新疆小热泉子铜(锌)矿床同位素研究

小热泉子矿床是我国最近发现的一个中型富铜( 锌) 矿床,其矿床成因为众多的矿床学家所关注。本文对该矿床中不同类型矿石、矿物的S、O、H、Si 及稀有( 惰性) 气体He、Ar 同位素特征作了较祥细的论述,同时用KAr 法对硫化物的年龄测定进行了初步尝试。该矿床硫化物的δ34S 值为+ 1-5 ‰～+ 11-1 ‰,平均为6-15 ‰(46) ;3 He/4 He( 初始) 值为5 ×10 - 8 ～2-17 ×10 - 6 ,平均为0-64 ×10 - 6(6) ,40 Ar/36Ar 值为305-27     

Cd~(2+)对青蛤(Cyclina sinensis)的毒性及蓄积过程研究

利用水生动物急性毒性实验方法,在6个浓度下Cd2+对青蛤的急性毒性进行测定,经回归分析后,得到Cd2+对青蛤96h半致死浓度为20.09mg/L,安全浓度为0.201mg/L。分别对半致死浓度和安全浓度下Cd2+在青蛤体内不同组织的蓄积情况进行了分析。结果表明,在半致死浓度条件下,168h青蛤各组织Cd2+的含量依次为肌肉内脏团鳃;而在安全浓度下,其结果为内脏团鳃肌肉,内脏团对于Cd2+富集能力远高于肌肉。讨论了青蛤的养殖环境及产品检验等问题。     

Observations and analyses of floc size and floc settling velocity in coastal salt marsh of Luoyuan Bay, Fujian Province, China

In coastal environments, fine-grain sediments often aggregate into large and porous flocs. ElectroMagnetic Current Meters (EMCM) and Laser In Situ Scattering and Transmissometry (LISST-ST) have been deployed within a Spartina alterniflora marsh of the Luoyuan Bay in Fujian Province, China, to measure the current velocity, the floc size and the settling velocity between 15 and 22 January 2008. During the observations, the near-bed water was collected in order to obtain the suspended sediment concentration (SSC) and constituent grain size. Data show that: (1) the nearbed current velocities vary from 0.1 to 5.6 cm/s in the central Spartina alterniflora marsh and 0.1–12.5 cm/s at the edge; (2) the SSCs vary from 47 to 188 mg/dm 3 . The mean grain size of constituent grains varies from 7.0 to 9.6 μm, and the mean floc sizes (MFS) vary from 30.4 to 69.4 μm. The relationship between the mean floc size and settling velocity can be described as: w s =ad b , in which w s is the floc settling velocity (mm/s), a and b are coefficients. The floc settling velocity varies from 0.17 to 0.32 mm/s, with a mean value of 0.26 mm/s, and the floc settling velocity during the flood tide is higher than that during the ebb tide. The current velocity and the SSC are the main factors controlling the flocculation processes and the floc settling velocity.     

Mechanism and enhancement of photoluminescence from silicon nanocrystals implanted in SiO2 matrix

Photoluminescence (PL) spectra of Si nanocrystals (NCs) prepared by 130 keV Si ions implantation onto SiO₂ matrix were investigated as a function of annealing temperature and implanted ion dose. PL spectra consist of two PL peaks, originated from smaller Si NCs due to quantum confinement effect (QCE) and the interface states located at the surface of larger Si NCs. The evolution of number of dangling bonds (DBs) on Si NCs was also investigated. For hydrogen-passivated samples, a monotonic increase in PL peak intensity with the dose of implanted Si ions up to 3× 10¹⁷ ions /cm² is observed. The number of DBs on individual Si NC, the interaction between DBs at the surface of neighbouring Si NCs and their effects on the efficiency of PL are discussed.     

LMWOA (low molecular weight organic acid) exudation by salt marsh plants: Natural variation and response to Cu contamination

This work aimed to evaluate, in vitro, the capability of roots of two salt marsh plants to release low molecular weight organic acids (LMWOAs) and to ascertain whether Cu contamination would stimulate or not organic acids exudation. The sea rush Juncus maritimus and the sea-club rush Scirpus maritimus, both from the lower Douro river estuary (NW Portugal), were used. Plants were collected seasonally, four times a year in 2004, during low tide. After sampling, plant roots were washed for removal of adherent particles and immersed for 2 h in a solution that matched salinity (3) and pH (7.5) of the pore water from the same location to obtain plant exudates. In one of the seasons, similar experiments were carried out but spiking the solution with different amounts of Cu in order to embrace the range between 0 and 1600 nM. In the final solutions as well as in sediment pore water LMWOAs were determined by high performance liquid chromatography. Plants were able to release, in a short period of time, relatively high amounts of LMWOAs (oxalate, citrate, malate, malonate, and succinate). In the sediment pore water oxalate, succinate and acetate were also detected. Therefore, plant roots probably contributed to the presence of some of these organic compounds in pore water. Exudation differed between the plant species and also showed some seasonally variation, particularly for S. maritimus. The release of oxalate by J. maritimus increased with Cu increase in the media. However, exudation of the other LMWOAs did not seem to be stimulated by Cu contamination in the media. This fact is compatible with the existence of alternative internal mechanisms for Cu detoxification, as denoted by the fact that in media contaminated with Cu both plant species accumulated relatively high amounts (29–83%) of the initially dissolved Cu. This study expands our knowledge on the contribution of globally dominant salt marsh plants to the release of LMWOAs into the environment.     

基于遥感光谱反射率反演黄河口海域Ⅱ类水体悬浮泥沙浓度模型

依据黄河口海域含沙水体野外实测光谱反射率为参考实验数据,结合水体表面光谱观测数据建立了经验回归模型,从而定量估测黄河口海域水体表层悬浮泥沙质量浓度,最终得出黄河口海域不同年份水体的悬浮泥沙质量浓度图,这对分析河口海岸带冲淤变化过程具有重要的意义。     

中国斑岩铜矿与埃达克(质)岩关系探讨

对比研究了中国26个主要斑岩铜矿的地球化学特征和年代学,结果表明其中25个矿床与埃达克(质)岩有成因联系,且多数与玄武质下地壳熔融形成的埃达克岩(C型)有关,现有数据表明土屋-延东和普朗斑岩铜矿可能与俯冲板片熔融形成的埃达克岩(O型)有关。容矿斑岩的初始锶值为0.7034～0.7090,均大于洋中脊玄武岩和亏损地幔的初始锶值,多数与EMI的初始锶值接近,推测其源区或源岩主要为玄武质下地壳,少数为洋中脊玄武岩,并受到中、上地壳不同程度的混染,这与两类埃达克岩的源区基本一致。虽然埃达克质岩浆具有形成斑岩铜矿的巨大潜力,但并非所有埃达克岩都能成矿,不同岩体需具体分析。     

四川盐源模范村喜马拉雅期斑岩铜矿床地质特征

文章通过野外地质观察,结合岩矿鉴定、化学分析、稳定同位素测定、稀土元素分析、成岩成矿同位素年龄测定、包裹体测温及成分等的研究,表明四川盐源模范村矿床具有典型斑岩铜矿的特征。成岩的多期次构成复式岩体,断裂构造控制的隐爆碎裂岩筒为成矿提供了通道和沉积场所。多期次成矿,特别是次生富集作用形成了中型规模的Ⅰ号矿体,影响次生富集带发育的F7断裂带起了重要作用。模范村矿床确系典型的斑岩铜矿,但又具独自的成矿特征。     

制造业活动地理转移视角下的中国产业集群问题

在简要回顾产业集群理论的基础上,在制造业活动地理转移的视角下,结合案例重新审视了我国劳动密集型产业集群的形成及发展.作者认为,一些锁定在低成本竞争的集群正在或已经老化,甚至衰亡.另一些集群中的企业有过度集聚的问题,还有一些中小企业集聚的区域根据产业特征需要增加产业集中度.因为集群的这些问题,随成本上升,出现了集群中企业的加工制造环节外移的现象.这种现象挑战了新产业区理论中集群是"在流动的全球空间中的粘结的区位"的观点.根据集群中企业外移现象,就产业承接地的规划和发展,以及转出地那些正在升级的集群的地理稳定性和生产者服务业的发展问题,提出了几点看法.     

浙江桂凋落物中可溶性有机物对铜离子络合能力研究

采用单配位体模型对不同分解阶段浙江桂凋落物中溶解性有机物(DOM)与铜离子的络合进行了研究.结果表明,DOM中存在络合条件稳定常数较高但络合容量较小和络合条件稳定常数较低但络合容量较大的2种组分.各阶段条件稳定常数(K)和络合容量(L)各不相同,各阶段中1g K与L存在着显著的负相关性(r=0.88,P＜0.05);各组分对铜离子的络合能力排列顺序为:Ⅱa＞Ⅰa＞Ⅰb＞Ⅲa＞Ⅱb＞Ⅲb,半分解阶段中凋落物所释放的DOM对铜离子的络合条件稳定常数最大.这可能与其在分解不同阶段所释放物质不同有关.