SLC9-2型直读式海流计的工作原理及维护使用

直读式流速仪在江河湖海的水文实验中得到了广泛的应用。本文介绍了SLC9-2型直读式海流计的基本结构、工作原理、使用和维护的经验。     

强流区测流方法及测流仪器的讨论

海洋水文观测中对实测流的定点观测,一般采用双联浮筒测表层流(0～2米层的流);用印刷式海流计或直读式海流计测表层以下的海流,如何对海峡、河口及海角附近的强流区测流?海洋水文调查规范中还没有明确规定。为开发利用成山头海区的潮流能,我们采用表层浮筒、HLS-1型声学多普勒海流计、LS25-A型旋浆式流速仪(河道流速仪)和ZD-3型直读式海流计进行了尝试。成山角位于山东半岛最东端,其尖端伸向黄海,此海区由于海底地形复杂,又离北黄海无潮点较近。因此,这里的潮汐、潮流特征是潮差小,潮流大。实测流速有时可达四节以上。由于海底石棚较多,流大水急,涡旋多,锚泊测流船只会出现走锚现象。在这样海流复     

河口海岸测流仪器比测研究

通过对直读式海流计、ENDECO海流计和ADP测流结果的对比分析表明,ENDECO所测流速比直读式海流计偏小约4.2%,流向偏小2.4%;ADP测得的流速比直读式海流计偏大6.1%,流向偏大3.6%,但ADP测量数据更稳定;由三种仪器测得的涨落潮平均流速相对偏差均在10%左右。三种仪器的观测数据可比性强,同时使用时完全能够相互对比分析。流速小于30 cm/s时,由于仪器的摩擦阻力作用,直读式海流计精度变低;流速大于30 cm/s时,三种仪器测得的结果相差较小。与直读式海流计和ADP相比,ENDECO海流计对流向变化较敏感。     

直读式测流仪的常见故障排除方法

本文简单介绍了ZLS-1型直读式流速仪显示器和ZSX-1型直读式流速流向仪的基本工作原理,并根据多次水文测验中所遇到的常见故障,总结了排除它的方法。     

一种轻便微电脑直读式海流计

本文介绍一种新研制的直读式海流计。海流计每百秒显示一次海流的速度和方向以及测量计时;每小时记录一次测量数据,无须人员值守。需要时,可将海流计存贮的记录取出。 本文介绍采用LP-6805微电脑的海流计的系统结构。这是在直读式海流计智能化方面所做的一次尝试。     

SLS1—1型便携式流速仪

本文介绍了一种新型直读式流速仪的特点、主要技术性能、基本原理、结构特征、现场试验情况及操作使用方法。     

自容/直读式温/深测量仪的设计

介绍一种水下温度和深度测量仪器的设计方案和关键技术。该仪器的特点是精度高、体积小、耗电省和成本低，具有自容式记录和直读显示两种工作方式。     

直读式流速仪升级的使用维修对策

通过对比、分析国产ＺＳＸ系列直读式流速仪Ⅰ和Ⅱ型显示器的不同之处,介绍它们的兼容方法,使之因仪器升级而被淘汰的流速仪资源被充分地利用。     

旋桨式海流计的水槽率定

旋桨式流速仪的特点是简单可靠，因此它得到了广泛的应用。本文分析了旋桨的基本特性，介绍了一般旋桨式流速仪的原理。文中详细地介绍了ＳＬＣ９－２直读式海流计的数据处理和水槽率定，探讨了简化其水槽率定的方法。     

新型浅海用旋桨式海流计——SLC9型直读式海流计

本文着重介绍适于表层水域中受波浪影响较小的一种新型(SLC9—IA型)直读式海流计的特点、主要技术性能、基本原理、结构特征、操作方法和注意事项、试验结果及其应用。     

Practical methods of extreme value estimation based on measured time series for ocean systems

Three practical methods for computing the expected maxima of Gaussian time series for ocean system analysis are developed. These methods utilize Pierce's sample scaling concept to overcome the maxima counting and correlation difficulties, but minimize the associated complexity and uncertainties. The first (Direct) method removes the dependence on the envelope for maxima estimation of the time series by directly operating on the time series itself. The second (Poisson clumping) employs the notion of sample scaling factor, but requires neither computing the envelope nor segmenting. The third (Log-fit) is a simple logarithm curve fitting, using the slowly varying, logarithmic growth property of the expected maximum. The accuracy and computational efficiency of these methods are examined. The Direct method and the Poisson clumping method are found to have comparable accuracy. Employment of the envelope does not improve the accuracy of the estimate in practice. Hence, the Direct method and the Poisson clumping method should be preferred. The Poisson clumping method is more efficient than both the Direct method and Pierce's method because of its straightforwardness in implementation. The Log-fit method is the simplest to implement, and computationally the most efficient. Its accuracy is acceptable for many engineering preliminary designs.     

Analysis of VIV for Barrel-Shaped Mast with Covering Ice by HPD-S Method

The vortex-induced vibrations (VIV) of barrel-shaped mast are calculated by three numerical methods, i.e. Newmark-b, HPD-L (High Precision Direct integration scheme-Linear form), and HPD-S (High Precision Direct integration scheme-Sinusoidal form). According to the measured value, the accuracy curves are given to show the advantages of HPD-S method over others. Based on the comparison above, HPD-S method is used to calculate the influence of ice covering on the mast to VIV responses. It has been proved that the vortex-induced responses of barrel-shaped mast are changed along with ice thicknesses and types.     

Numerical Simulation of the Sea Surface Rogue Waves within the Framework of the Potential Euler Equations

Izvestiya, Atmospheric and Oceanic Physics - Direct numerical simulations of wind-generated gravity waves on a 2D sea surface are carried out within the framework of the basic potential equations...     

On the Transfer of Microbubbles by Surface Waves

Izvestiya, Atmospheric and Oceanic Physics - Direct numerical simulation (DNS) is performed and the dynamics of a near-surface water layer populated by air bubbles in the presence of a stationary...     

海浪区湍流通量的涡度协方差观测

Turbulent eddies play a critical role in oceanic flows. Direct measurements of turbulent eddy fluxes beneath the sea surface were taken to study the direction of flux-carrying eddies as a means of supplementing our understanding of vertical fluxes exchange processes and their relationship to tides. The observations were made at 32 Hz at a water depth of ~1.5 m near the coast of Sanya, China, using an eddy covariance system, which mainly consists of an acoustic doppler velocimeter(ADV) and a fast temperature sensor. The cospectra-fit method-an established semi-empirical model of boundary layer turbulence to the measured turbulent cospectra at frequencies below those of surface gravity waves-was used in the presence of surface gravity waves to quantify the turbulent eddy fluxes(including turbulent heat flux and Reynolds stress). As much as 87% of the total turbulent stress and 88% of the total turbulent heat flux were determined as being at band frequencies below those of surface gravity waves. Both the turbulent heat flux and Reynolds stress showed a daily successive variation;the former peaked during the low tide period and the later peaked during the ebb tide period.Estimation of roll-off wavenumbers, k0, and roll-off wavelengths, λ0(where λ0=2π/k0), which were estimated as the horizontal length scales of the dominant flux-carrying turbulent eddies, indicated that the λ0 of the turbulent heat flux was approximately double that of the Reynolds stress. Wavelet analysis showed that both the turbulent heat flux and the Reynolds stress have a close relationship to the semi-diurnal and diurnal tides, and therefore indicate the energy that is transported from tides to turbulence.     

浙江沿海上升流区溶解氧含量与三种无机氮循环的关系

本文根据1980年7—8月我所对浙江沿海上升流区综合调查资料,着重讨论水体中的溶解氧含量分布与三种无机氮(NH_4~ ,NO_3~-和NO_2~-)循环的关系。     

Interspecific Competition between Tetrachthamalus oblitteratus and Tetraclita squamosa

Abstract. Direct evidence for interspecific competition between Tetrachthamalus oblitteratus and Tetraclita squamosa is provided. Tetrachthamalus oblitteratus is smothered and eliminated from the main midlittoral zone by encrusting Tetraclita. The disjunct distribution of Tetrachthamalus can be explained by elimination through competitive exclusion.     

Direct observation of radiative flux in the southern yellow sea

Direct measurements of four radiative components at air-sea boundary layer were conducted in the southern Yellow Sea during three cruises (seasons) in 2007. Simultaneous observations of meteorological (cloud cover, air temperature and humidity) and oceanographic (sea surface temperature) parameters were carried out. Observational results of radiative fluxes and meteorological and oceanographic parameters are presented. Mean diurnal cycles of four radiative components, net radiation, and sea surface albedo are calculated to achieve averages in different seasons. Net radiative fluxes in three seasons (winter, spring, autumn) are 8, 146, 60 W/m², respectively. Comparisons between the observed radiative fluxes and those estimated with formulas are taken.     

直接数字频率合成技术在声学释放器中的应用

直接数字频率合成技术(DDS)是一种新的频率合成方法,它具有转换时间短、相位变化连续、全数字可编程等优点.文中介绍了ADI公司生产的AD7008芯片作为频率信号源在声学释放器中的应用.     

Bacterial and primary production in the pelagic zone of the Kara Sea

Data on the bacterial and primary production, which were obtained simultaneously for the same water samples, are presented for three regions of the Kara Sea. The samples were collected for the transect westwards of the Yamal Peninsula, along the St. Anna Trough, and the transect in Ob Bay. Direct counts of the DAPI-stained bacterial cells were performed. The bacterial production and grazing rates were determined using a direct method when metabolic inhibitors vancomycin and penicillin were added. The primary production rates were estimated using the ¹⁴C method.