The excessive nitrogen （N） fertilizer input coupled with flood irrigation might result in higher N leaching and lower nitrogen recovery efficiency （NRE）. Under an intensive rice system in the Ningxia irrigation re...The excessive nitrogen （N） fertilizer input coupled with flood irrigation might result in higher N leaching and lower nitrogen recovery efficiency （NRE）. Under an intensive rice system in the Ningxia irrigation region, China, environmental friendly N management practices are hreavily needed to balance the amount of N input for optimum crop production while minimize the nitrogen loss. The objective of this study was to determine the influences of side-dressing （SD） technique in mechanical transplanting systems on the NRE, N leaching losses and rice yield in anthropogenic-alluvial soil during two rice growing seasons （2010-2011）. Four fertilizer N treatments were established, including conventional urea rate （CU, 300 kg ha-1 yr-1）; higher SD of controlled-release N fertilizer rate （SD1,176 kg ha-1 yr-1）; lower SD of controlled-release N fertilizer rate （SD2, 125 kg ha-1 yr-1）; and control （CK, no N fertilizer）. Field lysimeters were used to quantify drainage from undisturbed soil during six rice growing stages. Meanwhile, the temporal variations of total nitrigen （TN）, NO3--N, and NH4＋-N concentrations in percolation water were examined. The results showed that SD1 substantially improved NRE and reduced N leaching losses while maintaining rice yields. Across two years, the averaged NRE under SD1 treatment increased by 25.5% as relative to CU, but yet the rice yield was similar between two treatments. On average, the nitrogen loss defined as TN, NH4＋-N, and NO3--N under the SD1 treatment reduced by 27.4, 37.2 and 24.1%, respectively, when compared with CU during the study periods. Although the SD2 treatment could further reduce N leaching loss to some extent, this technique would sharply decline rice yield, with the magnitude of as high as 21.0% relative to CU treatment. Additionally, the average NRE under SD2 was 11.2% lower than that under SD1 treatment. Overall, the present study concluded that the SO technique is an effective strategy to reduce N leaching and increase NRE, thus potentially mitigate local environmental threat. We propose SD1 as a novel alternative fertilizer technique under an irrigated rice-based system in Ningxia irrigation region when higher yields are under consideration.展开更多
Based on loading-unloading test, tensile impact recovery experimental techniques have been developed to obtain the isothermal stress-strain curves of materials under high strain rates. The thermal softening effect can...Based on loading-unloading test, tensile impact recovery experimental techniques have been developed to obtain the isothermal stress-strain curves of materials under high strain rates. The thermal softening effect can be decoupled by comparing the isothermal stress-strain curves with the adiabatic stress-strain curves at the same strain rate. In the present paper, recovery experiments of brass have been carried out on a self-designed rotating disk tensile impact apparatus. According to the parabolic strain hardening power-law thermo-viscoplastic constitutive model, strain hardening parameter, strain rates strengthening parameter and thermal softening synthetical parameter have been decoupled from experimental results. Furthermore, from these parameters, one can determine the theoretical isothermal curves and adiabatic curves at high strain rates well-coinciding the experimental results respectively. It indicates that the recovery experimental techniques of tensile impact are effective and reliable and are important means for the study of thermo-mechanical coupling. The experimental results also reveals that brass is a typical thermo-viscoplastic material.展开更多
The paper presents a parametric study on interpolation techniques based postprocessed error estimation in finite element elastic analysis by varying important parameters of recovery,interpolation scheme and type of pa...The paper presents a parametric study on interpolation techniques based postprocessed error estimation in finite element elastic analysis by varying important parameters of recovery,interpolation scheme and type of patch construction.The quality of error estimation with recovery parameters is compared in terms of local and global effectivity of error estimation,rate of error convergence,and adaptively refined meshes.A mesh free moving least square interpolation technique with proven reliability and effectivity is introduced for improving the recovery of finite element solution errors.The post-processed finite element solutions of elastic problems are presented for performance study under different parameters of recovery technique.The study concludes that recovery parameters of interpolation method have pronounced effect on the recovery of finite element solution error and analysis in adaptive environment.展开更多
Service is a special product. It is intangible and unstored, so service er-rors are not avoided. Once service errors appear, the first line staffs who keep di-rect touch with customers wil play an important role in se...Service is a special product. It is intangible and unstored, so service er-rors are not avoided. Once service errors appear, the first line staffs who keep di-rect touch with customers wil play an important role in service recovery. The staffs＇ negative emotions during the recovery service should be recovered by internal ser-vice recovery. In this paper, critical incident technique is applied to analyse the re-covery strategies expected by the first line staff and the internal service recovery strategies such as inspiring, authorization, training and psychology service are put forward. the strategy most expected by the staff is reward.展开更多
随着快速康复外科(enhanced recovery after surgery,EARS)及舒适化医疗理念的发展,经皮椎间孔镜技术已成功应用于部分脊柱手术,其通过孔道式入路及内镜技术实现损伤最小化。为了避免术中医源性神经损伤,常采用区域阻滞联合静脉镇痛药...随着快速康复外科(enhanced recovery after surgery,EARS)及舒适化医疗理念的发展,经皮椎间孔镜技术已成功应用于部分脊柱手术,其通过孔道式入路及内镜技术实现损伤最小化。为了避免术中医源性神经损伤,常采用区域阻滞联合静脉镇痛药作为其主要的麻醉方式以保留病人意识及神经易感性。围手术期良好的镇痛管理不仅是术者手术操作顺利进行的基础,更是加快病人功能锻炼及康复的关键。现已有多种区域阻滞方式联合可视化技术成功应用于经皮椎间孔镜下腰椎手术的围手术期镇痛。本文将依次介绍近年应用于椎间孔镜技术区域阻滞的方案及其优劣势,旨在使病人更舒适更安全的完成微创手术,缩短病人术后功能锻炼和康复时间,提高满意度及再手术意愿,实现快速康复理念。展开更多
This paper presents a checkpoint setting technique to eliminate domino effect in backward recovery in distributed systems,which is very efficient,powerful,widely applicable and easy to be implememted.Besides theoretic...This paper presents a checkpoint setting technique to eliminate domino effect in backward recovery in distributed systems,which is very efficient,powerful,widely applicable and easy to be implememted.Besides theoretical analysis,an implementation on UNIX system and a package for software fault-tolerance are in- troduced.Then the problems of checkpoint management and process termination are discussed.展开更多
基金supported by the National Science and Technology Major Project of China (2014ZX07201009)the Special Foundation for Basic Scientific Research of Central Public Welfare Institute of China (BSRF201306)the Sustainable Agricultural Technique Research and Development Project Phase II between China and Japan
文摘The excessive nitrogen （N） fertilizer input coupled with flood irrigation might result in higher N leaching and lower nitrogen recovery efficiency （NRE）. Under an intensive rice system in the Ningxia irrigation region, China, environmental friendly N management practices are hreavily needed to balance the amount of N input for optimum crop production while minimize the nitrogen loss. The objective of this study was to determine the influences of side-dressing （SD） technique in mechanical transplanting systems on the NRE, N leaching losses and rice yield in anthropogenic-alluvial soil during two rice growing seasons （2010-2011）. Four fertilizer N treatments were established, including conventional urea rate （CU, 300 kg ha-1 yr-1）; higher SD of controlled-release N fertilizer rate （SD1,176 kg ha-1 yr-1）; lower SD of controlled-release N fertilizer rate （SD2, 125 kg ha-1 yr-1）; and control （CK, no N fertilizer）. Field lysimeters were used to quantify drainage from undisturbed soil during six rice growing stages. Meanwhile, the temporal variations of total nitrigen （TN）, NO3--N, and NH4＋-N concentrations in percolation water were examined. The results showed that SD1 substantially improved NRE and reduced N leaching losses while maintaining rice yields. Across two years, the averaged NRE under SD1 treatment increased by 25.5% as relative to CU, but yet the rice yield was similar between two treatments. On average, the nitrogen loss defined as TN, NH4＋-N, and NO3--N under the SD1 treatment reduced by 27.4, 37.2 and 24.1%, respectively, when compared with CU during the study periods. Although the SD2 treatment could further reduce N leaching loss to some extent, this technique would sharply decline rice yield, with the magnitude of as high as 21.0% relative to CU treatment. Additionally, the average NRE under SD2 was 11.2% lower than that under SD1 treatment. Overall, the present study concluded that the SO technique is an effective strategy to reduce N leaching and increase NRE, thus potentially mitigate local environmental threat. We propose SD1 as a novel alternative fertilizer technique under an irrigated rice-based system in Ningxia irrigation region when higher yields are under consideration.
文摘Based on loading-unloading test, tensile impact recovery experimental techniques have been developed to obtain the isothermal stress-strain curves of materials under high strain rates. The thermal softening effect can be decoupled by comparing the isothermal stress-strain curves with the adiabatic stress-strain curves at the same strain rate. In the present paper, recovery experiments of brass have been carried out on a self-designed rotating disk tensile impact apparatus. According to the parabolic strain hardening power-law thermo-viscoplastic constitutive model, strain hardening parameter, strain rates strengthening parameter and thermal softening synthetical parameter have been decoupled from experimental results. Furthermore, from these parameters, one can determine the theoretical isothermal curves and adiabatic curves at high strain rates well-coinciding the experimental results respectively. It indicates that the recovery experimental techniques of tensile impact are effective and reliable and are important means for the study of thermo-mechanical coupling. The experimental results also reveals that brass is a typical thermo-viscoplastic material.
文摘The paper presents a parametric study on interpolation techniques based postprocessed error estimation in finite element elastic analysis by varying important parameters of recovery,interpolation scheme and type of patch construction.The quality of error estimation with recovery parameters is compared in terms of local and global effectivity of error estimation,rate of error convergence,and adaptively refined meshes.A mesh free moving least square interpolation technique with proven reliability and effectivity is introduced for improving the recovery of finite element solution errors.The post-processed finite element solutions of elastic problems are presented for performance study under different parameters of recovery technique.The study concludes that recovery parameters of interpolation method have pronounced effect on the recovery of finite element solution error and analysis in adaptive environment.
基金Supported by the Fundamental Research Funds for the Central Universities
文摘Service is a special product. It is intangible and unstored, so service er-rors are not avoided. Once service errors appear, the first line staffs who keep di-rect touch with customers wil play an important role in service recovery. The staffs＇ negative emotions during the recovery service should be recovered by internal ser-vice recovery. In this paper, critical incident technique is applied to analyse the re-covery strategies expected by the first line staff and the internal service recovery strategies such as inspiring, authorization, training and psychology service are put forward. the strategy most expected by the staff is reward.
文摘随着快速康复外科(enhanced recovery after surgery,EARS)及舒适化医疗理念的发展,经皮椎间孔镜技术已成功应用于部分脊柱手术,其通过孔道式入路及内镜技术实现损伤最小化。为了避免术中医源性神经损伤,常采用区域阻滞联合静脉镇痛药作为其主要的麻醉方式以保留病人意识及神经易感性。围手术期良好的镇痛管理不仅是术者手术操作顺利进行的基础,更是加快病人功能锻炼及康复的关键。现已有多种区域阻滞方式联合可视化技术成功应用于经皮椎间孔镜下腰椎手术的围手术期镇痛。本文将依次介绍近年应用于椎间孔镜技术区域阻滞的方案及其优劣势,旨在使病人更舒适更安全的完成微创手术,缩短病人术后功能锻炼和康复时间,提高满意度及再手术意愿,实现快速康复理念。
文摘This paper presents a checkpoint setting technique to eliminate domino effect in backward recovery in distributed systems,which is very efficient,powerful,widely applicable and easy to be implememted.Besides theoretical analysis,an implementation on UNIX system and a package for software fault-tolerance are in- troduced.Then the problems of checkpoint management and process termination are discussed.
