Aquaculture-related trace metals in sediments and lobsters and relevance to environmental monitoring program ratings for near-field effects

The study was undertaken to assess the marine environmental effects from feed and waste associated with aquaculture activities. Metal compositions of sediment, lobster, and feed were used to evaluate the extent of detectable effects at 0 m (under the cage) and 50 m distance. Sediments that were collected under the cages and were characterised as hypoxic or anoxic, showed elevated levels of Cu, Zn, organic carbon, and % <63 microm particles, and low Mn and Fe. At 50 m there was a major reduction in waste chemical impact. Using lobster, a bioindicator species, as a tool for detecting near-field impacts, showed accumulations of high Cu associated with active aquaculture sites. Chemical compositions and metal ratios normalised with organic carbon, were used to assess the sediment conditions associated with environmental monitoring program ratings (EMP--normal, hypoxic, and anoxic). Principal component analysis (PCA) was used to explore chemical data at all sites for differentiating normal, hypoxic and anoxic sediment conditions. Selected variables (Cu, Zn, Fe, Mn, organic carbon, and particles <63 microm) were sufficient for the PCA approach with >90% explainable variance of first two components. The groupings based on PCA and cluster analysis were similar to EMP classifications with some exceptions of mis-identification by EMP. The sediment chemistry components were valid indicators for evaluating marine environmental conditions and for assessing aquaculture operating sites. The developed techniques, using chemical variables in combination with EMP and the statistical approach should be useful to predict the effects of aquaculture practices and the suitability of aquaculture operations.     

A coupled simple climate model and its global analysis

Summary An atmosphere-land coupled simple climate model is constructed and its climatic properties are analyzed by introducing a global analysis method, cell mapping. The simple model is a nonlinear six order simplified climate model featured with chaotic dynamics, dissipation, and forcing source, which are the main features of the real climate system. The cell mapping method is applied with this coupled system. Numerical experiments are carried out for investigating the interactions between the fast-changing atmospheric variables and slow-changing underlying surface variables. The predictability of the system is also investigated via the global analysis, with which the evolution of the system is translated to the evolution of probability transition on a Markov Chain. An effective scheme is proposed for computing the probability transition matrix for the coupled system. Predictions can be made based on the combination of dynamics and statistics. The importance of constructing the coupled model is shown by globally analyzing the predictability of the coupled system. The coupling mechanism prolongs the memorization of initial information, and then the predictability as well.     

利用GDSN宽频带资料研究青海地区1988—1990年强震的震源过程

１９８８至１９９０年，青海地区发生了４次震级大于６．０的强震。利用ＧＤＳＮ宽频带波形资料，通过波形模拟，结合地质构造的背景资料对这几次地震进行了震源破裂和发震构造背景的研究。使用台站的准震源时间函数和准时间差的分析方法，对震源和复杂性进行了讨论。     

Basement structure and yalu river fault belt in Dandong region

Some geophysical surveying works in the northeast part of Dandong, such as shallow shock refracted wave, electrical prospecting, electrical sounding and wave velocity measuring, are introduced in this paper, and the dynamic parameters are calculated. The results show that the basement structure in surveying region is very complex, the overburden thickness of the quaternary period, velocity distribution and dynamic parameters are of regional characteristics. The depth of basement is deep in the north and shallow in the west, the difference between north and west region is about 5–10 m. The south part of Yalu river fault belt is composed of F₁, F₂, F₃, F₄, F₅ fault, their strike direction is NE, we can determine that the F₂ fault is the main one in Yalu river fault belt, and the south part of Yalu river fault belt has no activity since Holocene Epoch. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 282–288, 1993.     

Parameter sensitivity study of the saline circulation

Saline circulation forced by fresh water alone is studied for a broad region of parameter space by varying the amplitude and profile of evaporation minus precipitation, the vertical and horizontal mixing of salt, vertical and horizontal dissipation of momentum, and the horizontal resolution. The model is a modified Bryan-Cox model with a freshwater flux as the natural boundary condition for the salinity balance. For a model forced by a linear freshwater flux profile, as the amplitude of freshwater flux is increased from 0.01 m year ^–1 to 1 m year^–1 with other parameters fixed, the system evolves from a steady state of no oscillation to a state of periodic oscillation whose frequency increases almost linearly with the amplitude of freshwater flux. When the freshwater flux is fixed and the vertical mixing coefficient is increased from 0.5 to 2.5 cm²s^–1, the system evolves from a steady state to a state of single-period oscillation, chaotic, a single period, and finally to a chaotic state when the vertical mixing coefficient is larger than 2 cm² s^–1. One set of numerical experiments forced by a cosine shape of freshwater flux clearly reveals the transition from a state of single period oscillation to period doubling, period quadrupling, and a state of chaotic oscillation. Simple scaling analysis and numerical experiments indicate that the strength of the meridional overturning increases with the square-root of the vertical mixing and the 1/4 power of the freshwater flux. The mean sea surface salinity (deviation from 35 psu) increases with the 3/4 power of the freshwater flux and decreases with the 1/2 power of the vertical salt mixing.Contribution No. 8191 from the Woods Hole Oceanographic Institution     

新发现的沂蒙矿类质同象系列矿物──K(Ti_5Fe_3Cr_2Mg_2)_(12)O_(19)及Ba(Ti_5Fe_4Mg_2Cr)_(12)O_(19)

在山东蒙阴金伯利岩中，首次发现了沂蒙矿类质同象系列新的富Ti矿物（变）种。理想的晶体化学式可表达为：K（Ti5Fe3Cr2Mg2）12O19（简称K－Ti沂蒙矿）（Ba，K）（Ti5Fe4Mg2Cr）12O19（简称Ba－Ti沂蒙矿）从而与原来确定的沂蒙矿K（Cr5Ti3Fe2Mg2）12O19和钡钛铁铝矿（Ba，K）（Cr4Fe4Ti3Mg）12O19一起构成了金伯利岩中AM12O19磁铁铅矿型矿物的K-Cr、Ba－Cr、K-Ti、Ba-Ti四种端元类型的复杂类质同象系列。新发现的两个矿物（变）种均产出于具叶片状尖晶石出溶体的镁钛铁矿中。根据结构已知的沂蒙矿中原子的占位和配位多面体情况，分析了K－Ti，Ba－Ti沂蒙矿中各原子的占位和配位多面体，认为新发现的两个（变）种在成分上与沂蒙矿和钡钛铁铬矿有明显的区别。根据镁钛铁矿、尖晶石、沂蒙矿新（变）种、钙钛矿之间的相互关系，探讨了它们的形成环境，从而为这类矿物的地幔成因提供了直接证据。     

Pseudopotential approaches to the structural energies of crystalline solids and solid surfaces

It is now feasible to predict accurately the structural energies of solids and solid surfaces from first principles computational techniques based on pseudopotential theory. We illustrate these techniques for several prototypical systems. We predict structural properties for binary crystalline systems of the form: A^NB^8–N where (A, B) are simple metals and metalloids and N is the number of valence electrons on A. We illustrate the chemical forces responsible for stabilizing rocksalt, zinc blende, and white tin structures as a function of pressure. Also we demonstrate the utility of these techniques for predicting the surface properties for insulators and transition metals.     

依据月平均资料作月预报——利用自然相似的探讨

本文利用1956年1月—1972年12月的月平均1000,500,100 hPa位势高度和太平洋、大西洋、印度洋的海表温度资料中存在的自然相似,对依据月平均资料作的海洋—大气变量月平均值的预报可能达到的水平进行了分析研究。结果表明在一个海—气耦合系统中,大气变量的预报是比海温预报更为困难的一环。根据月平均海表温度决定相应的月平均位势高度场的准确度较低,但在考虑了过去的海温和高度场资料后能有所改进。