The production of sexual and asexual larvae within single broods of the scleractinian coral, Pocillopora damicornis

The genotypic compositions of two populations of the brooding coral, Pocillopora damicornis, were studied by exhaustive sampling of adult colonies on a fine scale in southern Taiwan. In addition, 100 larvae were randomly selected among more than 1,000 brooded larvae collected from a single broodparent within each population. Using 7 polymorphic microsatellite markers, both populations were found to be highly clonal, and 7 clonal lineages were characterized. One clonal lineage (C1) dominated both study areas and comprises 54.9% of all colonies sampled, while any of the other 6 clonal lineages represented no more than 5%. Among the 100 larvae randomly selected for genotyping from each broodparent, the extent of clonal reproduction was high, and only 29 and 6 larvae, respectively, were found to be genotypically different from their broodparent. Among the 35 genotypically distinct larvae, 33 were thought to be derived from sexual reproduction, and 2 were assumed to be clonal propagules that had undergone somatic mutations. Two genotypically identical larvae were also found in one of the 2 sexually derived larva arrays, indicating the possible existence of polyembryony. The high proportions of clonality in both adult colonies and brooded larvae suggest that asexually produced larvae might significantly contribute to the recruitment of local populations. The dense clonal population of P. damicornis in the study area favors the quick recolonization view of clonal propagules after disturbances.     

粉煤灰中植物营养元素赋存状态及应用

土壤化学分析表明 ,粉煤灰中一般含有丰富的矿质营养元素。这些营养元素的赋存状态决定了粉煤灰的供养能力和供养特点。通过对粉煤灰的粉晶X 射线衍射分析、扫描电镜观察以及透射电镜分析、电子探针分析 ,揭示了粉煤灰中元素的赋存状态。粉煤灰中的营养元素主要赋存于玻璃相中。由于粉煤灰的玻璃质颗粒和矿物析晶体粒径细小、结构不稳定、活性很大 ,其中的营养元素易溶出。     

秦皇岛市大气污染的灰色关联分析

利用灰色关联分析方法对秦皇岛市大气环境质量的影响因素进行筛选,得出各项因素的主次关系。研究表明,煤炭使用量、港口吞吐量和机动车保有量的增加是影响秦皇岛市大气环境质量的重要因素。基于此,提出政府应大力发展清洁能源、加强港口煤尘治理和机动车污染防治等建议。     

Impacts of simulated acid rain on recalcitrance of two different soils

Laboratory experiments were conducted to estimate the impacts of simulated acid rain (SAR) on recalcitrance in a Plinthudult and a Paleudalfs soil in south China, which were a variable and a permanent charge soil, respectively. Simulated acid rains were prepared at pH 2.0, 3.5, 5.0, and 6.0, by additions of different volumes of H₂SO₄ plus HNO₃ at a ratio of 6 to 1. The leaching period was designed to represent 5 years of local annual rainfall (1,200 mm) with a 33 % surface runoff loss. Both soils underwent both acidification stages of (1) cation exchange and (2) mineral weathering at SAR pH?2.0, whereas only cation exchange occurred above SAR pH?3.5, i.e., weathering did not commence. The cation exchange stage was more easily changed into that of mineral weathering in the Plinthudult than in the Paleudalfs soil, and there were some K⁺ and Mg²⁺ ions released on the stages of mineral weathering in the Paleudalfs soil. During the leaching, the release of exchangeable base cations followed the order Ca²⁺?>?K⁺?>?Mg²⁺?>?Na⁺ for the Plinthudult and Ca²⁺?>?Mg²⁺?>?Na⁺?>?K⁺ for the Paleudalfs soil. The SARs above pH?3.5 did not decrease soil pH or pH buffering capacity, while the SAR at pH?2.0 decreased soil pH and the buffering capacity significantly. We conclude that acid rain, which always has a pH from 3.5 to 5.6, only makes a small contribution to the acidification of agricultural soils of south China in the short term of 5 years. Also, Paleudalfs soils are more resistant to acid rain than Plinthudult soils. The different abilities to prevent leaching by acid rain depend upon the parent materials, types of clay minerals, and soil development degrees.     

Identification of cadmium-induced genes in maize seedlings by suppression subtractive hybridization

A maize variety, Huatian-1, had an unusually low translocation rate of cadmium (Cd) (59.6 mg·kg^-1 in the roots and 0.093 mg·kg^-1 in the grain) compared to 24 other varieties while being grown in soils with 16.50 mg·kg^-1 Cd. This indicates that this particular species may have special mechanisms that affect the absorption and translocation pattern of Cd. In this paper, the technique of suppression subtractive hybridization (SSH) was used to isolate and identify Cd-induced genes from Huatian-1 hydroponically ?exposed? to? 0.1 mM ?CdCl₂ ?for? 1 h,? 12 h, 24 h, and 48 h. We found a total of 15 differentially expressed genes in the four groups; 2, 3, 4, and 6 genes were from the groups of 1 h, 12 h, 24 h, and 48 h treatment, respectively. Phospholipase PLDb1 mRNA, adenosine triphosphate (ATP) phosphoribosyl transferase 2, and Sp17 were turned on in the maize in response to Cd stress, and it might provide new clues to explain the mechanism of maize tolerance to Cd.     

生命周期评价在过程工业用水网络设计中的应用

介绍了考虑环境因素的过程工业用水网络设计研究进展,分析了典型的过程工业水系统的特点,肯定了在整个水系统生命周期内考察用水网络设计方案环境效益的重要性,给出了生命周期评价方法在用水网络设计中应用的技术框架。     

烟嘧磺隆降解菌SY-6的固定化、降解特性及其工程化应用

以海藻酸钠为载体,对烟嘧磺隆降解菌SY-6进行细胞固定化,通过单因素实验明确了菌株包埋SY-6的最优条件,并对其降解特性进行研究。结果表明,当海藻酸钠含量为4%,Ca Cl2含量为3%,固化时间为4 h,制得的固定化小球具有较强的机械强度和较好的传质性能及其对烟嘧磺隆的降解率较高。固定化细胞降解烟嘧磺隆的最佳条件为p H为7.0、温度为30℃、包菌量为5%。在不同p H或温度下,与游离细胞相比,固定化细胞有较宽泛的耐受性。将包埋的SY-6投加到序批式反应器(简称SBR)中处理烟嘧磺隆废水,结果表明,菌株SY-6在合适的使用周期内稳定性较高且对烟嘧磺隆废水降解效果较好,为烟嘧磺隆固定化细菌的工程化应用奠定了基础。     

张八岭构造带两种类型金矿次显微金赋存状态的质子探针分析

金属硫化物中次显微金的赋存状态已引起人们的重视。张八岭构造带蚀变构造岩型和石英脉型两类金矿金属硫化物中次显微金质子探针分析显示 ,Au与As、Fe、S、Cu、Pb呈正相关关系 ,Au以显微包裹体形式存在于金属硫化物中。与蚀变构造岩型金矿相比 ,晚期的石英脉型金矿可见自然金含量较高 ,硫化物中显微包裹体金含量较低 ,可能预示中低温热液金矿中 ,不仅普遍存在时空分异的金属硫化物中的类质同象金和自然金 ,还可能存在一定程度的时空分异的自然金和次显微包裹体金。     

Conjugation of Soybean Oil and It’s Free-Radical Copolymerization with Acrylonitrile

The conjugated soybean oil was synthesized through the isomerization reaction of soybean oil to transformed the structure of linoleic acid into conjugated linoleic acid structure, and Rhodium complexes (RhCl(Pph₃)₃) was used as catalyst. The efficiency on the conjugation of catalyst RhCl (Pph₃)₃, tin dichloride dehydrate (SnCl₂·2H₂O) and triphenylphosphine (Pph₃) were evaluated. The results showed when RhCl(Pph₃)₃, SnCl₂·2H₂O and Pph₃ are 9.25, 9.0 and 13.1 mg in 100 g soybean oil respectively, the highest conversion of conjugation achieved 96%. The free radical copolymerization of conjugated soybean oil with acrylonitrile (AN) and dicyclopentadiene (DCP) was studied. AIBN was used as the initiator. FT-IR and ¹H-NMR results indicates that the conjugated soybean oil with AN and DCP did occur free radical copolymerization with the initiator AIBN. The product is light yellow powder. The thermal properties of the soy-based copolymer were investigated by TG and DSC. The initial degradation temperature of polymers is higher then 250 °C.     

一个第四纪红色粘土母质发育的红壤剖面微形态特征的研究

发育在我国南方亚热带季风气候地区的第四纪红色粘土母质上的红壤早已为人们所注意。这是一类粘粒主要由结晶度不甚高的高岭石以及铝蛭石、伊利石，针铁矿所组成，具有一定脱硅富铝化程度且粘重的土壤．本文以微形态学方法对一个这类土壤剖面（江西余江）进行了详细研究．结果表明：该剖面微形态的演变主要表现在细粒物质及微结构特征的变化两方面。这些变化似乎与土体内的水分状况变化及因而引起的粘粒物质移动有关．令人感兴趣的是：在红色心土层的中上部（Ｂ１层）可观察到典型的微团聚化现象，说明这一过程不仅仅为热带湿润地区高度发育的铁铝土所特有，而且在北亚热带季风气候条件下发育的红壤中同样也有发生。