Objective Detection and quantification of RNA synthesis in cells is a widely used technique for monitoring cell viability,health,and metabolic rate.After exposure to environmental stimuli,both the internal reference g...Objective Detection and quantification of RNA synthesis in cells is a widely used technique for monitoring cell viability,health,and metabolic rate.After exposure to environmental stimuli,both the internal reference gene and target gene would be degraded.As a result,it is imperative to consider the accurate capture of nascent RNA and the detection of transcriptional levels of RNA following environmental stimulation.This study aims to create a Click Chemistry method that utilizes its property to capture nascent RNA from total RNA that was stimulated by the environment.Methods The new RNA was labeled with 5-ethyluridine(5-EU)instead of uracil,and the azido-biotin medium ligand was connected to the magnetic sphere using a combination of“Click Chemistry”and magnetic bead screening.Then the new RNA was captured and the transcription rate of 16S rRNA was detected by fluorescence molecular beacon(M.B.)and quantitative reverse transcription PCR(qRT-PCR).Results The bacterial nascent RNA captured by“Click Chemistry”screening can be used as a reverse transcription template to form cDNA.Combined with the fluorescent molecular beacon M.B.1,the synthesis rate of rRNA at 37℃is 1.2 times higher than that at 15℃.The 16S rRNA gene and cspI gene can be detected by fluorescent quantitative PCR,it was found that the measured relative gene expression changes were significantly enhanced at 25℃and 16℃when analyzed with nascent RNA rather than total RNA,enabling accurate detection of RNA transcription rates.Conclusion Compared to other article reported experimental methods that utilize screening magnetic columns,the technical scheme employed in this study is more suitable for bacteria,and the operation steps are simple and easy to implement,making it an effective RNA capture method for researchers.展开更多
Utilizing single atom sites doping into metal oxides to modulate their intrinsic active sites,achieving precise selectivity control in complex organic reactions,is a highly desirable yet challenging endeavor.Meanwhile...Utilizing single atom sites doping into metal oxides to modulate their intrinsic active sites,achieving precise selectivity control in complex organic reactions,is a highly desirable yet challenging endeavor.Meanwhile,identifying the active site also represents a significant obstacle,primarily due to the intricate electronic environment of single atom site doped metal oxide.Herein,a single atom Cu doped TiO_(2)catalyst(Cu_(1)-TiO_(2))is prepared via a simple“colloid-acid treatment”strategy,which switches aniline oxidation selectivity of TiO_(2)from azoxybenzene to nitrosobenzene,without using additives or changing solvent,while other metal or nonmetal doped TiO_(2)did not possess.Comprehensive mechanistic investigations and DFT calculations unveil that Ti-O active site is responsible for triggering the aniline to form a new PhNOH intermediate,two PhNOH condense to azoxybenzene over TiO_(2)catalyst.As for Cu_(1)-TiO_(2),the charge-specific distribution between the isolated Cu and TiO_(2)generates unique Cu_(1)-O-Ti hybridization structure with nine catalytic active sites,eight of them make PhNOH take place spontaneous dissociation to produce nitrosobenzene.This work not only unveils a new mechanistic pathway featuring the PhNOH intermediate in aniline oxidation for the first time but also presents a novel approach for constructing single-atom doped metal oxides and exploring their intricate active sites.展开更多
The flotation behavior of Xixia andalusite was studied with different collectors.The tests were conducted with a pure andalusite sample in micro-flotation cell and then with an ore sample in a mechanical flotation cel...The flotation behavior of Xixia andalusite was studied with different collectors.The tests were conducted with a pure andalusite sample in micro-flotation cell and then with an ore sample in a mechanical flotation cell.The surface charge was measured on pure andalusite sample and the isoelectric point(IEP) was found to be pH 5.2.Andalusite is floated with an amine collector above IEP where mineral surface is negatively charged.In contrast,an alkyl sulfonate collector(sodium dodecyl benzene sulfonate) is effective in the pH range where andalusite surface is positively charged.Furthermore,andalusite is floated with oleate in neutral and mildly alkaline pH values.55.3% Al2O3 is produced with 75.6% andalusite recovery when using the alkyl benzene sulfonate collector.Starch is found to be an effective depressant for gangue minerals in alkyl benzene sulfonate flotation.Moreover,slimes are found to have an adverse effect on the flotation of andalusite.Therefore,pretreatment by desliming and pre-float(to remove carbonaceous species) prior to andalusite flotation is necessary.展开更多
[Objective] This study was conducted to solve the problem of the lacking of special forage foxtail millet varieties. [Method] With wild large-grain foxtail millet as an original material, foxtail millet variety Jicaog...[Objective] This study was conducted to solve the problem of the lacking of special forage foxtail millet varieties. [Method] With wild large-grain foxtail millet as an original material, foxtail millet variety Jicaogu 1 (S724) for forage use was bred. [Result] Jicaogu 1 has following outstanding characteristics: (1) high content of crude protein: quality detection showed that the millet straw had a high content of crude protein up to 9.8%; (2) high yields of fresh grass and hay: in field detection, the average yield of fresh grass was 58 308.15 kg/hm2, which was higher than Sicao 2 (35 763.00 kg/hm2) by 58.29%, and the hay yield was 15 922.65 kg/hm2, which was higher than Sicao 2 (11 548.05 kg/hm2) by 37.88%; and (3) biological characteristics: Jicaogu 1 shows young seedlings with a growth period of 122 d, a plant height of 198.22 cm, an ear length of 23.65 cm, a stem/leaf ratio of 1.43 and a fresh weight/dry weight ratio of 37.86, there are 2-3 tillers generally, and the seed yield is 3 383.40 kg/hm2. [Conclusion] Summer seeding in vacant field in North China or spring seeding in Inner Mongolia could be carried out with Jicaogu 1, which is also adapt to mechanized harvest. The development of forage foxtail millet could be promoted by strengthening the extension of Jicaogu 1.展开更多
Edible sunflower variety AR9-9293 was approved by the Sunflower Variety Appraisal Committee with the country Identification number of sunflower 2015005. This paper introduced the breeding process, yield performance an...Edible sunflower variety AR9-9293 was approved by the Sunflower Variety Appraisal Committee with the country Identification number of sunflower 2015005. This paper introduced the breeding process, yield performance and characteristics, and the high-yield cultivation technology of new edible sunflower variety AR9-9293. The promotion of edible sunflower varieties and cultivation technology could achieve the effects of improving the level of the sunflower cultivation, promoting the development of rural and agricultural economy and increasing farmers' income, as well as positively promoting development of the society and adjusting agricultural industry structure.展开更多
Combining the characteristics of peer-to-peer (P2P) and grid, a super-peer selection algorithm--SSABC is presented in the distributed network merging P2P and grid. The algorithm computes nodes capacities using their...Combining the characteristics of peer-to-peer (P2P) and grid, a super-peer selection algorithm--SSABC is presented in the distributed network merging P2P and grid. The algorithm computes nodes capacities using their resource properties provided by a grid monitoring and discovery system, such as available bandwidth, free CPU and idle memory, as well as the number of current connections and online time. when a new node joins the network and the super-peers are all saturated, it should select a new super-peer from the new node or joined nodes with the highest capacity. By theoretical analyses and simulation experiments, it is shown that super-peers selected by capacity can achieve higher query success rates and shorten the average hop count when compared with super-peers selected randomly, and they can also balance the network load when all super-peers are saturated. When the number of total nodes changes, the conclusion is still valid, which explains that the algorithm SSABC is feasible and stable.展开更多
In order to achieve higher system energy efficiency (EE),a new coordinated multipoint (CoMP)-transmission-based scheme selection energy saving (CTSES)algorithm is proposed for downlink homogeneous cellular netwo...In order to achieve higher system energy efficiency (EE),a new coordinated multipoint (CoMP)-transmission-based scheme selection energy saving (CTSES)algorithm is proposed for downlink homogeneous cellular networks.The problem is formulated as an optimization of maximizing system EE,under the constraints of the data rate requirement and the maximum transmit power.The problem is decomposed into power allocation and alternative scheme selection problems.Optimal power allocation is calculated for CoMP-JT (joint transmission)and CoMP-CS (coordinated scheduling) transmissions,and the scheme with higher EE is chosen. Since the optimal problem is a nonlinear fractional optimization problem for both CoMP transmission schemes, the problem is transformed into an equivalent problem using the parametric method. The optimal transmit power and optimal EE are obtained by an iteration algorithm in CoMP-JT and CoMP-CS schemes.Simulation results show that the proposed algorithm offers obvious energy-saving potential and outperforms the fixed CoMP transmission scheme.Under the condition of the same maximum transmit power limit,the empirical regularity of user distribution for scheme choice is presented, and using this regularity, the computational complexity can be reduced.展开更多
Multi-target tracking(MTT) is a research hotspot of wireless sensor networks at present.A self-organized dynamic cluster task allocation scheme is used to implement collaborative task allocation for MTT in WSN and a s...Multi-target tracking(MTT) is a research hotspot of wireless sensor networks at present.A self-organized dynamic cluster task allocation scheme is used to implement collaborative task allocation for MTT in WSN and a special cluster member(CM) node selection method is put forward in the scheme.An energy efficiency model was proposed under consideration of both energy consumption and remaining energy balance in the network.A tracking accuracy model based on area-sum principle was also presented through analyzing the localization accuracy of triangulation.Then,the two models mentioned above were combined to establish dynamic cluster member selection model for MTT where a comprehensive performance index function was designed to guide the CM node selection.This selection was fulfilled using genetic algorithm.Simulation results show that this method keeps both energy efficiency and tracking quality in optimal state,and also indicate the validity of genetic algorithm in implementing CM node selection.展开更多
For a screening process, the collision and penetration phenomena between particles and screen plate is standard behavior and with collision the mechanical energy of the vibrating screen can be transmitted to the feed....For a screening process, the collision and penetration phenomena between particles and screen plate is standard behavior and with collision the mechanical energy of the vibrating screen can be transmitted to the feed. In order to recognize further the collision process and the law of penetrating motion, with the spring-dashpot-slider contact model of the distinct element method (DEM), a mathematical model which can describe the collision process has been established and a program for simulating the motion of a single particle on the screen plate developed by VC++. NET. To evaluate the handling capacity of the screen that deals with difficult screening material, an instantaneous penetrating coefficient is defined. The moving period of the screen plate is divided into four stages. By analyzing the state of contact collision at each stage, it is pointed out that the collision ranging from 3π/2 to 2π period is the most favorable aperture for penetration of particles, while the collision ranging from π/2 to n period is the most unfavorable. The numerical simulation result further indicates that increasing the amplitude of the screen plate has a much greater effect on the augmentation of instantaneous penetration coefficient than increasing the vibration frequency.展开更多
Labor migration to urban centers is a common phenomenon in the Panxi region of the southwestern mountainous region of China, mainly owing to inadequate livelihood capital in rural areas. Numerous studies have been con...Labor migration to urban centers is a common phenomenon in the Panxi region of the southwestern mountainous region of China, mainly owing to inadequate livelihood capital in rural areas. Numerous studies have been conducted to explore the relationship between labor migration and its causes, such as individual and family characteristics, but few studies have focused on livelihood capital. This paper examines the impact factors on labor migration employment location selection and duration from a household livelihood capital perspective. A case study of 279 households from 10 villages in the area was carried out in February 2016. We used both qualitative and quantitative methods to analyze the data. On the basis of the 279 questionnaires, the proportion of households with non-labor migration is 48.4%, whereas households with labor migration within a local city and migration across regions account for 28.7% and 22.9%, respectively. Social, financial, and human capitals are the primary factors that influence migrants' employment location choice positively. Among them, social capital has a significant impact on both migration within a local city and across regions; each of the regression coefficients is 1.111 and 1.183. Social, human, and financial capitals also have a positive impact on the duration of labor migration, and similarly, social capital is the highest coefficient with 2.489. However, physical capital only partly impacts labor migration across regions, whereas the impact of labor migration within a local city, and the duration, are not significant. Furthermore, the impact of household natural capital on migration space and time are all negative relationships, especially for labor migration across the regions and duration, with coefficient scores of 4.836 and 3.450, respectively. That is to say, a laborer is inclined to migrate within a local city for a short term, or not migrate at all, if natural capital is abundant. Our analysis results show that household livelihood capital has a strong spatio-temporal impact on labor migration.展开更多
Based on the characteristics of the air alliance environment saving transport mileage,the hub location problem of the air cargo network was studied.First,the air alliance selection probability model was introduced to ...Based on the characteristics of the air alliance environment saving transport mileage,the hub location problem of the air cargo network was studied.First,the air alliance selection probability model was introduced to determine the alliance self-operation or outsourcing probability in different segments.Then,according to the location center rule,with the goal of minimizing the total cost,the hub location model was built.The improved immune chaos genetic algorithm was used to solve this model.The results show that the improved algorithm has stronger convergence and better effect than the immune genetic algorithm.When the number of hubs increases,the fixed cost increases,but the transportation cost decreases.The greater the discount factor,the fixed cost,and the self operating cost sharing coefficient,the higher the total network cost.The airline which joins the air alliance can greatly reduce the operating cost of airlines.Therefore,airlines should consider joining the alliance.展开更多
To satisfy mobile terminals ’( MTs) offloading requirements and reduce MTs’ cost,a joint cloud and wireless resource allocation scheme based on the evolutionary game( JRA-EG) is proposed for overlapping heterogeneou...To satisfy mobile terminals ’( MTs) offloading requirements and reduce MTs’ cost,a joint cloud and wireless resource allocation scheme based on the evolutionary game( JRA-EG) is proposed for overlapping heterogeneous networks in mobile edge computing environments. MTs that have tasks offloading requirements in the same service area form a population. MTs in one population acquire different wireless and computation resources by selecting different service providers( SPs). An evolutionary game is formulated to model the SP selection and resource allocation of the MTs. The cost function of the game consists of energy consumption,time delay and monetary cost. The solutions of evolutionary equilibrium( EE) include the centralized algorithm based on replicator dynamics and the distributed algorithm based on Q-learning.Simulation results show that both algorithms can converge to the EE rapidly. The differences between them are the convergence speed and trajectory stability. Compared with the existing schemes,the JRA-EG scheme can save more energy and have a smaller time delay when the data size becomes larger. The proposed scheme can schedule the wireless and computation resources reasonably so that the offloading cost is reduced efficiently.展开更多
In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull"...In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull" migration theory, this paper utilizes sectional data from a 2013 survey of farmers in China's Three Gorges Reservoir area to empirically analyze the factors influencing migrant workers' choice of employment location. The results indicate that 60.46% of laborers have migrated from their home province, whereas 39.54% have remained in their home province. Focusing on personal, household, and community characteristics—in addition to the economic characteristics of the sample counties—multinomial logistic regression models reveal that farmer-laborers' employment location decisions are influenced by their personal capital endowment(age, years of education and social networks), family structure(the number of laborers, elders, children and students), home village characteristics(location, economic development level and the degree of relief of the land) and home county economic development level. Notably, male and female laborers' location decisions reveal a converging trend, and their differences are not pronounced. Per capita arable land area has little influence on location decisions, whereas the educational level of laborers has a significant impact. The results differ significantly from those found in previous studies.展开更多
Based on the real-time wind direction and speed data from an automatic meteorological monitoring network in Shenzhen, the wind characteristics of Jue Diao Sha maritime area are analyzed. As indicated in the results, t...Based on the real-time wind direction and speed data from an automatic meteorological monitoring network in Shenzhen, the wind characteristics of Jue Diao Sha maritime area are analyzed. As indicated in the results, the wind speed of this area is higher than that over the land, the average wind speed is above 3 m/s and the probability for the maximum wind speed to drop below 20 m/s is above 90%. Moreover, the probability for the hourly swing angle of wind direction to become less than 50o is above 80%, suggesting that the wind conditions in the Jue Diao Sha area could meet the requirements of the sporting events. According to the numerical simulation, this area is the best selected site among three candidates. Furthermore, the characteristics of daily land and sea breezes are such that it is suggested the game will be best carried out from 1000 to 1700 Beijing Standard Time.展开更多
The value of a European option satisfies the Black-Scholes equation with appropriately specified final and boundary conditions.We transform the problem to an initial boundary value problem in dimensionless form.There ...The value of a European option satisfies the Black-Scholes equation with appropriately specified final and boundary conditions.We transform the problem to an initial boundary value problem in dimensionless form.There are two parameters in the coefficients of the resulting linear parabolic partial differential equation.For a range of values of these parameters,the solution of the problem has a boundary or an initial layer.The initial function has a discontinuity in the first-order derivative,which leads to the appearance of an interior layer.We construct analytically the asymptotic solution of the equation in a finite domain.Based on the asymptotic solution we can determine the size of the artificial boundary such that the required solution in a finite domain in x and at the final time is not affected by the boundary.Also,we study computationally the behaviour in the maximum norm of the errors in numerical solutions in cases such that one of the parameters varies from finite (or pretty large) to small values,while the other parameter is fixed and takes either finite (or pretty large) or small values. Crank-Nicolson explicit and implicit schemes using centered or upwind approximations to the derivative are studied.We present numerical computations,which determine experimentally the parameter-uniform rates of convergence.We note that this rate is rather weak,due probably to mixed sources of error such as initial and boundary layers and the discontinuity in the derivative of the solution.展开更多
Background Transradial access for coronary catheterization is more technically challenging compared to the traditional transfemoral approach and radial access failure is quite common. The aim of this study is to descr...Background Transradial access for coronary catheterization is more technically challenging compared to the traditional transfemoral approach and radial access failure is quite common. The aim of this study is to describe the additional steps after initial radial access site failure in a high specialized forearm approach center. Methods A retrospective evaluation of all coronary catheterizations performed in our Department between January 2016 and December 2016 was performed, with focus on arterial access. Results One thousand three hundred forty six procedures were evaluated. The initial access site used was right radial [1173 procedures (87.1%)], left radial [120 procedures (8.9%)], fight ulnar [7 procedures (0.5%)], left ulnar [40 procedures (2.9%)] and femoral approach [6 procedures (0.4%)]. Radial artery can- nulation failure was observed in 37 procedures (2.9% of 1293 procedures with initial radial approach). Failure of procedure completion after successful radial sheath insertion was observed in 46 procedures (3.6%). The alternative access site after initial radial approach failure was contralateral radial [43 procedures (51.8%)], ipsilateral ulnar [22 procedures (26.5%), contralateral ulnar [12 patients (14.5%)] and femoral approach [6 procedures (7.2%)]. Conclusion Forearm arteries can be used as alternative access site after initial radial approach failure in order to reduce the use of femoral approach during cardiac catheterization.展开更多
HIV/AIDS is one of the most serious public health challenges globally. Despite the great efforts that are being devoted to prevent,treat and to better understand the disease,it is one of the main causes of morbidity a...HIV/AIDS is one of the most serious public health challenges globally. Despite the great efforts that are being devoted to prevent,treat and to better understand the disease,it is one of the main causes of morbidity and mortality worldwide. Currently,there are 30 drugs or combinations of drugs approved by FDA. Because of the side-effects,price and drug resistance,it is essential to discover new targets,to develop new technology and to find new anti-HIV drugs. This review summarizes the major targets and assays currently used in anti-HIV drug screening.展开更多
Bubble seed image filling is an important prerequisite for the image segmentation of flotation bubble that can be used to improve flotation automatic control. These common image filling algorithms in dealing with comp...Bubble seed image filling is an important prerequisite for the image segmentation of flotation bubble that can be used to improve flotation automatic control. These common image filling algorithms in dealing with complex bubble image exists under-filling and over-filling problems. A new filling algorithm based on boundary point feature and scan lines ~PFSL) is proposed in the paper. The filling a|gorithm describes these boundary points of image objects by means of chain codes. The features of each boundary point, including convex points, concave points, left points and right points, are defined by the point's entrancing chain code and leaving chain code. The algorithm firstly finds out all double-matched boundary points based on the features of boundary points, and fill image objects by these double-matched boundary points on scan lines. Experimental results of bubble seed image filling show that under-filling and over-filling problem can be eliminated by the proposed algorithm.展开更多
Quantitative information about solar radiation in agroforestry system is relatively limited. The research by survey was conducted from October 2002 to February 2003 in Central of Java. The aim of the research was to s...Quantitative information about solar radiation in agroforestry system is relatively limited. The research by survey was conducted from October 2002 to February 2003 in Central of Java. The aim of the research was to study the amount of solar radiation below forest trees stand. The locations of the survey were chosen or determined based on the kinds of trees and forests. They were Purwodadi (teak, mahogany and sonokeling production forest), Karanganyar and Purworejo (pines production forest) and Klaten (semolina and yucca as conservation forest). The decrease in the relative's irradiation fraction (RIF) under the trees is related to the increase in the tree aging, adjusted to the exponential decrease model (RIF = 1.25e - 0.18X). The RIF under tree canopy is clearly explained by diameter on the breast height diameter of trunk (DBH) divided by the half of tree row spacing (2D/(X + Y)), so the RIF model is RIF = e - 0.2829 (2D/(X+ Y)).展开更多
RJF (red jungle fowl) (Gallus gallus gallus) is territorial birds. Only males advertise and defend territory by metals of crows and combat fighting in severe cases. Crows are testosterone dependent and use up to 4...RJF (red jungle fowl) (Gallus gallus gallus) is territorial birds. Only males advertise and defend territory by metals of crows and combat fighting in severe cases. Crows are testosterone dependent and use up to 4-5% of their basal metabolic rate. Crows race individual voice signatures which differ in tone, duration and vibration. Crows together with radio-telemetry were used here to locate night roosts of dominant males. Between 2005 and 2009, 10 despots were intensively monitored. Outermost locations of individual's roosts were connected to form territory and a distance of 50 m was buffered to individual's territory to yield home range. Data indicated strong site fidelity of dominant males. The longest territory tenure was 31 months. The life time territory of males was on average 10.24 ha (±1.73 SE) and a home range was 17.59 ha (±2.15 SE). Average yearly territory vmcied between 5.48 and 10.88 ha per individual and rarely overlapped. Some roosts were used repeatedly at the same point. In the night, RJF was relatively safe and difficult to approach both vertically and horizontally. Roost site selections were thus a trade-off between security and territory proclamation.展开更多
文摘Objective Detection and quantification of RNA synthesis in cells is a widely used technique for monitoring cell viability,health,and metabolic rate.After exposure to environmental stimuli,both the internal reference gene and target gene would be degraded.As a result,it is imperative to consider the accurate capture of nascent RNA and the detection of transcriptional levels of RNA following environmental stimulation.This study aims to create a Click Chemistry method that utilizes its property to capture nascent RNA from total RNA that was stimulated by the environment.Methods The new RNA was labeled with 5-ethyluridine(5-EU)instead of uracil,and the azido-biotin medium ligand was connected to the magnetic sphere using a combination of“Click Chemistry”and magnetic bead screening.Then the new RNA was captured and the transcription rate of 16S rRNA was detected by fluorescence molecular beacon(M.B.)and quantitative reverse transcription PCR(qRT-PCR).Results The bacterial nascent RNA captured by“Click Chemistry”screening can be used as a reverse transcription template to form cDNA.Combined with the fluorescent molecular beacon M.B.1,the synthesis rate of rRNA at 37℃is 1.2 times higher than that at 15℃.The 16S rRNA gene and cspI gene can be detected by fluorescent quantitative PCR,it was found that the measured relative gene expression changes were significantly enhanced at 25℃and 16℃when analyzed with nascent RNA rather than total RNA,enabling accurate detection of RNA transcription rates.Conclusion Compared to other article reported experimental methods that utilize screening magnetic columns,the technical scheme employed in this study is more suitable for bacteria,and the operation steps are simple and easy to implement,making it an effective RNA capture method for researchers.
文摘Utilizing single atom sites doping into metal oxides to modulate their intrinsic active sites,achieving precise selectivity control in complex organic reactions,is a highly desirable yet challenging endeavor.Meanwhile,identifying the active site also represents a significant obstacle,primarily due to the intricate electronic environment of single atom site doped metal oxide.Herein,a single atom Cu doped TiO_(2)catalyst(Cu_(1)-TiO_(2))is prepared via a simple“colloid-acid treatment”strategy,which switches aniline oxidation selectivity of TiO_(2)from azoxybenzene to nitrosobenzene,without using additives or changing solvent,while other metal or nonmetal doped TiO_(2)did not possess.Comprehensive mechanistic investigations and DFT calculations unveil that Ti-O active site is responsible for triggering the aniline to form a new PhNOH intermediate,two PhNOH condense to azoxybenzene over TiO_(2)catalyst.As for Cu_(1)-TiO_(2),the charge-specific distribution between the isolated Cu and TiO_(2)generates unique Cu_(1)-O-Ti hybridization structure with nine catalytic active sites,eight of them make PhNOH take place spontaneous dissociation to produce nitrosobenzene.This work not only unveils a new mechanistic pathway featuring the PhNOH intermediate in aniline oxidation for the first time but also presents a novel approach for constructing single-atom doped metal oxides and exploring their intricate active sites.
文摘The flotation behavior of Xixia andalusite was studied with different collectors.The tests were conducted with a pure andalusite sample in micro-flotation cell and then with an ore sample in a mechanical flotation cell.The surface charge was measured on pure andalusite sample and the isoelectric point(IEP) was found to be pH 5.2.Andalusite is floated with an amine collector above IEP where mineral surface is negatively charged.In contrast,an alkyl sulfonate collector(sodium dodecyl benzene sulfonate) is effective in the pH range where andalusite surface is positively charged.Furthermore,andalusite is floated with oleate in neutral and mildly alkaline pH values.55.3% Al2O3 is produced with 75.6% andalusite recovery when using the alkyl benzene sulfonate collector.Starch is found to be an effective depressant for gangue minerals in alkyl benzene sulfonate flotation.Moreover,slimes are found to have an adverse effect on the flotation of andalusite.Therefore,pretreatment by desliming and pre-float(to remove carbonaceous species) prior to andalusite flotation is necessary.
基金Supported by Science and Technology Innovation Incentive Subsidizing Project in 2015Special Fund of Scientific Research in Public Interest from Ministry of Agriculture(20120304201)~~
文摘[Objective] This study was conducted to solve the problem of the lacking of special forage foxtail millet varieties. [Method] With wild large-grain foxtail millet as an original material, foxtail millet variety Jicaogu 1 (S724) for forage use was bred. [Result] Jicaogu 1 has following outstanding characteristics: (1) high content of crude protein: quality detection showed that the millet straw had a high content of crude protein up to 9.8%; (2) high yields of fresh grass and hay: in field detection, the average yield of fresh grass was 58 308.15 kg/hm2, which was higher than Sicao 2 (35 763.00 kg/hm2) by 58.29%, and the hay yield was 15 922.65 kg/hm2, which was higher than Sicao 2 (11 548.05 kg/hm2) by 37.88%; and (3) biological characteristics: Jicaogu 1 shows young seedlings with a growth period of 122 d, a plant height of 198.22 cm, an ear length of 23.65 cm, a stem/leaf ratio of 1.43 and a fresh weight/dry weight ratio of 37.86, there are 2-3 tillers generally, and the seed yield is 3 383.40 kg/hm2. [Conclusion] Summer seeding in vacant field in North China or spring seeding in Inner Mongolia could be carried out with Jicaogu 1, which is also adapt to mechanized harvest. The development of forage foxtail millet could be promoted by strengthening the extension of Jicaogu 1.
文摘Edible sunflower variety AR9-9293 was approved by the Sunflower Variety Appraisal Committee with the country Identification number of sunflower 2015005. This paper introduced the breeding process, yield performance and characteristics, and the high-yield cultivation technology of new edible sunflower variety AR9-9293. The promotion of edible sunflower varieties and cultivation technology could achieve the effects of improving the level of the sunflower cultivation, promoting the development of rural and agricultural economy and increasing farmers' income, as well as positively promoting development of the society and adjusting agricultural industry structure.
基金The National High Technology Research and Development Program of China (863 Program) (No.2007AA01Z422)the NaturalFoundation of Anhui Provincial Education Department (No.2006KJ041B,KJ2007B073)
文摘Combining the characteristics of peer-to-peer (P2P) and grid, a super-peer selection algorithm--SSABC is presented in the distributed network merging P2P and grid. The algorithm computes nodes capacities using their resource properties provided by a grid monitoring and discovery system, such as available bandwidth, free CPU and idle memory, as well as the number of current connections and online time. when a new node joins the network and the super-peers are all saturated, it should select a new super-peer from the new node or joined nodes with the highest capacity. By theoretical analyses and simulation experiments, it is shown that super-peers selected by capacity can achieve higher query success rates and shorten the average hop count when compared with super-peers selected randomly, and they can also balance the network load when all super-peers are saturated. When the number of total nodes changes, the conclusion is still valid, which explains that the algorithm SSABC is feasible and stable.
基金The National Science and Technology Major Project(No.2013ZX03001032-004)the National High Technology Research and Development Program of China(863 Program)(No.2014AA01A702)+1 种基金Jiangsu Province Science and Technology Support Program(No.BE2012165)Foundation of Huawei Corp.Ltd
文摘In order to achieve higher system energy efficiency (EE),a new coordinated multipoint (CoMP)-transmission-based scheme selection energy saving (CTSES)algorithm is proposed for downlink homogeneous cellular networks.The problem is formulated as an optimization of maximizing system EE,under the constraints of the data rate requirement and the maximum transmit power.The problem is decomposed into power allocation and alternative scheme selection problems.Optimal power allocation is calculated for CoMP-JT (joint transmission)and CoMP-CS (coordinated scheduling) transmissions,and the scheme with higher EE is chosen. Since the optimal problem is a nonlinear fractional optimization problem for both CoMP transmission schemes, the problem is transformed into an equivalent problem using the parametric method. The optimal transmit power and optimal EE are obtained by an iteration algorithm in CoMP-JT and CoMP-CS schemes.Simulation results show that the proposed algorithm offers obvious energy-saving potential and outperforms the fixed CoMP transmission scheme.Under the condition of the same maximum transmit power limit,the empirical regularity of user distribution for scheme choice is presented, and using this regularity, the computational complexity can be reduced.
基金Projects(90820302,60805027)supported by the National Natural Science Foundation of ChinaProject(200805330005)supported by the Research Fund for the Doctoral Program of Higher Education,ChinaProject(2009FJ4030)supported by Academician Foundation of Hunan Province,China
文摘Multi-target tracking(MTT) is a research hotspot of wireless sensor networks at present.A self-organized dynamic cluster task allocation scheme is used to implement collaborative task allocation for MTT in WSN and a special cluster member(CM) node selection method is put forward in the scheme.An energy efficiency model was proposed under consideration of both energy consumption and remaining energy balance in the network.A tracking accuracy model based on area-sum principle was also presented through analyzing the localization accuracy of triangulation.Then,the two models mentioned above were combined to establish dynamic cluster member selection model for MTT where a comprehensive performance index function was designed to guide the CM node selection.This selection was fulfilled using genetic algorithm.Simulation results show that this method keeps both energy efficiency and tracking quality in optimal state,and also indicate the validity of genetic algorithm in implementing CM node selection.
基金Projects 50025411 supported by the China National Science Foundation for Distinguished Young Scholars 92010035 by National Natural Science Foun-dation of China 20030290015 by the Specific Research Foundation for Doctor Discipline of Colleges and Universities
文摘For a screening process, the collision and penetration phenomena between particles and screen plate is standard behavior and with collision the mechanical energy of the vibrating screen can be transmitted to the feed. In order to recognize further the collision process and the law of penetrating motion, with the spring-dashpot-slider contact model of the distinct element method (DEM), a mathematical model which can describe the collision process has been established and a program for simulating the motion of a single particle on the screen plate developed by VC++. NET. To evaluate the handling capacity of the screen that deals with difficult screening material, an instantaneous penetrating coefficient is defined. The moving period of the screen plate is divided into four stages. By analyzing the state of contact collision at each stage, it is pointed out that the collision ranging from 3π/2 to 2π period is the most favorable aperture for penetration of particles, while the collision ranging from π/2 to n period is the most unfavorable. The numerical simulation result further indicates that increasing the amplitude of the screen plate has a much greater effect on the augmentation of instantaneous penetration coefficient than increasing the vibration frequency.
基金Under the auspices of the National Natural Science Foundation of China(No.41471469,41601141)the National Key Basic Research Program of China(No.2015CB452706)+1 种基金the Humanities and Social Sciences Youth Project of Ministry of Education in China(No.14YJCZH130)Youth Talent Team Program of the Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(No.SDSQB-2015-01)
文摘Labor migration to urban centers is a common phenomenon in the Panxi region of the southwestern mountainous region of China, mainly owing to inadequate livelihood capital in rural areas. Numerous studies have been conducted to explore the relationship between labor migration and its causes, such as individual and family characteristics, but few studies have focused on livelihood capital. This paper examines the impact factors on labor migration employment location selection and duration from a household livelihood capital perspective. A case study of 279 households from 10 villages in the area was carried out in February 2016. We used both qualitative and quantitative methods to analyze the data. On the basis of the 279 questionnaires, the proportion of households with non-labor migration is 48.4%, whereas households with labor migration within a local city and migration across regions account for 28.7% and 22.9%, respectively. Social, financial, and human capitals are the primary factors that influence migrants' employment location choice positively. Among them, social capital has a significant impact on both migration within a local city and across regions; each of the regression coefficients is 1.111 and 1.183. Social, human, and financial capitals also have a positive impact on the duration of labor migration, and similarly, social capital is the highest coefficient with 2.489. However, physical capital only partly impacts labor migration across regions, whereas the impact of labor migration within a local city, and the duration, are not significant. Furthermore, the impact of household natural capital on migration space and time are all negative relationships, especially for labor migration across the regions and duration, with coefficient scores of 4.836 and 3.450, respectively. That is to say, a laborer is inclined to migrate within a local city for a short term, or not migrate at all, if natural capital is abundant. Our analysis results show that household livelihood capital has a strong spatio-temporal impact on labor migration.
基金The National Social Science Foundation of China(No.17XGL013)。
文摘Based on the characteristics of the air alliance environment saving transport mileage,the hub location problem of the air cargo network was studied.First,the air alliance selection probability model was introduced to determine the alliance self-operation or outsourcing probability in different segments.Then,according to the location center rule,with the goal of minimizing the total cost,the hub location model was built.The improved immune chaos genetic algorithm was used to solve this model.The results show that the improved algorithm has stronger convergence and better effect than the immune genetic algorithm.When the number of hubs increases,the fixed cost increases,but the transportation cost decreases.The greater the discount factor,the fixed cost,and the self operating cost sharing coefficient,the higher the total network cost.The airline which joins the air alliance can greatly reduce the operating cost of airlines.Therefore,airlines should consider joining the alliance.
基金The National Natural Science Foundation of China(No.61741102,61471164)
文摘To satisfy mobile terminals ’( MTs) offloading requirements and reduce MTs’ cost,a joint cloud and wireless resource allocation scheme based on the evolutionary game( JRA-EG) is proposed for overlapping heterogeneous networks in mobile edge computing environments. MTs that have tasks offloading requirements in the same service area form a population. MTs in one population acquire different wireless and computation resources by selecting different service providers( SPs). An evolutionary game is formulated to model the SP selection and resource allocation of the MTs. The cost function of the game consists of energy consumption,time delay and monetary cost. The solutions of evolutionary equilibrium( EE) include the centralized algorithm based on replicator dynamics and the distributed algorithm based on Q-learning.Simulation results show that both algorithms can converge to the EE rapidly. The differences between them are the convergence speed and trajectory stability. Compared with the existing schemes,the JRA-EG scheme can save more energy and have a smaller time delay when the data size becomes larger. The proposed scheme can schedule the wireless and computation resources reasonably so that the offloading cost is reduced efficiently.
基金financial supports from the National Natural Science Foundation of China (Grant Nos. 41571527, 41301193, 41101552,41401198)Main Direction Program (KZCX2-EW317)West Light Foundation of the Chinese Academy of Sciences (2013Yuhui)
文摘In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull" migration theory, this paper utilizes sectional data from a 2013 survey of farmers in China's Three Gorges Reservoir area to empirically analyze the factors influencing migrant workers' choice of employment location. The results indicate that 60.46% of laborers have migrated from their home province, whereas 39.54% have remained in their home province. Focusing on personal, household, and community characteristics—in addition to the economic characteristics of the sample counties—multinomial logistic regression models reveal that farmer-laborers' employment location decisions are influenced by their personal capital endowment(age, years of education and social networks), family structure(the number of laborers, elders, children and students), home village characteristics(location, economic development level and the degree of relief of the land) and home county economic development level. Notably, male and female laborers' location decisions reveal a converging trend, and their differences are not pronounced. Per capita arable land area has little influence on location decisions, whereas the educational level of laborers has a significant impact. The results differ significantly from those found in previous studies.
基金Project on Meteorological Conditions for Selection of Site of Maritime Sporting Base for 26th Summer Universiade 2011
文摘Based on the real-time wind direction and speed data from an automatic meteorological monitoring network in Shenzhen, the wind characteristics of Jue Diao Sha maritime area are analyzed. As indicated in the results, the wind speed of this area is higher than that over the land, the average wind speed is above 3 m/s and the probability for the maximum wind speed to drop below 20 m/s is above 90%. Moreover, the probability for the hourly swing angle of wind direction to become less than 50o is above 80%, suggesting that the wind conditions in the Jue Diao Sha area could meet the requirements of the sporting events. According to the numerical simulation, this area is the best selected site among three candidates. Furthermore, the characteristics of daily land and sea breezes are such that it is suggested the game will be best carried out from 1000 to 1700 Beijing Standard Time.
基金partially supported by the Russian Foundation for Basic Research(grant No.07-01-00729)the Singapore Academic Research Funds R-146-000-064-112 and R-146-000-099-112the Boole Centre for Research in Informatics at the National University of Ireland,Cork and by the Mathematics Applications Consortium for Science and Industry in Ireland(MACSI)under the Science Foundation Ireland Mathematics Initiative.
文摘The value of a European option satisfies the Black-Scholes equation with appropriately specified final and boundary conditions.We transform the problem to an initial boundary value problem in dimensionless form.There are two parameters in the coefficients of the resulting linear parabolic partial differential equation.For a range of values of these parameters,the solution of the problem has a boundary or an initial layer.The initial function has a discontinuity in the first-order derivative,which leads to the appearance of an interior layer.We construct analytically the asymptotic solution of the equation in a finite domain.Based on the asymptotic solution we can determine the size of the artificial boundary such that the required solution in a finite domain in x and at the final time is not affected by the boundary.Also,we study computationally the behaviour in the maximum norm of the errors in numerical solutions in cases such that one of the parameters varies from finite (or pretty large) to small values,while the other parameter is fixed and takes either finite (or pretty large) or small values. Crank-Nicolson explicit and implicit schemes using centered or upwind approximations to the derivative are studied.We present numerical computations,which determine experimentally the parameter-uniform rates of convergence.We note that this rate is rather weak,due probably to mixed sources of error such as initial and boundary layers and the discontinuity in the derivative of the solution.
文摘Background Transradial access for coronary catheterization is more technically challenging compared to the traditional transfemoral approach and radial access failure is quite common. The aim of this study is to describe the additional steps after initial radial access site failure in a high specialized forearm approach center. Methods A retrospective evaluation of all coronary catheterizations performed in our Department between January 2016 and December 2016 was performed, with focus on arterial access. Results One thousand three hundred forty six procedures were evaluated. The initial access site used was right radial [1173 procedures (87.1%)], left radial [120 procedures (8.9%)], fight ulnar [7 procedures (0.5%)], left ulnar [40 procedures (2.9%)] and femoral approach [6 procedures (0.4%)]. Radial artery can- nulation failure was observed in 37 procedures (2.9% of 1293 procedures with initial radial approach). Failure of procedure completion after successful radial sheath insertion was observed in 46 procedures (3.6%). The alternative access site after initial radial approach failure was contralateral radial [43 procedures (51.8%)], ipsilateral ulnar [22 procedures (26.5%), contralateral ulnar [12 patients (14.5%)] and femoral approach [6 procedures (7.2%)]. Conclusion Forearm arteries can be used as alternative access site after initial radial approach failure in order to reduce the use of femoral approach during cardiac catheterization.
文摘HIV/AIDS is one of the most serious public health challenges globally. Despite the great efforts that are being devoted to prevent,treat and to better understand the disease,it is one of the main causes of morbidity and mortality worldwide. Currently,there are 30 drugs or combinations of drugs approved by FDA. Because of the side-effects,price and drug resistance,it is essential to discover new targets,to develop new technology and to find new anti-HIV drugs. This review summarizes the major targets and assays currently used in anti-HIV drug screening.
基金supported by the National Science & Technology Support Plan of China (No. 2009BAB48B02)the Basic Scientific Research Foundation for Institution of Higher Education (No.2008AA062101)
文摘Bubble seed image filling is an important prerequisite for the image segmentation of flotation bubble that can be used to improve flotation automatic control. These common image filling algorithms in dealing with complex bubble image exists under-filling and over-filling problems. A new filling algorithm based on boundary point feature and scan lines ~PFSL) is proposed in the paper. The filling a|gorithm describes these boundary points of image objects by means of chain codes. The features of each boundary point, including convex points, concave points, left points and right points, are defined by the point's entrancing chain code and leaving chain code. The algorithm firstly finds out all double-matched boundary points based on the features of boundary points, and fill image objects by these double-matched boundary points on scan lines. Experimental results of bubble seed image filling show that under-filling and over-filling problem can be eliminated by the proposed algorithm.
文摘Quantitative information about solar radiation in agroforestry system is relatively limited. The research by survey was conducted from October 2002 to February 2003 in Central of Java. The aim of the research was to study the amount of solar radiation below forest trees stand. The locations of the survey were chosen or determined based on the kinds of trees and forests. They were Purwodadi (teak, mahogany and sonokeling production forest), Karanganyar and Purworejo (pines production forest) and Klaten (semolina and yucca as conservation forest). The decrease in the relative's irradiation fraction (RIF) under the trees is related to the increase in the tree aging, adjusted to the exponential decrease model (RIF = 1.25e - 0.18X). The RIF under tree canopy is clearly explained by diameter on the breast height diameter of trunk (DBH) divided by the half of tree row spacing (2D/(X + Y)), so the RIF model is RIF = e - 0.2829 (2D/(X+ Y)).
文摘RJF (red jungle fowl) (Gallus gallus gallus) is territorial birds. Only males advertise and defend territory by metals of crows and combat fighting in severe cases. Crows are testosterone dependent and use up to 4-5% of their basal metabolic rate. Crows race individual voice signatures which differ in tone, duration and vibration. Crows together with radio-telemetry were used here to locate night roosts of dominant males. Between 2005 and 2009, 10 despots were intensively monitored. Outermost locations of individual's roosts were connected to form territory and a distance of 50 m was buffered to individual's territory to yield home range. Data indicated strong site fidelity of dominant males. The longest territory tenure was 31 months. The life time territory of males was on average 10.24 ha (±1.73 SE) and a home range was 17.59 ha (±2.15 SE). Average yearly territory vmcied between 5.48 and 10.88 ha per individual and rarely overlapped. Some roosts were used repeatedly at the same point. In the night, RJF was relatively safe and difficult to approach both vertically and horizontally. Roost site selections were thus a trade-off between security and territory proclamation.