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Analysis of stability of coal pillars with multi-coal seam strip mining 被引量:8
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作者 ZHANG Li-ya, DENG Ka-zhong, ZHU Chuan-guang, XING Zheng-quan Jiangsu Key Laboratory of Resources and Environmental Information Engineering, China University of Mining and Technology, Xuzhou 221116, China 《中国有色金属学会会刊:英文版》 CSCD 2011年第S3期549-555,共7页
Strip mining is one of the efficient measures to control surface subsidence and mining damage. However, the researches on the laws of the geological mining factors to upper and lower pillar's stability are still d... Strip mining is one of the efficient measures to control surface subsidence and mining damage. However, the researches on the laws of the geological mining factors to upper and lower pillar's stability are still deficient in multi-coal seam strip mining at present. Based on the three dimension fast Lagrangian analysis of continua (short for FLAC3D) numerical simulation software, the laws of the stress increasing coefficient on the coal pillar and its stability were systematically studied for different depths, different mining widths, different interlayer spacings, different mining thicknesses, different properties of interstratified rock and the spacial relations of the upper and lower pillars in vertical alignment in multi-coal seam strip mining. The function relation between the stress increasing coefficient of upper and lower pillars with the mining depth, mining widths, interlayer spacing, mining thickness, property of interstratified rock and the spatial relationship were obtained. 展开更多
关键词 multi-coal SEAM STRIP MINING FLAC3D numerical simulation stability of COAL pillar
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Multi-features Based Approach for Moving Shadow Detection 被引量:4
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作者 周宁 周曼丽 +1 位作者 许毅平 方宝红 《Journal of Donghua University(English Edition)》 EI CAS 2004年第6期76-80,共5页
In the video-based surveillance application, moving shadows can affect the correct localization and detection of moving objects. This paper aims to present a method for shadow detection and suppression used for moving... In the video-based surveillance application, moving shadows can affect the correct localization and detection of moving objects. This paper aims to present a method for shadow detection and suppression used for moving visual object detection. The major novelty of the shadow suppression is the integration of several features including photometric invariant color feature, motion edge feature, and spatial feature etc. By modifying process for false shadow detected, the averaging detection rate of moving object reaches above 90% in the test of Hall-Monitor sequence. 展开更多
关键词 MOVING SHADOW detection multi - features MOVING OBJECT DETECTION
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The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) 被引量:42
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作者 Xiang-Qun Cui Yong-Heng Zhao +52 位作者 Yao-Quan Chu Guo-Ping Li Qi Li Li-Ping Zhang Hong-Jun Su Zheng-Qiu Yao Ya-Nan Wang Xiao-Zheng Xing Xin-Nan Li Yong-Tian Zhu Gang Wang Bo-Zhong Gu A-Li Luo Xin-Qi Xu Zhen-Chao Zhang Gen-Rong Liu Hao-Tong Zhang De-Hua Yang Shu-Yun Cao Hai-Yuan Chen Jian-Jun Chen Kun-Xin Chen Ying Chen Jia-Ru Chu Lei Feng Xue-Fei Gong Yong-Hui Hou Hong-Zhuan Hu Ning-Sheng Hu Zhong-Wen Hu Lei Jia Fang-Hua Jiang Xiang Jiang Zi-Bo Jiang Ge Jin Ai-Hua Li Yan Li Ye-Ping Li Guan-QunLiu Zhi-Gang Liu Huo-Ming Shi Zheng-Hong Tang Qing-Sheng Tao Xiang-Yan Yuan Chao Zhai Jing Zhang Yan-Xia Zhang Yong Zhang Ming Zhao Fang Zhou Guo-Hua Zhou Jie Zhu Si-Cheng Zou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第9期1197-1242,共46页
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effecti... The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects. 展开更多
关键词 techniques: wide field telescope - active optics - multi fiber - spectroscopy survey - data reduction
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A Comparative Study of Acute Hemodynamic Effects of Multi -site Cardiac Pacing in patients with cardiac function NYHA class ⅠtoⅡ without bundle branch block 被引量:2
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作者 朱参战 崔长琮 +5 位作者 张全发 薛小临 刘维维 刘引会 《South China Journal of Cardiology》 CAS 2001年第2期101-105,共5页
Objective To compare the acute hemodynamic effects of five different pacing modes in patients with cardiac function NYHA class Ⅰ to Ⅱ without bundle branch block (BBB). Methods This study included 12 patients (SSS ... Objective To compare the acute hemodynamic effects of five different pacing modes in patients with cardiac function NYHA class Ⅰ to Ⅱ without bundle branch block (BBB). Methods This study included 12 patients (SSS 7, Ⅲ°AVB 5) undergoing pacemaker implantation. Right ventricular apex (RVA), right ventricular outflow tract (RVOT), right ventricular bifocal (RV-Bi), left ventricular base (LVB) and bi -ventricular (Bi-Ⅴ) pacing at 60 -80 ppm were done in VVI mode prior to implantation of DDD pacemaker. The cardiac index (CI), mean pulmonary artery pressure (mPAP) and pulmonary capillary wedge pressure (PCWP) were measured with Swan - Ganz thermodilution catheter after 5 minutes of each pacing mode. Results (1) Comparing to pacing at RVA (CI: 2. 41± 0. 38 L/min per m2, PCWP: 16. 7 ±3.3 mmHg), the CI increased and the PCWP decreased significantly in pacing at RVOT(CI: 2. 63 ± 0.46, PCWP: 13. 8±2. 3), LVB(CI: 2. 78±0.52, PCWP: 14. 4±3.1), RV-Bi(CI: 2. 83±0.57, PCWP: 12. 8± 2. 5) and Bi -Ⅴ pacing (CI: 2. 94± 0.60, PCWP: 12. 7±2. 5), P < 0. 01, respectively. (2) The CI of RV-Bi and Bi-Ⅴ pacing was higher than that of RVOT and LVB pacing, the PCWP was lower, P < 0. 05, respectively. (3) There was no significant difference between RV - Bi pacing and Bi-Ⅴ pacing in CI and PCWP. Conclusion There is no significant difference between RV - Bi pacing and Bi -V pacing in the acute hemodynamic effects; however,dual - site pacing is much better than single site pacing in that aspect for patients with cardiac function NYHA class Ⅰ to Ⅱ without BBB. Among single site pacing, the RVOT and LVB pacing is better than RVA pacing in cardiac function. 展开更多
关键词 multi - site cardiac pacingHemodynamics
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Research on A Master - slave Multi - microcomputers Control System for Hollow Spindle Fancy Yarn Spinning Machine
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作者 李志蜂 陈子展 阵瑞琪 《Journal of China Textile University(English Edition)》 EI CAS 1999年第1期49-52,共4页
In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardwar... In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardware construction, is introduced. Spinning experiments show that the system achieves satisfactory result. This system can solve the diftkultles of mechatronical fusion between domestic hollow splndk fancy yarn spuming muchine and its microcomputer control technology. 展开更多
关键词 hollow SPINDLE FANCY YAM spinning machine mechatrvnical fusion MASTER - SLAVE multi - microcomputers control system PC - BUS.
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On the Representation of Multi-layer Woven Structure
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作者 易洪雷 丁辛 《Journal of China Textile University(English Edition)》 EI CAS 1999年第3期14-16,共3页
A quantitative method is developed to identify the structures of multi-layer woven fabric in this study. Six structural parameters are selected to represent the fabric structure. With some design criteria for the rein... A quantitative method is developed to identify the structures of multi-layer woven fabric in this study. Six structural parameters are selected to represent the fabric structure. With some design criteria for the reinforcement of textile composites, the relationships among the structural parameters are derived for different binding patterns of the fabric structure. The conditions, which meet the requirements of structural cell stability,are also discussed. 展开更多
关键词 multi - layer woven FABRIC structural parame-ter BINDING PATTERN TEXTILE composite .
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Computer-aided Pattern Design of Multi-bar Warp Knitted Fabrics
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作者 李炜 《Journal of China Textile University(English Edition)》 EI CAS 2000年第1期85-87,共3页
To meet the development trend of multi-bar warp knit-ting machine towards high-speed,advanced technologyand computer control and the requirements of variousproducts with small quantity,there are many researcheson the ... To meet the development trend of multi-bar warp knit-ting machine towards high-speed,advanced technologyand computer control and the requirements of variousproducts with small quantity,there are many researcheson the computer-aided pattern design of multi-barwarp knitted fabrics.In terms of the special propertiesof the computer-aided pattern design of multi-barwarp knitted fabrics,the Object Oriented Program(OOP)programming-Object Windows class Library(OWL)programming is selected.According to thecharacters of the OWL programming,various functionsare defined.Pattern design and technical parameters canbe output,which offers a great convenience for the fac-tory. 展开更多
关键词 multi - bar WARP KNITTED fabric computer -aided PATTERN design PATTERN Object Windows class Library (OWL) programming.
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MODS: A Novel Metaheuristic of Deterministic Swapping for the Multi-Objective Optimization of Combinatorials Problems
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作者 Elias David Nifio Ruiz Carlos Julio Ardila Hemandez +2 位作者 Daladier Jabba Molinares Agustin Barrios Sarmiento Yezid Donoso Meisel 《Computer Technology and Application》 2011年第4期280-292,共13页
This paper states a new metaheuristic based on Deterministic Finite Automata (DFA) for the multi - objective optimization of combinatorial problems. First, a new DFA named Multi - Objective Deterministic Finite Auto... This paper states a new metaheuristic based on Deterministic Finite Automata (DFA) for the multi - objective optimization of combinatorial problems. First, a new DFA named Multi - Objective Deterministic Finite Automata (MDFA) is defined. MDFA allows the representation of the feasible solutions space of combinatorial problems. Second, it is defined and implemented a metaheuritic based on MDFA theory. It is named Metaheuristic of Deterministic Swapping (MODS). MODS is a local search strategy that works using a MDFA. Due to this, MODS never take into account unfeasible solutions. Hence, it is not necessary to verify the problem constraints for a new solution found. Lastly, MODS is tested using well know instances of the Bi-Objective Traveling Salesman Problem (TSP) from TSPLIB. Its results were compared with eight Ant Colony inspired algorithms and two Genetic algorithms taken from the specialized literature. The comparison was made using metrics such as Spacing, Generational Distance, Inverse Generational Distance and No-Dominated Generation Vectors. In every case, the MODS results on the metrics were always better and in some of those cases, the superiority was 100%. 展开更多
关键词 METAHEURISTIC deterministic finite automata combinatorial problem multi - objective optimization metrics.
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不同国家多层次养老保险构成差异及对就业率的影响--以经合组织OECD国家为例 被引量:2
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作者 丁少群 杨诗画 《中国劳动》 2020年第4期64-79,共16页
OECD成员国大都建立了多层次的养老保险制度,在老龄化背景下各国的公共养老保险制度面临巨大挑战。论文比较分析了OECD成员国中35个国家不同层次养老保险的养老金替代率、退休年龄及失业率水平,并研究了养老保险制度设计对就业水平的影... OECD成员国大都建立了多层次的养老保险制度,在老龄化背景下各国的公共养老保险制度面临巨大挑战。论文比较分析了OECD成员国中35个国家不同层次养老保险的养老金替代率、退休年龄及失业率水平,并研究了养老保险制度设计对就业水平的影响,通过多因子实证分析发现,一国的公共养老金替代率、私人养老金替代率、退休后预期余命对失业率有显著影响。其中,公共养老金替代率、退休后预期余命与失业率正相关,私人养老金替代率与失业率负相关,说明一国公共养老金水平过高、退休后预期余命越长,越不利于提升就业。论文指出我国多层次养老保险体系中第二、第三层次制度加快建设的迫切性,建议基本养老金水平设定要适度,企业年金动力机制和弹性延迟退休政策等亟待建立。 展开更多
关键词 多层次养老保险 替代率 退休政策 失业率
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基于Gray-Taguchi方法的汽车中立柱强度分布多目标优化设计 被引量:4
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作者 刘润泽 宋燕利 +1 位作者 刘鹏 冯维 《塑性工程学报》 CAS CSCD 北大核心 2021年第1期29-37,共9页
基于Gray-Taguchi稳健性优化设计方法,采用动力显式碰撞仿真与网格映射技术,对汽车中立柱的强度分布进行了考虑冲压塑性变形效应的多目标优化设计。首先建立考虑冲压效应的中立柱碰撞模型,分析了冲压效应对中立柱碰撞性能的影响;接着基... 基于Gray-Taguchi稳健性优化设计方法,采用动力显式碰撞仿真与网格映射技术,对汽车中立柱的强度分布进行了考虑冲压塑性变形效应的多目标优化设计。首先建立考虑冲压效应的中立柱碰撞模型,分析了冲压效应对中立柱碰撞性能的影响;接着基于正交试验,选择最大侵入位移、最大侵入速度和吸能量3个指标为优化目标,采用Gray-Taguchi优化设计方法得到优化结果,并对最终的优化结果进行了整车侧碰仿真验证。经过优化,中立柱中部节点的最大侵入位移下降了5.6%,最大侵入速度下降了3.9%,吸能量提升了18.8%,即综合碰撞性能得到较大的提升。 展开更多
关键词 Gray-Taguchi方法 汽车中立柱 网格映射 多目标优化设计
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Pressure Gradient Force,Saffman Lift,and Magnus Lift on the Fiber-like Particle in Fluid 被引量:5
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作者 朱泽飞 林建忠 《Journal of China Textile University(English Edition)》 EI CAS 2000年第2期23-27,共5页
Flher-like particle suspensions are common in both na-ture and industry, but there is little work reported on it.The forces acting on the fiber - like particle in fluid arestudied in this paper, and the Magnus lift, S... Flher-like particle suspensions are common in both na-ture and industry, but there is little work reported on it.The forces acting on the fiber - like particle in fluid arestudied in this paper, and the Magnus lift, Saffman lift,pressure gradient force, and then the dynamics modelhave been received. The numerical study of the simpleshear flow past the cylinders shows that the particles ’motion is controlled by the vortex. 展开更多
关键词 multi - phase FLUID FIBER - LIKE PARTICLE FORCE analysis
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Numerical Study on an Applicable Underground Mining Method for Soft Extra-Thick Coal Seams in Thailand 被引量:4
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作者 Nay Zarlin Takashi Sasaoka +1 位作者 Hideki Shimada Kikuo Matsui 《Engineering(科研)》 2012年第11期739-745,共7页
The EGAT Mae Moh Mine is the largest open pit lignite mine in Thailand and it produces lignite about 16 million tons annually. In the near future, the pit limit of the mine will be reached and underground mine will th... The EGAT Mae Moh Mine is the largest open pit lignite mine in Thailand and it produces lignite about 16 million tons annually. In the near future, the pit limit of the mine will be reached and underground mine will then be developed through the open pit in the depth of 400 - 600 m from the surface. However, due to the challenges for underground mining such as poor geological conditions, extra thickness (20 - 30 m) of coal seams, and weak mechanical properties of coal seams and the surrounding rock, the success possibility of underground mining and an applicable underground mining method is being investigated at the present. The paper discusses the applicability of multi-slice bord-and-pillar method for the soft extra thick coal seams in the Mae Moh mine by means of numerical analyses using the 3D finite difference code “FLAC3D”. 展开更多
关键词 multi-Slice Bord-and-pillar Method SOFT Extra-Thick Coal Seams Numerical Analyses FLAC3D
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个人养老金税收优惠政策何以可为?——来自美国、德国和澳大利亚的经验与启示 被引量:5
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作者 谢勇才 范傲 《人口与经济》 CSSCI 北大核心 2024年第1期16-33,共18页
发展个人养老金是健全养老保险体系和积极应对人口老龄化挑战的重要举措,而灵活高效的税收优惠政策则是推动个人养老金制度高质量发展的关键要素。虽然近年来我国制定了个人养老金税收优惠政策,但是仍存在诸多问题,严重掣肘个人养老金... 发展个人养老金是健全养老保险体系和积极应对人口老龄化挑战的重要举措,而灵活高效的税收优惠政策则是推动个人养老金制度高质量发展的关键要素。虽然近年来我国制定了个人养老金税收优惠政策,但是仍存在诸多问题,严重掣肘个人养老金制度的高质量发展。基于文献研究法、比较分析法对美国、德国和澳大利亚等典型国家个人养老金税收优惠政策的主要实践、基本特征、实施效果以及对中国的启示等重要问题进行深入探讨。研究发现,经过数十年的积极探索,美国、德国和澳大利亚逐步建立了灵活高效的个人养老金税收优惠政策,主要体现在激励方式灵活多样、政策制定立法先行、政策调整循序渐进、关注低收入群体的需求以及鼓励以家庭为参保对象等五个方面,有效推动了其个人养老金制度的发展与成熟。不过,这些典型国家个人养老金税收优惠政策在取得瞩目成就的同时,仍然面临对低收入群体的吸引力不足等现实困境。结合典型国家的有益经验和深刻教训,对我国个人养老金税收优惠政策存在的主要问题进行剖析,并提出更具针对性的见解,认为我国个人养老金税收优惠政策应当从四个方面作出改进:一是引入多种税收优惠模式,增强政策的吸引力;二是凸显税收优惠政策的精准性,助推优惠资源向低收入群体倾斜;三是提升税收优惠政策的灵活性,鼓励个人合理配置税收优惠额度;四是税收优惠政策应支持以家庭形式参保。 展开更多
关键词 个人养老金 税收优惠政策 多支柱养老保险体系
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我国个人养老金制度理念、设计和运行的若干问题辨析 被引量:5
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作者 张盈华 《华中科技大学学报(社会科学版)》 CSSCI 北大核心 2024年第1期51-61,90,共12页
我国个人养老金制度试点一年以来,呈现“三多三少”特点,反映出理念认知、制度设计和管理运行方面存在误区。研究发现个人养老金在层次划界、功能目标、覆盖群体、责任主体、政策支持、账户管理、经办运营、投资选择等八个方面的认知误... 我国个人养老金制度试点一年以来,呈现“三多三少”特点,反映出理念认知、制度设计和管理运行方面存在误区。研究发现个人养老金在层次划界、功能目标、覆盖群体、责任主体、政策支持、账户管理、经办运营、投资选择等八个方面的认知误区和行动偏误,有针对性地提出政策建议,包括明确“层次”和“支柱”双定位,整合“待遇叠加”和“覆盖补缺”双功能,取消以参加基本养老保险为前置条件的限制,鼓励雇主承担匹配缴费责任,整合第二、三支柱的政策优惠,连通第二、三支柱个人账户管理,促进个人养老金产品提供商平等竞争,协助个人投资理性选择。 展开更多
关键词 个人养老金 多层次多支柱养老保险体系 制度理念
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多层次、多支柱体系中的个人养老金制度——路径依赖与制度完善 被引量:5
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作者 高庆波 《华中科技大学学报(社会科学版)》 CSSCI 北大核心 2024年第1期71-81,共11页
在20世纪90年代,中国已提出了构建“多层次”养老保险体系的构想。受现实条件影响,中国的“多层次”与世界银行的“多支柱”理念虽然相似但也存在着明显的差别——“多层次”子制度之间只具备叠加性,而不具备“多支柱”的独立性。在中... 在20世纪90年代,中国已提出了构建“多层次”养老保险体系的构想。受现实条件影响,中国的“多层次”与世界银行的“多支柱”理念虽然相似但也存在着明显的差别——“多层次”子制度之间只具备叠加性,而不具备“多支柱”的独立性。在中国养老保险制度目标转化为“多层次、多支柱”的情况下,个人养老金制度迎来了最好的发展契机。与此同时,受路径依赖效应的影响,个人养老金制度不仅面临公共养老金制度的约束,还需面对各方主体间关系不清,制度目标未形成合力等挑战,由此导致财税优惠补贴政策、剥离个人账户以及建立统一平台等举措陷入两难困境。为此,建议:一是引入有条件的高额缴费与城镇职工基本养老保险制度缴费关联的机制;二是构建企业(职业)年金与个人养老金制度协调机制,尽力消除扩大产品规模的障碍;三是切实保障个人养老金制度各方参与者的利益。 展开更多
关键词 养老保险 路径依赖 多层次 多支柱
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“一枝独秀”还是“并驾齐驱”?——基于北京养老金三支柱体系的研究
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作者 李瀚林 高建伟 +1 位作者 朱志伟 高芳杰 《金融经济》 2024年第1期51-65,共15页
我国人口老龄化问题日益加剧,基本养老金即将面临给付危机,为此我国提出要发展多层次、多支柱的养老保障体系。为了检验我国多支柱养老金体系是否能够保障职工退休后的生活水平,本文以延迟退休为研究背景,以北京城镇职工为研究对象,结合... 我国人口老龄化问题日益加剧,基本养老金即将面临给付危机,为此我国提出要发展多层次、多支柱的养老保障体系。为了检验我国多支柱养老金体系是否能够保障职工退休后的生活水平,本文以延迟退休为研究背景,以北京城镇职工为研究对象,结合2022年11月出台的个人养老金账户,构建多支柱养老金财富和替代率的精算模型。研究发现,适度延迟退休年龄能够提高职工的养老金财富和替代率。敏感性分析发现,养老金财富和替代率对名义工资增长率的变动最为敏感。其中,第一支柱对养老金财富和替代率的贡献最大,第二、第三支柱起到补充作用。建议在采取灵活的延迟退休政策的基础上,稳定推进第一、第二支柱,加强完善个人养老金制度。 展开更多
关键词 延迟退休 多支柱 养老金财富 替代率 养老保障 个人养老金制度
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分段空场嗣后充填法人工矿柱多源信息融合稳定性评价模型
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作者 张泽群 钟文 +4 位作者 杨华泽 周伶杰 林圣杰 毛基腾 赵奎 《黄金科学技术》 CSCD 北大核心 2024年第5期894-904,共11页
针对分段空场嗣后充填法人工矿柱(充填体)稳定性评价指标因素概率分配过程和权重分配中存在的问题,综合考虑工程地质环境、岩体质量、力学响应指标、声发射参数特征和几何形态5类信息源的影响,建立了涵盖17项稳定性影响因素的人工矿柱(... 针对分段空场嗣后充填法人工矿柱(充填体)稳定性评价指标因素概率分配过程和权重分配中存在的问题,综合考虑工程地质环境、岩体质量、力学响应指标、声发射参数特征和几何形态5类信息源的影响,建立了涵盖17项稳定性影响因素的人工矿柱(充填体)稳定性多源信息评价指标体系,并基于此确立了人工矿柱(充填体)稳定性D-S证据理论的识别框架及评价指标分级标准。通过引入正态隶属度函数及改进的K-L距离对指标因素概率分配和权重分配进行优化,构建了基于改进D-S证据理论多源信息融合的人工矿柱(充填体)稳定性评价模型。选取某分段空场嗣后充填开采矿山5个典型人工矿柱(充填体)对模型的适用性进行验证,结果表明:多源信息融合稳定性评价等级分别为AP-2、AP-3和AP-5(Ⅱ级)>AP-4(Ⅲ级)>AP-1(Ⅳ级),稳定性评价结果与前期位移、声发射现场监测分析评价和数值模拟分析评价结果基本吻合,验证了评价模型在实际应用中的科学有效性。该模型为人工矿柱(充填体)稳定性分析提供了一种更全面的综合评价方法。 展开更多
关键词 分段空场嗣后充填法 人工矿柱(充填体) 多源信息融合 稳定性评价模型 D-S证据理论 隶属度函数
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双臂切缝钻机新型多变幅机构的研制
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作者 钟自成 《煤炭技术》 CAS 2024年第8期287-290,共4页
基于双臂切缝钻机的工况需求,创新研制出一款满足多方位、大角度施工需求的多变幅机构。通过对双臂切缝钻机多变幅机构的总体结构进行设计,并采用有限元分析软件对关键部件进行动态仿真分析,仿真结果表明关键部件设计合理;另外对双臂切... 基于双臂切缝钻机的工况需求,创新研制出一款满足多方位、大角度施工需求的多变幅机构。通过对双臂切缝钻机多变幅机构的总体结构进行设计,并采用有限元分析软件对关键部件进行动态仿真分析,仿真结果表明关键部件设计合理;另外对双臂切缝钻机进行了型式试验,试验表明性能参数达到了设计要求,并具有良好的多自由度调节性能。研究成果为无煤柱开采方法的关键装备提供了可靠的多变幅机构。 展开更多
关键词 切缝钻机 无煤柱开采 多变幅机构 动态分析
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基于多灾害因素区段煤柱留设宽度研究
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作者 田发 《煤炭科技》 2024年第4期59-64,共6页
以某矿1105工作面为研究对象,针对本矿井冲击地压灾害突出,瓦斯、煤层自燃、水害等多灾害并存条件下1105工作面区段煤柱合理留设尺寸进行研究。采用工程类比、理论计算以及有限元数值模拟等分析方法,结合矿井地质以及开采技术因素,对矿... 以某矿1105工作面为研究对象,针对本矿井冲击地压灾害突出,瓦斯、煤层自燃、水害等多灾害并存条件下1105工作面区段煤柱合理留设尺寸进行研究。采用工程类比、理论计算以及有限元数值模拟等分析方法,结合矿井地质以及开采技术因素,对矿井采用吸能抗冲击支护技术留设小煤柱的可行性以及煤柱留设尺寸进行分析研究。结果表明:工作面留设宽度为10 m小煤柱可以使工作面侧向支承压力集中区域向实体煤支承区转移,降低煤柱冲击危险性,且煤柱留设宽度满足采空区隔水防火要求。 展开更多
关键词 冲击地压 多灾害耦合 屈服煤柱 数值模拟 支承压力
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人口老龄化高原背景下加快我国养老金体系结构化改革的思考 被引量:30
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作者 董克用 张栋 《新疆师范大学学报(哲学社会科学版)》 CSSCI 北大核心 2018年第6期13-25,2,共13页
改革开放以来,经过多年努力,我国已经初步建立起了一个覆盖范围广泛、多方主体参与的规模庞大、制度复杂的多层次养老金体系。但总体来看,我国养老金体系仍面临着一系列挑战,尤其是在人口老龄化风险加剧的背景下,我国养老金体系面临长... 改革开放以来,经过多年努力,我国已经初步建立起了一个覆盖范围广泛、多方主体参与的规模庞大、制度复杂的多层次养老金体系。但总体来看,我国养老金体系仍面临着一系列挑战,尤其是在人口老龄化风险加剧的背景下,我国养老金体系面临长期的供需矛盾,最突出的挑战是养老金体系的结构性失衡,公共养老金制度压力过大,基本养老保险制度一支独大,补充性养老金制度进展缓慢,待遇水平充足性有限;同时还面临着一系列的制度管理困境。应对这些挑战,必须充分借鉴国际经验,建设和完善符合我国国情的多支柱养老金体系。 展开更多
关键词 人口老龄化高原 养老金体系 结构性改革 多支柱 职业养老金 个人养老金
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