A novel process was proposed for synergistic extraction and separation of valuable elements from high-alumina fly ash.A thermodynamic analysis revealed that to achieve effective carbochlorination,it is crucial to cond...A novel process was proposed for synergistic extraction and separation of valuable elements from high-alumina fly ash.A thermodynamic analysis revealed that to achieve effective carbochlorination,it is crucial to conduct carbochlorination of the fly ash within the temperature range from 700 to 1000℃.The experimental results demonstrated that under the optimal conditions,the carbochlorination efficiency for Al,Si,Ca,Ti,and Mg exceeded 81.18%,67.62%,58.87%,82.15%,and 59.53%,respectively.The XRD patterns indicated that Al and Si in the mullite phase(Al_(6)Si_(2)O_(13))were chlorinated during the carbochlorination process,resulting in the formation of mullite mesophases(Al_(4.75)Si_(1.25)O_(9.63) and Al_(1.83)Si_(1.08)O_(4.85)).After the carbochlorination process,Al was accumulated as AlCl_(3) in the condenser,while SiCl_(4) and TiCl_(4) were enriched in the exhaust gas,and CaCl_(2),MgCl_(2),and unreacted oxides remained in the residue for further recycling.展开更多
Objectives:This study aimed to survey the geriatric nursing competencies of clinical nursing staff in Chongqing City,China,and provide suggestions to enhance these competencies.Methods:This study was conducted in 204 ...Objectives:This study aimed to survey the geriatric nursing competencies of clinical nursing staff in Chongqing City,China,and provide suggestions to enhance these competencies.Methods:This study was conducted in 204 hospitals in Southwest China from December 24,2022 to January 7,2023.The“Geriatric Nursing Competence of Clinical Nurse Investigation Tool”was used to explore factors that influence geriatric nurses’competencies via stratified sampling.The survey was conducted by distributing and collecting questionnaires through the online platform Wenjuanxing.Results:A total of 10,692 nurses answered the questionnaires.Of these questionnaires,9,442 were valid.The total geriatric nursing competence score of the clinical nursing staff was 2.29±0.81,the secondary hospital score was 2.23±0.78,and the tertiary hospital’s overall mean score was 2.33±0.83.The factors that influenced secondary hospitals included the department of medicine,age of nurses and total length of career(P<0.05).The factors that influenced tertiary hospitals included the department of medicine,age of nurses,nurses’professional title,and geriatric practical advanced nurses’certification(P<0.05).Conclusions:Geriatric nursing competence among clinical nursing staff is imbalanced at a lower-middle level and is influenced by various factors.Thefindings highlight the need for further clinical training in geriatric nursing.The training of geriatric nurses should focus on necessary clinical skills and on preparing them to adequately manage comprehensive geriatric syndromes.展开更多
The thermally and wind-driven ocean circulation is a complicated natural phenomenon in the atmospheric physics. Hence we need to reduce it using basic models and solve the models using approximate methods. A non-linea...The thermally and wind-driven ocean circulation is a complicated natural phenomenon in the atmospheric physics. Hence we need to reduce it using basic models and solve the models using approximate methods. A non-linear model of the thermally and wind-driven ocean circulation is used in this paper. The results show that the zero solution of the linear equation is a stable focus point, which is the path curve trend origin point as time (t) trend to infinity. By using the homotopic mapping perturbation method, the exact solution of the model is obtained. The homotopic mapping perturbation method is an analytic solving method, so the obtained solution can be used for analytic operating sequentially. And then we can also obtain the diversified qualitative and quantitative behaviors for corresponding physical quantities.展开更多
The accumulative roll-bonding(ARB)process was applied on the strips of aluminum alloy 1050 in two processing conditions:cold ARB and warm ARB.The results of tensile tests and microhardness measurement show that the wa...The accumulative roll-bonding(ARB)process was applied on the strips of aluminum alloy 1050 in two processing conditions:cold ARB and warm ARB.The results of tensile tests and microhardness measurement show that the warm ARB process exhibits the lower tensile strength and microhardness,more homogeneous distribution of the microhardness,higher elongation,and especially superior planar isotropy of the tensile properties in comparison to the cold ARB,because of the intermediate heat treatment as well as the elevated temperature rolling in the warm ARB process.Furthermore,with increasing the cycles of both processes,the planar isotropy decreases progressively.展开更多
Common short bolts of equal length are widely used to support the roofs of roadways in coal mines.However, they are insufficient to keep the roof stable against large deformations, so docking long bolts with high leve...Common short bolts of equal length are widely used to support the roofs of roadways in coal mines.However, they are insufficient to keep the roof stable against large deformations, so docking long bolts with high levels of elongation that can adapt to large deformations of the surrounding rock have been adopted. This paper proposes a collaborative support method that uses long and short bolts. In this study,the mechanism of docking long bolts and collaborative support was studied. Numerical simulation, similarity simulation, and field testing were used to analyze the distribution law of the displacement, stress,and plastic failure in the surrounding rock under different support schemes. Compared with the equal-length short bolt support, the collaborative support changed the maximum principal stress of the shallow roof from tensile stress to compressive stress, and the minimum principal stress of the roof significantly increased. The stress concentration degree of the anchorage zone clearly increased. The deformation of the roof and the two sides was greatly reduced, and the subsidence shape of the shallow roof changed from serrated to a smooth curve. The roof integrity was enhanced, and the roof moved down as a whole. Plastic failure significantly decreased, and the plastic zone of the roof was within the anchorage range. The similarity simulation results showed that, under the maximum mining stress,the roof collapsed with the equal-length short bolt support but remained stable with the collaborative support. The collaborative support method was successfully applied in the field and clearly improved the stability of the surrounding rock for a large deformation roadway.展开更多
A new kind of region pair grey difference classifier was proposed. The regions in pairs associated to form a feature were not necessarily directly-connected, but were selected dedicatedly to the grey transition betwee...A new kind of region pair grey difference classifier was proposed. The regions in pairs associated to form a feature were not necessarily directly-connected, but were selected dedicatedly to the grey transition between regions coinciding with the face pattern structure. Fifteen brighter and darker region pairs were chosen to form the region pair grey difference features with high discriminant capabilities. Instead of using both false acceptance rate and false rejection rate, the mutual information was used as a unified metric for evaluating the classifying performance. The parameters of specified positions, areas and grey difference bias for each single region pair feature were selected by an optimization processing aiming at maximizing the mutual information between the region pair feature and classifying distribution, respectively. An additional region-based feature depicting the correlation between global region grey intensity patterns was also proposed. Compared with the result of Viola-like approach using over 2 000 features, the proposed approach can achieve similar error rates with only 16 features and 1/6 implementation time on controlled illumination images.展开更多
This research was carried out in Iranian EFL (English as a foreign language) reading comprehension classes in an attempt to answer three research questions: (1) Does collaborative reading lead to greater comprehe...This research was carried out in Iranian EFL (English as a foreign language) reading comprehension classes in an attempt to answer three research questions: (1) Does collaborative reading lead to greater comprehension of a text than private reading?; (2) If so, what strategies are used by the students during collaborative reading?; and (3) In what ways might these strategies contribute to the higher level of comprehension?. A quasi-experimental design was used to answer the first question. The participants were pre-tested and streamed into two classes of equal reading comprehension abilities. The intervention consisted of four texts of equal length, comprising two rated in a pilot study as conceptually difficult/linguistically easy, and two rated as conceptually easy/linguistically difficult. The subjects in each class were involved in reading the two types of texts collaboratively and privately for four sessions. After reading the text, the subjects were asked to answer in writing 10 comprehension questions. Collaborative reading resulted in consistently and significantly higher scores than private reading for all four texts. Qualitative methods were employed to answer the last two questions. Group interactions during collaborative reading were tape recorded and transcribed, and 10 students selected at random from the two classes were interviewed in depth. Analysis of the group interaction transcripts revealed that the participants were using five major strategies in co-constructing meaning from the texts. These strategies included brainstorming, clarifying the language, summarizing, paraphrasing, and interaction management. Other minor (i.e., infrequent) strategies were also identified, such as making PCU/NCU (positive/negative claim to understand), eliciting confirmation, and confirming.展开更多
To provide a risk-sharing mechanism that encourages a component supplier and a manufacturer to expand their production capacity of components and products, many researches on SCM suggested that it is better for the SC...To provide a risk-sharing mechanism that encourages a component supplier and a manufacturer to expand their production capacity of components and products, many researches on SCM suggested that it is better for the SC players to connect a long-term contract with flexible preconditions before doing the decision-making of production capacity. With considering of the uncertainty of demand and integrity problems between SC players, it is difficult to set reasonable preconditions. As a result, under-investment problems still occur frequently. In this paper, after we had discussed the decision-making of production capacity with the preconditions by analyzing the character of the players, we verified the under-investment problem of the supply chain. In order to clarify the optimum preconditions to alleviate the under-investment problem, we also analyzed the relations between preconditions and supply capacity of the whole supply chain. In the last part of this paper, we proposed a method of preconditions setting in such uncertain situations.展开更多
From the mechanical similarity point of view, the centrifugal effect, Ar, and the Stokes number, St, as well as the Reynolds number, Re_c for the motion of solid particles in the cyclone are the relevant parameters. I...From the mechanical similarity point of view, the centrifugal effect, Ar, and the Stokes number, St, as well as the Reynolds number, Re_c for the motion of solid particles in the cyclone are the relevant parameters. In order to apply these similarity laws for the prediction of the characteristics of the collection efficiency, ηc, geometrically similar types of uni-flow cyclones were used. The body diameters of the cyclones were D_1=30, 50, 69 and 99 mm, respectively. The feed particle concentration of the fly-ash particles was up to C_o = 60g/m^3. From the experimental results: (1) the pressure drop, △pc, in the cyclones was a function of not only the Reynods number, Re_c, but also the body diameter, D_1; (2) the collection efficiency, η_c, did not always increase with decreasing body diameter but there existed an optimal body size; (3) application of the mechanical similarity laws to the collection efficiency was not always sufficient for estimating the collection efficiency, since the feed particle concentration was an additional important factor; (4) a new parameter which was the ratio, E_(pf), of the apparent separation energy, W_p, of the solid particles to the energy loss, E_c, of the gas flow in the cyclone was introduced for discussing the collection efficiency; (5) Fuchs theory, used to estimate the collection efficiency, was examined. Fuchs theory may be applied for high feed particle concentration.展开更多
Based on the magnetospheric kinetic theory, a model is developed to specify the flux of energetic electrons in the inner and middle magnetosphere. Under the assumption of adiabatic motion and isotropic particle distri...Based on the magnetospheric kinetic theory, a model is developed to specify the flux of energetic electrons in the inner and middle magnetosphere. Under the assumption of adiabatic motion and isotropic particle distribution maintained by pitch-angle scattering, the model calculates the electron flux by following bounce-averaged electric field, gradient, and curvature drift in the time dependent electric and magnetic field, meanwhile it counts the electron loss caused by pitch angle scattering. Using the model, the clectron flux distribution during a magnetic storm was calculated and compared with the observation data from the geosynchronous orbit. It is shown that the model can successfully reproduce most of the major electron flux enhancements observed at the geosynchronous orbit and generally tracks the satellite data well. The rms errors of the modeled logarithm of flux are between 0.5-1.0.展开更多
基金the National Natural Science Foundation of China (Nos.52304364,U1710257)the financial support of the National Key Research and Development Program of China (No.2022YFB3504502)。
文摘A novel process was proposed for synergistic extraction and separation of valuable elements from high-alumina fly ash.A thermodynamic analysis revealed that to achieve effective carbochlorination,it is crucial to conduct carbochlorination of the fly ash within the temperature range from 700 to 1000℃.The experimental results demonstrated that under the optimal conditions,the carbochlorination efficiency for Al,Si,Ca,Ti,and Mg exceeded 81.18%,67.62%,58.87%,82.15%,and 59.53%,respectively.The XRD patterns indicated that Al and Si in the mullite phase(Al_(6)Si_(2)O_(13))were chlorinated during the carbochlorination process,resulting in the formation of mullite mesophases(Al_(4.75)Si_(1.25)O_(9.63) and Al_(1.83)Si_(1.08)O_(4.85)).After the carbochlorination process,Al was accumulated as AlCl_(3) in the condenser,while SiCl_(4) and TiCl_(4) were enriched in the exhaust gas,and CaCl_(2),MgCl_(2),and unreacted oxides remained in the residue for further recycling.
基金supported by a key Program of the Chongqing Scientific and Technological Commission(Grant Number.CSTB2022TIAD-KPX0165).
文摘Objectives:This study aimed to survey the geriatric nursing competencies of clinical nursing staff in Chongqing City,China,and provide suggestions to enhance these competencies.Methods:This study was conducted in 204 hospitals in Southwest China from December 24,2022 to January 7,2023.The“Geriatric Nursing Competence of Clinical Nurse Investigation Tool”was used to explore factors that influence geriatric nurses’competencies via stratified sampling.The survey was conducted by distributing and collecting questionnaires through the online platform Wenjuanxing.Results:A total of 10,692 nurses answered the questionnaires.Of these questionnaires,9,442 were valid.The total geriatric nursing competence score of the clinical nursing staff was 2.29±0.81,the secondary hospital score was 2.23±0.78,and the tertiary hospital’s overall mean score was 2.33±0.83.The factors that influenced secondary hospitals included the department of medicine,age of nurses and total length of career(P<0.05).The factors that influenced tertiary hospitals included the department of medicine,age of nurses,nurses’professional title,and geriatric practical advanced nurses’certification(P<0.05).Conclusions:Geriatric nursing competence among clinical nursing staff is imbalanced at a lower-middle level and is influenced by various factors.Thefindings highlight the need for further clinical training in geriatric nursing.The training of geriatric nurses should focus on necessary clinical skills and on preparing them to adequately manage comprehensive geriatric syndromes.
基金Under the auspices of National Natural Science Foundation of China(No.40876010)Main Direction Program of Knowledge Innovation Programs of the Chinese Academy of Sciences(No.KZCX2-YW-Q03-08)+3 种基金R & D Special Fund for Public Welfare Industry(meteorology)(No.GYHY200806010)LASG State Key Laboratory Special FundFoundation of Shanghai Municipal Education Commission(No.E03004)Natural Science Foundation of Zhejiang Province(No.Y6090164)
文摘The thermally and wind-driven ocean circulation is a complicated natural phenomenon in the atmospheric physics. Hence we need to reduce it using basic models and solve the models using approximate methods. A non-linear model of the thermally and wind-driven ocean circulation is used in this paper. The results show that the zero solution of the linear equation is a stable focus point, which is the path curve trend origin point as time (t) trend to infinity. By using the homotopic mapping perturbation method, the exact solution of the model is obtained. The homotopic mapping perturbation method is an analytic solving method, so the obtained solution can be used for analytic operating sequentially. And then we can also obtain the diversified qualitative and quantitative behaviors for corresponding physical quantities.
文摘The accumulative roll-bonding(ARB)process was applied on the strips of aluminum alloy 1050 in two processing conditions:cold ARB and warm ARB.The results of tensile tests and microhardness measurement show that the warm ARB process exhibits the lower tensile strength and microhardness,more homogeneous distribution of the microhardness,higher elongation,and especially superior planar isotropy of the tensile properties in comparison to the cold ARB,because of the intermediate heat treatment as well as the elevated temperature rolling in the warm ARB process.Furthermore,with increasing the cycles of both processes,the planar isotropy decreases progressively.
基金supported by the State Key Program of National Natural Science Foundation of China(No.51234005)the State Key Program of National Natural Science Foundation-Coal Joint Fund(No.51134018)
文摘Common short bolts of equal length are widely used to support the roofs of roadways in coal mines.However, they are insufficient to keep the roof stable against large deformations, so docking long bolts with high levels of elongation that can adapt to large deformations of the surrounding rock have been adopted. This paper proposes a collaborative support method that uses long and short bolts. In this study,the mechanism of docking long bolts and collaborative support was studied. Numerical simulation, similarity simulation, and field testing were used to analyze the distribution law of the displacement, stress,and plastic failure in the surrounding rock under different support schemes. Compared with the equal-length short bolt support, the collaborative support changed the maximum principal stress of the shallow roof from tensile stress to compressive stress, and the minimum principal stress of the roof significantly increased. The stress concentration degree of the anchorage zone clearly increased. The deformation of the roof and the two sides was greatly reduced, and the subsidence shape of the shallow roof changed from serrated to a smooth curve. The roof integrity was enhanced, and the roof moved down as a whole. Plastic failure significantly decreased, and the plastic zone of the roof was within the anchorage range. The similarity simulation results showed that, under the maximum mining stress,the roof collapsed with the equal-length short bolt support but remained stable with the collaborative support. The collaborative support method was successfully applied in the field and clearly improved the stability of the surrounding rock for a large deformation roadway.
基金Supported by the Joint Research Funds of Dalian University of Technology and Shenyang Automation Institute,Chinese Academy of Sciences
文摘A new kind of region pair grey difference classifier was proposed. The regions in pairs associated to form a feature were not necessarily directly-connected, but were selected dedicatedly to the grey transition between regions coinciding with the face pattern structure. Fifteen brighter and darker region pairs were chosen to form the region pair grey difference features with high discriminant capabilities. Instead of using both false acceptance rate and false rejection rate, the mutual information was used as a unified metric for evaluating the classifying performance. The parameters of specified positions, areas and grey difference bias for each single region pair feature were selected by an optimization processing aiming at maximizing the mutual information between the region pair feature and classifying distribution, respectively. An additional region-based feature depicting the correlation between global region grey intensity patterns was also proposed. Compared with the result of Viola-like approach using over 2 000 features, the proposed approach can achieve similar error rates with only 16 features and 1/6 implementation time on controlled illumination images.
文摘This research was carried out in Iranian EFL (English as a foreign language) reading comprehension classes in an attempt to answer three research questions: (1) Does collaborative reading lead to greater comprehension of a text than private reading?; (2) If so, what strategies are used by the students during collaborative reading?; and (3) In what ways might these strategies contribute to the higher level of comprehension?. A quasi-experimental design was used to answer the first question. The participants were pre-tested and streamed into two classes of equal reading comprehension abilities. The intervention consisted of four texts of equal length, comprising two rated in a pilot study as conceptually difficult/linguistically easy, and two rated as conceptually easy/linguistically difficult. The subjects in each class were involved in reading the two types of texts collaboratively and privately for four sessions. After reading the text, the subjects were asked to answer in writing 10 comprehension questions. Collaborative reading resulted in consistently and significantly higher scores than private reading for all four texts. Qualitative methods were employed to answer the last two questions. Group interactions during collaborative reading were tape recorded and transcribed, and 10 students selected at random from the two classes were interviewed in depth. Analysis of the group interaction transcripts revealed that the participants were using five major strategies in co-constructing meaning from the texts. These strategies included brainstorming, clarifying the language, summarizing, paraphrasing, and interaction management. Other minor (i.e., infrequent) strategies were also identified, such as making PCU/NCU (positive/negative claim to understand), eliciting confirmation, and confirming.
文摘To provide a risk-sharing mechanism that encourages a component supplier and a manufacturer to expand their production capacity of components and products, many researches on SCM suggested that it is better for the SC players to connect a long-term contract with flexible preconditions before doing the decision-making of production capacity. With considering of the uncertainty of demand and integrity problems between SC players, it is difficult to set reasonable preconditions. As a result, under-investment problems still occur frequently. In this paper, after we had discussed the decision-making of production capacity with the preconditions by analyzing the character of the players, we verified the under-investment problem of the supply chain. In order to clarify the optimum preconditions to alleviate the under-investment problem, we also analyzed the relations between preconditions and supply capacity of the whole supply chain. In the last part of this paper, we proposed a method of preconditions setting in such uncertain situations.
文摘From the mechanical similarity point of view, the centrifugal effect, Ar, and the Stokes number, St, as well as the Reynolds number, Re_c for the motion of solid particles in the cyclone are the relevant parameters. In order to apply these similarity laws for the prediction of the characteristics of the collection efficiency, ηc, geometrically similar types of uni-flow cyclones were used. The body diameters of the cyclones were D_1=30, 50, 69 and 99 mm, respectively. The feed particle concentration of the fly-ash particles was up to C_o = 60g/m^3. From the experimental results: (1) the pressure drop, △pc, in the cyclones was a function of not only the Reynods number, Re_c, but also the body diameter, D_1; (2) the collection efficiency, η_c, did not always increase with decreasing body diameter but there existed an optimal body size; (3) application of the mechanical similarity laws to the collection efficiency was not always sufficient for estimating the collection efficiency, since the feed particle concentration was an additional important factor; (4) a new parameter which was the ratio, E_(pf), of the apparent separation energy, W_p, of the solid particles to the energy loss, E_c, of the gas flow in the cyclone was introduced for discussing the collection efficiency; (5) Fuchs theory, used to estimate the collection efficiency, was examined. Fuchs theory may be applied for high feed particle concentration.
基金supported by the National Natural Science Foundation of China(Grant No.40704032)
文摘Based on the magnetospheric kinetic theory, a model is developed to specify the flux of energetic electrons in the inner and middle magnetosphere. Under the assumption of adiabatic motion and isotropic particle distribution maintained by pitch-angle scattering, the model calculates the electron flux by following bounce-averaged electric field, gradient, and curvature drift in the time dependent electric and magnetic field, meanwhile it counts the electron loss caused by pitch angle scattering. Using the model, the clectron flux distribution during a magnetic storm was calculated and compared with the observation data from the geosynchronous orbit. It is shown that the model can successfully reproduce most of the major electron flux enhancements observed at the geosynchronous orbit and generally tracks the satellite data well. The rms errors of the modeled logarithm of flux are between 0.5-1.0.