廷塔亚——秘鲁的最新铜矿即将于1985年投产

秘鲁廷塔亚特殊矿业公司(EmpresaMinera Especial Tintaya SA)是由秘鲁矿业公司(50%)、秘鲁中部矿业公司(41%)和国家开发信贷机构科菲德(Cofjde)公司(9%)组成特殊的国营公司。该公司经营的廷塔亚这座秘鲁最新的露天铜矿和选矿联合企业。将于1985年二季度投产。这项工程的基建投资为3.16亿美元,日处理能力为8000吨硫化矿,年产16万吨含铜33%的铜精矿。精矿供给出口,其中含有4盎司/吨的银和0.14盎司/吨的金副产品。

秘鲁高海拔地区廷塔亚矿发展近况

本文阐述了秘鲁廷塔亚矿归属马格马铜公司经营前后的发展状况，对比表明：通过优化设备配套、改善作业制度等措施，该矿的采选生产都得到很大的发展。

热带安第斯山脉20世纪后期几十年的冰川演变:玻利维亚的查卡尔塔亚冰川和厄瓜多尔的安蒂扎纳冰川

自1991年起对玻利维亚的查卡尔塔亚冰川(16°S,雷亚尔山)和1995年起对厄瓜多尔的安蒂扎纳15号冰川(0°,厄瓜多尔)的质量平衡作了连续监测。在冰川消融区,按一个月尺度测量了质量平衡,提供了有关两种不同热带环境中季节性变化模式的有意义的详细数据。这两个地区最近40年来都有关于冰后退的断断续续的报道。这些资料指出,这10年来冰川退缩明显加速了;消融速率已比前几十年高3～4倍。以前在秘鲁北部测量3条冰川的变动,使我们可以假定:安第斯山脉热带山段冰川退却的速率在20世纪70年代增高了。小规模冰川(<1km)的现状特别令人担忧,象查卡尔塔亚等许多冰川将在今后10年内消失。已经收集的资料证明,在ENSO(厄尔尼诺南方涛动)变暖期消融作用显著增强,而在变冷期(拉尼娜)减弱。自20世纪70年代晚期以来,变暖事件变得更频繁、更强烈了。可以假定,它们已对安第斯山脉中部现代冰川退缩起了显著作用,还有全球气候变暖的影响。

股利信号理论模型及其应用

股利信号理论认为在信息不对称的状态下,对于拥有信息优势的公司经理来说,他们通常把股利政策当作一种信号,向投资者传递企业当前和未来盈利的信息。典型的理论模型有巴恰塔亚模型、米勒—罗克模型、约翰—威廉斯模型、约翰—朗模型等。

美国大兵环球作恶现丑记

当今世界,几乎哪里有风波,哪里就有美国大兵的影子,可谓出尽了风头。然而,这支星条旗下的“国际宪兵”却劣迹斑斑,不断在环球播洒着恶行和臭名,令世人咋舌唾骂。

Effects of co-existing microalgae and grazers on the production of hemolytic toxins in Karenia mikimotoi

Karenia mikimotoi （Miyake ＆ Kominami ex Oda） Hansen ＆ Moestrup is associated with harmful algal blooms in temperate and subtropical zones of the world. The hemolytic substances produced by K. mikimotoi are thought to cause mortality in fishes and invertebrates. We evaluated the composition of the hemolytic toxin produced by K. mikimotoi cultured in the laboratory using thin-layer chromatography. In addition, we evaluated the effect of co-occuring algae （Prorocentrum donghaiense and Alexandrium tamarense） and the cladoceran grazer Moina mongoliea on hemolytic toxin production in K. mikimotoi. The hemolytic toxins from K. mikimotoi were a mixture of 2 liposaccharides and 1 lipid. Waterborne clues from P. donghaiense and A. tamarense inhibited the growth of K. mikimotoi but increased the production of hemolytic toxins. Conversely, K. mikimotoi strongly inhibited the growth of caged P. donghaiense and A. tamarense. In addition, the ingestion of K. mikimotoi by M. mongolica induced the production of hemolytic toxins in K. mikimotoi. Taken together, our results suggest that the presence of other microalgae and grazers may be as important as environmental factors for controlling the production of hemolytic substances. K. mikimotoi secreted allelochemicals other than unstable fatty acids with hemolytic activity. The production of hemolytic toxins in dinofiagellates was not only dependent on resource availability, but also on the risk of predation. Hemolytic toxins likely play an important role as chemical deterrents secreted by K. mikimotoi.

Optimization of Culture Conditions and Medium Composition for the Marine Algicidal Bacterium Alteromonas sp. DH46 by Uniform Design

Harmful algal blooms(HABs) have led to extensive ecological and environmental issues and huge economic losses.Various HAB control techniques have been developed,and biological methods have been paid more attention.Algicidal bacteria is a general designation for bacteria which inhibit algal growth in a direct or indirect manner,and kill or damage the algal cells.A metabolite which is strongly toxic to the dinoflagellate Alexandrium tamarense was produced by strain DH46 of the alga-lysing bacterium Alteromonas sp.The culture conditions were optimized using a single-factor test method.Factors including carbon source,nitrogen source,temperature,initial pH value,rotational speed and salinity were studied.The results showed that the cultivation of the bacteria at 28℃ and 180 r min-1with initial pH 7 and 30 salt contcentration favored both the cell growth and the lysing effect of strain DH46.The optimal medium composition for strain DH46 was determined by means of uniform design experimentation,and the most important components influencing the cell density were tryptone,yeast extract,soluble starch,NaNO3 and MgSO4.When the following culture medium was used(tryptone 14.0g,yeast extract 1.63g,soluble starch 5.0 g,NaNO3 1.6 g,MgSO4 2.3 g in 1L),the largest bacterial dry weight(7.36 g L-1) was obtained,which was an enhancement of 107% compared to the initial medium;and the algal lysis rate was as high as 98.4% which increased nearly 10% after optimization.

Upper trophic structure in the Atlantic Patagonian shelf break as inferred from stable isotope analysis

The Patagonian Shelf is a very productive region with dif ferent ecosystem structures. A long history of fishing in the Southwestern Atlantic Ocean combined with a complex hydrographic structure, with a permanent front over the shelf-break and dif ferent coastal frontal regions, and a wide non-frontal area in between have made the food web in this area more complex and have resulted in changes to the spatialtemporal scale. Stable isotopes of carbon and nitrogen were used to determine the trophic structure of the Patagonian shelf break which was previously poorly understood. The results indicated that the average δ^(15)N value of pelagic guild(I llex argentinus) was remarkable lower than those of the other guilds. The δ^(13)C values of almost all species ranged from-17‰ to-18‰, but S tromateus brasiliensis had a significant lower δ^(13)C value. Compared with the southern Patagonian shelf, short food chain length also occurred. The impact of complex oceanographic structures has resulted in food web structure change to the temporal-spatial scale on the Patagonian shelf. The Patagonian shelf break can be considered as a separated ecosystem structure with lower δ^(15)N values.

Development and evaluation of a DNA microarray assay for the simultaneous detection of nine harmful algal species in ship ballast and seaport waters

Rapid,high-throughput and reliable methods are urgently required to accurately detect and monitor harmful algae,which are responsible for algal blooms,such as red and green tides. In this study,we successfully developed a multiplex PCR-based DNA microarray method capable of detecting nine harmful algal species simultaneously,namely A lexandrium tamarense,Gyrodinium instriatum,Heterosigma akashiwo,Karenia mikimotoi,Prorocentrum donghaiense,Prorocentrum minimum,Ulva compressa,Ulva ohnoi and Ulva prolifera. This method achieved a limit of detection(LOD) of 0.5 ng of genomic DNA(orders of magnitude of the deci-nanogram range) in the tested algae cultures. Altogether,230 field samples from ship ballast waters and seaport waters were used to evaluate the DNA microarray. The clinical sensitivity and specificity of the DNA microarray assay in detecting field samples were 96.4% and 90.9%,respectively,relative to conventional morphological methods. This indicated that this high-throughput,automatic,and specific method is well suited for the detection of algae in water samples.

Fractal dimensions of flocs between clay particles and HAB organisms

The impact of harmful algal blooms （HABs） on public health and related economics have been increasing in many coastal regions of the world. Sedimentation of algal cells through flocculation with clay particles is a promising strategy for controlling HABs. Previous studies found that removal efficiency （RE） was influenced by many factors, including clay type and concentration, algal growth stage, and physiological aspects of HAB cells. To estimate the effect of morphological characteristics of the aggregates on HAB cell removal, fractal dimensions were measured and the RE of three species of HAB organism, Heterosigma akashiwo, Alexandrium tamarense, and Skeletonema eostatum, by original clay and modified clay, was determined. For all HAB species, the modified clay had a higher RE than original clay. For the original clay, the two-dimensional fractal dimension （D2） was 1.92 and three-dimensional ffactal dimension （D3） 2.81, while for the modified clay, D2 was 1.84 and D3 was 2.50. The addition of polyaluminum chloride （PAC1） lead to a decrease of the repulsive barrier between clay particles, and resulted in lower D2 and D3. Due to the decrease of D3, and the increase of the effective sticking coefficient, the flocculation rate between modified clay particles and HAB organisms increased, and thus resulted in a high RE. The fractal dimensions of flocs differed in HAB species with different cell morphologies. For example, Alexandrium tamarense cells are ellipsoidal, and the D3 and D2 of flocs were the highest, while for Skeletonema costatum, which has filamentous cells, the D3 and D2 of flocs were the lowest.

Effect of Alexandrium tamarense on three bloom-forming algae

We investigated the allelopathic properties of Alexandrium tamarense(Laboar) Balech on the growth of Prorocentrum donghaiense Lu,Chattonella marina(Subrahmanyan) Hara et Chihara and Heterosigma akashiwo(Hada) Hada in a laboratory experiment.We examined the growth of A.tamarense,C.marina,P.donghaiense and H.Akashiwo in co-cultures and the effect of filtrates from A.tamarense cultures in various growth phases,on the three harmful algal bloom(HAB)-forming algae.In co-cultures with A.tamarense,both C.marina and H.akashiwo were dramatically suppressed at high cell densities;in contrast,the growth of P.donghaiense varied in different inoculative ratios of A.tamarense and P.donghaiense.When the ratio was 1:1(P.donghaiense:A.tamarense),growth of P.donghaiense was inhibited considerably,while the growth of P.donghaiense was almost the same as that of the control when the ratio was 9:1.The growth difference of P.donghaiense,C.marina and H.akashiwo when co-cultured with A.tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession involving A.tamarense.In addition,the filtrate from A.tamarense culture had negative impacts on these three HAB algae,and such inhibition varied with different growth phases of A.tamarense in parallel with reported values of PSP toxin content in Alexandrium cells.This implied that PSP toxin was possibly involved in allelopathy of A.tamarense.However,the rapid decomposition and inactivation of PSP toxin above pH7 weakened this possibility.Further studies on the allelochemicals responsible for the allelopathy of A.tamarense need to be carried out in future.

Toxic Dinoflagellate Alexandrium tamarense Induces Oxidative Stress and Apoptosis in Hepatopancreas of Shrimp(Fenneropenaeus chinensis)

This study investigated the inductive effect ofAlexandrium tamarense, a toxic dinoflagellate producing paralytic shell- fish poison, on oxidative stress and apoptosis in hepatopancreas of Chinese shrimp, Fenneropenaeus chinensis. The individuals of E chinensis were exposed to 200 and 1000 cells mL-1 of A. tamarense with their superoxide dismutase （SOD）, glutathione S-transferase （GST） activities, malonyldialdehyde （MDA） concentration, and caspase gene （FcCasp） expression in hepatopancreas determined at 12, 24, 48, 72 and 96 h. In addition, apoptosis in hepatopancreas of E chinensis at 96 h after exposure was determined through terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） assay. The hepatopancreatic SOD and GST activities of F. chinensis exposed to 1000 cells mL-1 ofA. tamarense showed a bell-shaped response to exposure time. The hepatopancreatic MDA concentration ofF. chinensis exposed to 1000 cellsmL-1 ofA. tamarense increased gradually from 48 to 96h, and such a trend corresponded to the decrease of GST activity. The hepatopancreatic FcCasp transcript abundance of F. chinensis exposed to 1000 cells mL-1 ofA. tamarense was positively and linearly correlated to MDA concentration. Results of TUNEL assay showed that exposure to 1000 cells mL-1 of A. tamarense induced apoptosis in the hepatopancreas of E chinensis. Our study revealed that A. tamarense exposure influenced the antioxidative status ofF. chinensis and caused lipid peroxidation and apoptosis in the hepatopancreas of shrimp.

Applications of immuno-magnetic bead and immunofluorescent flow cytometric techniques for the quantitative detection of HAB microalgae

Overthelastseveraldecades,harmfulalgalblooms(HABs)havebecomeaseriousenvironmental problem in many parts of the world. A rapid and accurate detection process for HAB algae has yet to be developed. Heterosigma akashiwo is one of the most important HABs species in China. The objective of this study was to develop an immunologic technique that can rapidly and sensitively count H. akashiwo cells. Five HABs species (Alexandrium catenella, Thalassiosira sp., Cryptomonas sp., Alexandrium tamarense and Symbiodinium sp.,) were used in this study to evaluate the analysis process we developed. A polyclonal antibody with high titers against H. akashiwo was obtained by injecting H. akashiwo cells into rabbits. Immuno-magnetic beads (IMB) were produced via conjugated polyclonal antibodies with magnetic beads and applied to isolate and count H. akashiwo cells from the culture. Results show that 66.7%-91.6% of the cells were captured from unialgal culture by IMBs, and only 5.3%-12.5% of the four other HAB microalgae species were captured, indicating that the constructed IMBs combined specifically with the H. akashiwo cells. At the same time, flow cytometry (FCM) sorting was exploited to screen H. akashiwo cells after labeling with FITC conjugated polyclonal antibodies. Using the FCM technique, 91.7% of the targeted cells were sorted out from mixed microalgae samples in just a few minutes. These results indicate that both antibody-involved IMB and antibody-based FCM techniques are highly effective at detecting and quantifying HAB species. These techniques, especially immuno-magnetic separation, have low associated cost, and are fast and simple processes compared with other techniques currently in use.

A Comparative Architectural Study of the Structural Form between Two Religious Buildings in Brasilia： The Cathedral and the Tibetan Stupa

Brasilia, born of the urban plan by Lficio Costa and of the unexpected concrete structural forms designed by Oscar Niemeyer, knew how to adapt to the new forms that came from the country＇s religious syncretism. This article aims to compare, through religious symbolism, structural forms and architectural spaces, two sacred monuments： The cathedral of Brasilia （1958-1967） and the stupa of the Tibetan Buddhist Center, inaugurated in 2006. The millenary construction form of the stupa, one of the primordial sacred structures for all Buddhism traditions, the sacred symbol of enlightenment, must obey some construction rules according to its lineage＇s Buddhist tradition. In this way, the stupa is the opposite of a strong and fearless structural form embodied in the cathedral, with its 16 revolution hyperboloid concrete pillars and its subterranean entrance. Although built in concrete both are unusual forms of architecture with distinct spatial conception and sculptural form structures. While respecting religious differences, it is noticeable a real commitment between form and structure, volume and religious symbolism. At the conclusion, it is perceivable how distinct forms--the Cathedral and the Stupa--can respond in analog manners to the necessity of a gathering space where visitors go in search of expressing their faith. Along with them, Buddhism and Catholicism are rooted in Brazil＇s new capital.

Archetypes of Both Sexes and Their Relations as Reflected in To the Lighthouse

Virginia Woolf＇s To the Lighthouse has gained wide recognition and is regarded by many scholars as her best work This novel is looked upon as an autobiographical novel of her family, and generally considered to represent Woolf＇s viewpoint on the relationship between two sexes. In addition to the feminist approach, this paper intends to study complex relations between male and female characters mainly from an archetypal perspective. Based on the study of archetypes in both sexes, we find that the main characters come through various psychological changes, so that their relations can be summed up respectively, as cooperative and finally harmonious

Physiological Characteristics of Rhizobia Isolated from Retama raetam （Forsk） and Lupinus various （L.） Indigenous to Libyan Desert

A total of 20 rhizobial isolates obtained from root-nodules of Retama raetam （Forsk） and Lupinus various （L.） were studied for their ability to tolerate local environmental and chemical stresses. Six fast and one slow growing reference strains were included for comparison. Numerical analysis showed that the reference strains were separated from test isolates. The majority of isolates displayed a high tolerance to extreme temperatures; some even grew at 48 ℃ and grew at alkaline and acid pH. Regarding tolerance to salinity on agar medium, the majority of the isolates grew at 6% NaCl, but some isolates from Lupinus various were more resistant, grew even at 8% NaCl. Most isolates were resistant to heavy metals, but were sensitive to most antibiotics tested.

The Characteristics of Mesoscale Convective Systems (MCSs) over East Asia in Warm Seasons

Mesoscale convective system (MCS) cloud clusters,defined using an objective recognition analysis based on hourly geostationary infrared satellite data over East Asia during the warm seasons of 1996-2008 (except 2004),were investigated in this study.The geographical pattern of MCS distribution over East Asia shows several high-frequency centers at low latitudes,including the Indo-China peninsula,the Bay of Bengal,the Andaman Sea,the Brahmaputra river delta,the south China coastal region,and the Philippine Islands.There are several middle-frequency centers in the middle latitudes,e.g.,the central-east of the Tibet Plateau,the Plateau of west Sichuan,Mount Wuyi,and the Sayan Mountains in Russia;whereas in Lake Baikal,the Tarim Basin,the Taklimakan Desert,the Sea of Japan,and the Sea of Okhotsk,rare MCS distributions are observed.MCSs are most intensely active in summer,with the highest monthly frequency in July,which is partly associated with the breaking out and prevailing of the summer monsoon in East Asia.An obvious diurnal cycle feature is also found in MCS activities,which shows that MCSs are triggered in the afternoon,mature in the evening,and dissipate at night.MCS patterns over East Asia can be characterized as small,short-lived,or elongated,which move slowly and usually lead to heavy rains or floods.

Analysis of Soil Water Dynamics in a Tropical Rain Forest Soil （Arinic lixisol）, Abeokuta, Nigeria

Soil water dynamics in the dominant lwo soil series （Arinic lixisol） were evaluated at the Federal University of Agriculture, Alabata, Abeokuta, Nigeria. Field capacity, infiltration and water retention characteristics were evaluated in situ for a period of 161 d in the dry season for two root zone depths. Results show that the Iwo soil series has a field capacity ranging from 2.6%-5.5% at 0-45 cm and 45-90 cm root zone depths, respectively. The soil is quick draining with high infiltration rate and very poor water retention capacity confirming that the soil will require a short irrigation interval of about 2-3 d since available water for plant growth in predominantly sandy soils ranges between 2%-8%. Based on the foregoing, sprinkler irrigation is best suited for the lwo soil series, it should, however, be noted that the water application rate must be less than the infiltration rate of the soil in order to prevent surface ponding and runoff. A multivariate model relating soil moisture content with soil moisture tension and soil temperature calibrated within the study had very low model accuracy of 56% and 45% for the two root zone depths, respectively, implying the need for further studies.

Suitability of marble powders in production of high strength concrete

A tremendous amount of non-biodegradable waste is created during mining and processing tasks of layered stones like marble.Over time,this has become a global problem because it harms the environment in multiple ways.Hence,it is necessary to find an alternate way to securely dispose and reuse marble wastes.The construction sector is one of the significant consumers of natural resources for the production of material binders and aggregates.As a result,in recent years,number of researchers have carried out studies in which various kinds of marble waste have been incorporated into concrete with the intention of substituting either cement or aggregates or both.This paper presents the effect of two locally sourced waste marble powders Kadapa marble powder(KMP)and Bethamcherla marble powder(BMP)as partial replacement of cement on mechanical and durability properties of high strength concrete(HSC).Their effect at different replacement levels in HSC is evaluated in compressive,indirect tensile and flexural strengths,elastic modulus,chloride penetration resistance and freeze-thaw durability properties.Micro-structural investigation is also conducted to evaluate their impact on the matrix of HSC containing waste marble powders as additional cementitious materials.Results show that the HSC consisting of KMP and BMP content of 10%and 15%,respectively exhibited higher mechanical and durability properties than the control HSC.Micro-structural investigation also supports this finding.It can be concluded that the use of marble powders as partial replacement of cement does not have any adverse impact on the properties of concrete.The use of KMP and BMP reduces the vast amount of energy required to produce cement,cost and time with reduction in environmental hazards.