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21.
作者根据大量试验和调查数据的分析,提出烟单14号夏玉米在高产条件下,亩穗数、穗粒数、千粒重三因素的最佳取值范围。 亩穗数:3569~4980 穗/亩; 穗粒数:423~526 粒/穗; 千粒重:259~278 克/1000粒。 相似文献
22.
23.
产复合酶菌株Pseudomonas sp.NJ197产酶发酵条件的研究 总被引:2,自引:0,他引:2
从南极普利兹湾深海900m的沉积物中筛选到一株同时产多种低温复合酶的菌 株NJ197,作者对其进行碳源、氮源、无机盐、起始pH值、培养时间、接种量等发酵条 件的优化实验.实验结果证明,在以0.5%可溶性淀粉为碳源,以0.5%豆饼粉为氮 源,无机盐:0.424%NH4H2PO4、0.075%K2HPO4、0.02%MgSO4、0.5%CaCO3,起始 pH值8.5,接种36h种龄的种子10%,20℃、250r/min的条件下在旋转摇床中培养 72h,产复合酶菌株产脂肪酶和淀粉酶活性最高.最佳的生理条件下复合酶中的碱性 脂肪酶和淀粉酶的产量分别提高到22.4U/cm3和30.9U/cm3,该产复合酶菌株可以 作为诱变育种、基因工程菌改造的出发菌株,在洗涤和制革工业中有良好的应用前 景. 相似文献
24.
Quantum yield for the photochemical production of dissolved inorganic carbon in seawater 总被引:2,自引:0,他引:2
The direct photooxidation of coloured dissolved organic matter (CDOM) to dissolved inorganic carbon (DIC) may provide a significant sink for organic carbon in the ocean. To calculate the rate of this reaction on a global scale, it is essential to know its quantum yield, or photochemical efficiency. We have determined quantum yield spectra, φ(λ), (moles DIC/mole photons absorbed) for 14 samples of seawater from environments ranging from a turbid, eutrophic bay to the Gulf Stream. The spectra vary among locations, but can be represented quite well by three pooled spectra for zones defined by location and salinity: inshore φ(λ)=e−(6.66+0.0285(λ−290)); coastal φ(λ)=e−(6.36+0.0140(λ−290)); and open ocean φ(λ)=e−(5.53+0.00914(λ−290)). Production efficiency increases offshore, which suggests that the most highly absorbing and quickly faded terrestrial chromophores are not those directly responsible for DIC photoproduction. 相似文献
25.
26.
闽江口水动力和污染扩散数值模拟 总被引:3,自引:0,他引:3
本文建立了闽江口二维水动力、污染扩散数值模型,模型采用ADI双向隐式求解。在水动力模拟中,对岸界的丁坝有用线性边界进行拟合,并考虑到河口区侧向摩擦作用;在污染扩散模拟中,用动态拟合的方法对浓度水边界进行了较为合理的改进。计算结果表明,本模型是成功的。 相似文献
27.
Hitoshi Kawabata Hisashi Narita Koh Harada Shizuo Tsunogai Masashi Kusakabe 《Journal of Oceanography》2003,59(5):651-661
Thirteen vertical profiles of 226Ra and 222Rn in the near-surface water were obtained in the western North Pacific in winter, and the gas transfer velocities across
the air-sea interface were estimated. The transfer velocities found by applying a steady state model varied widely from 2.1
to 30.2 m day−1 with a mean of 9.4 m day−1. The mean value is almost 5 times higher than that in summer in other oceans, and the maximum value is a record high for
world oceans. This is partly due to the inadequacy of the steady state model, which overestimates when stronger winds blow
in more recent days than the 222Rn half-life of about 4 days. In fact, a strong low pressure zone passed through the station about 2 days earlier, which was
one of the low pressure zones that with a period of develop once a week or so in the northwestern North Pacific in winter.
Instead of steady-state removal, if half of the radon removal occurred sporadically every 7 days, and the last removal took
place two days before the observation, the transfer velocity would be 26 m day−1. Our mean transfer velocity, which is less than 20% different from the steady state value including both overestimated and
underestimated values, 9.4 ± 4.8 m day−1, seems to represent the mean state of this region in winter. This suggests that the gas exchange fluxes under extremely rough
conditions in the open ocean are larger than those estimated by using a transfer velocity equation with a linear or quadratic
relationship with wind speed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
28.
本文根据分析结果阐述了两种不同样品处理方法所获得的硅藻丰度和微型硅藻的人主要种类和相对百分含量。研究表明洗涤富集法所获得的硅藻丰度存在较大误差;微型硅藻的含量普遍介于10%-20%之间,最高可达42.31%,最低为5.66%,并指出了在微型硅藻相对含量大于20%的样品中 ,其主要种类为具槽直链藻和条纹小环藻等沿岸底格格不入中,并成群体产出。 相似文献
29.
30.
A finite-difference scheme and a modified marker-and-cell (MAC) algorithm have been developed to investigate the interactions of fully nonlinear waves with two- or three-dimensional structures of arbitrary shape. The Navier–Stokes (NS) and continuity equations are solved in the computational domain and the boundary values are updated at each time step by the finite-difference time-marching scheme in the framework of a rectangular coordinate system. The fully nonlinear kinematic free-surface condition is implemented by the marker-density function (MDF) technique developed for two fluid layers.To demonstrate the capability and accuracy of the present method, the numerical simulation of backstep flows with free-surface, and the numerical tests of the MDF technique with limit functions are conducted. The 3D program was then applied to nonlinear wave interactions with conical gravity platforms of circular and octagonal cross-sections. The numerical prediction of maximum wave run-up on arctic structures is compared with the prediction of the Shore Protection Manual (SPM) method and those of linear and second-order diffraction analyses based on potential theory and boundary element method (BEM). Through this comparison, the effects of non-linearity and viscosity on wave loading and run-up are discussed. 相似文献