Formation Mechanisms of Some Features in Siliceous Upper Cretaceous-Lower Tertiary Beds of Jordan-Undulations, Geodes, Boudinages

Geode, boudinage, and undulation structures are widely distributed in the siliceous beds of the Upper Cretaceous/Tertiary rocks in Jordan. Their formation was attributed to tectonic forces, syngenetic processes, organic disintegration processes, subaquatic gliding, compaction and settlement, and meteoritic impacts. In this work, the structural features in the siliceous beds of Jordan are attributed to an interplay of load and directed pressures, and mineralogical transformation processes (opal-A to opal-CT to quartz), governed by pH changes. Tectonic directed pressure was acting in an ESE-WSW direction and is common in the silicified limestone of Upper Cretaceous.

Calculation of geoid undulations and gravity anomaliesin the Northwest Pacific by using the Topex/Poseidonand Geosat altimeter data

The geoid undulations in the Northwest Pacific were calculated by usingtheTopex/Poseidon and Geosataltimeter data. Firstly the bias between two types of the altimeter data was removed and the geoid undulations in theNorthwest Pacific were acquired by a long wave bias diminishing model with a resolution of 30 km and precision of 14cm. Then an algorithm of inversion of gravity anomalies was derived , and the gravity anomalies in the East China Seawere calculated by using the algorithm and the geoid undulations. The rms of difference between the in situ measure-ments the gravity anomalies from altimeter data was 3 .8× 10-5 m/s2. A method to colculate the gravity anomaliesin a larger area was developed which combined gravity anomalies in four subregions overlapping each other into one data set in a larger region. The error analysys shaws that the model and result of the inversion of gravity anomalies were reliable.

Enchanting Undulations

WHEN Sammia Du took her first step on stage in a Cairo five-star hotel, the public looked a bit ambivalent. Her Asian features were unlike those of any other Egyptian belly dancers who performed that night, But as she closed her eyes and began to ripple to the rhythm of the drums, the young Chinese dancer was quick to dispel any doubts.

Interaction of Water Waves with Small Undulations on a Porous Bed in a Two-layer Ice-covered Fluid

The scattering problem involving water waves by small undulation on the porous ocean-bed in a two-layer fluid,is investigated within the framework of the two-dimensional linear water wave theory where the upper layer is covered by a thin uniform sheet of ice modeled as a thin elastic plate.In such a two-layer fluid there exist waves with two different modes,one with a lower wave number propagate along the ice-cover whilst those with a higher wave number propagate along the interface.An incident wave of a particular wave number gets reflected and transmitted over the bottom undulation into waves of both modes.Perturbation analysis in conjunction with the Fourier transform technique is used to derive the first-order corrections of reflection and transmission coefficients for both the modes due to incident waves of two different modes.One special type of bottom topography is considered as an example to evaluate the related coefficients in detail.These coefficients are depicted in graphical forms to demonstrate the transformation of wave energy between the two modes and also to illustrate the effects of the ice sheet and the porosity of the undulating bed.

Enchanting Undulations

When Sammia Du took her first step on stage in a Cairo five-star hotel, the public looked a bit ambivalent.

波纹唇鱼染色体核型分析

为了解波纹唇鱼(Cheilinus undulates)的细胞生物学特征,采用植物血凝集素PHA、秋水仙素腹腔注射和空气干燥制片法以头肾组织为材料,对波纹唇鱼的染色体核型进行了研究。结果表明,波纹唇鱼具有染色体48条,核型公式为2n=48=6m+42t,NF=54,未发现随体、次溢痕及性染色体,其核型符合典型的高位类群鱼类核型特征。

极小长高比腔体内混合流体Undulation行波对流

通过二维流体力学基本方程组模拟了具有较强Soret效应(分离比ψ=-0.47)的混合流体在极小长高比(Γ=4)腔体内的Rayleigh-Benard对流运动.研究了极小长高比行波对流的动力学特性,得到了稳定的Undulation行波存在的r值范围,给出了稳定后的Undulation行波摆动周期Tp的变化规律,分析了极小长高比行波对流的r依赖性及稳定性.首次发现极小长高比Γ=4时,与长高比Γ=12和Γ=8时相比,在腔体两端的滚动生成和消失的现象不再出现.讨论了长高比对Undulation行波向行波过渡的影响.

中等长高比腔体内的混合流体Undulation行进波

通过二维流体力学基本方程组模拟了具有较强Soret效应(分离比ψ=-0.47)的混合流体在中等长高比(Γ=12)腔体内的Rayleigh-Benard对流运动。研究了不同瑞利数情况下腔体内出现的各种行进波状态,详细地探讨了Undulation行进波(UTW)的特性、时空结构及稳定性。

野生波纹唇鱼Cheilinus undulates营养成分分析与评价

该研究测定了野生波纹唇鱼Cheilinus undulates肌肉的营养成分。结果显示,波纹唇鱼肌肉(鲜样)的水分、粗蛋白、粗脂肪和粗灰分的含量分别为80.97%、18.38%、0.10%和0.49%。肌肉中含有18种氨基酸,总量为15.70%(鲜重),必需氨基酸含量占氨基酸总量的39.37%,必需氨基酸的组成符合FAO/WHO的标准。氨基酸的支/芳值为2.5654,接近正常人的支/芳值;依据氨基酸评分(AAS)结果,第一限制性氨基酸为苏氨酸(Thr),第二限制性氨基酸为色氨酸(Trp);必需氨基酸指数(EAAI)为68.46;4种鲜味氨基酸(SAA)的总量为31.85%。脂肪酸中二十碳五烯酸(EPA)+二十二碳六烯酸(DHA)的含量为21.86%。含有人体所必需的钠、钾、钙、镁、铁、铜、锌等元素,表明波纹唇鱼具有较高的营养价值。

具有强SORET效应的混合流体Undulation行进波对流斑图

本文通过流体力学基本方程组的数值模拟,探讨了具有强Soret效应(分离比ψ=-0.6)的混合流体Un-dulation行进波对流斑图的动力学特性。在相对瑞利数r<6.436时,首次发现一种没有源缺陷的左右相对传播的CPW(Counter propagating waves)状态向行进波状态的过渡形式。在r=6.436—10.8的范围内,发现了两种不同结构的Undulation行进波对流斑图。当6.436<r<10时,出现了腔体内的平均波数在时间上变化且局部波数或当地波数在空间和时间上连续变化的Undulation行进波对流斑图。当r=10—10.8时,出现了腔体内的平均波数在时间上保持为常数而局部波数或当地波数在空间和时间上连续变化的Undulation行进波斑图。在两种状态下,Undulation行进波的摆动周期随瑞利数r增大而减小,它的对流振幅和Nusselt数随瑞利数r增大而增加。在Undulation行进波斑图形成以前,存在以中心为对称的Undulation行进波斑图,它的存活时间依赖于r。当r增加到11.0时,Undulation行进波过渡到定常对流状态。

波纹巴非蛤小分子肽在水剂化妆品中的稳定性

试验考察了含量、空气暴露时长、光照、pH、化妆品常用防腐剂等因素对波纹巴非蛤（Paphi0 Undu-Zctte）小分子肽抗氧化活性的影响，并研究了其在化妆品体系中的稳定性。结果表明．波纹巴非蛤小分子肽在含量为0．2％～1．0％（m／V）时对自由基的清除能力随含量增大而增强，当含量达到1．0％时，羟自由基清除率为66％，超氧阴离子自由基清除率为70％，且24h空气暴露对自由基清除能力无影响：波纹巴非蛤小分子肽的光和pH稳定性良好；常用化妆品防腐剂对其稳定性基本无影响，但避免加入量过大。波纹巴非蛤小分子肽作为抗氧化活性物质适于与大部分水剂化妆品原料进行配伍．

Wave scattering by undulating bed topography in a two-layer ocean

The problem of wave scattering by undulating bed topography in a two-layer ocean is investigated on the basis of linear theory. In a two-layer fluid with the upper layer having a free surface, there exist two modes of waves propagating at both the free surface of the upper layer and the interface between the two layers. Due to a wave train of a particular mode incident on an obstacle which is bottom-standing on the lower layer, reflected and transmitted waves of both modes are created by the obstacle. For small undulations on the bottom of the lower layer, a perturbation method is employed to obtain first-order reflection and transmission coefficients of both modes for incident wave trains of again both modes in terms of integrals involving the bed-shape fimction. For sinusoidal undulations, numerical results are presented graphically to illustrate the energy transfer between the waves of different modes by the undulating bed.

Wave Scattering by Porous Bottom Undulation in a Two Layered Channel

The scattering of plane surface waves by bottom undulations in channel flow consisting of two layers is investigated by assuming that the bed of the channel is composed of porous material. The upper surface of the fluid is bounded by a rigid lid and the channel is unbounded in the horizontal directions. There exists only one wave mode corresponding to an internal wave. For small undulations, a simplified perturbation analysis is used to obtain first order reflection and transmission coefficients in terms of integrals involving the shape function describing the bottom. For sinusoidal bottom undulations and exponentially decaying bottom topography, the first order coefficients are computed. In the case of sinusoidal bottom the first order transmission coefficient is found to vanish identically. The numerical results are depicted graphically in a number of figures.

Direct pre-stack depth migration on rugged topography

Engineering seismic exploration aims at shallow imaging which is confused by statics if the surface is uneven. Direct pre-stack depth migration （DPDM） is based on accurate elevations of sources and receivers, by which static correction is completely abandoned before migration and surely the imaging quality is remarkably improved. To obtain some artificial shot gathers, high-order staggered-grid finite-difference （FD） method is adapted to model acoustic wave propagation. Since the shot gathers are always disturbed by regular interferences, the statics still must be applied to supporting the interference elimination by apparent velocity filtering method. Then all the shot gathers should be removed back to their original positions by reverse statics. Finally, they are migrated by pre-stack reverse-time depth migration and imaged. The numerical experiments show that the DPDM can ideally avoid the mistakes caused by statics and increase imaging precision.

Topography of the Moho Undulation in Cameroon from Gravity Data:Preliminary Insights into the Origin,the Age and the Structure of the Crust and the Upper Mantle across Cameroon and Adjacent Areas

In this paper, the complete Bouguer anomaly data from Cameroon and part of the neighboring countries has been examined to compute the topography of the Moho undulations. This work is based on an improved filtering technique and an appropriate density contrast between the crust and the upper mantle. Comparison with seismic data shows that our Moho map defines better the continuity and morphology of the crust-mantle interface than the scattered seismic data in Cameroon. The present relief map, although may not give real depths at some areas provides a better surface correlation with the surface geology better than seismic techniques. Comparison between the Moho undulations and the topography maps reveals that the crust in Cameroon seems to not be in isostatic equilibrium. The Moho in the Central African Shear Zone (CASZ) must be linked with different dextral movements during the opening of the south Atlantic in the Cretaceous time. In the Chad basin, the Moho is associated to the opening of the central and south Atlantic ~130 Ma. In the case of the Congo basin, the Moho undulations are related to the post rift subsidence. The correlation between the Moho undulations map with the surface geology indicates that the actual morphology of the crust mantle interface in Cameroon can be related to the build-up of the West and Central African rift system dating back to the Early Cretaceous to Palaeogene, where the presence of intraplate tensional stresses reactivated previous shear zones of lithospheric weakness during the break up of Gondwana.

Singularity-free expression of magnetic field of cuboid under undulating terrain

Most of the current computing methods used to determine the magnetic field of a uniformly magnetized cuboid assume that the observation point is located in the upper half space without a source. However, such methods may generate analytical singularities for conditions of undulating terrain. Based on basic geomagnetic field theories, in this study an improved magnetic field expression is derived using an integration method of variable substitution, and all singularity problems for the entire space without a source are discussed and solved. This integration process is simpler than that of previous methods, and final integral results with a more uniform form. AT at all points in the source-flee space can be calculated without requiring coordinate transformation; thus forward modeling is also simplified. Corresponding model tests indicate that the new magnetic field expression is more correct because there is no analytical singularity and can be used with undulating terrain.

Auto-pick first breaks with complex raypaths for undulate surface conditions

First-break picking is the key step in seismic data processing for surveying undulate surfaces, and directly infl uences the precision of near-surface modeling and effects of static corrections. The current first-break auto-picking methods may fail when the signalto-noise ratio（SNR） is low for seismic data in the undulate area, and require labor and time intensive manual picking. This study develops an improved super-virtual interferometry（SVI） method that combines multichannel and multidomain quality control（MMQC） techniques to achieve auto-picked first breaks. The improved SVI method extends the SVI application to enhance the SNR for near-surface scattered waves for the first time, which allows for the SVI method to adapt to first breaks with complex raypaths by linear combination of refractions and near-surface scattered waves. Methods of inverse and multidomain interferometry are developed to effectively enhance the virtual records extracted by the SVI method. The deconvolution filter for waveforms is used to increase resolution and reduce false picks, while the MMQC technique is designed to auto-correct false picks and increase the stability of auto-picking first breaks. The robust technique developed in this study enables stable processing of large 3D seismic datasets. Higher quality results are obtained using the approach presented in this paper to actual field data from the mountain areas in western China, when compared to some commonly used commercial software.

Computational Study on a Squid-Like Underwater Robot with Two Undulating Side Fins

The undulating fin propulsion system is an instance of the bio-inspired propulsion systems. In the current study, the swimming motion of a squid-like robot with two undulating side fins, mimicking those of a Stingray or a Cuttlefish, was investigated through flow computation around the body. We used the finite analytic method for space discretization and Euler implicit scheme for time discretization along with the PISO algorithm for velocity pressure coupling. A body-fitted moving grid was generated using the Poisson equation at each time step. Based on the computed results, we discussed the features of the flow field and hydrodynamic forces acting on the body and fin. A simple relationship among the fin＇s principal dimensions was established. Numerical computation was done for various aspect ratios, fin angles and frequencies in order to validate the proposed relationship among principal dimensions. Subsequently, the relationship was examined base on the distribution of pressure difference between upper and lower surfaces and the distribution of the thrust force. In efficiency calculations, the undulating fins showed promising results. Finally, for the fin, the open characteristics from computed data showed satisfactory conformity with the experimental results.

Computational Research on Modular Undulating Fin for Biorobotic Underwater Propulsor

Biomimetic design employs the principles of nature to solve engineering problems. Such designs which are hoped to be quick, efficient, robust, and versatile, have taken advantage of optimization via natural selection. In the present research, an environment-friendly propulsion system mimicking undulating fins of stingray was built. A non-conventional method was considered to model the flexibility of the fins of stingray. A two-degree-of-freedom mechanism comprised of several linkages was designed and constructed to mimic the actual flexible fin, The driving linkages were used to form a mechanical fin consisting of several fin segments, which are able tO produce undulations, similar to those produced by the actual fins. Owing to the modularity of the design of the mechanical fin, various undulating patterns can be realized. Some qualitative observations, obtained by experiments, predicted that the thrusts produced by the mechanical fin are different among various undulating patterns. To fully understand this experimental phenomenon is very important for better performance and energy saving for our biorobotic underwater propulsion system. Here, four basic undulating patterns of the mechanical fin were performed using two-dimensional unsteady computational fluid dynamics （CFD） method. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive re-meshing was used to compute the unsteady flow around the fin through twenty complete cycles. The pressure distribution on fin surface was computed and integrated to provide fin forces which were decomposed into rift and thrust. The pressure force and friction force were also computed throughout the swimming cycle. Finally, vortex contour maps of these four basic fin undulating patterns were displayed and compared.

Identification of Odor Volatile Compounds and Deodorization ofPaphia undulata Enzymatic Hydrolysate

Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase mi- croextraction gas chromatography mass spectrometry （HS-SPME-GC-MS） analysis of volatiles from untreated samples and three deodorized samples （under the optimal conditions） ofPaphia undulata enzymatic hydrolysate revealed that the compounds contrib- uting to the distinctive odor were 1-octen-3-ol, n-hexanal, n-heptanal, 2,4-heptadienal, and 2,4-decadienal, whereas n-pentanal, n-octanal, n-octanol, benzaldehyde, 2-ethylfuran and 2-pentylfuran were the main contributors to the aromatic flavor. The deodoriz- ing effects of activated carbon （AC） adsorption, yeast extract （YE） masking and tea polyphenol （TP） treatment on a P. undulata en- zymatic hydrolysate were investigated using orthogonal experiments with sensory evaluation as the index. The following optimized deodorization conditions were obtained： AC adsorption （35 mg mL-1, 80℃, 40 rain）, YE masking （7 mgmL l, 45 ℃, 30 min） and TP treatment （0.4mgmL-l, 40℃, 50min）. AC adsorption effectively removed off-flavor volatile aldehydes and ketones. YE masking modified the odor profile by increasing the relative contents of aromatic compounds and decreasing the relative contents of aldehydes and ketones. The TP treatment was not effective in reducing the odor score, but it significantly reduced the relative content of alde- hydes while increasing that of alkanes. It is also notable that TP effectively suppressed trimethylamine （TMA） formation in a P. un- dulate hydrolysate solution for a period of 72 h.