中国对虾配合饵料中维生素C添加量的研究

于１９９１年７月２１日－８月１９日在河北省唐海县西林养殖场以养成期中国对虾为材料，在其配合饵料中添加维生素Ｃ进行中国对虾对维生素Ｃ需要量的试验。结果表明，当中国对虾体长为５．５－７．５ｃｍ时，若以本项研究采用的配合饵料的基本成分和配比为基础，配饵中维生素Ｃ的最佳变化添加量为０．０１８％－０．０３０％。研究发现，变动的维生素Ｃ适宜添加量对于中国对虾具有明显的促进生长，增强抗病力和抗低氧能力以及提高存     

Late Quaternary clay minerals off Middle Vietnam in the western South China Sea: Implications for source analysis and East Asian monsoon evolution

High-resolution clay mineral records combined with oxygen isotopic stratigraphy over the past 450 ka during late Quaternary from Core MD05-2901 off Middle Vietnam in the western South China Sea are re-ported to reconstruct a history of East Asian monsoon evolution. Variations in Illite, chlorite, and kaolinite contents indicate a strong glacial-interglacial cyclicity, while changes in smectite content present a higher frequency cyclicity. The provenance analysis indicates a mixture of individual clay minerals from various sources surrounding the South China Sea. Smectite derived mainly from the Sunda shelf and its major source area of the Indonesian islands. Illite and chlorite originated mainly from the Mekong and Red rivers. Kaolinite was provided mainly by the Pearl River. Spectral analysis of the kaolin-ite/(illite chlorite) ratio displays a strong eccentricity period of 100 ka, implying the ice sheet-forced win-ter monsoon evolution; whereas higher frequency changes in the smectite content show an ice sheet-forced obliquity period of 41 ka, and precession periods of 23 and 19 ka and a semi-precession period of 13 ka as well, implying the tropical-forced summer monsoon evolution. The winter monsoon evolution is generally in coherence with the glacial-interglacial cyclicity, with intensified winter monsoon winds during glacials and weakened winter monsoon winds during interglacials; whereas the summer monsoon evolution provides an almost linear response to the summer insolation of low latitude in the Northern Hemisphere, with strengthened summer monsoon during higher insolation and weakened summer monsoon during lower insolation. The result suggests that the high-latitude ice sheet and low-latitude tropical factor could drive the late Quaternary evolution of East Asian winter and summer monsoons, respectively, implying their diplex and self-contained forcing mechanism.     

On the period of the periodic orbits of the restricted three body problem

We will show that the period T of a closed orbit of the planar circular restricted three body problem (viewed on rotating coordinates) depends on the region it encloses. Roughly speaking, we show that, \(2 T=k\pi +\int _\Omega g\) where k is an integer, \(\Omega \) is the region enclosed by the periodic orbit and \(g:{\mathbb {R}}^2\rightarrow {\mathbb {R}}\) is a function that only depends on the constant C known as the Jacobian constant; it does not depend on \(\Omega \). This theorem has a Keplerian flavor in the sense that it relates the period with the space “swept” by the orbit. As an application we prove that there is a neighborhood around \(L_4\) such that every periodic solution contained in this neighborhood must move clockwise. The same result holds true for \(L_5\).     

鄂东北大别杂岩中混合岩形成的动力学机制

本文针对中小位移量伸缩缝构造进行设计研究，提出了一种常温固化型桥梁伸缩缝。经过对伸缩量Δ２０ｃｍ，Δ＝４０ｃｍ的多座桥梁的实验应用表明，这是一种适用于中小位移量桥梁中性能良好的伸缩缝，施工简便。其桥缝具体结构为，在两侧拍击区采用钢纤维混凝土增，缝内用高分子聚合物与一定比例的水泥及掺合物拌和均匀，经一段时间与桥面和加固铺装层固化成具有较高弹性和一定强度的整体式桥梁伸缩缝。其效果良好，供应用参考。     

Earthquakes in Switzerland and surrounding regions during 2006

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2006. During this period, 572 earthquakes and 91 quarry blasts were detected and located in the region under consideration. Of these earthquakes, two occurred in conjunction with the construction of the new Gotthard railway tunnel and 165 were induced artificially by the stimulation of a proposed geothermal reservoir beneath the city of Basel. With 20 events with M _L ≥ 2.5, five of which were artificially induced, the seismic activity in the year 2006 was far below the average over the previous 31 years. Nevertheless, six events were felt by the public, most prominently the strongest of the induced Basel events (M _L 3.4), which caused some non-structural building damage. Noteworthy are also the two earthquakes near Cortaillod (M _L 3.2), on the shore of Lake Neuchatel, and in Val Mora (M _L 3.5), between the Engadin and Val Müstair, as well as the 42 aftershocks of the M _L 4.9 Vallorcine earthquake, between Martigny and Chamonix, of September 2005. Editorial handling: Stefan Bucher     

Late Carboniferous porphyry copper mineralization at La Voluntad,Neuquén,Argentina: Constraints from Re–Os molybdenite dating

The La Voluntad porphyry Cu–Mo deposit in Neuquén, Argentina, is one of several poorly known porphyry-type deposits of Paleozoic to Early Jurassic age in the central and southern Andes. Mineralization at La Voluntad is related to a tonalite porphyry from the Chachil Plutonic Complex that intruded metasedimentary units of the Piedra Santa Complex. Five new Re–Os molybdenite ages from four samples representing three different vein types (i.e., quartz–molybdenite, quartz–sericite–molybdenite and quartz–sericite–molybdenite ± chalcopyrite–pyrite) are identical within error and were formed between ~312 to ~316 Ma. Rhenium and Os concentrations range between 34 to 183 ppm and 112 to 599 ppb, respectively. The new Re–Os ages indicate that the main mineralization event at La Voluntad, associated to sericitic alteration, was emplaced during a time span of 1.7 ± 3.2 Ma and that the deposit is Carboniferous in age, not Permian as previously thought. La Voluntad is the oldest porphyry copper deposit so far recognized in the Andes and indicates the presence of an active magmatic arc, with associated porphyry style mineralization, at the proto-Pacific margin of Gondwana during the Early Pennsylvanian.     

Inverse Analysis of Deep Excavation Using Differential Evolution Algorithm

This paper presents the applications of the differential evolution (DE) algorithm in back analysis of soil parameters for deep excavation problems. A computer code, named Python‐based DE, is developed and incorporated into the commercial finite element software ABAQUS, with a parallel computing technique to run an FE analysis for all trail vectors of one generation in DE in multiple cores of a cluster, which dramatically reduces the computational time. A synthetic case and a well‐instrumented real case, that is, the Taipei National Enterprise Center (TNEC) project, are used to demonstrate the capability of the proposed back‐analysis procedure. Results show that multiple soil parameters are well identified by back analysis using a DE optimization algorithm for highly nonlinear problems. For the synthetic excavation case, the back‐analyzed parameters are basically identical to the input parameters that are used to generate synthetic response of wall deflection. For the TNEC case with a total of nine parameters to be back analyzed, the relative errors of wall deflection for the last three stages are 2.2, 1.1, and 1.0%, respectively. Robustness of the back‐estimated parameters is further illustrated by a forward prediction. The wall deflection in the subsequent stages can be satisfactorily predicted using the back‐analyzed soil parameters at early stages. Copyright © 2014 John Wiley & Sons, Ltd.     

东北冷涡背景下一次龙卷过程的观测分析

2012年6月12日在吉林省白城市洮北区发生一次龙卷过程 (简称“612”龙卷),对此次龙卷过程天气形势和雷达资料分析结果表明:龙卷发生在高空冷涡的东南象限、中高空急流北侧、低空急流左侧的对流不稳定区域及地面较暖湿的环境中,大气对流参数计算结果显示龙卷过程低层 (0~1 km) 的垂直风切变较强 (为6.0×10-3s-1),抬升凝结高度较低 (低于1 km),且龙卷发生前对流有效位能较大。同时,龙卷过程超过50 dBZ的强核高度均在4 km以下,为低质心的对流系统,龙卷产生于一条带状回波与一近似团状回波合并加强后的强回波带中,并逐渐演变成“S”型,伴有“V”型缺口,中心最强值达61 dBZ。根据多普勒天气雷达导出产品并结合径向速度图反映出“612”龙卷是发生在以龙卷涡旋特征为主的尺度较小且垂直涡度较大 (约为3.65×10-2~3.83×10-2s-1) 的强对流风暴中,持续时间较短。     

http://www.sciencedirect.com/science/article/pii/S1674987111000752

A series of environmentalegeological problems have been caused by over-exploitation of deep groundwater (i.e., confined aquifer water) in the North China Plain. In order to better understand the status of deep groundwater over-exploitation and the resultant environmentalegeological problems on a regional scale, the over-exploitation of groundwater has been assessed by way of the groundwater exploitation potential coefficient (i.e., the ratio of exploitable amount of deep groundwater to current exploitation), cumulative land subsidence, and long-term average lowering rate of the groundwater table. There is a good correlation among the results calculated by the different methods. On a regional scale, deep groundwater has been over-exploited and there is no further exploitation potential under the current conditions. The groundwater exploitation degree index takes the exploitation in 2003 as the reference for the calculations, so the results mainly reflect the degree of current groundwater exploitation. The results of over-exploitation of deep groundwater obtained by land subsidence data and long-term average rate of depression of the water table mainly reflect environmentalegeological problems caused by exploitation of deep groundwater.