第23周太阳活动峰年北京天文台太阳射电观测

An introduction to the instrumonts to be used for solar radio observations in Beijing in Solar Cycle 23 is made in this paper. They are 10cm solar radio telescope which has been used for a long time,and 1.0～2.0GHz,2.6～3.8GHz and 5.2～7.6GHz spectrometers. The former two spectrometers has passed a test,showing high guality,and the 5.2～7.6GHz one will be in operation from 1999. It is believed that highl gualified data should be obtained in the next solar cycle.     

古昆虫植食的自然历史

昆虫植食是昆虫与植物相互作用关系中最重要的组成部分。探索地史时期陆地生态系统中昆虫植食行为的起源与演化是探究古环境重建及古气候变化的重要切入点，其结果将更好地揭示现生昆虫取食行为背后的生物学及生态学意义。本文梳理了昆虫植食的研究历史；阐述了植物化石上的生物损伤与非生物损伤的主要区别；介绍了昆虫植食研究的化石证据以及功能性取食组 损伤类型研究体系(Functional feeding group damage type, FFG DT)。昆虫植食多样性在地质历史时期的演化过程分为8个阶段：① 志留纪—泥盆纪(444~359 Ma)为昆虫植食的起源时期；② 石炭纪(359~299 Ma)为昆虫植食的扩张时期；③ 二叠纪(299~252 Ma)为昆虫植食的稳定时期；④ 三叠纪(252~201 Ma)晚期，昆虫植食再次多样化；⑤ 侏罗纪(201~145 Ma)昆虫植食程度进一步加强；⑥ 白垩纪(145~66 Ma)裸子植物逐渐为被子植物所替代，昆虫植食大幅度增加；白垩纪末期，昆虫植食水平下降；⑦ 古近纪(66~23 Ma)昆虫植食水平提高；⑧ 新近纪(23~26 Ma)昆虫植食与现代基本相似。影响昆虫植食的主要因素包括气候环境、昆虫和植被多样性、昆虫口器类型、植物群落组成和微生物等。目前，统一昆虫植食研究体系和方法、填补各历史阶段的缺失信息等问题在昆虫植食研究中亟待解决。     

Timing and Processes of Ore Formation in the Qingchengzi Polymetallic Orefield, Northeast China: Evidence from 40Ar/39Ar Geochronology

The Qingchengzi orefield is a large polymetallic ore concentration area in the Liaodong peninsula,northeastern China,that includes twelve Pb-Zn deposits and five Au-Ag deposits along its periphery.The ore-forming age remains much disputed,which prevents the identification of the relationship between the mineralization and the associated magmatism.In this paper,we quantitatively present the feasibility of making ore mineral ~(40)Ar/~(39)Ar dating and report reliable ~(40)Ar/~(39)Ar ages of lamprophyre groundmass,K-feldspar and sphalerite from the Zhenzigou deposit.Direct and indirect methods are applied to constrain the timing of mineralization,which plays a vital role in discussing the contribution of multistage magmatism to ore formation.The low-potassium sphalerite yielded an inverse isochron age of 232.8±41.5 Ma,which features a relatively large uncertainty.Two lamprophyre groundmasses got reliable inverse isochron ages of 193.2±1.3 Ma and 152.3±1.5 Ma,respectively.K-feldspar yielded a precise inverse isochron age of 134.9±0.9 Ma.These four ages indicate that the mineralization is closely associated with Mesozoic magmatism.Consequently,regarding the cooling age of the earliest Mesozoic Shuangdinggou intrusion(224.2±1.2 Ma)as the initial time of mineralization,we can further constrain the age of the sphalerite to 224–191 Ma.These new and existing geochronological data,combined with the interaction cutting or symbiotic relationship between the lamprophyre veins and ore veins,suggest that the Pb-Zn-Au-Ag mineralization in the Qingchengzi orefield mainly occurred during three periods:the late Triassic(ca.224–193 Ma),the late Jurassic(ca.167–152 Ma)and the early Cretaceous(ca.138–134 Ma).This polymetallic deposits are shown to have been formed during multiple events coinciding with periods of the Mesozoic magmatic activity.In contrast,the Proterozoic magmatism and submarine exhalative and hydrothermal sedimentation in the Liaolaomo paleorift served mainly to transport and concentrate the ore-forming substances at the Liaohe Group with no associated Pb-Zn-Au-Ag mineralization.     

1980～～2014年中国中东部持续性霾天气的多尺度变化特征

对1980～2014年中国中东部地区324个台站的持续性霾天气的时空变化和相关气象影响因子进行分析，结果表明:中东部地区年平均持续性霾事件和其在所有霾事件的贡献比例逐年增加，增长率分别为0.79 (10 a)-1和2.7% (10 a)-1。主要表现为3个大值区:华北平原地区（包括山西省、京津冀地区）、长江三角洲和四川盆地东部，增加最显著的区域位于黄淮地区，增长率分别为6.3 (10 a)-1、13.95 d (10 a)-1。1月是持续性霾事件的高发月，月均2.56 d。夏季和秋季持续性霾事件增加最为明显，增长率分别为0.38 (10 a)-1和0.46 (10 a)-1。不利的气象条件，如静风日数的增加，风速和大风日数的减少，以及不利的环流形势，如东亚冬季风的减弱，都可能造成持续性霾天气的增加和异常维持。     

GPM卫星降水数据在沿海地区的适用性分析——以三亚市为例

选取2016年1—12月GPM(Global Precipitation Measurement)卫星的IMERG月尺度降水数据为研究对象,以同时期的气象站点实测降水数据为参考,利用相关系数、标准偏差、相对误差等多种统计分析指标对其在沿海地区估测能力进行评价。结果表明:IMERG月尺度降水量与站点实测降水数据相关性较好,IMERG估测的降水与气象站点实测降水量的时空变化规律也较为一致,但是量化到具体数值而言,其对山区、海岛站的估测能力不及地势平坦的区域;同时,选取降水个例对IMERG日尺度和半小时尺度降水数据的分析表明,日尺度IMERG估测的不同等级降水量也存在偏差,半小时尺度IMERG降水数据对海岛站的降水估测偏高。总体而言,IMERG降水数据对降水的时间变化规律和空间分布格局估测较为合理,但是对山区、海岛地区,其降水估测值还存在偏差,在今后应用中需结合地形特征加以合理利用。     

Solar flare injection and propagation of low-energy protons and electrons in the event of 7–9 July, 1966

Simultaneous observations of the 7–9 July 1966 solar particle event by energetic particle detectors on three satellites, IMP-III, OGO-III and Explorer 33 are utilized to show that large spatial gradients are present in the fluxes of 0.5–20 meV protons and 45 keV electrons. The event is divided into three parts: the ordinary diffusive component, the halo, and the core. The core corotates with the interplanetary field, and therefore it and the surrounding halo are interpreted as spatial features which are connected by the interplanetary magnetic field lines to the vicinity of the flare region. Upper limits to the interplanetary transverse diffusion coefficient for 4–20 meV protons at 1 AU are derived from the width of the halo. These are at least two orders of magnitude less than the parallel diffusion coefficient for the same energy particles.It is argued that the observed flux variations cannot be explained by an impulsive point source injection for any physically reasonable diffusion model. Instead, since the interplanetary transverse-diffusion coefficient is small for these low-energy particles, the observed spatial features are interpreted as the projection to 1 AU by the interplanetary field lines of an extensive injection profile at the sun. The geometry of the injection mechanism is discussed and it is suggested that some temporary storage of the flare particles occurs near the sun.Now at NASA, Goddard Space Flight Center, Greenbelt, Md., U.S.A.     

Cosmic-ray exposure histories of two Antarctic meteorites from Chinese collections and the Guangmingshan and Zhuanghe chondrites

In this paper, we report cosmic-ray exposure ages (3He, 21Ne, 38Ar) and gas retention ages (4He, 40Ar) of two Antarctic meteorites, and the Guangmingshan and Zhuanghe ordinary chondrites. The Antarctic meteorites (GRV98002 and GRV98004) were collected on …     

Evaluation of aluminum speciation in surface waters in China and its environmental risk assessment

As the ongoing global research on acid precipitation is developing in depth, more and more attention has been paid to the ecological effects of aluminum (Al) due to its toxicity to plants and animals, which is caused by acid precipitation. As a very serious problem of terrestrial and aquatic environmental acidification occurs in China, especially in southwestern China, a systematic investigation of Al speciation in these regions is very important. In this paper, the Al speciation results of surface waters in China are reported and its ecological impacts is evaluated. More than 100 water samples were collected from about twenty provinces of China. Driscoll's Al speciation scheme combined with the modified MINQEL computer model is used for speciation of Al. This study shows that the ecological impacts of acidification are quite different between China and Western countries, because of different geographical environments and geological settings. In Western countries, acidification is mainly caused by NO₂^-. Due to low concentrations of K⁺, Na⁺, Ca²⁺, Mg²⁺, the buffer capacities of soil and water are weak. Therefore, natural waters can be acidified to pH<5 very easily, resulting in a considerable mobilization of Al and worsening of the ecological environment. In China, acid precipitation is mainly in the form of sulfuric acid. In northwestern China, concentrations of K⁺, Na⁺, Ca²⁺, Mg²⁺ are high in soil and surface waters. This leads to much higher capacity and a high resistance ability to acidification. The pH values of waters in this region are high (around 7) and no serious Al toxicity is found at present. However, in northeastern and southeastern China, the soil is rich in Al (unsaturated aluminosilicates in northeastern China, saturated aluminosilicates in north and central China, aluminum-rich soil in southeastern and southwestern China). The concentrations of K⁺, Na⁺, Ca²⁺, Mg²⁺ in soil and waters are lower than those of northwestern China. Therefore the buffer capacity is limited. Numerous surface waters have already been acidified and pH values declined to 5. The impacts of Al toxicity on ecological systems in these regions are very serious, especially in Jiangxi, Hubei Provinces and Chongqing Municipality.     

"96.1"高原暴雪过程三维条件性对称不稳定的数值研究

利用“96．1”青藏高原东北部暴雪过程的较成功的中尺度模拟的输出资料,用非纬向非平行基流中的对称不稳定模式,对“96．1”暴雪发生发展过程的动力学机制进行了三维基流中二维非线性对称不稳定数值模拟试验。结果表明,ψ场和ω场的三维配置与切变线的演变过程相当一致,说明用三维基流中二维非线性对称不稳定可能能较好地描述SI在切变线东伸南移过程中所起的作用。     

The dose-response relationship between No. 2 fuel oil and the growth of the salt marsh grass,Spartina alterniflora

The effect of No. 2 fuel oil on the biomass production of the salt marsh plant, Spartina alterniflora, was studied in a greenhouse dose-response experiment. S. alterniflora were transplanted into soil with 10 dosage levels of No. 2 fuel oil ranging from 0 to 456 mg g(-1) dry soil. Three months after transplantation, values for plant biomass, stem density, and shoot height decreased significantly with increasing fuel oil level in a dose-response fashion. Evapo-transpiration rates were correlated with the total biomass response. Relative to the control, a significant decrease in total (above- plus below-ground) plant biomass was observed at concentrations above 57 mg g(-1) dry soil. Within the 3-month experimental period, detrimental effects on below-ground biomass accumulation and bioluminescence of the marine bacterium Viberio fisheri in the Microtox Solid Phase Test were observed at oil concentrations >29 mg g(-1) dry soil, suggesting that biological effects of oil within the sediment matrix may be more pronounced than on above-ground biomass, requiring a dosage 228 mg g(-1) dry soil to elicit a significant detrimental effect. Hence, measurements of oil effects with biological end-points based solely on above-ground responses may underestimate the potential impacts of petroleum hydrocarbon spills, especially when the oil has penetrated the soil. While S. alterniflora was proved to be relatively tolerant to the No. 2 fuel oil spills, its effectiveness in phytoremediation operations may be limited at fuel oil levels 228 mg g(-1) dry soil, as both plant growth and microbial activity may be constrained.