Based on the current indoor natural ventilation and lighting in the space of traditional residential buildings,this paper starts from the passive-design optimization of the spatial natural ventilation and lighting,and...Based on the current indoor natural ventilation and lighting in the space of traditional residential buildings,this paper starts from the passive-design optimization of the spatial natural ventilation and lighting,and makes quantitative evaluation on the quality of current interior natural ventilation and lighting for two typical residential buildings by three indexes,including wind speed,static wind area ratio and satisfaction ratio about minimum lighting coefficient. Based on that, this paper conducts the passive design optimization, and establishes the quantitative association and reevaluation among the passive reformation design, natural ventilation,and lighting environmental quality,proposing the general strategy for the existing residential buildings to respond to the passive reformation design of the natural ventilation and lighting. The special reconstruction of core functionary space of integration of "the living room + dining room + partial space"is researched,and the redesign for the optimization and replacement of both indoor and outdoor enclosure parts is explored,which is expected to provide practical exploration on the strategies for passive construction of spatial natural environmental quality within a large number of highly-energy-consumed residential buildings in China,as well as the green design of residential buildings.展开更多
The study of English passive construction has always been one of the hot topics in the literature of Generative Grammar. Although many attempts have been made, the study of this structure is still not systematic enoug...The study of English passive construction has always been one of the hot topics in the literature of Generative Grammar. Although many attempts have been made, the study of this structure is still not systematic enough especially in terms of its essential natures. The present study is designed to give a full explanation of natures of English passive construction from the perspective of theta theory, which can provide English learners with a deeper understanding of passive structure.展开更多
High-density development is becoming an inevitable tendency in Chinese urbanization. In this study,the application of natural ventilation in high-density urban development is discussed. Based on the domestic and forei...High-density development is becoming an inevitable tendency in Chinese urbanization. In this study,the application of natural ventilation in high-density urban development is discussed. Based on the domestic and foreign study on natural ventilation,indoor and outdoor natural ventilated strategies,and the application on natural ventilation in underground space development are analyzed. From the study,the relationship between passive and active ventilated technologies is interpreted into what is described to be synergistic,complementary and additive.展开更多
The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger elect...The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.展开更多
The tube inside and outside heat transfer mechanism of Passive Residual Heat Removal Heat Exchanger (PRHR HX) was analyzed. The calculation method of this special heat exchanger under natural convection condition in I...The tube inside and outside heat transfer mechanism of Passive Residual Heat Removal Heat Exchanger (PRHR HX) was analyzed. The calculation method of this special heat exchanger under natural convection condition in In-containment Refueling Water Storage Tank (IRWST) was carried out. The single-tube coupling model three-dimensional natural circulation in the IRWST was simulated numerically using Fluent. The heat transfer and flow characteristics of the fluid in IRWST were obtained. The comparison of the results between theoretical arithmetic and numerical simulation showed that the theoretical calculation method is suitable for the heat transfer calculation of PRHR HX.展开更多
The design of an integral pressurized water reactor (IPWR) focuses on enhancing the safety and reliability of the reactor by incorporating a number of inherent safety features and engineered safety features. However, ...The design of an integral pressurized water reactor (IPWR) focuses on enhancing the safety and reliability of the reactor by incorporating a number of inherent safety features and engineered safety features. However, the characteristics of passive safety systems for the marine reactors are quiet different from those for the land nuclear power plant because of the more formidable and dangerous operation environments of them. This paper presents results of marine black out accident analyses. In the case of a transient, the passive residual heat removal system (PRHRS) is designed to cool the reactor coolant system (RCS) from a normal operation condition to a hot shutdown condition by a natural circulation, and the shutdown cooling system (SCS) is designed to cool the primary system from a hot shutdown condition to a refueling condition by a forced circulation. A realistic calculation has been carried out by using the RELAP5/MOD3.4 code and a sensitivity analysis has been performed to evaluate a passive cooldown capability. The results of the accident analyses show that the reactor coolant system and the passive residual heat removal system adequately remove the core decay heat by a natural circulation.展开更多
The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor...The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor, and tractor induced unwanted vibration to sprayer because of uneven soil or terrain. This oscillation leads to over-doses and under-doses of chemical sprayed on the field. For this reason, many commercial and some theoretical suspension were made to reduce undesirable vibration. Therefore, in this study a finite element based model was established to represent the dynamic behavior of spray boom structure with 8m width. The first tenth natural frequencies were obtained between 9.25 Hz to 1,182.5 Hz. Also, a passive vertical suspension was designed to remove unwanted vibration with 0.5 vibration transmissibility. Finally, the suspension system was simulated to be as certain of its efficiency. The results of simulation have good agreement to the proposed aim.展开更多
Natural dynamics can be exploited in the control of biped walking robots: the swing leg can swing passively, the compliant ankle can naturally transfer the center of pressure along the foot and help in toe off. These ...Natural dynamics can be exploited in the control of biped walking robots: the swing leg can swing passively, the compliant ankle can naturally transfer the center of pressure along the foot and help in toe off. These mechanisms simplify control and result in motion that is smooth and natural looking. Imitated human being’s behavior, we presented a control strategy for HIT III biped robot, in which active and passive motions were combined. The experiment result shows that robot walked at a faster speed (approximately 0.25m/s) than previous and had a natural and smooth looking gait.展开更多
Given the perennial incidence of thermal discomfort, health issues, as well as energy costs associated with naturally ventilated classrooms in Yola, the study aimed at enhancing the effectiveness of classroom designs ...Given the perennial incidence of thermal discomfort, health issues, as well as energy costs associated with naturally ventilated classrooms in Yola, the study aimed at enhancing the effectiveness of classroom designs for natural ventilation comfort by examining the effects of six architectural design variables—size and position of openings, form of buildings, orientation of buildings, site planning, topography, and physical features, on the ventilation coefficients of 61 classrooms selected from nine stratified clusters in Yola, Adamawa State, Nigeria. Data were analyzed using percentages, ratios, means as well as standard deviation, and then sorted in groups using tables. The study revealed that the form and orientation of the classroom-buildings, as well as topography, site planning and other physical features, have no significant effect on ventilation coefficient. In addition, a new mean ventilation coefficient was obtained in ten classrooms against an earlier claim that ventilation coefficient cannot exceed a fixed average regardless of the ratio of wall opening to floor area.展开更多
In underground space,daylighting plays an important role in increasing the spacious sense,improving the ventilation effect,and more importantly,reducing the negative visual and psychological effects brought by the und...In underground space,daylighting plays an important role in increasing the spacious sense,improving the ventilation effect,and more importantly,reducing the negative visual and psychological effects brought by the underground space,such as enclosed monotony,unknown direction and isolation.In this paper,the technical means of utilizing natural light in underground space were elaborated from the two aspects of passive daylighting method and active daylighting method,aiming to bring natural light into the underground as much as possible so as to fully satisfy people's longing for nature for those who work and live in the underground space.展开更多
Although William Wordsworth and Ralph Waldo Emerson lived in the same century, they formed their different con ceptions of nature. This paper tries to summarize their similarities and differences; what's more, it ...Although William Wordsworth and Ralph Waldo Emerson lived in the same century, they formed their different con ceptions of nature. This paper tries to summarize their similarities and differences; what's more, it tries to explore their different reasons through anglicizing their representative works. Through comparison, exploration and researching, the conception of na ture from Wordsworth and Emerson can be defined. The reason for Wordsworth had such views of nature comes from his pas siveness; and to Emerson, from Germany philosophy and bold individualism.展开更多
Passive residual heat removal heat exchanger(PRHR HX),which is a newly designed equipment in the advanced reactors of AP1000 and CAP1400,plays an important role in critical accidental conditions.The primary and second...Passive residual heat removal heat exchanger(PRHR HX),which is a newly designed equipment in the advanced reactors of AP1000 and CAP1400,plays an important role in critical accidental conditions.The primary and secondary side coupling heat transfer characteristics of the passive residual heat removal system(PRHRS)determine the capacity to remove core decay heat during the accidents.Therefore,it is necessary to investigate the heat transfer characteristics and develop applicable heat transfer formulas for optimized design.In the present paper,an overall scaled-down natural circulation loop of PRHRS in AP1000,which comprises a scaleddown in-containment refueling water storage tank(IRWST)and PRHR HX models and a simulator of the reactor core,is built to simulate the natural circulation process in residual heat removal accidents.A series of experiments are conducted to study thermal-hydraulic behaviors in both sides of the miniaturized PRHR HX which is simulated by 12 symmetric arranged C-shape tubes.For the local PRHR HX heat transfer performance,traditional natural convection correlations for both the horizontal and vertical bundles are compared with the experimental data to validate their applicability for the specific heat transfer condition.Moreover,the revised natural convection heat transfer correlations based on the present experimental data are developed for PRHR HX vertical and lower horizontal bundles.This paper provides essential references for the PRHRS operation and further optimized design.展开更多
基金Sponsored by the Key Project of National Natural Science Foundation of China (Grant No.51138004)the South China Key Laboratory Fund (Grant No.20121458321)the Architect Design on Energy-saving Residence in Shanghai (Grant No.08-2A-0183-zong)
文摘Based on the current indoor natural ventilation and lighting in the space of traditional residential buildings,this paper starts from the passive-design optimization of the spatial natural ventilation and lighting,and makes quantitative evaluation on the quality of current interior natural ventilation and lighting for two typical residential buildings by three indexes,including wind speed,static wind area ratio and satisfaction ratio about minimum lighting coefficient. Based on that, this paper conducts the passive design optimization, and establishes the quantitative association and reevaluation among the passive reformation design, natural ventilation,and lighting environmental quality,proposing the general strategy for the existing residential buildings to respond to the passive reformation design of the natural ventilation and lighting. The special reconstruction of core functionary space of integration of "the living room + dining room + partial space"is researched,and the redesign for the optimization and replacement of both indoor and outdoor enclosure parts is explored,which is expected to provide practical exploration on the strategies for passive construction of spatial natural environmental quality within a large number of highly-energy-consumed residential buildings in China,as well as the green design of residential buildings.
文摘The study of English passive construction has always been one of the hot topics in the literature of Generative Grammar. Although many attempts have been made, the study of this structure is still not systematic enough especially in terms of its essential natures. The present study is designed to give a full explanation of natures of English passive construction from the perspective of theta theory, which can provide English learners with a deeper understanding of passive structure.
基金Sponsored by the 12th Five-year National Science and Technology Support Program:Research on the Key Technologies of Efficiency Optimization of High-density Urban Space(Grant No.2012BAJ15B03)
文摘High-density development is becoming an inevitable tendency in Chinese urbanization. In this study,the application of natural ventilation in high-density urban development is discussed. Based on the domestic and foreign study on natural ventilation,indoor and outdoor natural ventilated strategies,and the application on natural ventilation in underground space development are analyzed. From the study,the relationship between passive and active ventilated technologies is interpreted into what is described to be synergistic,complementary and additive.
文摘The natural passive films forrned on Fe_(40)Ni_(40)P_(14)B_6 and Fe_(54.6)Ni_(38)Si_(4.1)B_(2.3)V_1 amorphous alloys long-term exposed in air have been studied by X-ray photoelectron spectroscopy (XPS) and Auger electron (including Ar+ ion depth profiling) spectroscopy (AES). The following aspects have been investigated: (1) chemical states of the elements in the films. binding energies and the chemical shifts measured by XPSf (2) structure and composition of the films fand (3) thickness of the passive films determined by AES depth profiling and XPS analysis.
文摘The tube inside and outside heat transfer mechanism of Passive Residual Heat Removal Heat Exchanger (PRHR HX) was analyzed. The calculation method of this special heat exchanger under natural convection condition in In-containment Refueling Water Storage Tank (IRWST) was carried out. The single-tube coupling model three-dimensional natural circulation in the IRWST was simulated numerically using Fluent. The heat transfer and flow characteristics of the fluid in IRWST were obtained. The comparison of the results between theoretical arithmetic and numerical simulation showed that the theoretical calculation method is suitable for the heat transfer calculation of PRHR HX.
文摘The design of an integral pressurized water reactor (IPWR) focuses on enhancing the safety and reliability of the reactor by incorporating a number of inherent safety features and engineered safety features. However, the characteristics of passive safety systems for the marine reactors are quiet different from those for the land nuclear power plant because of the more formidable and dangerous operation environments of them. This paper presents results of marine black out accident analyses. In the case of a transient, the passive residual heat removal system (PRHRS) is designed to cool the reactor coolant system (RCS) from a normal operation condition to a hot shutdown condition by a natural circulation, and the shutdown cooling system (SCS) is designed to cool the primary system from a hot shutdown condition to a refueling condition by a forced circulation. A realistic calculation has been carried out by using the RELAP5/MOD3.4 code and a sensitivity analysis has been performed to evaluate a passive cooldown capability. The results of the accident analyses show that the reactor coolant system and the passive residual heat removal system adequately remove the core decay heat by a natural circulation.
文摘The most usual way of using chemical method to protect crop against weed, insects, and fungi is spraying the mixture of chemicals and water onto crop through the nozzles. Sprayers usually moved on the field by tractor, and tractor induced unwanted vibration to sprayer because of uneven soil or terrain. This oscillation leads to over-doses and under-doses of chemical sprayed on the field. For this reason, many commercial and some theoretical suspension were made to reduce undesirable vibration. Therefore, in this study a finite element based model was established to represent the dynamic behavior of spray boom structure with 8m width. The first tenth natural frequencies were obtained between 9.25 Hz to 1,182.5 Hz. Also, a passive vertical suspension was designed to remove unwanted vibration with 0.5 vibration transmissibility. Finally, the suspension system was simulated to be as certain of its efficiency. The results of simulation have good agreement to the proposed aim.
文摘Natural dynamics can be exploited in the control of biped walking robots: the swing leg can swing passively, the compliant ankle can naturally transfer the center of pressure along the foot and help in toe off. These mechanisms simplify control and result in motion that is smooth and natural looking. Imitated human being’s behavior, we presented a control strategy for HIT III biped robot, in which active and passive motions were combined. The experiment result shows that robot walked at a faster speed (approximately 0.25m/s) than previous and had a natural and smooth looking gait.
文摘Given the perennial incidence of thermal discomfort, health issues, as well as energy costs associated with naturally ventilated classrooms in Yola, the study aimed at enhancing the effectiveness of classroom designs for natural ventilation comfort by examining the effects of six architectural design variables—size and position of openings, form of buildings, orientation of buildings, site planning, topography, and physical features, on the ventilation coefficients of 61 classrooms selected from nine stratified clusters in Yola, Adamawa State, Nigeria. Data were analyzed using percentages, ratios, means as well as standard deviation, and then sorted in groups using tables. The study revealed that the form and orientation of the classroom-buildings, as well as topography, site planning and other physical features, have no significant effect on ventilation coefficient. In addition, a new mean ventilation coefficient was obtained in ten classrooms against an earlier claim that ventilation coefficient cannot exceed a fixed average regardless of the ratio of wall opening to floor area.
文摘In underground space,daylighting plays an important role in increasing the spacious sense,improving the ventilation effect,and more importantly,reducing the negative visual and psychological effects brought by the underground space,such as enclosed monotony,unknown direction and isolation.In this paper,the technical means of utilizing natural light in underground space were elaborated from the two aspects of passive daylighting method and active daylighting method,aiming to bring natural light into the underground as much as possible so as to fully satisfy people's longing for nature for those who work and live in the underground space.
文摘Although William Wordsworth and Ralph Waldo Emerson lived in the same century, they formed their different con ceptions of nature. This paper tries to summarize their similarities and differences; what's more, it tries to explore their different reasons through anglicizing their representative works. Through comparison, exploration and researching, the conception of na ture from Wordsworth and Emerson can be defined. The reason for Wordsworth had such views of nature comes from his pas siveness; and to Emerson, from Germany philosophy and bold individualism.
基金the National Science and Technology Major Project of China(Grant No.2017ZX06004002-006-002)the National Natural Science Foundation of China(Grant No.51906069)。
文摘Passive residual heat removal heat exchanger(PRHR HX),which is a newly designed equipment in the advanced reactors of AP1000 and CAP1400,plays an important role in critical accidental conditions.The primary and secondary side coupling heat transfer characteristics of the passive residual heat removal system(PRHRS)determine the capacity to remove core decay heat during the accidents.Therefore,it is necessary to investigate the heat transfer characteristics and develop applicable heat transfer formulas for optimized design.In the present paper,an overall scaled-down natural circulation loop of PRHRS in AP1000,which comprises a scaleddown in-containment refueling water storage tank(IRWST)and PRHR HX models and a simulator of the reactor core,is built to simulate the natural circulation process in residual heat removal accidents.A series of experiments are conducted to study thermal-hydraulic behaviors in both sides of the miniaturized PRHR HX which is simulated by 12 symmetric arranged C-shape tubes.For the local PRHR HX heat transfer performance,traditional natural convection correlations for both the horizontal and vertical bundles are compared with the experimental data to validate their applicability for the specific heat transfer condition.Moreover,the revised natural convection heat transfer correlations based on the present experimental data are developed for PRHR HX vertical and lower horizontal bundles.This paper provides essential references for the PRHRS operation and further optimized design.
