Schedule management is an important part of construction management, which will directly affect the construction time, quality, cost and benefit. In the construction process, it is necessary to accurately understand t...Schedule management is an important part of construction management, which will directly affect the construction time, quality, cost and benefit. In the construction process, it is necessary to accurately understand the factors affecting the construction schedule, clarify the key points of construction schedule management, coordinate the relationship between quality, schedule and cost, monitor and control, and dynamically manage the construction schedule to effectively avoid problems. This paper analyzes the function and influence factors of construction schedule management, and reviews the construction schedule management and control measures in order to clarify the level of construction schedule management and maximize the overall benefit of project construction.展开更多
Objective： To explore the effect of phlegm-heat syndrome on the degree of neurological deficit and provide some data support for the correct recognition of the relationship between phlegm-heat syndrome and neurologic...Objective： To explore the effect of phlegm-heat syndrome on the degree of neurological deficit and provide some data support for the correct recognition of the relationship between phlegm-heat syndrome and neurological deficits in stroke patients. Methods： Clinical information were collected on 294 patients with acute ischemic stroke （AIS） whose syndrome and National Institute of Health stroke scale （NIHSS） score were checked at baseline （within the first 3-day admission） and at 7, 14, 28, and 90 days after admission to our clinical research centre. We explored the effect of phlegm-heat syndrome on the degree of neurological deficit following stroke by applying a repeated measures analysis of variance. Results： Stroke patients with phlegm-heat syndrome had higher NIHSS score than patients without the syndrome （P〈0.01）, and there appeared to be a decrease in NIHSS score over time in all patients （P〈0.01）. Conduslons： Phlegm-heat syndrome in patients who have suffered stroke has an effect on the degree of neurological deficiency. Disappearance of phlegm-heat syndrome may improve the degree of neurological deficit observed in stroke patients.展开更多
Lightning strike initiation is an important factor affecting the reliability of 10kV railway transmission lines distributed in the field. Due to the randomness and complexity of lightning activity in the atmosphere, t...Lightning strike initiation is an important factor affecting the reliability of 10kV railway transmission lines distributed in the field. Due to the randomness and complexity of lightning activity in the atmosphere, there are still many unknowns in power line lightning hazard cognition research around the world. Therefore, the search for effective demining measures and the reduction of the occurrence of cross-line lightning strikes has been a concern for most railway power workers.展开更多
The problems including excessive flow of attemperating water for boiler, failure of butterfly valve at the outlet of circulating water pump, burnt-out of thyristor for excitation regulator, load variation rate of CCS ...The problems including excessive flow of attemperating water for boiler, failure of butterfly valve at the outlet of circulating water pump, burnt-out of thyristor for excitation regulator, load variation rate of CCS not complying with the contract target, etc. occurred during start-up and debugging of two 600 MW generating units in Yangzhou No.2 Thermal Power Plant. Through analysis on these problems. the remedial measures were put forward, to which can be referred for similar units.展开更多
The problem discussed in this paper is building energy saving technology. First of all, the relevant background and significance of building energy saving, and then clear the selection principle of building energy sav...The problem discussed in this paper is building energy saving technology. First of all, the relevant background and significance of building energy saving, and then clear the selection principle of building energy saving technology, from the perspective of building practical application of multiple building energy saving measures application direction, combined with the industry development site and future development demand briefly discusses the relevant content of technology development. This paper can be used as a reference in construction enterprises in the process of implementing energy saving buildings and optimization of energy saving measures.展开更多
In this work, a three-dimensional （3D） Computational Fluid Dynamics （CFD） model was built to simulate the tail fin motion of a fish robot actuated by a piezoceramic composite actuator, and to determine the maximum...In this work, a three-dimensional （3D） Computational Fluid Dynamics （CFD） model was built to simulate the tail fin motion of a fish robot actuated by a piezoceramic composite actuator, and to determine the maximum thrust tail-beat frequency. A simulation of the tail fin at a tail-beat frequency was performed to confirm measured thrust data from a previous study. The computed and measured thrusts were in good agreement. A series of thrust simulations were conducted for various tail-beat frequencies to confirm the maximum thrust frequency that was obtained from thrust measurements in the previous study. The largest thrust was calculated at a tail-beat frequency of 3.7 Hz and vortices around the tail were fully separated. The calculated maximum thrust tail-beat frequency was in good agreement with the measured frequency. Flow characteristics during tail fin motion were examined to explain why the largest thrust occurred at this particular tail-beat frequency.展开更多
Traditional Global Sensitivity Analysis（GSA） focuses on ranking inputs according to their contributions to the output uncertainty.However,information about how the specific regions inside an input affect the output ...Traditional Global Sensitivity Analysis（GSA） focuses on ranking inputs according to their contributions to the output uncertainty.However,information about how the specific regions inside an input affect the output is beyond the traditional GSA techniques.To fully address this issue,in this work,two regional moment-independent importance measures,Regional Importance Measure based on Probability Density Function（RIMPDF） and Regional Importance Measure based on Cumulative Distribution Function（RIMCDF）,are introduced to find out the contributions of specific regions of an input to the whole output distribution.The two regional importance measures prove to be reasonable supplements of the traditional GSA techniques.The ideas of RIMPDF and RIMCDF are applied in two engineering examples to demonstrate that the regional moment-independent importance analysis can add more information concerning the contributions of model inputs.展开更多
A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconductin...A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids （Nb-Ti/Cu） and six superconducting sextupoles （Nb-Ti/Cu）. Different from the conventional supercon- ducting ECR magnetic structure, the SEC17AL Ⅱ includes three superconducting solenoid coils＇ that are located inside the superconducting sextupoles. The SECRAL Ⅱ can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL Ⅱ generating its self field of -8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at 〈200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL Ⅱ structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the based on our analysis, the stresses and deformations optimized. strains developments of a sextupole is reported. Finally, for its assembly of each SECRAL Ⅱ coil will be further展开更多
This paper analyzes current spectrum utilization from all aspects based on related methods of spectrum measurement. The measurement results show that some spectrum resources are not used effectively due to current fix...This paper analyzes current spectrum utilization from all aspects based on related methods of spectrum measurement. The measurement results show that some spectrum resources are not used effectively due to current fixed spectrum allocation policy, and the spectrum occupancy varies dramatically in terms of time and space. These results provide basis for the development of next generation wireless communication technologies such as Cognitive Radio (CR).展开更多
For the best dynamic performance of a co-cured composite damping instrument panel with light weight and high strength, a multilayer sandwich structure with polymethaerylimide （PMI） foam combined with embedded and co...For the best dynamic performance of a co-cured composite damping instrument panel with light weight and high strength, a multilayer sandwich structure with polymethaerylimide （PMI） foam combined with embedded and co-cured composite damping structure is proposed. The struetue can maintain the excellent mechanical properties of composite materials, and achieve the damping and light effect at the same time. Input variables which may affect the dynamic performance of the instrument panel were selected and variance based importance measure was analyzed through multi- finite element method （FEM） analysis. Using the results of the importance measure analysis, with other design requirements, the important design variable was optimized and an instrument panel with the best dynamic performance under the requirements of light weight and high strength was obtained. The structure of the instrument panel can provide reference for the design of precision, high speed, and dynamic composite component. The importance measure analysis of dynamic performance of the instrument panel can provide a reference for relative design.展开更多
Long piles of the ocean oil platform are usually manufactured as the integration of several segments, which have to be assembled one by one during installation. During pile driving, excessive pore pressure will build ...Long piles of the ocean oil platform are usually manufactured as the integration of several segments, which have to be assembled one by one during installation. During pile driving, excessive pore pressure will build up in such a high level that hydraulic fracturing in the soil round the pile may take place, which will cause the soil to consolidate much faster during pile extension period. Consequently, after pile extension, the soil strength will recover to some extent and the driving resistance will increase considerably, which makes restarting driving the pile very difficult and even causes refusal. A finite element （FE） analysis procedure is presented for judging the risk of refusal by estimating the blow counts after pile extension, in which the regain of soil strength is considered. A case analysis in Bohai Gulf is performed using the proposed orocedure to exolain the nile refusal phenomenon.展开更多
With the increase of the convenience of the construction object, to improve the quality of housing construction, it is necessary to be competent in construction management, master the key points of construction techno...With the increase of the convenience of the construction object, to improve the quality of housing construction, it is necessary to be competent in construction management, master the key points of construction technology. This paper mainly analyzes and discusses the highlight of housing project management and building technology, examines the development status and shortcomings of housing project management and building technology, and puts forward effective measures to strengthen housing project management. Based on this, the paper puts forward some technical points of construction projects.展开更多
Water supply and drainage engineering is a key project in infrastructure construction, and various pipes, appliances and construction quality control are the key monitoring contents in water supply and drainage engine...Water supply and drainage engineering is a key project in infrastructure construction, and various pipes, appliances and construction quality control are the key monitoring contents in water supply and drainage engineering. In the face of people's increasing demand for water, the anti leakage problem in water supply and drainage engineering is more prominent. In order to solve the most concerned problems and improve the safety of water supply and drainage system, design, implementation and material use are very important for anti leakage treatment and prevention.展开更多
Objective: to discuss and reveal the application efficiency of nursing quality checklist based on nursing management in obstetrics and gynecology. Methods: from February 2020 to November 2021, 144 inpatients in obstet...Objective: to discuss and reveal the application efficiency of nursing quality checklist based on nursing management in obstetrics and gynecology. Methods: from February 2020 to November 2021, 144 inpatients in obstetrics and gynecology department were randomly divided into two groups, 72 in each group. The routine nursing management was used as the reference group, and the nursing management based on the nursing quality check table was used as the research group. The measurement items of nursing satisfaction, nursing quality, SAS, SDS, life quality and sleep quality before and after nursing intervention were measured and compared between the two groups. Results: the nursing satisfaction of the research group was higher than that of the reference group (P < 0.05). The measurement items of nursing environment, basic nursing, service attitude and nursing technology in the study group were higher than those in the reference group (P < 0.05). Before nursing, the SAS measurement items and SDS measurement items of the research group were roughly equal to those of the reference group (P > 0.05). After nursing, the SAS measurement items and SDS measurement items of the research group were lower than those of the reference group (P < 0.05). Before nursing, the quality of life measurement items and sleep quality measurement items of the research group were roughly the same as those of the reference group (P > 0.05). After nursing, the quality of life and sleep of the research group were better than those of the reference group (P < 0.05). Conclusion: promoting nursing management based on nursing quality checklist for inpatients in obstetrics and gynecology department is effective and worth popularizing.展开更多
Objective To explore the differences between anatomic and CT measurements for anterior transoral axial pedicle screw placement. Methods C2 vertebrae of 60 adult spines were measured anatomically,while 20 adult spine v...Objective To explore the differences between anatomic and CT measurements for anterior transoral axial pedicle screw placement. Methods C2 vertebrae of 60 adult spines were measured anatomically,while 20 adult spine vertebrae were展开更多
The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,expl...The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,exploring the provincial variations in carbon emission efficiency(CEE)in the building sector and identifying the effect of BEESs on CEE is crucial.This study focuses on commercial buildings in China and applies a difference in differences model to evaluate the impact of BEESs on the CEE of commercial buildings.The slacks-based measure–data envelopment analysis model is employed to assess the CEE of commercial buildings in 30 Chinese provinces from 2000 to 2019.Furthermore,heterogeneous tests are used to explore how climate characteristics and economic conditions affect the efficiency of BEESs.The results indicate that BEESs positively influence the CEE of commercial buildings.Specifically,a 1%increase in the intensity of BEESs causes a 0.1484%increase in the CEE of commercial buildings.Moreover,the impact of BEESs is particularly pronounced in the southern and western provinces.This study provides valuable scientific evidence for governments to enhance BEESs implementation.展开更多
A provenance experiment involving five native provenances and an Australian landrace of Pinus radiata （D. Don） was established over three sites in the dry river valley area of Sichuan, southwest China in 2004 in ord...A provenance experiment involving five native provenances and an Australian landrace of Pinus radiata （D. Don） was established over three sites in the dry river valley area of Sichuan, southwest China in 2004 in order to select the most suitable provenance for environmental planting on the dry, steep and degraded slopes to reduce soil erosion. Although with much lower soil moisture supply and mean minimum temperatures in winter compared to P. radiata provenance trials estab- lished elsewhere in the world, these sites are within the working limits of the species defined by previous climate modelling and matching. Be- cause of the difficult site conditions and severe natural disturbances after the experiment was established, mortality was high across the three sites in comparison to provenance trials in other countries.展开更多
Urban water supply and drainage engineering is an important part of urban infrastructure, and reasonable overall planning and design of urban water system has an important impact on the long-term development of the ci...Urban water supply and drainage engineering is an important part of urban infrastructure, and reasonable overall planning and design of urban water system has an important impact on the long-term development of the city. At present, some cities have not implemented complete urban water supply and drainage system planning and design in planning and construction, which has caused increasingly serious water resource waste and pollution problems, seriously restricted the long-term development of urban water supply and drainage system, and also restricted the long-term development of many areas of the city. Therefore, it is necessary to further improve the urban water supply and drainage planning and design, reasonably develop and utilize resources, meet the needs of social and economic development, and fundamentally promote the long-term development of modern cities.展开更多
This paper seeks to enhance the understanding that the horizontal stresses build up and release during coal pillar loading and unloading(post-failure) drawing upon three decades of observations, geomechanical monitori...This paper seeks to enhance the understanding that the horizontal stresses build up and release during coal pillar loading and unloading(post-failure) drawing upon three decades of observations, geomechanical monitoring and numerical modeling in bump-prone U.S. mines. The focus is on induced horizontal stress in mine pillars and surrounding strata as highly stressed pillars punch into the roof and floor, causing shear failure and buckling of strata; under stiff stratigraphic units of some western US mines, these events could be accompanied by violent failure of pillar cores. Pillar punching eventually results in tensile stresses at the base of the pillar, facilitating transition into the post-failure regime; this transition will be nonviolent if certain conditions are met, notably the presence of interbedded mudstones with low shear strength properties and proper mine designs for controlling seismicity and dynamic loads. The study clearly shows high confining stress build-up in coal pillars resulting in up to twice higher peak vertical stress and high strain energy accumulations in some western US mines in comparison with peak stresses predicted using common empirical pillar design methods. It is the unstable release of this strain energy that can cause significant damage resulting from pillar dilation and ground movements. These forces are much greater than the capacity of most common internal support systems, resulting in horizontal stressinduced roof falls locally, in mines under unremarkable far-field horizontal stress. Attention should be placed on pillar designs as increasing support density may prove to be ineffective. This mechanism is analyzed using field measurements and generic finite-difference stress analyses. The study confirms the higher load carrying capacity of confinement-controlled coal seams in comparison with structurally controlled coal seams. Such significant differences in confining stresses are not taken into account when estimating peak pillar strength using most common empirical techniques such as those proposed by Bieniawski and Salamon. While using lower pillar strength estimates may be considered conservative,it underestimates the actual capacity of pillars in accumulating much higher stress and strain energies,misleading the designer and inadvertently diminishing mine safety. The role of induced horizontal stress in mine pillars and surrounding strata is emphasized in coal pillar mechanics of violent failure. The triggering mechanism for the violent events is sudden loss of pillar confinement due to dynamic loading resulting from failure of overlying stiff and strong strata. Evidence of such mechanism is noted in the field by observed red-dust at the coal-rock interfaces at the location of coal bumps and irregular, periodic caving in room-and-pillar mines quantified through direct pressure measurements in the gob.展开更多
文摘Schedule management is an important part of construction management, which will directly affect the construction time, quality, cost and benefit. In the construction process, it is necessary to accurately understand the factors affecting the construction schedule, clarify the key points of construction schedule management, coordinate the relationship between quality, schedule and cost, monitor and control, and dynamically manage the construction schedule to effectively avoid problems. This paper analyzes the function and influence factors of construction schedule management, and reviews the construction schedule management and control measures in order to clarify the level of construction schedule management and maximize the overall benefit of project construction.
基金The Chinese Journal of Integrated Traditional and Western Medicine Press and Springer-Verlag Berlin Heidelberg 2012 ＇Supported by the State Administration of Traditional Chinese Medcine of China （No. 200707001）, the Major State Basic Research Development Program of China （973 Program, No. 2003CB517102a）, the Independent Subject Project of Beijing University of Chinese Medicine （No. 2009JYBZZ-XS060）, and the State“ Major Science and Technology New Drugs”（No. 2009ZX09502-028） Special Project ＂Major Creation of New Drugs＂ （No. 2009ZX09502-028）
文摘Objective： To explore the effect of phlegm-heat syndrome on the degree of neurological deficit and provide some data support for the correct recognition of the relationship between phlegm-heat syndrome and neurological deficits in stroke patients. Methods： Clinical information were collected on 294 patients with acute ischemic stroke （AIS） whose syndrome and National Institute of Health stroke scale （NIHSS） score were checked at baseline （within the first 3-day admission） and at 7, 14, 28, and 90 days after admission to our clinical research centre. We explored the effect of phlegm-heat syndrome on the degree of neurological deficit following stroke by applying a repeated measures analysis of variance. Results： Stroke patients with phlegm-heat syndrome had higher NIHSS score than patients without the syndrome （P〈0.01）, and there appeared to be a decrease in NIHSS score over time in all patients （P〈0.01）. Conduslons： Phlegm-heat syndrome in patients who have suffered stroke has an effect on the degree of neurological deficiency. Disappearance of phlegm-heat syndrome may improve the degree of neurological deficit observed in stroke patients.
文摘Lightning strike initiation is an important factor affecting the reliability of 10kV railway transmission lines distributed in the field. Due to the randomness and complexity of lightning activity in the atmosphere, there are still many unknowns in power line lightning hazard cognition research around the world. Therefore, the search for effective demining measures and the reduction of the occurrence of cross-line lightning strikes has been a concern for most railway power workers.
文摘The problems including excessive flow of attemperating water for boiler, failure of butterfly valve at the outlet of circulating water pump, burnt-out of thyristor for excitation regulator, load variation rate of CCS not complying with the contract target, etc. occurred during start-up and debugging of two 600 MW generating units in Yangzhou No.2 Thermal Power Plant. Through analysis on these problems. the remedial measures were put forward, to which can be referred for similar units.
文摘The problem discussed in this paper is building energy saving technology. First of all, the relevant background and significance of building energy saving, and then clear the selection principle of building energy saving technology, from the perspective of building practical application of multiple building energy saving measures application direction, combined with the industry development site and future development demand briefly discusses the relevant content of technology development. This paper can be used as a reference in construction enterprises in the process of implementing energy saving buildings and optimization of energy saving measures.
文摘In this work, a three-dimensional （3D） Computational Fluid Dynamics （CFD） model was built to simulate the tail fin motion of a fish robot actuated by a piezoceramic composite actuator, and to determine the maximum thrust tail-beat frequency. A simulation of the tail fin at a tail-beat frequency was performed to confirm measured thrust data from a previous study. The computed and measured thrusts were in good agreement. A series of thrust simulations were conducted for various tail-beat frequencies to confirm the maximum thrust frequency that was obtained from thrust measurements in the previous study. The largest thrust was calculated at a tail-beat frequency of 3.7 Hz and vortices around the tail were fully separated. The calculated maximum thrust tail-beat frequency was in good agreement with the measured frequency. Flow characteristics during tail fin motion were examined to explain why the largest thrust occurred at this particular tail-beat frequency.
基金supported by the National Natural Science Foundation of China(No.NSFC51608446)the Fundamental Research Fund for Central Universities of China(No.3102016ZY015)
文摘Traditional Global Sensitivity Analysis（GSA） focuses on ranking inputs according to their contributions to the output uncertainty.However,information about how the specific regions inside an input affect the output is beyond the traditional GSA techniques.To fully address this issue,in this work,two regional moment-independent importance measures,Regional Importance Measure based on Probability Density Function（RIMPDF） and Regional Importance Measure based on Cumulative Distribution Function（RIMCDF）,are introduced to find out the contributions of specific regions of an input to the whole output distribution.The two regional importance measures prove to be reasonable supplements of the traditional GSA techniques.The ideas of RIMPDF and RIMCDF are applied in two engineering examples to demonstrate that the regional moment-independent importance analysis can add more information concerning the contributions of model inputs.
基金Supported by the National Natural Science Foundation of China under Grant No 11302225the China Postdoctoral Science Foundation under Grant Nos 2014M560820 and 2015T81071
文摘A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids （Nb-Ti/Cu） and six superconducting sextupoles （Nb-Ti/Cu）. Different from the conventional supercon- ducting ECR magnetic structure, the SEC17AL Ⅱ includes three superconducting solenoid coils＇ that are located inside the superconducting sextupoles. The SECRAL Ⅱ can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL Ⅱ generating its self field of -8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at 〈200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL Ⅱ structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the based on our analysis, the stresses and deformations optimized. strains developments of a sextupole is reported. Finally, for its assembly of each SECRAL Ⅱ coil will be further
文摘This paper analyzes current spectrum utilization from all aspects based on related methods of spectrum measurement. The measurement results show that some spectrum resources are not used effectively due to current fixed spectrum allocation policy, and the spectrum occupancy varies dramatically in terms of time and space. These results provide basis for the development of next generation wireless communication technologies such as Cognitive Radio (CR).
文摘For the best dynamic performance of a co-cured composite damping instrument panel with light weight and high strength, a multilayer sandwich structure with polymethaerylimide （PMI） foam combined with embedded and co-cured composite damping structure is proposed. The struetue can maintain the excellent mechanical properties of composite materials, and achieve the damping and light effect at the same time. Input variables which may affect the dynamic performance of the instrument panel were selected and variance based importance measure was analyzed through multi- finite element method （FEM） analysis. Using the results of the importance measure analysis, with other design requirements, the important design variable was optimized and an instrument panel with the best dynamic performance under the requirements of light weight and high strength was obtained. The structure of the instrument panel can provide reference for the design of precision, high speed, and dynamic composite component. The importance measure analysis of dynamic performance of the instrument panel can provide a reference for relative design.
基金supported by the National Natural Science Foundation of China(51322904 and 51279127)the Program for New Century Excellent Talents in University(HCET-11-0370)
文摘Long piles of the ocean oil platform are usually manufactured as the integration of several segments, which have to be assembled one by one during installation. During pile driving, excessive pore pressure will build up in such a high level that hydraulic fracturing in the soil round the pile may take place, which will cause the soil to consolidate much faster during pile extension period. Consequently, after pile extension, the soil strength will recover to some extent and the driving resistance will increase considerably, which makes restarting driving the pile very difficult and even causes refusal. A finite element （FE） analysis procedure is presented for judging the risk of refusal by estimating the blow counts after pile extension, in which the regain of soil strength is considered. A case analysis in Bohai Gulf is performed using the proposed orocedure to exolain the nile refusal phenomenon.
文摘With the increase of the convenience of the construction object, to improve the quality of housing construction, it is necessary to be competent in construction management, master the key points of construction technology. This paper mainly analyzes and discusses the highlight of housing project management and building technology, examines the development status and shortcomings of housing project management and building technology, and puts forward effective measures to strengthen housing project management. Based on this, the paper puts forward some technical points of construction projects.
文摘Water supply and drainage engineering is a key project in infrastructure construction, and various pipes, appliances and construction quality control are the key monitoring contents in water supply and drainage engineering. In the face of people's increasing demand for water, the anti leakage problem in water supply and drainage engineering is more prominent. In order to solve the most concerned problems and improve the safety of water supply and drainage system, design, implementation and material use are very important for anti leakage treatment and prevention.
文摘Objective: to discuss and reveal the application efficiency of nursing quality checklist based on nursing management in obstetrics and gynecology. Methods: from February 2020 to November 2021, 144 inpatients in obstetrics and gynecology department were randomly divided into two groups, 72 in each group. The routine nursing management was used as the reference group, and the nursing management based on the nursing quality check table was used as the research group. The measurement items of nursing satisfaction, nursing quality, SAS, SDS, life quality and sleep quality before and after nursing intervention were measured and compared between the two groups. Results: the nursing satisfaction of the research group was higher than that of the reference group (P < 0.05). The measurement items of nursing environment, basic nursing, service attitude and nursing technology in the study group were higher than those in the reference group (P < 0.05). Before nursing, the SAS measurement items and SDS measurement items of the research group were roughly equal to those of the reference group (P > 0.05). After nursing, the SAS measurement items and SDS measurement items of the research group were lower than those of the reference group (P < 0.05). Before nursing, the quality of life measurement items and sleep quality measurement items of the research group were roughly the same as those of the reference group (P > 0.05). After nursing, the quality of life and sleep of the research group were better than those of the reference group (P < 0.05). Conclusion: promoting nursing management based on nursing quality checklist for inpatients in obstetrics and gynecology department is effective and worth popularizing.
文摘Objective To explore the differences between anatomic and CT measurements for anterior transoral axial pedicle screw placement. Methods C2 vertebrae of 60 adult spines were measured anatomically,while 20 adult spine vertebrae were
基金funded by the National Social Science Foundation of China[Grant No.23CJY018]the Fundamental Research Funds for the Central Universities[Grant No.JBK2406049]+2 种基金the National Natural Science Foundation of China[Grant No.72003151],[Grant No.72173100]the Soft Science Research Program of Sichuan Province[Grant No.2022JDR0227]Projects from the Research Center on Xi Jinping’s Economic Thought,and the Fundamental Research Funds for the“Guanghua Talent Program”of the Southwestern University of Finance and Economics.
文摘The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,exploring the provincial variations in carbon emission efficiency(CEE)in the building sector and identifying the effect of BEESs on CEE is crucial.This study focuses on commercial buildings in China and applies a difference in differences model to evaluate the impact of BEESs on the CEE of commercial buildings.The slacks-based measure–data envelopment analysis model is employed to assess the CEE of commercial buildings in 30 Chinese provinces from 2000 to 2019.Furthermore,heterogeneous tests are used to explore how climate characteristics and economic conditions affect the efficiency of BEESs.The results indicate that BEESs positively influence the CEE of commercial buildings.Specifically,a 1%increase in the intensity of BEESs causes a 0.1484%increase in the CEE of commercial buildings.Moreover,the impact of BEESs is particularly pronounced in the southern and western provinces.This study provides valuable scientific evidence for governments to enhance BEESs implementation.
基金sponsored by the Australian Centre for International Agricultural Research(ACIAR),State Forests of New South Wales,Australia,Chinese Academy of Forestry and Department of Forestry of Sichuan Province,China
文摘A provenance experiment involving five native provenances and an Australian landrace of Pinus radiata （D. Don） was established over three sites in the dry river valley area of Sichuan, southwest China in 2004 in order to select the most suitable provenance for environmental planting on the dry, steep and degraded slopes to reduce soil erosion. Although with much lower soil moisture supply and mean minimum temperatures in winter compared to P. radiata provenance trials estab- lished elsewhere in the world, these sites are within the working limits of the species defined by previous climate modelling and matching. Be- cause of the difficult site conditions and severe natural disturbances after the experiment was established, mortality was high across the three sites in comparison to provenance trials in other countries.
文摘Urban water supply and drainage engineering is an important part of urban infrastructure, and reasonable overall planning and design of urban water system has an important impact on the long-term development of the city. At present, some cities have not implemented complete urban water supply and drainage system planning and design in planning and construction, which has caused increasingly serious water resource waste and pollution problems, seriously restricted the long-term development of urban water supply and drainage system, and also restricted the long-term development of many areas of the city. Therefore, it is necessary to further improve the urban water supply and drainage planning and design, reasonably develop and utilize resources, meet the needs of social and economic development, and fundamentally promote the long-term development of modern cities.
文摘This paper seeks to enhance the understanding that the horizontal stresses build up and release during coal pillar loading and unloading(post-failure) drawing upon three decades of observations, geomechanical monitoring and numerical modeling in bump-prone U.S. mines. The focus is on induced horizontal stress in mine pillars and surrounding strata as highly stressed pillars punch into the roof and floor, causing shear failure and buckling of strata; under stiff stratigraphic units of some western US mines, these events could be accompanied by violent failure of pillar cores. Pillar punching eventually results in tensile stresses at the base of the pillar, facilitating transition into the post-failure regime; this transition will be nonviolent if certain conditions are met, notably the presence of interbedded mudstones with low shear strength properties and proper mine designs for controlling seismicity and dynamic loads. The study clearly shows high confining stress build-up in coal pillars resulting in up to twice higher peak vertical stress and high strain energy accumulations in some western US mines in comparison with peak stresses predicted using common empirical pillar design methods. It is the unstable release of this strain energy that can cause significant damage resulting from pillar dilation and ground movements. These forces are much greater than the capacity of most common internal support systems, resulting in horizontal stressinduced roof falls locally, in mines under unremarkable far-field horizontal stress. Attention should be placed on pillar designs as increasing support density may prove to be ineffective. This mechanism is analyzed using field measurements and generic finite-difference stress analyses. The study confirms the higher load carrying capacity of confinement-controlled coal seams in comparison with structurally controlled coal seams. Such significant differences in confining stresses are not taken into account when estimating peak pillar strength using most common empirical techniques such as those proposed by Bieniawski and Salamon. While using lower pillar strength estimates may be considered conservative,it underestimates the actual capacity of pillars in accumulating much higher stress and strain energies,misleading the designer and inadvertently diminishing mine safety. The role of induced horizontal stress in mine pillars and surrounding strata is emphasized in coal pillar mechanics of violent failure. The triggering mechanism for the violent events is sudden loss of pillar confinement due to dynamic loading resulting from failure of overlying stiff and strong strata. Evidence of such mechanism is noted in the field by observed red-dust at the coal-rock interfaces at the location of coal bumps and irregular, periodic caving in room-and-pillar mines quantified through direct pressure measurements in the gob.
