, no synthetic attractants for E. obliqua moths have been developed. By measuring the behavioral responses of the moth to a series of chemicals in the lab, we found that a blend containing a ternary mixture containing (Z)-3-hexenal, (Z)-3-hexenyl hexanoate and benzyl alcohol clearly attracted toE. obliqua moths of both sex and that (Z)-3-hexenyl acetate could enhance the attractiveness of the ternary blend. Moreover, we found that the volatiles emitted from the plant-E. obliqua larva com-plex have the same attractiveness as: 1) the blend of volatiles containing the ternary mixture and 2) the blend containing (Z)-3-hexenyl acetate plus the ternary mixture to both male and female moths. In a ifeld bioassay, more male moths were observed on traps that were baited with the blend containing (Z)-3-hexenyl acetate plus the ternary mixture than on control traps. Our study raises the tantalizing possibility that synthetic blends could be deployed as attractants for pests in the ifeld.
基金supported by the National Natural Science Foundation of China (No. 30771113, 30870810)the Program for New Century Excellent Talents in Universityprovided by the Caenorhabdits Genetics Center (funded by the NIH National Center for Research Resource, USA).
文摘Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals, such as Pb, Cu, Ag, and Cr, would result in severe defects of chemotaxis to water-soluble attractants of NaCl, cAMP, and biotin. Moreover, the morphology of ASE neuron structures as observed by relative fluorescent intensities and relative size of fluorescent puncta of cell bodies, relative lengths of sensory endings in ASE neurons, and the expression patterns of che-1 were obviously altered in metal exposed animals when they meanwhile exhibited obvious chemotaxis defects to water-soluble attractants. In addition, the dendrite morphology could be noticeably changed in animals exposed to 150 μmol/L of Pb, Cu, and Ag. Furthermore, we observed significant decreases of chemotaxis to water-soluble attractants in Pb exposed che-1 mutant at concentrations more than 2.5 μmol/L, and in Cu, Ag, and Cr exposed che-1 mutant at concentrations more than 50 μmol/L. Therefore, impairment of the ASE neuron structures and functions may largely contribute to the appearance of chemotaxis defects to water-soluble attractants in metal exposed nematodes.
基金funded by Special Fund for Agro-scientific Research in the Public Interest(201003055)National Key Technology Research and Development Program in the 12th Five Year Plan of China(2012BAD25B10)the Fundamental Research Funds for the Central Institutes of HRFRI(201103)
文摘[ Objective] The aim was to study the effects of four feeding attractants(dimethyl-15-propiothetin, trimethylamine oxide, betaine, sodium- 5'-inosinate) on feed intake, growth performance, body composition, digestive enzyme activities and serum indices of Hucho taimen with initial body weight 9.39 ±0.26 g. [ Method] The Hucho taimen was raised in water flow system. There was one control group and four process group. Each diet was randomly assigned to triplicates of 50 fish for 56 days. During the experiment, the water temperature fluctuated from 9.3℃ to 14.2℃ and the dissolved oxygen was above 8.0 mg/L. [ Result ] The weight gain rate and specific growth rate increased significantly by adding 0.2% dimethyl- 13-propiothetin, 0.2% trimethylamine oxide, 0.2% betaine, but there were no changes with 0.05% sodium-5'-inosinate supplementation ( P 〉 0.05). The body crude protein increased significantly by supplementing 0.2% dimethyl-15-propiothetin( P 〈0.05), and body crude lipid decreased signifi- cantly by adding 0.2% trimethylamine oxide and 0.2% betaine( P 〈0.05), but body composition had no changes by supplementing 0.05% sodium- 5'-inosinate( P 〉0.05). The digestive enzyme activities increased significantly by adding 0.2% dimethyl-13-propiothetin and 0.2% trimethylamine oxide( P 〈0.05), and the lipase increased significantly by supplementing 0.2% betaine( P 〈 0.05), but digestive enzyme activities had no changes supplemented 0.05% sodium-5'-inosinate( P 〉 0.05). The serum total protein, albumin and globulin increased significantly added 0.2% dimethyl-15- propiothetin( P 〈0.05), and the high density lipoprotein content increased while cholesterol, triglycedde and low density lipoprotein decreased sig- nificantly added 0.2% trimethylamine oxide and 0.2% betaine( P 〈 0.05), and serum complement 3 and complement 4 increased significantly sup- plemented 0.05% sodium-5'-inosinate ( P 〈 0.05). [ Conclusion] The food intake, growth performance, body composition and digestive ability of taimen were improved supplemented with 0.2% dimethyl-15-propiothetin, 0.2% trimethylamine oxide and 0.2% betaine, respectively( P 〈 0.05), but not 0.05% sodium-5'-inosinate. The immunity of body was improved by adding 0.05% sodium-5'-inosinate.
基金the Special Fund for Qingdao Marine Biomedical Science and Technology Innovation Center,China(No.2017-CXZX01-3-13).
文摘In the present study,we isolated the lactic acid bacterium strain SC-01 from Pacific white shrimp(Litopenaeus vannamei)intestine.Using conventional and molecular methods,we identified the bacterium as Enterococcus faecium,and found it had the function of feeding attractant and could inhibit the development of Vibrio parahaemolyticus(zone of inhibition:14 mm).The attractant effect of its fermentation broth is significantly better than that of the chemical attractant trimethylamine oxide(TMAO)(P<0.05),and is equivalent to that of dimethyl-beta-propiothetin(DMPT)based on the feeding behavior of shrimp.High performance liquid chromatography(HPLC)analysis suggested that inosine-5’-monophosphate(IMP)may be a component of the attractant.A biosecurity evaluation revealed a negative result in hemolytic assays,and no shrimp mortality was resulted from SC-01 fermentation broth challenge.Feeding trials(60 days)indicated that the SC-01 fermentation broth(viable counts:5.7×109 cfu mL−1)could improve feed intake,weight gain rate(WGR)and specific growth rate(SGR),and decrease the count of Vibrio sp.in the intestine of shrimp.
文摘The Tianji brand highly effective nitrogen-phosphate compound fertilizer is produced by the Shanxi Cheyenne Fertilizer Plant, one of the main compound fertilizer producers in the country. The fertilizer is made through the chemical reaction between the nitric acid and the fine phosphate ore and a series of purifying and condensing processes. It contains nitrogen, phosphate, calcium, magnesium, zinc, copper and iron. It has high and lasting fertility
基金Supported by Science and Technology Project of Taizhou City"Research,Integration and Industrial-ization Development of Broccoli Production Technology Coping with Japan’s Affirmative List System(Research and Application of Key Technologies in Promoting Broccoli Industry)"(071TG04)Taizhou Broccoli Breeding and Promotion Integration Innovation Team Project(TRCL[2014]No.7)。
文摘[Objective]The paper was to explore the comprehensive sexual attraction control technology of main pests in broccoli,and to improve the green control technology of main pests in broccoli.[Method]The comprehensive control technology of sex attractants against major pests in broccoli was studied by using special sex attractants,lures and traps.[Result]The mixed quantities of Spodoptera litura,Spodoptera exigua and Plutella xylostella were fluctuated in a"W"shape in broccoli growing season in coastal area of Taizhou,central Zhejiang province,including seedling growth period(July to August),rosette and bud growth period(late September to early November),late harvest period of late-ripening broccoli(after early march).S.exigua and S.litura occurred severely at seedling stage;S.litura,S.exigua and P.xylostella occurred simultaneously at rosette and bud growth period;P.xylostella damaged florets of lateral branches in late harvest period.The trapping effects of combination A and E against S.litura,S.exigua and P.xylostella were the best;more than 1260 individuals of S.litura,S.exigua and P.xylostella were daily trapped per hectare,and the occurrence and damage of the three insect pests could be basically controlled.With the sex attract produced in Ningbo as an example,the combination of S.litura S type∶S.exigua S type∶P.xylostella blue type=1∶1∶4 distributed in five stars of clubs(space 10-20 cm)showed good comprehensive trapping effect in large area demonstration;traps were hung at the height of 0.5 m(0.2 m for P.xylostella),and lures were replaced once every 30-40 d.[Conclusion]Using special sex attractants,the comprehensive effects on S.litura,S.exigua and P.xylostella were determined at rosette and bud growth period of broccoli through combination modes,and supporting application technology were put forward,making great progress in exploring and improving sex attractant combination against insect pests.
文摘Contemporary villages of the mountain region are subject to uncontrolled structural and spatial transformations,which cause deformation of centuries-old spatial systems of high cultural and natural value.The aim of the study is to confront the opinions of the inhabitants and experts regarding the condition of the cultural landscape of the villages in south-eastern Poland.This area belongs to the Carpathian region of Central Europe.The historical and economic conditions of the studied region,related to the functioning in the post-war period,and then its breakdown and the development of the free market economy,constitute an interesting background for the proposed research.Local communities still remembering the period of difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,many difficulties related to the period of systemic transformations,are currently experiencing a relative prosperity,which is also expressed in a completely new,previously unknown way of managing the landscape.Investments implemented in villages are associated by the inhabitants with the improvement of the standards and quality of life.They assess them rather positively.An expert assessment of these landscape transformations indicates their negative dimension and the risk of losing timeless values.The discrepancy in the assessment of experts and local residents creates difficulties in the protection of the rural landscape.Therefore,high-quality visual landscape features among rural residents is necessary from the point of view of its multi-faceted and effective protection.Local initiatives and actions in the field of industry policy should play a significant role in this respect by consolidating the images of a harmonious landscape in the public awareness.
文摘The persistent challenges in attracting and retaining a diverse healthcare workforce, with a specific focus on nurses, have become increasingly pronounced in recent years. These hurdles have been exacerbated by a growing difficulty in retaining young nurses, thereby exacerbating labor shortages driven by demographic shifts and the retirement of experienced nursing professionals. While most research efforts have concentrated on the broader issue of nurse retention, our study is centered on a specific demographic—young nurses. Our research endeavors to shed light on the unique challenges faced by young nurses through a qualitative survey involving nursing students who are simultaneously employed. We seek to discern the multifaceted obstacles they encounter in both their academic environment and the healthcare organizations where they work. While certain challenges are linked to course organization, examinations, and the time required for studying, our respondents overwhelmingly emphasize the pivotal role of the work environment in facilitating the harmonization of work, family, and educational commitments. This reconciliation is achieved through measures such as flexible working arrangements and the efficient organization of nursing duties. The primary objective of our research is to provide insights into how these diverse challenges can be effectively addressed and how a range of measures can significantly contribute to the attraction and retention of nursing students, as well as the long-term retention of nurses within the healthcare system. Our recommendations are intended to be of practical use to a wide array of stakeholders, including academic institutions, particularly colleges and universities offering nursing programs, as well as hospitals, clinics, and other healthcare institutions that hire nurses. By collaboratively addressing these challenges and implementing the recommended measures, we aim to fortify the healthcare workforce and ensure the continued provision of quality care to patients. .
文摘With the penetration of the Internet, virtual groups have become more and more popular. The reliability and accuracy of interpersonal perception in the virtual environment is an intriguing issue. Using the Social relations model (SRM) [1], this paper investigates interpersonal perception in virtual groups from a multilevel perspective. In particular, it examines the following three areas: homophily, identification, and individual attraction, and explores how much of these directional and dyadic relational evaluations can be attributed to the effect of the actor, the partner, and the relationship.
基金the Fundamental Research Funds for the Northwest A&F University(Grant No./Z1090220172)the Scientific Research Foundation of the Natural Science Foundation of Shaanxi Province,China(Grant No.2019JLP-24)+1 种基金the Shaanxi Province Innovation Talent Promotion PlanScience and Technology Innovation Team,China(Grant No.2020TD-025)the Water Conservancy Science and Technology Program of Shaanxi Province,China(Grant No.2018slkj-9)。
文摘This work studies the stability and hidden dynamics of the nonlinear hydro-turbine governing system with an output limiting link,and propose a new six-dimensional system,which exhibits some hidden attractors.The parameter switching algorithm is used to numerically study the dynamic behaviors of the system.Moreover,it is investigated that for some parameters the system with a stable equilibrium point can generate strange hidden attractors.A self-excited attractor with the change of its parameters is also recognized.In addition,numerical simulations are carried out to analyze the dynamic behaviors of the proposed system by using the Lyapunov exponent spectra,Lyapunov dimensions,bifurcation diagrams,phase space orbits,and basins of attraction.Consequently,the findings in this work show that the basins of hidden attractors are tiny for which the standard computational procedure for localization is unavailable.These simulation results are conducive to better understanding of hidden chaotic attractors in higher-dimensional dynamical systems,and are also of great significance in revealing chaotic oscillations such as uncontrolled speed adjustment in the operation of hydropower station due to small changes of initial values.