From the perspective of carbon disclosure goal,the paper defined the detail types of contents about carbon information disclosure,then constructed the carbon information disclosure index,by using the indices to 2011 a...From the perspective of carbon disclosure goal,the paper defined the detail types of contents about carbon information disclosure,then constructed the carbon information disclosure index,by using the indices to 2011 annual report of A-share listed companies in Shanghai and Shenzhen Security Exchange,we found that Chinese enterprises' carbon disclosure scattered,industry structure quite different characteristics,quantity information and quality information asymmetry.展开更多
采用频率测量实现目标定位具有成本低、可靠性高的特点,仅利用到达频率差(frequency difference of arrival,FDOA)测量,提出了一种静态目标位置的精确定位方法。针对所建立的频率测量方程的高度非线性这一问题,通过引入辅助变量,将其转...采用频率测量实现目标定位具有成本低、可靠性高的特点,仅利用到达频率差(frequency difference of arrival,FDOA)测量,提出了一种静态目标位置的精确定位方法。针对所建立的频率测量方程的高度非线性这一问题,通过引入辅助变量,将其转化为矩阵形式的伪线性方程;然后利用半正定松弛(semi-definite relaxation,SDR)方法将非凸的加权最小二乘(weighted least square,WLS)问题松弛为半正定规划(semidefinite programming,SDP)问题,从而进一步精确估计未知变量;最后对所提出方法的均方根误差(rootmean-square error,RMSE)进行了分析,以验证其性能。仿真结果表明,在较低的高斯噪声水平下,所采用的半正定松弛方法的性能能够达到克拉美罗下界(Cramer-Rao lower bound,CRLB),且该算法对几何形状具有较高的鲁棒性;此外,在使用较少数量的传感器时,其RMSE性能要优于两阶段加权最小二乘(two-stage weighted least square,TSWLS)法。展开更多
Mountain road tunnels are prone to water leakage and lining corrosion under the complex geological conditions and corrosive envi-ronments,which will reduce the strength of the lining structure until it loses its load-...Mountain road tunnels are prone to water leakage and lining corrosion under the complex geological conditions and corrosive envi-ronments,which will reduce the strength of the lining structure until it loses its load-bearing capacity;eventually,the definitive lining will need to be replaced.In this paper,a highway tunnel in a mountainous area in Southwest China is taken as an example.Field investi-gation found that the tunnel was seriously corroded by sulfate,the strength of the definitive lining decreased,and large-scale cracks and spalling appeared on the surface,so the operator decided to replace the definitive lining by the method of interval replacement.Based on the data obtained from drilling and coring,a numerical model of long-distance replacement of the definitive lining of the damaged tunnel is established.First,the back analysis of the calculation parameters is carried out,and the modified calculation results are com-pared with the field monitoring results for verification.Then,the deformation trend of the tunnel and the development of the plastic zone during the process of long-distance replacement of the definitive lining are studied.Finally,the construction scheme is optimized.Numer-ical analysis results show that the replacement of the definitive lining of the tunnel mainly leads to the settlement of the arch crown and the uplift of the inverted arch.The deformation of the tunnel shows two rapid growth stages and two stable stages during the replace-ment process;after replacement,the deformation of the arch crown and the inverted arch is divided into two buffer zones and one stable zone.In the progress of the replacement of the definitive lining,the plastic zone does not change.Regarding the reinforcement measures,with the increase in the grouting range,the grouting efficiency decreases,and the effect of the temporary steel arch on controlling the overall deformation is not obvious.The length of the replacement of the single section should be determined according to the geological conditions of the replacement section and the monitoring data during construction.The research results can provide a reference for sim-ilar projects for the replacement of the definitive lining.展开更多
The common characteristic criteria of all functional gastrointestinal(GI)disorders are the persistence and recurrence of variable gastrointestinal symptoms that cannot be explained by any structural or biochemical abn...The common characteristic criteria of all functional gastrointestinal(GI)disorders are the persistence and recurrence of variable gastrointestinal symptoms that cannot be explained by any structural or biochemical abnormalities. Functional dyspepsia (FD) represents one of the important GI disorders in Western countries because of its remarkably high prevalence in general population and its impact on quality of life. Due to its dependence on both subjective determinants and diverse country-specific circumstances, the definition and management strategies of FD are still variably stated.Clinical trials with several drug classes (e.g., proton pump inhibitors, H2-blockers, prokinetic drugs) have been performed frequently without validated diseasespecific test instruments for the outcome measurements.Therefore, the interpretation of such trials remains difficult and controversial with respect to comparability and evaluation of drug efficacy, and definite conclusions can be drawn neither for diagnostic management nor for efficacious drug therapy so far. In view of these unsolved problems, guidelines both on the clinical management of FD and on the performance of clinical trials are needed. In recent years, increasing research work has been done in this area. Clinical trials conducted in adequately diagnosed patients that provided validated outcome measurements may result in better insights leading to more effective treatment strategies.Encouraging perspectives have been recently performed by methodologically well-designed treatment studies with herbal drug preparations. Herbal drugs, given their proven efficacy in clinical trials, offer a safe therapeutic alternative in the treatment of FD which is often favored by both patients and physicians. A fixed combination of peppermint oil and caraway oil in patients suffering from FD could be proven effective by well-designed clinical trials.展开更多
运用系统回顾法,对Web of Science核心合集中搜索的40项有关网络信息分享动机的文献进行分析归纳,基于以往研究,对网络信息分享动机的基本概念进行定义和分类,并对测量方法进行总结。结果表明,网络信息分享动机可以定义为:为了满足某种...运用系统回顾法,对Web of Science核心合集中搜索的40项有关网络信息分享动机的文献进行分析归纳,基于以往研究,对网络信息分享动机的基本概念进行定义和分类,并对测量方法进行总结。结果表明,网络信息分享动机可以定义为:为了满足某种特定的需求或愿望,个体通过社交媒体平台或网络社区希望并试图展示信息、交换信息,包括搜索信息以便向他人提供信息、经验、想法、专长的愿望或动力;网络信息分享动机可分为内在动机与外在动机两类;网络信息分享动机的测量通常根据不同的分享动机类型和情境使用不同的量化方法。展开更多
In this note a multidimensional Hausdorff truncated operator-valued moment problem, from the point of view of “stability concept” of the number of atoms of the obtained atomic, operator-valued representing measure f...In this note a multidimensional Hausdorff truncated operator-valued moment problem, from the point of view of “stability concept” of the number of atoms of the obtained atomic, operator-valued representing measure for the terms of a finite, positively define kernel of operators, is studied. The notion of “stability of the dimension” in truncated, scalar moment problems was introduced in [1]. In this note, the concept of “stability” of the algebraic dimension of the obtained Hilbert space from the space of the polynomials of finite, total degree with respect to the null subspace of a unital square positive functional, in [1], is adapted to the concept of stability of the algebraic dimension of the Hilbert space obtained as the separated space of some space of vectorial functions with respect to the null subspace of a hermitian square positive functional attached to a positive definite kernel of operators. In connection with the stability of the dimension of such obtained Hilbert space, a Hausdorff truncated operator-valued moment problem and the stability of the number of atoms of the representing measure for the terms of the given operator kernel, in this note, is studied.展开更多
为了探究中国数字内容贸易出口规模和结构特征等问题,借鉴联合国贸易和发展会议(United Nations Conference on Trade and Development,UNCTAD)的测算思路,对中国与世界范围内135个主要经济体开展的数字内容贸易出口规模进行测算。除贸...为了探究中国数字内容贸易出口规模和结构特征等问题,借鉴联合国贸易和发展会议(United Nations Conference on Trade and Development,UNCTAD)的测算思路,对中国与世界范围内135个主要经济体开展的数字内容贸易出口规模进行测算。除贸易总额外,还分别测算了数字视听、数字游戏和数字图书3个不同类别数字内容产品的出口金额;更进一步地,对中国数字内容贸易的总体发展趋势、主要出口对象、对不同出口对象的主力贸易产品进行分析。研究认为,欧盟、美国、日本及韩国等经济体是中国数字内容贸易最主要的出口对象;数字游戏和数字视听是中国主要的贸易产品,其中数字游戏在海外有更强的竞争力;受限于消费者偏好以及互联网发展水平等多重因素影响,不同经济体的消费者对于中国不同类别数字内容产品喜好存在较大差异,如日韩及北美消费者更偏好数字游戏、中国其他地方的消费者则更偏好于数字视听。研究表明,面对数字内容贸易迅速发展的现实情况,中国应该积极参与国际数字贸易治理,提升数字贸易规则制定的话语权,尽早建立国际统一的数字贸易规则;加强文化和科技的融合,进一步提升中国数字内容产品的国际竞争力,向价值链高端延伸;针对不同类别的数字内容产品,有针对性的制定出口推广策略,如提升翻译质量、举办文化交流活动、关注新兴市场等。展开更多
道路全息测绘是新型基础测绘体系建设的重要组成部分之一。相较于传统道路测绘成果,道路全息测绘产品具有信息更全面、更精细、更准确及更易于更新的特点。本文以道路全息测绘应用为目标,结合车载移动测量的技术优势,提出了从移动测量...道路全息测绘是新型基础测绘体系建设的重要组成部分之一。相较于传统道路测绘成果,道路全息测绘产品具有信息更全面、更精细、更准确及更易于更新的特点。本文以道路全息测绘应用为目标,结合车载移动测量的技术优势,提出了从移动测量车数据采集、数据处理到道路全息测绘产品制作的完整流程,制作了静态高清道路地图、精细道路三维模型和自动驾驶高精地图3种新型道路全息测绘产品。此外,以武汉市中心城区3 km 2试验区内的市政道路作为研究对象,开展了道路全息测绘产品生产应用试验。结果表明,该成果精度不仅能满足1∶500地形图更新等传统城市测绘工作需求,也可为自动驾驶提供重要的道路数据基础。展开更多
文摘From the perspective of carbon disclosure goal,the paper defined the detail types of contents about carbon information disclosure,then constructed the carbon information disclosure index,by using the indices to 2011 annual report of A-share listed companies in Shanghai and Shenzhen Security Exchange,we found that Chinese enterprises' carbon disclosure scattered,industry structure quite different characteristics,quantity information and quality information asymmetry.
文摘采用频率测量实现目标定位具有成本低、可靠性高的特点,仅利用到达频率差(frequency difference of arrival,FDOA)测量,提出了一种静态目标位置的精确定位方法。针对所建立的频率测量方程的高度非线性这一问题,通过引入辅助变量,将其转化为矩阵形式的伪线性方程;然后利用半正定松弛(semi-definite relaxation,SDR)方法将非凸的加权最小二乘(weighted least square,WLS)问题松弛为半正定规划(semidefinite programming,SDP)问题,从而进一步精确估计未知变量;最后对所提出方法的均方根误差(rootmean-square error,RMSE)进行了分析,以验证其性能。仿真结果表明,在较低的高斯噪声水平下,所采用的半正定松弛方法的性能能够达到克拉美罗下界(Cramer-Rao lower bound,CRLB),且该算法对几何形状具有较高的鲁棒性;此外,在使用较少数量的传感器时,其RMSE性能要优于两阶段加权最小二乘(two-stage weighted least square,TSWLS)法。
基金supported by the National Natural Science Foundation of China,China(Grant Nos.41972266,52104076,and 12102230)the China Postdoctoral Science Foundation,China(Grant No.2022M711862).
文摘Mountain road tunnels are prone to water leakage and lining corrosion under the complex geological conditions and corrosive envi-ronments,which will reduce the strength of the lining structure until it loses its load-bearing capacity;eventually,the definitive lining will need to be replaced.In this paper,a highway tunnel in a mountainous area in Southwest China is taken as an example.Field investi-gation found that the tunnel was seriously corroded by sulfate,the strength of the definitive lining decreased,and large-scale cracks and spalling appeared on the surface,so the operator decided to replace the definitive lining by the method of interval replacement.Based on the data obtained from drilling and coring,a numerical model of long-distance replacement of the definitive lining of the damaged tunnel is established.First,the back analysis of the calculation parameters is carried out,and the modified calculation results are com-pared with the field monitoring results for verification.Then,the deformation trend of the tunnel and the development of the plastic zone during the process of long-distance replacement of the definitive lining are studied.Finally,the construction scheme is optimized.Numer-ical analysis results show that the replacement of the definitive lining of the tunnel mainly leads to the settlement of the arch crown and the uplift of the inverted arch.The deformation of the tunnel shows two rapid growth stages and two stable stages during the replace-ment process;after replacement,the deformation of the arch crown and the inverted arch is divided into two buffer zones and one stable zone.In the progress of the replacement of the definitive lining,the plastic zone does not change.Regarding the reinforcement measures,with the increase in the grouting range,the grouting efficiency decreases,and the effect of the temporary steel arch on controlling the overall deformation is not obvious.The length of the replacement of the single section should be determined according to the geological conditions of the replacement section and the monitoring data during construction.The research results can provide a reference for sim-ilar projects for the replacement of the definitive lining.
文摘The common characteristic criteria of all functional gastrointestinal(GI)disorders are the persistence and recurrence of variable gastrointestinal symptoms that cannot be explained by any structural or biochemical abnormalities. Functional dyspepsia (FD) represents one of the important GI disorders in Western countries because of its remarkably high prevalence in general population and its impact on quality of life. Due to its dependence on both subjective determinants and diverse country-specific circumstances, the definition and management strategies of FD are still variably stated.Clinical trials with several drug classes (e.g., proton pump inhibitors, H2-blockers, prokinetic drugs) have been performed frequently without validated diseasespecific test instruments for the outcome measurements.Therefore, the interpretation of such trials remains difficult and controversial with respect to comparability and evaluation of drug efficacy, and definite conclusions can be drawn neither for diagnostic management nor for efficacious drug therapy so far. In view of these unsolved problems, guidelines both on the clinical management of FD and on the performance of clinical trials are needed. In recent years, increasing research work has been done in this area. Clinical trials conducted in adequately diagnosed patients that provided validated outcome measurements may result in better insights leading to more effective treatment strategies.Encouraging perspectives have been recently performed by methodologically well-designed treatment studies with herbal drug preparations. Herbal drugs, given their proven efficacy in clinical trials, offer a safe therapeutic alternative in the treatment of FD which is often favored by both patients and physicians. A fixed combination of peppermint oil and caraway oil in patients suffering from FD could be proven effective by well-designed clinical trials.
文摘运用系统回顾法,对Web of Science核心合集中搜索的40项有关网络信息分享动机的文献进行分析归纳,基于以往研究,对网络信息分享动机的基本概念进行定义和分类,并对测量方法进行总结。结果表明,网络信息分享动机可以定义为:为了满足某种特定的需求或愿望,个体通过社交媒体平台或网络社区希望并试图展示信息、交换信息,包括搜索信息以便向他人提供信息、经验、想法、专长的愿望或动力;网络信息分享动机可分为内在动机与外在动机两类;网络信息分享动机的测量通常根据不同的分享动机类型和情境使用不同的量化方法。
文摘In this note a multidimensional Hausdorff truncated operator-valued moment problem, from the point of view of “stability concept” of the number of atoms of the obtained atomic, operator-valued representing measure for the terms of a finite, positively define kernel of operators, is studied. The notion of “stability of the dimension” in truncated, scalar moment problems was introduced in [1]. In this note, the concept of “stability” of the algebraic dimension of the obtained Hilbert space from the space of the polynomials of finite, total degree with respect to the null subspace of a unital square positive functional, in [1], is adapted to the concept of stability of the algebraic dimension of the Hilbert space obtained as the separated space of some space of vectorial functions with respect to the null subspace of a hermitian square positive functional attached to a positive definite kernel of operators. In connection with the stability of the dimension of such obtained Hilbert space, a Hausdorff truncated operator-valued moment problem and the stability of the number of atoms of the representing measure for the terms of the given operator kernel, in this note, is studied.
文摘为了探究中国数字内容贸易出口规模和结构特征等问题,借鉴联合国贸易和发展会议(United Nations Conference on Trade and Development,UNCTAD)的测算思路,对中国与世界范围内135个主要经济体开展的数字内容贸易出口规模进行测算。除贸易总额外,还分别测算了数字视听、数字游戏和数字图书3个不同类别数字内容产品的出口金额;更进一步地,对中国数字内容贸易的总体发展趋势、主要出口对象、对不同出口对象的主力贸易产品进行分析。研究认为,欧盟、美国、日本及韩国等经济体是中国数字内容贸易最主要的出口对象;数字游戏和数字视听是中国主要的贸易产品,其中数字游戏在海外有更强的竞争力;受限于消费者偏好以及互联网发展水平等多重因素影响,不同经济体的消费者对于中国不同类别数字内容产品喜好存在较大差异,如日韩及北美消费者更偏好数字游戏、中国其他地方的消费者则更偏好于数字视听。研究表明,面对数字内容贸易迅速发展的现实情况,中国应该积极参与国际数字贸易治理,提升数字贸易规则制定的话语权,尽早建立国际统一的数字贸易规则;加强文化和科技的融合,进一步提升中国数字内容产品的国际竞争力,向价值链高端延伸;针对不同类别的数字内容产品,有针对性的制定出口推广策略,如提升翻译质量、举办文化交流活动、关注新兴市场等。
文摘道路全息测绘是新型基础测绘体系建设的重要组成部分之一。相较于传统道路测绘成果,道路全息测绘产品具有信息更全面、更精细、更准确及更易于更新的特点。本文以道路全息测绘应用为目标,结合车载移动测量的技术优势,提出了从移动测量车数据采集、数据处理到道路全息测绘产品制作的完整流程,制作了静态高清道路地图、精细道路三维模型和自动驾驶高精地图3种新型道路全息测绘产品。此外,以武汉市中心城区3 km 2试验区内的市政道路作为研究对象,开展了道路全息测绘产品生产应用试验。结果表明,该成果精度不仅能满足1∶500地形图更新等传统城市测绘工作需求,也可为自动驾驶提供重要的道路数据基础。