Evaluation ofCitrullus colocynthis, a desert plant native in Israel, as a potential source of edible oil

Citrulus colocynthis(wild gourd) is a desert plant of the Cucurbitaceae, naturally adapted to arid environments. It was known in biblical times as a source of seed oil and its fruits were used as an efficient laxative. Accessions were collected in Israel and evaluated as a potential oil seed crop adapted to arid zones. It was found that its oil composition is similar to safflower oil, with a total of 80-85% unsaturated fatty acids. A potential yield of oil of 250-400 l ha⁻¹was calculated. The best yield was obtained during the first 4 weeks of the 10-week maturation period. Yield potential should be estimated under desert conditions in order to evaluate the plant's economic future as a crop suitable for an arid environment.     

中国半干旱草原施氮梯度下的土壤激发效应（英文）

为了探究施氮对土壤有机质(SOM)的激发效应,本研究在施氮梯度样地(0、4和16 g N m^–2 yr^–1)上进行了¹³C标记葡萄糖的原位添加实验,并对土壤CO_2排放量和磷脂脂肪酸(PLFA)含量进行了测定。研究发现施氮降低了土壤CO_2排放、土壤PLFA含量以及土壤真菌细菌比。在0 g N m^–2 yr^–1样地上葡萄糖添加导致的正向激发效应最强,同时4 g N m^–2 yr^–1样地释放的葡萄糖来源的碳最多。因此,施氮减少了土壤中SOM转化产生的CO_2,微生物碳的来源由SOM转变为添加的易分解碳。本研究采样早期土壤微生物生物量和群落结构稳定,表明该草原存在"表观激发效应",因此未来研究应着重对微生物功能的多样性进行探讨。     

桉树腐殖酸(HA)专用肥区域试验与配方的优选

采用随机区组设计,以等价投入的常规化肥为对照,开展专用肥多点施肥试验研究.通过专用肥对林木生长量、林相特征的影响分析,结果表明:与等价投入(肥料成本)的常规化肥相比,施用系列专用肥的林分生长量均显著或极显著地高于常规化肥处理,且叶片浓绿、树势强壮,施后19个月内,树高、胸径、材积分别提高了7.8%~51.8%、9.8%~53.0%和30%以上,叶片叶绿素含量提高26.3%~94.2%,叶面积指数提高41.0%~172.8%.经对HA桉树专用肥的增产性、适应性和稳定性的综合分析与评定,选出基肥专用的优化配方为:有机质≥30.0%、N P2O5 K2O≥6.0%(2.5-2.0-1.5)、腐殖酸总量≥8.0%,并加上适量的"绿滴"复合微生物菌剂(于施用时和基肥按每50 kg∶1 kg的量掺入);追肥专用的优化配方为:有机质≥20.0%、N P2O5 K2O≥20.0%(9-8-3)、腐殖酸总量≥6.0%.     

Fast tidal cycling and the origin of life

Replicating prebiotic polymers are thought to predate the emergence of true life-forms. The initial mode of replication, a prerequisite for Darwinian selection, is unknown, but demands an explanation based on local physicochemistry. Dual consideration of the conditions of the early terrestrial surface, with the unusual physicochemical properties of nucleic acids like DNA, could explain the emergence of nucleic acids as key biomolecules. The early impact that produced the Moon, and fast terrestrial rotation, subjected coastal areas 3.9 Ga ago to rapid tidal flooding (dilution) and drying (concentration), with a likely periodicity in the range of 2-6 h, and could have provided a driving force for cyclic replication of early biomolecules. Such a mechanism applies only to molecules capable of association/polymerization at high salt concentration, and of dissociation at low salinity. Nucleic acids meet these criteria. It is suggested that tidal cycling, resembling the polymerase chain reaction (PCR) mechanism, could only replicate and amplify DNA-like polymers. This mechanism suggests constraints on the evolution of extra-terrestrial life.     

高硫酸盐矿山废水的处理方法研究进展

高硫煤矿闭坑后成为埋藏在地表以下深部的产酸污染场,对相邻含水层和周边环境造成了潜在危害,且因采动效应影响和矿井空间分布复杂导致相邻含水层的污染过程与污染程度评价困难。以某闭坑矿区为研究对象,选取SO₄ ²⁻作为特征污染物,考虑多煤层采动裂隙对含水层结构的破坏影响,运用数值模拟技术对闭坑矿区酸性矿井水中SO₄ ²⁻污染迁移特征进行研究,并分析流体扩散系数对含水层污染物运移的影响。结果表明：SO₄ ²⁻在二叠系童子岩组砂岩含水层中水平迁移面积随时间增大而增大,增大速率逐渐减小,垂向渗透系数扩大10倍,空间变异性增强;闭坑5、10、15 a后,最大水平迁移距离分别为215、414、612 m,最大垂向迁移距离分别达到50、65、70 m;而扩散系数越大,产酸时间越长,SO₄ ²⁻迁移距离和污染范围将随之增大,相较于水平方向,垂向上SO₄ ²⁻浓度变化对扩散系数的敏感度更高。基于模拟结果,结合闭坑矿区实际条件,针对性提出了“源头减量−过程阻断−末端治理”的综合防控与治理方案。研究结果将为该闭坑煤矿酸性矿井水污染治理与防控提供理论基础,也为其他同类矿井提供科学借鉴。

     

Characterization of two newArtemia populations from two solar saltworks of Lesbos Island (Greece): biometry,hatching characteristics and fatty acid profile

Cysts of two parthenogeneticArtemia strains from the Kalloni and Polychnitos saltworks on Lesbos Island were evaluated for their potential use in aquaculture. The characterizations performed were: cyst and naupliar biometrics, cyst hatching characteristics, and fatty acid profile of instar-I nauplii. Deactivation of diapause after treatment with H₂O₂ and/or decapsulation were applied in order to improve cyst hatchability. The evaluation revealed that the strains studied exhibit acceptable hatching characteristics for parthenogeneticArtemia and that the fatty acid profile of the Kalloni strain is excellent for use in culturing marine fishes and crustaceans. Statistical analyses on cyst and naupliar biometrics showed that the two populations characterized are almost identical and very similar to other Greek parthenogenetic strains.     

磺化层柱状有机膦酸锆的合成及催化反应研究

在氢氟酸溶液中,混合亚磷酸、4,4’-联苯二膦酸和锆离子反应生成4,4’-联苯二膦酸锆／亚磷酸锆（简称MCZP）,改变有机酸和亚磷酸的比例,可以合成具有相同组分但结构不同的一系列化合物。通过磺化反应,在苯环上接上磺酸基团后,它具有类似强酸性阳离子交换树脂特性．该文首次对这类化合物催化酯化、醚化等典型的酸催化有机反应进行了研究,结果表明其催化转化率高、催化剂可重复使用和再生,是一种很有发展前途的新型固体酸催化剂．     

Limnology of Opal Lake

Opal Lake, a cold, acid lake on the central volcanic plateau of the North Island, New Zealand, had an average pH of 4.3 and was highly eutrophic. The biota was less diverse than in neighbouring near‐neutral waters. Macrophytes were rare; phytoplankton were mainly represented by the Chlorophyceae, and there were only 4 zooplankton species. The mean standing crop of macroinvertebrates was 6240 per square metre; this was higher than in other eutrophic lakes in the region and comprised more than 98% chironomid larvae represented by 4 species. Molluscs were absent. The fauna was more diverse than in more acid lakes of the .central volcanic plateau.     

敞开酸溶-电感耦合等离子体发射光谱法测定石煤钒矿中钒铁铝磷

石煤钒矿资源的勘探、研究和利用均需对其成分进行准确的分析测试,其中钒、铁、铝、磷等主要成分的测定尚未建立标准方法,当前所用的分析测试方法各有不足。采用碱熔电感耦合等离子体发射光谱法(ICP-OES)测定石煤钒矿样品时,高浓度的可溶性盐会导致高背景,干扰测定。酸溶法可避免上述问题,但由于常规的氢氟酸-盐酸-硝酸-高氯酸四酸体系不能消除碳和有机质对样品的吸附和包裹,待测成分无法完全释放,需先将样品高温灼烧除碳,过程繁琐。本文采用少量硫酸加四酸的五酸体系处理样品,电热板加热,盐酸浸提,利用硫酸的强氧化性将样品中大量的碳氧化成二氧化碳,免却了灼烧除碳流程,消除了含碳物质对样品的吸附和包裹,显著增强了消解效果。由此建立了ICP-OES测定石煤钒中钒、铁、铝、磷的分析方法,在称样量为0.1g、浓硫酸加入量为0.30mL时,样品消解率达到99%以上。方法检出限为17~51mg/kg,相对标准偏差(RSD, n=11)在1.7%~5.1%之间;相对误差为-4.6%~2.7%。该方法背景低、测定结果准确,可满足石煤钒矿石样品的检测要求。