南海珠江口东部海底沉积物腐蚀性研究

总结了1994年在南海东部石油开发区及毗邻近岸海区开展的海底沉积物和海水共17个环境因子大面积调查研究的成果。文中探索性地提出一套适合于南海亚热带海区海底沉积物腐蚀性评价的方法，并根据调查和评价的结果评定出本海区各测站海底沉积物的腐蚀性等级。     

厄尔尼诺现象及预测现状

厄尔尼诺现象是目前发现的最明显气候异常信号.本文简短地介绍了厄尔尼诺的研究和预测现状,指出厄尔尼诺的预测水平还很低,其主要因素是一、没有建立起全球立体的厄尔尼诺监测网;二、研究局限于热带太平洋或热带印度洋-太平洋;三、缺乏多尺度相互作用的深入研究.另外,本文描述了厄尔尼诺发生前热带太平洋大气-海洋环流异常的几个特征.     

ENSO-coupled precipitation records (1959–2004) based on shells of freshwater bivalve mollusks (<Emphasis Type="Italic">Margaritifera falcata</Emphasis>) from British Columbia

We present the results of sclerochronologically calibrated growth and stable isotope analyses of the freshwater bivalve Margaritifera falcata collected from an agricultural, suburban setting near Vancouver, BC. The oxygen isotope range of shell aragonite can be explained by the temperature range during the growing season, assuming the water δ ¹⁸O composition remained constant. However, shell growth is strongly influenced by local summer precipitation and potentially runoff of nutrient-rich stormwater. About 44% of the variability of annual shell growth can be explained by amounts of local summer (June–September) rainfall. Local winter precipitation and El Niño–Southern Oscillation (ENSO) strength during the preceding year exert a weak, but significant control on shell growth. In combination, summer and winter precipitation can explain up to 50% of the variability in annual shell growth. Spectral analyses substantiate the effect of precipitation on shell growth and demonstrate that shell growth and ENSO are coupled by precipitation. Common spectral density was found at periods of 6.5–9 years, particularly between 1985 and 2004. Higher frequency oscillation corresponding to periods of 3–5 years occurred during the early 1970s, early to mid 1980s, and later 1990s. These results suggest that skeletal records of bivalve mollusks provide suitable archives of ENSO-coupled precipitation in areas where other climate proxies such as tree-rings and speleothems may not be available.     

南天山坎岭铅锌矿矿床地质特征及S、Pb同位素特征研究

坎岭铅锌矿床是中国新疆南天山造山带内典型的铅锌矿床之一,矿床产于塔里木盆地西北缘柯坪隆起带内。通过野外地质调查和同位素研究发现:矿床具有后生成矿特征,赋矿围岩主要为上寒武统—奥陶系碳酸盐岩,矿体主要受构造和围岩控制,矿体形态以脉状、似层状和透镜状为主,矿石矿物组合简单,主要金属矿物为方铅矿和闪锌矿,围岩蚀变较弱。矿石S同位素组成分布较宽(δ34S=-1‰~12.2‰),硫主要来源于深部地幔及沉积地层;矿石Pb同位素组成较为均一,206Pb/204Pb值为17.262~17.269,207Pb/204Pb值为15.571~15.675,208Pb/204Pb值为38.062~38.396,通过对比矿石与主要赋矿围岩的Pb同位素特征,发现二者存在亲缘性,说明成矿金属主要由沉积地层供给。综合矿床地质、地球化学特征,初步认为坎岭铅锌矿床为赋存于台地碳酸盐岩中的MVT矿床。     

基于三维矿化域数字模型对澳大利亚Camel 1金矿找矿预测研究

Camel 1金矿是澳大利亚Pilbara地台最重要的金矿之一,矿区地表被第四系风成沙和冲积物覆盖,地表矿化信息少,找矿难度大。鉴于此,在该矿区引入"数字矿山"技术手段,结合Camel 1金矿的地质特征,特别是控矿构造特征,使用Surpac软件,建立Camel 1金矿三维矿化域数字模型,综合研究金矿化空间分布规律。Camel 1矿床金矿化总体上沿Mallina韧性剪切带分布,且严格受Mallina韧性剪切控制;金矿化与后期北西向断裂关系密切,矿区在未来找矿工作中应该重视北西向构造,可能会有更好的找矿突破。本文通过对金矿化空间分布规律的研究以及其与构造之间的关系,在矿区圈定了三处找矿预测靶区。三维矿化域数字模型找矿预测方法工作成本低,可作为一种新的找矿思路在该区找矿工作中应用。     

The Predictability of Ocean Environments that Contributed to the 2020/21 Extreme Cold Events in China:2020/21 La Niña and 2020 Arctic Sea Ice Loss

Several consecutive extreme cold events impacted China during the first half of winter 2020/21,breaking the low-temperature records in many cities.How to make accurate climate predictions of extreme cold events is still an urgent issue.The synergistic effect of the warm Arctic and cold tropical Pacific has been demonstrated to intensify the intrusions of cold air from polar regions into middle-high latitudes,further influencing the cold conditions in China.However,climate models failed to predict these two ocean environments at expected lead times.Most seasonal climate forecasts only predicted the 2020/21 La Ni?a after the signal had already become apparent and significantly underestimated the observed Arctic sea ice loss in autumn 2020 with a 1-2 month advancement.In this work,the corresponding physical factors that may help improve the accuracy of seasonal climate predictions are further explored.For the 2020/21 La Ni?a prediction,through sensitivity experiments involving different atmospheric-oceanic initial conditions,the predominant southeasterly wind anomalies over the equatorial Pacific in spring of 2020 are diagnosed to play an irreplaceable role in triggering this cold event.A reasonable inclusion of atmospheric surface winds into the initialization will help the model predict La Ni?a development from the early spring of 2020.For predicting the Arctic sea ice loss in autumn 2020,an anomalously cyclonic circulation from the central Arctic Ocean predicted by the model,which swept abnormally hot air over Siberia into the Arctic Ocean,is recognized as an important contributor to successfully predicting the minimum Arctic sea ice extent.     

Structural analysis of the Subbriançonnais and Valais units in the area of Moûtiers (Savoy, Western Alps): paleogeographic and tectonic consequences

Valais and Subbriançonnais units of the Western Alps of Savoie underwent a common structural evolution, postdating peak pressure conditions associated with high-pressure metamorphism of internal parts of the Valais units. The first two phases, due to roughly north/south-directed shortening, are interpreted to be related to a NNE/SSW-striking corridor of sinistral transpression between the internal Western Alps and the European foreland. Both phases led to nappe formation, isoclinal folding and north–south elongation. Only the third phase of deformation is related to WNW-directed orogen-perpendicular shortening, thus far regarded as the predominant thrusting direction in the Western Alps. Late (post 5?Ma) normal faulting, evidenced by fission-track dating, reactivated the Houiller Front in the north and the Penninic Front in the south. Kinematics of movement, observed along the present-day Houiller Front and Penninic Front, change from north to south. In the north the Houiller Front indicates post-D3 normal faulting while the Penninic Front preserved WNW-directed thrusting (D3). In the south the Houiller Front preserves syn-D2 north-directed thrusting, whereas the Penninic Front is partly reactivated by post-D3 normal faulting. Our observations clearly favor tectonic reasons for the disappearance of the Valais units south of Moûtiers in present-day map view.     

A time-minimizing hybrid method for fitting complex Mössbauer spectra

The present study includes results of the application of a program consisting of a genetic algorithm routine and a conventional refinement part (“hybrid method”) for the evaluation of Mössbauer spectra published elsewhere. It is shown that the saving of total evaluation time compared with conventional refinement routines is very high due to the rapid finding of adequate starting parameters. Contrary to a recently published work on a similar topic our algorithm provides solutions of the combined interaction Hamiltonian with a minimum of conventional input data.     

2-[2′-(6-甲氧基-苯并噻唑)-偶氮]-1,8-二羟基萘-3,6-二磺酸的合成及其与钛的显色反应

合成了新的杂环偶氮变色酸类试剂———２［２′（６甲氧基苯并噻唑）偶氮］１,８二羟基萘３,６二磺酸,并系统探讨了在ｐＨ４．５的邻苯二甲酸氢钾ＮａＯＨ介质中显色试剂与钛的显色反应特性。结果表明,在溴化十六烷基吡啶存在下,试剂与Ｔｉ（Ⅳ）形成２∶１的络合物,显色反应１５ｍｉｎ完全并至少稳定４ｈ,最大吸收波长为６７０ｎｍ,表观摩尔吸光系数达１．６７×１０５Ｌ·ｍｏｌ－１·ｃｍ－１,钛的质量浓度在０～４００μｇ／Ｌ时符合比尔定律。用拟定的方法测定了硅砖等标准物质中的Ｔｉ（Ⅳ）,所得结果与标准值的相对误差均小于４％,ＲＳＤ（ｎ＝５）小于３．５％。     

Instability in the 3rd Dimension of the Extended Störmer Problem

The problem of motions of charged particles or charged grains of matter in the field of two magnetic dipoles in rotation about a common center are studied by means of computing families of periodic solutions and their stability. Ten such families are found and their stability study shows that only two out of the ten have short arcs of stable members, all with low inclination to the plane of the two dipoles, while the rest of the families consist exclusively of unstable solutions. Hence the impact of adding one dipole to the configuration of the Störmer problem, leads to the conclusion that in the modified system the three-dimensional motions are basically unstable unlike those of the one-dipole case. The model magnetic field used in this study is a first approximation of the Z3model of the magnetic field of Saturn as computed from the Pioneer 11 and Voyager 1 and 2 measurements.