Research on China’s aquaculture efficiency evaluation and influencing factors with undesirable outputs

Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable ...     

中国西部区域经济增长差异的因素分析——制造业省级面板数据的实证研究

采用中国西部1991—2010年制造业省级面板数据,实证分析西部制造业的产业集聚、西部开发战略、产业结构等因素对区域经济增长的影响,结果显示:2000年以来西部省份的产业集聚度的差异是造成区域差异的主要因素之一;西部开发战略的后续效应递减,特别是人才匮乏、产业结构不合理、基础设施水平低等问题凸显;西部各省份的经济发展方式的转变迫在眉睫。针对西部经济发展的不均衡现状提出了相应的解决措施。     

Space–time distribution of interplate moment release including slow earthquakes and the seismo-geodetic coupling in the Sanriku-oki region along the Japan trench

Along the Japan trench where some Mw8 class interplate earthquakes occurred in the past century such as the 1896 Sanriku tsunami earthquake (M6.8, Mt8.6, 12×10²⁰ N m) and the 1968 Tokachi-oki earthquake (Mw8.2, 28×10²⁰ N m), the Pacific plate is subducting under northeast Japan at a rate of around 8 cm/year. The seismic coupling coefficient in this region has been estimated to be 20–40%. In the past decade, three ultra-slow earthquakes have occurred in the Sanriku-oki region (39°N–42°N): the 1989 Sanriku-oki (Mw7.4), the 1992 Sanriku-oki (Mw6.9), and the 1994 Sanriku-oki (Mw7.7) earthquakes. Integrating their interplate moments released both seismically and aseismically, we have the following conclusions. (1) The sum of the seismic moments of the three ultra-slow earthquakes was (4.8–6.6)×10²⁰ N m, which was 20–35% of the accumulated moment (18.6–23.0)×10²⁰ N m, in the region (39°N–40.6°N, 142°E–144°E) for the 21–26 years since the 1968 Mw8.2 Tokachi-oki earthquake. This is consistent with the previous estimates of the seismic coupling coefficient of 20–40%. On the other hand, the sum of the interplate moments including aseismic faulting is (11–16)×10²⁰ N m, leading to a “seismo-geodetic coupling coefficient” of 50–85%, which is an extension of the seismic coupling coefficient to include slow events. (2) The time constants showed a large range from 1 min (10² s) for the 1968 Tokachi-oki earthquake to 10–20 min (10³ s) for the 1896 Sanriku tsunami earthquake, to one day (10⁵ s) for the 1992 Sanriku-oki ultra-slow earthquake, to on the order of one year (10⁷ s) for the 1994 Sanriku-oki ultra-slow earthquakes. (3) Based on the space–time distribution, three “gaps of moment release,” (40.6°N–42°N, 142°E–144°E) 39°N–40°N, 142°E–143°E) and (39°N–40°N, 142°E–144°E), are identified, instead of the gaps of seismicity.     

Cooling and inferred exhumation history of the Ryoke metamorphic belt in the Yanai district, south-west Japan: Constraints from Rb–Sr and fission-track ages of gneissose granitoid and numerical modeling

Abstract The Ryoke metamorphic belt in south-west Japan consists mainly of I-type granitoids and associated low-pressure/high-temperature metamorphic rocks. In the Yanai district, it has been divided into three structural units: northern, central and southern units. In this study, we measured the Rb–Sr whole-rock–mineral isochron ages and fission-track ages of the gneissose granodiorite in the central structural unit. Four Rb–Sr ages fall in a range of ca 89–87 Ma. The fission-track ages of zircon and apatite are 68.9 ± 2.6 Ma and 57.4 ± 2.5 Ma (1σ error), respectively. Combining the newly obtained ages with previously reported (Th–)U–Pb ages from the same unit, thermochronologic study revealed two distinctive cooling stages; 1) a rapid cooling (> 40°C/Myr) for a period (~7 Myr) soon after the peak metamorphism (~ 95 Ma) and 2) the subsequent slow cooling stage (~ 5°C/Myr) after ca 88 Ma. The first rapid cooling stage corresponds to thermal relaxation of the intruded granodiorite magma and its associated metamorphic rocks, and to the uplift by a displacement along low-angle faults which initiated soon after the intrusion of the magma. Uplift by the later stage deformation having formed large-scale upright folds resulted in progress of the exhumation during the first stage. The average exhumation velocity of the stage is ≥ 2 mm/yr. During the second stage, the rocks were not accompanied by ductile deformation and were exhumed with the rate of 0.1–0.2 mm/yr. The difference in the exhumation velocity between the first and second cooling stages resulted from the difference in the thickness of the crust and in the activity of ductile deformation between the early and later stages of the orogenesis.     

1994年世界灾害地震综述

本文综合叙述了１９９４年世界地震灾害的概况和特征；不同国情的地震灾害特点；成灾主要原因：地震预测、预报和抗震减灾的一些问题。     

罕见的“强烈震群”活动

本文介绍了全世界范围内的“强烈震群”的地区分布、活动频率和强度等特征，并指出“强烈震群”主要分布在太平洋西半部的岛弧－海沟地带，这些“强烈震群”是依据近百年来的现代地震仪观测数据获得的。     

松散堆积物中活断层的破裂位移形式及其对确定古地震破裂时间的意义

活断层作用产生的地震破裂，曾使地表产生破裂变形，地面建筑物遭到严重破坏，但由于第四纪松散沉积物变形方式复杂，破裂形迹往往不清晰或不显示，使得在探糟剖面上很难发现这些破裂作用的上部形迹。通过研究不同松散沉积层中断层破裂位移的形式，从宏观、细观与微观相结合的角度，初步探讨了探槽剖面上确定古地震破裂时间的标志与方法。     

The Characteristics of Seismic Activity Before the Devastating Earthquake with M_W9.0 Off the West Coast of Northern Sumatra

INTRODUCTIONMeasured bythe China Earthquake Networks Center ,a great earthquake withMS8·7 occurred offthe west coast of Northern Sumatra at Beijing Time 08 :58 :55·2 on December 26 , 2004·Themagnitude of the earthquake determined by the National Earthquake Information Center of USA(NEIC) wasMW9·0 .The earthquakeisthe biggestinthe world afterthe 1964 Prince WilliamSound,Alaska earthquake .The tsunami triggered bythe Sumatra earthquake brought about severe devastationfor ten …     

北京地区地基验槽常见工程地质问题及其处理

通过建筑地基验槽实践,介绍了北京地区建筑地基开挖后常见的工程地质问题及其处理,为地基验槽提供借鉴。