南方大口鲶的池塘养殖技术

南方大口鲶是鲶科鱼类中体型最大的一种,一般个体2—3kg,最大者可达30kg,近年来,经过科学工作者的不断努力,已将大口鲶驯养成功,使其成为池塘养殖的一个优良品种。一、南方大口鲶的形态特征南方大口鲶头长且扁平,眼小,常为圆形。下颌比上颌突出;口裂较深,其末端至少与眼球中部相对,也有略超过眼后缘的。南方大口鲶成体仅有2对须,无第2对下颌须,但8cm 长以下的鱼种常见到     

南方大口鲶咽部粘膜上皮的组织结构观察研究

用光镜和扫描电镜对南方大口鲶咽部的粘膜上皮进行了观察.结果表明,南方大口鲶的咽部粘膜上皮为复层上皮组织,分布有多种上皮细胞,其中大多为混和性的粘液腺细胞.在粘膜中还有味蕾的分布,此处的味蕾为Ⅲ型味蕾.     

南方大口鲶颅骨形态的研究

本文对南方大口鲶的颅骨进行了逐一的研究和描述。指出了其反映鲶科鱼类共同特点的几个方面以及它与东北大口鲶所具有的一些共同特点。尤其突出地反映了它对底栖、凶猛捕食习性的适应性。对于观察到的与前人意见不同的解剖事实和一些骨块的命名问题提出了我们的看法。     

南方大口鲶两种寄生虫病的研究

南方大口鲶是重要的经济鱼类，在人工养殖过程中，鱼苗期出现了两种严重的寄生虫病，即鲶盘虫病和斜管虫病。作者深入研究了两种寄生虫病的病原体及防治。     

河蛙早期胚胎发育研究

本文对河蛙 (Rana(Aquarana)heckscheriWright) )早期胚胎发育进行了研究。用人工催产和人工授精方法获得受精卵。在水温 2 1～ 2 6.5℃下 ,从受精卵开始至鳃盖完全闭合为止的整个胚胎发育历时 2 2 6小时 37分。河蛙的早期胚胎发育可划分为 2 6期。胚胎发育特点与牛蛙、虎纹蛙相似 ,但纤毛动作期前的发育阶段比牛蛙发育速度快 ,以后各发育阶段较慢 ,在 14～ 18℃的低温下 ,河蛙胚胎发育良好 ,虎纹蛙在同一温度下胚胎停止发育 ,甚至死亡     

花背蟾蜍(Bufo naddei Strauch)的早期胚胎发育及分期

花背蟾蜍 Bufo raddei Strauch 是兰州地区一种常见的、数量较多的无尾两栖类.本文详细研究了20℃条件下它的正常胚胎发育分期及其外部形态变化.根据胚胎的形态特征,花背蟾蜍的早期胚胎发育可以分成25个时期.从人工授精开始到蝌蚪的鳃盖封闭为止,共需185.1小时,比黑斑蛙 Rana nigromaculata 和中华大蟾蜍 Bufo bufo gargarizans 要快.花背蟾蜍发育过程的形态特征和其它无尾两栖类相似.但在某些方面有所不同.本文对它们的早期发育进行了分析和比较.     

高山蛙的早期胚胎发育及分期的研究

高山蛙（ＡｌｔｉａｎａＰｒａｋｅｒｉＳｔｅｊｅｇｅｒ）拉萨地区一种常见的,数量较多的无尾两栖类。本文详细研究了１６－２２℃条件下它的正常胚通渠道胎发育分期及其外部形态变化,根据胚胎发育的形态特征及具体情况,高山蛙的早期胚胎发育可以分成２０个时期,以人工授精开始到蝌蚪的鳃盖封闭为止,共需２１２个小时,比黑斑蛙（ＲａｎａＮｉｇｒｏｍａｃｕｌａｔａ）和中华大蟾蜍（ＢｕｆｏＢｕｆｏＧａｒｇｒｉｚａｎｓ）,花背蟾蜍（ＢｕｆｏＲａｄｄｅｉＳｔｒａｕｃｈ）等要慢。高山蛙发育过程的形态特征和其它无尾两栖类相似,但在某些方面有所不同,本文对它的早期胚胎发育进行了分析和比较。     

温度对蓝点马鲛胚胎发育的影响

蓝点马鲛属暖温性大型中上层经济鱼类,具有高度集群和洄游的习性,广泛分布于中国、日本和朝鲜半岛的亚热带和温带水域,具有十分重要的经济价值。不同温度下蓝点马鲛胚胎发育的速度模型研究是基于产卵量方法的亲鱼资源量和补充资源量评估所必须的资料。本研究对不同水温对蓝点马鲛胚胎发育的影响进行了实验研究。实验用受精卵于2016年春季产卵盛期在宁波象山港经海上人工授精获得,实验用蓝点马鲛卵径范围1.58~1.72 mm,平均直径(1.64±0.03)mm。实验共设置5个温度梯度(12、15、18、21、24℃),于100 L的实验水槽中对不同温度下蓝点马鲛胚胎的发育过程进行了跟踪观察。结果表明,蓝点马鲛胚胎发育速度和温度关系密切,12℃时,胚胎未完成发育,胚胎发育的最高临界水温24℃,最适水温范围是15~21℃,胚胎发育所需时间与水温成负相关关系。不同温度下胚胎不同时期发育所需时间表明Ⅲ期可能是蓝点马鲛胚胎发育的敏感期。     

黑脊倒刺鲃胚胎发育的观察

通过人工授精的方法获得黑脊倒刺Ba的受精卵，详细观察了黑脊倒刺Ba的胚胎发育过程。根据外部形态特征及胚胎行为，将黑脊倒刺Ba的胚胎发育划分为6个阶段，22个胚期。在25－28℃水温条件下，从受精到孵化出膜，胚胎发育历时45h15min。和其他鲤科鱼类的胚胎发育相比，黑脊倒刺Ba的胚胎发育时间较长。黑脊倒刺Ba的胚盘下包卵黄3／4时就进入神经胚期，而一般淡水鱼类往往在胚盘下包卵黄4／5时才进入神经胚期。仔鱼孵出时，器官发育程度与其他鲤科鱼类相似。     

花背蟾蜍的实验室养殖技术

两栖类胚胎发育在胚胎学、发育生物学及细胞生物学的研究中占有重要位置,而温度对两栖类胚胎发育有着十分重要的作用.花背蟾蜍（Bufo raddei Strauch）是兰州地区一种常见的、数量较多的无尾两栖类.本文就20℃条件下,从人工授精开始到蝌蚪的鳃盖封闭直至变态为幼蟾的整个实验室养殖技术作一报道.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to