砂粒粒径与砂层厚度对单体筐养养殖系统中三疣梭子蟹幼蟹摄食行为与生长特性的影响研究*

提要 在梭子蟹的单体筐养养殖系统中,试验了生态掩体(砂盒)中不同的砂粒粒径大小以及砂层厚度对梭子蟹幼蟹摄食行为与生长特性的影响。砂粒粒径设三个水平,分别为：>2 mm、<0.2 mm以及混合砂;砂层厚度有0cm、2cm、5cm、8cm四个水平。试验共进行6天,结果表明：砂粒粒径及砂层厚度对梭子蟹幼蟹的摄食与生长都有明显的影响。从砂粒粒径看,幼蟹在细砂(SPS)中挖洞休息,蟹体与砂面呈30-45°角,仅露眼睛及触角在外。一天内有3-6次进食,总进食时间为142.7±22.52 min,在摄食次数、总进食时间、平均摄食量(0.2427±0.0137 g/gBW)、以及脱皮及成活率都远高于其他粒径组,该组中幼蟹的体重增长最快,增加了0.814±0.113 g,增长率为91.5±3.43%;而该组的饵料系数(FCR)最低为1.17±0.11。因此,筐养养殖系统砂掩体的砂粒粒径最好为0.2 mm以下。砂层厚度也有类似结果,5 cm以上厚度养殖效果最佳。平均摄食量为0.2087±0.0046 g/gBW,该厚度下,幼蟹无死亡、100%脱皮,体重也增加最快,增加了0.791±0.121 g,增长率为88.9±3.74%,饵料系数(FCR)达到1.37±0.23,表明筐养系统掩体中砂层厚度要在5 cm以上。三种保护性酶类(SOD, POD, CAT)活性随着砂粒粒径变小和砂层厚度增加而降低,而消化酶类(淀粉酶、蛋白酶、脂酶)活性则表现与保护性酶类相反特性。从两类酶的活性变化也能证实,在优选条件下(细砂、厚度>5 cm),幼蟹所受的胁迫在降低。     

基于VRMap平台上的电子沙盘研制

通过与国内外数字沙盘制作方式及功能的比较，详细介绍了数字沙盘研究方面的一些方法，并以中原油田数字沙盘的研制为例，选择北京灵图公司的VRMap2．3软件作为平台制作中原油田数字沙盘，为油田开发提供基本资料。     

六种成膜封堵剂的室内实验优选与评价

为更好地服务深部钻探工程,准确了解冲洗液封堵性能,对6种成膜封堵剂开展了砂床实验、API静失水量实验、流变性能实验及抗温实验等室内实验进行优选与评价。实验结果表明,2号和4号成膜封堵剂在6种成膜封堵剂中封堵性能最好,它们在基浆中的最优加量均为2%,100 ℃温度条件下加入这2种封堵剂的冲洗液具有较好的抗温性能;冲洗液中膨润土含量和处理剂是影响冲洗液封堵性能的2个重要因素：膨润土含量越高,冲洗液封堵性能越好,加入聚合物、降滤失剂等处理剂可以提高冲洗液的封堵性能。砂床实验是评价冲洗液封堵性能好坏的重要依据。     

长江口悬沙颗粒的现场测量

我们利用自．行研制的“光学悬浮沙粒径谱仪”对长江口悬沙颗粒进行了现场测量,同时作了现场采样,经华东师范大学河口海岸国家重点实验室分析,分析结果与仪器现场测量结果进行了对比,结果表明,两种方法得到的平均粒径和悬沙浓度基本一致。     

The evolution of the Dutch and Belgian coasts and the role of sand supply from the North Sea

During the Holocene, the Dutch and Belgian coasts evolved, controlled by post-glacial eustatic sea-level rise, spatially varying vertical subsurface motions (glacio-isostatic crustal rebound, compaction, tectonics) and spatially varying sediment supply (mainly marine sand). The marine sand supply changed as the tidal dynamics and the wave climate changed due to the changing geometry and depth of the North Sea during the Holocene transgression. These changes influenced the coastal evolution. This study compares the results of separate numerical model calculations of the large-scale Holocene tide- and wave-induced sand transport in the southern North Sea with existing geological data of the Dutch and Belgian large-scale coastal evolution, resulting in a qualitatively good correlation. The large-scale coastal evolution is interpreted in terms of the oceanographical forcing, and an integrated conceptual model of the Holocene evolution of the Dutch and Belgian coasts is proposed. The large-scale wave-driven bed-load transport was an order of magnitude smaller than the tidal transports. The modelled tidal transport direction changed from onshore before 6 ka BP to along shore at present for the Zeeland and Holland coasts; the influence that waves may have had on the tidal transport by suspending sand gradually decreased. This change in direction caused the modelled tidal sand supply to the coast to decrease for the Belgian, Zeeland and Holland coasts. While the offshore area of the Holland coast remained a zone of (small) deposition due to decreasing northward sand transports, the offshore area of the Zeeland coast became increasingly erosional after 6 ka BP due to the encroaching divergence of the tidal transports. Due to uncertainty in the magnitude of the modelled sand transports, but robustness in the transport patterns, the focus is on the qualitative rather than the quantitative model results. When compared with the trend of closure, expansion and later erosion and reopening of the coast, the above decrease in sand supply must have been slow enough compared with the decrease in sea-level rise to cause a temporary sand surplus which decayed to a slight deficit as the decrease in supply and the rise in sea level continued. The Wadden Sea coast exchanged little or no sand with the adjacent deeper North Sea throughout the Holocene.     

方斑东风螺两种养殖模式的比较

在室内水泥池，利用沙层自净养殖模式和直接铺沙养殖模式对不同规格的方斑东风螺（Babylonia areolata Link）进行了高密度养殖的研究。结果表明，沙层自净养殖模式养殖小螺、中螺、大螺组日均增重分别为0．031、0．088、0．098g／d，沙层NH4^＋-N最高含量ω分别为1．3、2．1、3．1mg,／L,H2S最高含量ω分别为0．03、0．07、0．14mg／L．各规格组东风螺保持正常生长和活动，成活率92．9％以上；直接铺沙养殖模式养殖小螺、中螺、大螺日均增重分别为：0．023、0．051、0．068g／d．成活率分别为95．2％、86．7％、84．9％，沙层NH4^＋-N最高含量ω达到13．7mg／L，H2S最高含量ω达到0．47mg／L，沙层底质恶化，东风螺活动异常、不摄食。可见，沙层自净养殖模式对方斑东风螺的生长、成活率、沙层水质控制效果显著，在一定程度上克服了直接铺沙养殖底质恶化问题。     

磺酸自硬砂引起球铁件表层异常组织的研究

通过实验研究,用甲苯磺酸作催化剂的呋喃树脂自硬砂与稀土镁作催化剂生产的球铁件,通常在其铸件表层出现异常组织。提出导致异常组织产生的原因,同时又降低了试件的冲击值,并且采用反应型或屏蔽型涂料将可防止球铁件表层异常组织缺陷,为生产性能良好的球铁件提供技术依据。     

Development in modeling cyclic loading of sands based on kinematic hardening

In this paper, there is presented an elastoplastic constitutive model to predict sandy soils behavior under monotonic and cyclic loadings. This model is based on an existing model (Cambou‐Jafari‐Sidoroff) that takes into account deviatoric and isotropic mechanisms of plasticity. The flow rule used in the deviatoric mechanism is non‐associated and a mixed hardening law controls the evolution of the yield surface. In this research the critical state surface and history surface, which separates the virgin and cyclic states in stress space, are defined. Kinematic hardening modulus and stress–dilatancy law for monotonic and cyclic loadings are effectively modified. With taking hardening modulus as a function of deviatoric and volumetric plastic strain and with defining the history surface and stress reversal, the model has the ability to predict the sandy soils' behavior. All of the model parameters have clear physical meanings and can be determined from usual laboratory tests. In order to validate the model, the results of homogeneous tests on Hostun and Toyoura sands are used. The results of validation show a good capability of the proposed model. Copyright © 2009 John Wiley & Sons, Ltd.     

热带风暴过程中珊瑚礁坪示踪砂运移的现场实验研究

１９９５年１０月在小东海珊瑚礁海岸的礁坪上进行了示踪砂运动的现场实验。本次实验对浪,流以及示踪砂采样作了同步观测。根据所获的实验数据,分析在９５１６号热带风暴天气过程礁坪上示踪砂运移的基本规律。在一级近似下,测定并计算了泥沙在波生流作用下的漂移速度与流速比因子０．００２,混合深度小于２ｃｍ。这一结果与其它已往结果相比明显小得多。     

渤海湾盆地黄骅坳陷孔南地区古近系孔店组二段物源分析*

根据重力异常资料、地震资料,综合运用重矿物法、碎屑岩类分析法并结合砂体展布特征,基本明确了黄骅坳陷孔南地区孔店组二段的物源区位置及来源方向。区域布格重力异常场从宏观上勾绘出了孔南地区地势的起伏状况,对物源分析具有重要参考意义。在研究区湖盆周缘都发育砂体,在各物源口的砂体展布规律在平面上表现为呈扇形展布的特征,宏观上指示了物源的涉及范围。盆外下切沟槽能大致确定研究区周缘各物源口位置,前积反射结构也能指示出存在物源供给的地区。重矿物以锆石、电气石、金红石、石榴石、磁铁矿为主,不同的物源区具有不同的重矿组合特征,其变化规律指示了碎屑物质的搬运方向和搬运途径。碎屑岩组分以长石为主,其次为石英,岩屑含量较低,主要为岩浆岩岩屑,岩屑类型指示了物源区母岩类型主要为岩浆岩。该区孔店组二段沉积时期在东南、西南、西北、东北4个方向上都存在物源,进一步可识别出乌马营、叶三拔、舍女寺等10个子物源,它们共同控制了孔南地区孔店组二段沉积时期砂体的形成和分布,形成多物源环湖盆分布的特征。