RESIDENCE TIME OF WATER DISCHARGING FROM THE HANGING GARDENS OF ZION PARK1

ABSTRACT: The Hanging Gardens are a unique feature of Zion National Park. Knowledge of the source and residence time of water discharging from the Hanging Gardens is necessary to help preserve these features. Ground-water chemical and isotopic data distinguish the discharge from seeps and springs into two groups, one of low and one of high conductivity. Water with low conductivity likely originates as recharge near the seeps and springs, and it only interacts with the Navajo Sandstone. High conductivity water, on the other hand, originates as recharge on the tops of plateaus to the east, where it interacts with marine rocks of the Carmel Formation. Carbon dating of these ground waters indicates that the low conductivity water is essentially modern recharge, while the high conductivity water was recharged 1,000 to 4,000 years ago.     

Historical Weathering Based on Chemical Analyses of Two Spodosols in Southern Sweden

Chemical weathering losses were calculated for two conifer stands in relation to ongoing studies on liming effects and ash amendments on chemical status, soil solution chemistry and soil genesis. Weathering losses were based on elemental depletion trends in soil profiles since deglaciation and exposure to the weathering environment. Gradients in total geochemical composition were assumed to reflect alteration over time. Study sites were Horröd and Hasslöv in southern Sweden. Both Horröd and Hasslöv sites are located on sandy loamy Weichselian till at an altitude of 85 and 190 m a.s.l., respectively. Aliquots from volume determined samples from a number of soil levels were fused with lithium metaborate, dissolved in HNO₃, and analysed by ICP – AES. Results indicated highest cumulative weathering losses at Hasslöv. The weathering losses for the elements are in the following order:Si > Al > K > Na > Ca > MgTotal annual losses for Ca+Mg+K+Na, expressed in mmol_c m^-2 yr^-1, amounted to c. 28 and 58 at Horröd and Hasslöv, respectively. Variations between study sites could not be explained by differences in bulk density, geochemistry or mineralogy. The accumulated weathering losses since deglaciation were larger in the uppermost 15 cm than in deeper B horizons for most elements studied.     

呼伦贝尔盟野生药用植物资源的分布与利用

本文论述了内蒙古呼伦贝尔盟主要野生药用植物分布区域及其生态环境特点，并对北黄芪等１５种药用植物的生态生物学特征、区系地理成分和药用价值进行了重点描述，对如何保护与合理利用药用植物资源提出了建议。     

医疗垃圾焚烧飞灰中重金属浸出的影响因素

以四川某城市为例,对医疗垃圾焚烧飞灰进行了重金属的浸出特性实验,探讨了不同液固比、初始pH值及浸取剂对飞灰中重金属Cu、Zn、Pb、Cd、Ni的浸出影响.结果表明,重金属的浸出率随着液固比的增加而增加;重金属在酸性条件下较易浸出,而在碱性条件下渗滤较少;不同的浸取剂对重金属的浸出也有一定影响.     

国际地震救援行动中的医疗力量配置分析

强烈地震在造成大量建筑物倒塌的同时也造成了大量的人员伤亡,如何快速有效抢救埋压在废墟下的幸存者,如何快速救治因建筑物倒塌的压伤人员,如何有效防止灾后的疾病肆虐,在简要分析了几次国际地震救援行动的医疗力量配置情况之后认为,合理配置的医疗力量和快速的医疗救助行动将可以极大程度地抢救垂危的伤员。     

Streambed Sediment Geochemical Controls on In-Stream Phosphorus Concentrations during Baseflow

A spatially extensive geochemical data set of stream water and bed sediment composition across the Tamar catchment in south-west England was analysed to identify the key bed sediment properties that control the in-stream dissolved reactive phosphorus (DRP) concentrations during baseflow conditions. Linear regression analysis of the streamwater DRP concentrations and the distribution coefficient K _d for DRP revealed that the former is positively correlated with total SiO₂ and Al₂O₃, and negatively correlated with K₂O. The primary control on these major element distributions is the dominant bedrock geology. The data suggest that streamwater DRP concentrations are mainly controlled by adsorption to clay minerals. Where P concentrations in streamwater were considerably elevated by inputs from point sources, DRP concentrations are also controlled by precipitation of hydroxyapatite.     

现代生物医学模式与作业场所职业危害控制

进行医学模式研究的目的是利用科学的医学模式来指导医学实践，借鉴“生物-心理-社会”现代生物医学模式，结合职业危害控制的具体内容和主要环节。本文提出“作业环境-作业人员（群体）特征-劳动组织与管理”的职业危害控制模式，并初步探讨了该模式与与法规、部门职能及人-自然-社会和谐发展的关系。     

岱海硅藻类浮游植物初级生产力Si限制初探

以岱海水-沉积物系统中BSi的地球化学特征为基础,结合沉积物中BSi的空间分布和垂向分布以及BSi与古环境古气候的响应关系,对岱海硅藻类浮游植物初级生产力的Si限制理论进行了探索.研究发现,岱海上覆水中Si的平均含量仅为0.38 mg/L,而表层沉积物中BSi的平均含量达到7.5 mg/g;水-沉积物系统中SiO32-和BSi的空间分布特征揭示了生源硅的主要来源;水-沉积物系统中Si与C、N、P的比值及BSi与古环境古气候的响应关系阐明了Si成为硅藻浮游植物初级生产力限制因子的主要原因;不同历史时段内,Si成为岱海硅藻浮游植物初级生产力限制因子的主导原因不同.     

湘北华容地区小墨山花岗岩体SHRIMPU—Pb年龄及地球化学特征

小墨山岩体侵位于中元古代冷家溪群中,由两期侵入体组成,早期为粗中粒—中粒斑状黑云母二长花岗岩;末期为细粒黑(二)云母二长花岗岩。通过锆石SHRIMP U-Pb法测得岩体侵位年龄为122.5±2.1 Ma(2σ),MSWD=1.9,成岩时代为早白垩世。主元素中,SiO2变化于67.20%~75.16%,K2O含量高,且K2O>Na2O,K2O/Na2O为1.16~1.72;ASI值变化于0.96~1.10之间,平均1.02,属准铝质-微过铝质、高钾钙碱性系列。岩石明显富集大离子亲石元素,亏损高场强元素,Rb/Sr=0.27~15.13;Nb/Ta=15.9~17.1,为锶和铌亏损型。ΣREE总体较高,重稀土含量相对较高,轻重稀土分馏稍弱,ΣCe/ΣY为0.49~6.18,(La/Yb)N为0.66~15.54。有较高的εNd(t),为-6.8~-8.7;T2DM相对较小(1.47~1.62 Ga)。综合研究表明,小墨山花岗岩石为壳源型富黑云母过铝花岗岩类(CPG),其成因应为下地壳物质和上地壳物质混合而成,与花岗岩底侵作用或注入地壳中的幔源岩浆有关,形成的构造背景为陆内挤压造山向非造山转换的后造山拉张环境,是在...     

铊,铊中毒及铊在生态系中迁移径迹

铊属于分散元素,独立矿物稀少,极难形成独立铊矿床。铊世界年产量约15吨,几乎都是从有色金属选冶产品中作为副产品顺便回收。我国铊资源比较丰富,按相同等级资源相比,我国铊储量居世界首位。铊的地球化学性质受其电子构型和地质地球化学作用制约,铊原子处于基态时的电子构型为6S26P1。铊有两个地球化学价态,正一价和正三价,在自然界多数呈正一价。铊具有低温成矿,亲硫和高温分散,亲石的双重地球化学性质。铊是有用元素,也是有毒元素。铊被广泛用于超导、电子、合金、光学、化工、玻璃和医药等工业。铊的毒性对哺乳动物比汞、隔、铅、铜、锌还强。铊对生物有毒害,高含量的铊对人体可导致不同程度的铊病,甚至死亡。由于铊矿床的开发利用,使采挖出的含铊岩矿石和冶炼矿渣堆积地表,在长期风化淋滤作用下,使释放的铊进入地表水体、土壤、植物、动物和人体生态链,故引起铊环境污染和铊中毒。