数据缺乏条件下的渔业资源评估方法研究进展

全球范围内绝大多数渔业处于数据缺乏的状态,而常规的资源评估方法需要准确的生物学信息和完整的渔获数据,通常并不适合此类渔业资源的评估。数据缺乏方法(DLM)正是适用于此类情况的渔业资源评估方法,DLM的研究已经成为渔业资源研究的热点。作者对DLM的近期发展作了简要回顾,重点对主要的DLM方法和数据需求进行了分析比较,指出这些方法的应用需要注意的问题。历史渔获量是大多数DLM方法运用的必要数据(如DCAC、Catch-MSY模型),而关于资源丰度的相对指标和重要生活史参数(如种群内禀增长率、自然死亡系数),则是运用这些方法的必要补充。此外,对运用DLM所需的主要生物学参数的估算方法进行了简介。最后对DLM方法的使用及其在国内渔业中的运用提出了建议。     

2022年夏季长江流域干旱的水循环模拟和分析

基于WRF-WVT水汽追踪模式,对2022年6—8月长江流域极端干旱情况下的水循环进行模拟研究,分析了长江流域蒸散发对长江流域局地和非局地降水的影响。结果表明,2022年夏季干旱导致长江中下游陆地水储量在5—8月期间减少100～150 mm。6—8月长江流域约45％的蒸散发在当地和华北形成降水,其中6月长江流域蒸散发主要贡献当地降水,而7、8月对当地和华北降水的贡献大致相等。6—8月长江流域蒸散发贡献的当地降水逐月减少,总量为8.2×10⁷ m³(长江流域平均91.2 mm),并且降水强度越高当地蒸散发贡献率越小,对当地降水贡献最大的区域为四川盆地附近(最大超过40％)。长江流域蒸散发为华北提供的降水在6—8月先增多后小幅度减少,总量为5.3×10⁷ m³(华北平均58.4 mm),并且降水强度越高长江流域蒸散发贡献率越大。2022年夏季长江流域蒸散发对当地和华北地区暴雨的贡献率都为12％左右。     

Co-seismic Coulomb stress changes on the northern Tanlu fault zone caused by the Tohoku-Oki MW9.0 earthquake*

Based on the spherical earth dislocation theory and a fault slip model of the Tohoku-Oki M_W9.0 earthquake, the co-seismic Coulomb failure stress changes (ΔCFS) on the northern Tanlu fault zone at depths of 0–40 km are calculated. By comparing two sets of results from the spherical earth dislocation theory and the semi-infinite space one, the effect of earth curvature on the calculation results is analyzed quantitatively. First, we systematically summarize previous researches related to the northern Tanlu fault zone, divide the fault zone as detailed as possible, give the geometric parameters of each segment, and establish a segmented structural model of the northern Tanlu fault zone. Second, we calculate the Coulomb stress changes on the northern Tanlu fault zone by using the spherical earth dislocation theory. The result shows the Coulomb stress changes are no more than 0.003 MPa, which proves the great earthquake did not significantly change the stress state of the fault zone. Finally, we quantitatively analyze the disparities between the results of semi-infinite space dislocation theory and the spherical earth one. The average disparity between them is about 7.7% on the northern Tanlu fault zone and is 16.8% on the Fangzheng graben, the maximum disparity on this graben reaches up to 25.5%. It indicates that the effect of earth curvature can not be ignored. So it’s necessary to use the spherical earth dislocation theory instead of the semi-infinite space one to study the Coulomb stress change in the far field.     

地震微破裂成核过程的实验模拟研究

以透明试件受压破裂过程模拟均匀岩体的破裂过程, 用实时全息干涉摄影系统记录试件应力场分布及其变化, 用瞬态波形自动记录仪记录微破裂的位置和强度.通过两种方式所获数据来探索地震微破裂成核过程与应力场关系.      

单江拱坝右坝肩岩体变形稳定计算分析

用有限元计算了单江拱坝右坝肩岩体的变形,着重分析了断层F1对于坝肩岩体变形的影响。用极限分析方法,计算了断层、层面等结构面切割形成的块体的抗滑稳定安全系数。结果表明,在一定范围内断层F1对于坝肩岩体的变形具有很大的影响,块体不能满足规范规定的抗滑稳定要求,需要加固。并对加固方式提出了建议。     

Differential exhumation in response to episodic thrusting along the eastern margin of the Tibetan Plateau

Thermochronological data from the Songpan-Ganze˛Fold Belt and Longmen Mountains Thrust-Nappe Belt, on the eastern margin of the Tibetan Plateau in central China, reveal several phases of differential cooling across major listric thrust faults since Early Cretaceous times. Differential cooling, indicated by distinct breaks in age data across discrete compressional structures, was superimposed upon a regional cooling pattern following the Late Triassic Indosinian Orogeny. ⁴⁰Ar/³⁹Ar data from muscovite from the central and southern Longmen Mountains Thrust-Nappe Belt suggest a phase of differential cooling across the Wenchuan-Maouwen Shear Zone during the Early Cretaceous. The zircon fission track data also indicate differential cooling across a zone of brittle re-activation on the eastern margin of the Wenchuan-Maouwen Shear Zone during the mid-Tertiary, between 38 and 10 Ma. Apatite fission track data from the central and southern Longmen Mountains Thrust-Nappe Belt reveal differential cooling across the Yingxiu-Beichuan and Erwangmiao faults during the Miocene. Forward modelling of apatite fission track data from the northern Longmen Mountains Thrust-Nappe Belt suggests relatively slow regional cooling through the Mesozoic and early Tertiary, followed by accelerated cooling during the Miocene, beginning at ca. 20 Ma, to present day.

Regional cooling is attributed to erosion during exhumation of the evolving Longmen Mountains Thrust-Nappe Belt (LMTNB) following the Indosinian Orogeny. Differential cooling across the Wenchuan-Maouwen Shear Zone and the Yingxiu-Beichuan and Erwangmiao faults is attributed to exhumation of the hanging walls of active listric thrust faults. Thermochronological data from the Longmen Mountains Thrust-Nappe Belt reveal a greater amount of differential exhumation across thrust faults from north to south. This observation is in accord with the prevalence of Proterozoic and Sinian basement in the hanging walls of thrust faults in the central and southern Longmen Mountains. The two most recent phases of reactivation occurred following the initial collision of India with Eurasia, suggesting that lateral extrusion of crustal material in response to this collision was focused along discrete structures in the LMTNB.     

吴岭水库枢纽工程渗流分析

对湖北省京山县吴岭水库枢纽工程中土坝剖面进行了有限元渗流计算，分析了大坝基础部位的残坡积土和强风化砂岩的强透水性以及下游排水体对于大坝渗流场的影响，指出现有坝体断面设计的不合理是导致大坝下游坡面散浸的原因，为大坝的工程处理提供了依据，也为今后土坝设计提供了借鉴。     

铼—锇同位素分析中样品的预处理

文章对近年来在Ｒｅ＿Ｏｓ同位素质谱分析中样品的预处理方法进行了介绍和总结评述，重点介绍了样品的分解和元素的分离纯化。引用主要文献１８篇。     

A numerical model on sea surface wind of typhoon and its hindcasting calibration

Ａｎｕｍｅｒｉｃａｌｍｏｄｅｌｏｎｓｅａｓｕｒｆａｃｅｗｉｎｄｏｆｔｙｐｈｏｏｎａｎｄｉｔｓｈｉｎｄｃａｓｔｉｎｇｃａｌｉｂｒａｔｉｏｎ￥ＳｈｅＪｕｎ；ＹｕａｎＹｅｌｉａｎｄＰａｎＺｅｎｇｄｉ（ＲｅｃｅｉｖｅｄＡｐｒｉｌ１４，１９９３；ａｃｃｅｐｔｅ...     

厌氧接触消化技术处理高浓度淀粉废水研究

实验采用厌氧接触消化技术，分别在中温（３２℃）和自然温度条件下处理淀粉厂的高浓度废水。结果表明，采用中温厌氧消化可取得较好的处理效果，原水不调ｐＨ（原水ｐＨ为４．０～４．９）直接进反应器，容积负荷最高达５．０６ｋｇＣＯＤｃｒ／ｍ３·ｄ，进水ＣＯＤｃｒ平均１１．６０４×１０３ｍｇ／ｌ，出水ＣＯＤｃｒ平均１．７７８×１０３ｍｇ／ｌ，ＣＯＤｃｒ去除率达８５．８％，出水ｐＨ提高到６．４～７．０。采用自然温度消化，当气温大于２４℃时，可取得较好的处理效果