玉林地区秋旱气候特征分析及防御对策

利用玉林地区５个测站１９５８～１９９６年降雨量资料,统计分析了玉林地区秋旱天气的气候规律,并在此基础上,提出秋旱的防御对策,为做好秋旱预报、减少秋旱灾害给农业生产造成的损失提供可靠的依据。     

226Ra distribution in the Antarctic Ocean

²²⁶Ra data on eleven vertical profiles taken during the GEOSECS program from the Antarctic Ocean and its vicinity in both the Atlantic and the Pacific are presented. Replicate measurements were made on each sample using the Rn-emanation method. The precision (1 σ) based on triplicate analyses averages about ±2.5%. Waters all around the Antarctic continent below 2 km depth appear to exhibit a uniform²²⁶Ra concentration of 21.5 ± 1dpm/100kg, except perhaps locally such as the Ross Sea and the Drake Passage where small variations may be present. Higher in the water column, the²²⁶Ra contents decrease toward the surface with gradients which vary as a function of the influence exerted by the Antarctic Convergence. Across this oceanic front, a north-to-south increase of²²⁶Ra occurs (the increase being the largest near the surface: from 8 to 18 dpm/100 kg), reflecting the combining effect of deep-water upwelling and meridional water mixing. The core layer of the Antarctic Intermediate Water contains about 14 dpm/100 kg of²²⁶Ra and that of the Circumpolar Intermediate Water (O₂ minimum and local T maximum) about 18 dpm/100 kg. To a first approximation,²²⁶Ra covaries with Si in the circumpolar waters.     

江淮气旋发生发展和暴雨过程及有关预报问题的研究

本文就一次典型过程作为例子,分析了江淮气旋发生发展和暴雨过程的特点,指出有利于江淮气旋发生发展的高空天气形势,地面一些中尺度低压和暴雨核的演变与气旋发展的互相联系。发现气旋区内可存在若干个中尺度低压,这些中尺度低压可先于或后于暴雨核生成而出现,并可增强、减弱或合并。文中计算了潜热释放的加热对涡度制造的贡献,指出潜热加热对气旋发展起着极为重要的作用。作者对于影响气旋发展的因子进行了讨论,并对如何根据湿度场、流场和降水分布(或卫星云图)特征来预报江淮气旋提出建议。     

一次强飑线的中分析

本文对一次强飑线过程进行分析,指出高空“阶梯槽”的出现是这次飑线过程大尺度环流背景的重要特征。在此背景下,苏北和山东广大地区,有一支西南低空急流输送水汽和热量,大气层结趋于不稳定,为鼬线发展提供了不稳定能量,而高空疏散槽为不稳定能释放的一种触发机构。在飑线过境前,大气的层结在800毫巴附近的强下沉逆温,对不稳定能的储存和积累有重要意义。 这次飑线发展如此之强,除一般所说的一些条件之外,同飑线内部对流云体的合并以及与其它天气系统的碰头有密切关系;另外,中低空之间的强垂直风切变也有特殊作用。     

A systematic approach to the input determination for neural network rainfall–runoff models

Input determination has a great influence on the performance of artificial neural network (ANN) rainfall–runoff models. To improve the performance of ANN models, a systematic approach to the input determination for ANN models is proposed. In the proposed approach, the irrelevant inputs are removed. Then an adequate ANN model, which only includes highly relevant inputs, is constructed. Unlike the trial‐and‐error procedure, the proposed approach is more systematic and avoids unnecessary trials. To demonstrate the effectiveness of the proposed approach, an application to actual typhoon events is presented. The results show that the proposed ANN model, which is constructed by the proposed approach, has advantages over those obtained by the trial‐and‐error procedure. The proposed ANN model has a simpler architecture, needs less training time, and performs better. The proposed ANN model is recommended as an alternative to existing rainfall–runoff ANN models. Copyright © 2007 John Wiley & Sons, Ltd.     

Effect of NH4-non the pigment content ofLaminaria japonica

Experiments withLaminaria japonica were conducted in Meidao Bay and Pier Bay, Qingdao, China, Nitrogen-starved plants were fertilized intermittently with 7.1 mM NH₄−N solution for 1 hour at 3 day intervals, after which chlorophyll a, fucoxanthin, chlorophyll c and β-carotene contents were analyzed. Photosynthetic and growth rates of plants and nitrogen content of seawater were determined. their contents of chlorophyll a, fucoxanthin, chlorophyll c and β-carotene were 1.65, 0.67, 0.33 and 0.06 mg.dm⁻² respectively, or 2.46, 2.03, 1.86 and 1.81 times those of the controls. The ratio of fucoxanthin to chlorophyll a in nitrogen-enriched plants was lower than that of the controls. Normal growth rate of the plants (2 cm·day⁻¹ in length) were reached when the chlorophyll a content exceeded 0.1 mg·g⁻¹ fresh wt., indicating that chlorophyll a content can serve as an indicator of normal growth. Experimental results show that seawater is regarded as fertile for the normal growth ofLaminaria if the total inorganic nitrogen (including ammonium salt, nitrate and nitrite) content in seawater is about 2 μm, and infertile if less than 1 μm, in which case fertilizer should be applied. Contribution No. 1703 from the Institute of Oceanology, Academia Sinica     

GROUNDWATER QUALITY AND CONTAMINATION INDEX MAPPING IN CHANGCHUN CITY, CHINA

1INTRODUCTIONGroundwater in Changchun City assures about 45% of total water supply. Drinking water supply of Chang-chun City was mostly served by surface water from Shitoukoumen and Xinlicheng reservoirs located in the east and south of the city (ZHANG, 1993). However, with the development of urban construction the ground-water especially from deep boreholes is also used for drinking purpose in suburban areas. The urbanization process in Changchun City threatens the groundwater quali…     

Variations of b‐values at the western edge of the Ryukyu Subduction Zone,north‐east Taiwan

Using earthquakes relocated in north‐east Taiwan, we estimated b‐value distribution along a cross‐section located near the Ryukyu slab edge, and four b‐value anomalous areas are evidenced: (1) a high b‐value body lying on top of a low Vp, low Vs and high Vp/Vs sausage‐like body was considered as a region of enhanced partial melt or water supply above which seismicity occurs; (2) beneath the Ilan Plain, an anomalous area characterized by b‐values slightly higher than 1.1 might give evidence to the magma conduits to the Kueishantao Island; (3) above the Ryukyu Wadati‐Benioff zone, at depths ranging from 90 to 110 km, a high b‐value anomaly might correspond to the depth where dehydration occurs in the subducting oceanic plate; and (4) a low b‐value area located within the Ryukyu slab, at depths ranging from 70 to 90 km, might be linked to the compressive mechanisms shown by focal mechanisms and the bending of the subducting plate.     

红旗连锁顾客满意度测评与改进措施研究

顾客满意状态与企业利润率之间有着密切的联系,提高顾客满意度成了许多企业的重要经营目标.对红旗连锁的现状进行了分析,确定顾客满意度的各项指标与权重,建立了一个完善的指标和级度体系,通过对红旗连锁的顾客展开调查,综合评价了顾客现有的满意程度,并提出了提高顾客满意度的途径.     

In situ LA-ICP-MS zircon U-Pb age of ultrahigh-pressure eclogites in the Yukahe area,northern Qaidam Basin

Zircon grains were selected from two types of ultrahigh-pressure (UHP) eclogites, coarse-grained phengite eclogite and fine-grained massive eclogite, in the Yukahe area, the western part of the North Qaidam UHP metamorphic belt. Most zircon grains show typical metamorphic origin with residual cores in some irregular grains and sector, planar or misty internal textures on the cathodoluminescence (CL) images. The contents of REE and HREE of the core parts of grains range from 173 to 1680 μg/g and 170 to 1634 μg/g, respectively, in phengite eclogite, and from 37 to 2640 μg/g and 25.7 to 1824 μg/g, respectively, in massive eclogite. The core parts exhibit HREE-enriched patterns, representing the residual zircons of protolith of the Yukahe eclogite. The contents of REE and HREE of the rim parts and the grains free of residual cores are much lower than those for the core parts. They vary from 13.1 to 89.5 μg/g and 12.5 to 85.7 μg/g, respectively, in phengite eclogite, and from 9.92 to 45.8 μg/g and 9.18 to 43.8 μg/g, respectively, in massive eclogite. Negative Eu anomalies and Th/U ratios decrease from core to rim. Positive Eu anomalies are shown in some grains. These indicate that the presence of garnet and the absence of plagioclase in the peak metamorphic mineral assemblage, and the zircons formed under eclogite facies conditions. LA-ICP-MS zircon U-Pb age data indicate that phengite eclogite and massive eclogite have similar metamorphic age of 436±3Ma and 431±4Ma in the early Paleozoic and magmatic protolith age of 783–793 Ma and 748–759 Ma in the Neo-proterozoic. The weighted mean age of the metamorphic ages (434±2 Ma) may represent the UHP metamorphic age of the Yukahe eclogites. The metamorphic age is well consistent with their direct country rocks of gneisses (431±3 Ma and 432±19 Ma) and coesite-bearing pelitic schist in the Yematan UHP eclogite section (423–440 Ma). These age data together with field observation and lithology, allow us to conclude that the Yukahe eclogites were Neo-proterozoic igneous rocks and may have experienced subduction and UHP metamorphism with continental crust at deep mantle during the early Paleozoic, therefore the metamorphic age of 434±2 Ma of the Yukahe eclogites probably represents the continental deep subduction time in this area.