超钾碱性杂岩体中的碳酸岩矿床

<正> 与默隆超钾碱性杂岩体中的碳酸岩有关的查洛石[charoite,化学式:(Ca、Na、K、Sr、Ba)_sSi_4O_(10)(OH、F)0.5-1H_2O,1976年发现的新矿物——译者注]、菱碱土矿、碱锰闪石——石棉和高钾岩石(钾长石岩)矿床是目前世界上独一无二的。除上述矿物外,还含有新的外来矿物:钛钾钙硅石、硅碱钙石、硅钠钙石等以及纤维状的石英、方解石、     

苏联深部作用实验地球化学研究

<正> 1981年3月24—25日,在苏联科学院地球化学与分析化学研究所召开了地壳和地幔地球化学作用研究的实验工作者的例行学术讨论会。 会议除讨论了有关热液系统、岩浆系统、同质多相、类质同相和高参数条件下固相反应等的实验研究及实验技术和方法的论题以外,还讨论了有关深部作用物理-化学模拟研究方面的实验资料的提供问题。 苏联科学院通讯院士在开幕式     

用渗透法采样长时间监测二氧化硫

本文介绍了一种长时间监测二氧化硫的新方法。此法能提供为期数周或数月内二氧化硫的时间—重量平均浓度。其根据是气态二氧化硫能定量地渗透过二甲基硅聚合物薄膜,进入一种锰盐溶液中,随后被催化氧化成硫酸。同二氧化铅柱法一样,它不需要泵或者电机,产物对光和热均稳定。而与前者不同的是它能提供二氧化硫浓度的绝对数值,方法特效,不受湿度影响,可以放置长达三个月。放置七天的检出限为10μg/m~3二氧化硫。在测定和控制大气质量方面,长期以来就认为二氧化硫是个重要的参数。过去,曾用过氧化铅柱(Camdle)及Huey板监测硫酸盐化效应。将Masen,或Peti碟分别涂以二氧化铅糊之后,就可以硫酸铅的形式收集二氧化硫。这种方法单调复杂,且受外界条件影响,一般不被采用。因为硫酸盐气溶胶有干扰、湿度、风速对硫酸盐化速率亦有影响,使其缺乏特效,这就大大降低了这种方法的使用价值。尤其严重的是硫酸盐化速率与大气中二氧化硫的浓度没有一种定量的关系。近来,在收集和测定二氧化硫技术方面,Reiszner与West提出了结合渗透采样法的新技术,为长时间监测二氧化硫提供了一种有效的方法。二氧化硫以dichlorosulfitomercurate(Ⅱ)的形式约能稳定7天;但Sulfito络合物会受热和光化学作用而分解,因而使用时间不能延长。现在提出的一种较好的方法能够在不使用电的或者其它复杂先进仪器的情况下,监测二氧化硫几周甚至数月,其结果为大气中二氧化硫的完整数值,因而它对联帮政府的规定有着直接的联系。此法包括用渗透法采样,使气体穿过薄膜进入一种催化氧化溶液中,该溶液使二氧化硫以硫酸盐形式稳定下来。产生的样品以2—咱啶基铵硫酸盐(2—Perimidinylammonium sulfate)形式沉淀,然后用比浊法分析。     

电凝聚净化废水法

机器制造、电气技术和无线电技术工业的迅速发展使得含重金属的生产废水日益增多。由于进行多道工序的金属化学与电化学加工,污水中的铬、锌、铜、镍、镉和铁等金属元素都以各种原子价的离子     

14、用毛细管气相色谱的滞留指数比鉴定PCB的组份

许多研究证明,多氯联苯(PCB)是常见的环境化合物。 PCB分析的主要问题就是可能有大量的单一成份。在商品PCB混合物中,一共发现了209种含氯同系物异构体中的100多种。由环境样品尤其是由生物体中得到的PCB残留物表明是一种与含氯40—60％的商     

废纸的水解

水解植物纤维素并发酵制造其它产物的方法有几种。本文只对酸水解法和酶水解法的经济优点进行比较。所使用的原料是生活垃圾中的废纸。现已得出结论:酶水解法的费用仍然大大高于酸水解法,其重要原因是酶的价格较高。酸水解法生产每吨葡萄糖     

土地利用和理化环境对莫比尔-亚拉巴马河系中水甲基汞含量的影响

最近我们对美国东南部地区许多水域系统肉食性鱼类身上可能造成健康危险的超标汞(Hg)含量进行了测量.根据从出版的有关汞的水地球化学的实验数据得出的假设,我们调查了某些自然和人为的条件对莫尔比-亚拉巴马河系(MARS)中现场甲基汞(MeHg)含量的影响.从不同类型的环境采集了水样,假设这些水样具有不同的水甲基汞含量,并分析了总汞(THg)和甲基汞浓度以及一些主要的地球化学参数.结果如下:①总的来说,莫比尔-亚拉巴马河系水域中的总汞浓度分布相当均匀,从0.2ng/L到6ng/L不等,表明除了地质来源外,大气沉降肯定是所研究的水系中汞输入的主要来源.②在具有可比较的总汞含量的地点,以甲基汞形式存在的汞部分在从莫比尔-亚拉巴马河系的沿岸平原部分采集的样品中的含量始终比从其他地质区域采集的样品中的高.③我们的现场观测证实了从实验室试验获得的结论,即:甲基汞在水域系统中的丰度与硫酸盐(但只是在较窄的浓度范围内)有关,以及与pH的减少相关,而与硝酸盐或磷酸盐均无直接的关系.④对单一场所生物区中汞的累积的调查表明,在总汞浓度较低但甲基汞/总汞之比较高的水域系统中,生物的汞含量可能超出安全界限.因此,即使水相没有显示出有汞严重富集的迹象,也可能存在对食鱼人群的潜在健康威胁.     

Genetic variation in natural honeybee populations,<Emphasis Type="Italic"> Apis mellifera capensis</Emphasis>

Genetic variation in honeybee, Apis mellifera, populations can be considerably influenced by breeding and commercial introductions, especially in areas with abundant beekeeping. However, in southern Africa apiculture is based on the capture of wild swarms, and queen rearing is virtually absent. Moreover, the introduction of European subspecies constantly failed in the Cape region. We therefore hypothesize a low human impact on genetic variation in populations of Cape honeybees, Apis mellifera capensis. A novel solution to studying genetic variation in honeybee populations based on thelytokous worker reproduction is applied to test this hypothesis. Environmental effects on metrical morphological characters of the phenotype are separated to obtain a genetic residual component. The genetic residuals are then re-calculated as coefficients of genetic variation. Characters measured included hair length on the abdomen, width and length of wax plate, and three wing angles. The data show for the first time that genetic variation in Cape honeybee populations is independent of beekeeping density and probably reflects naturally occurring processes such as gene flow due to topographic and climatic variation on a microscale.     

Silvery mole-rats (<Emphasis Type="Italic">Heliophobius argenteocinereus</Emphasis>, Bathyergidae) change their burrow architecture seasonally

Little is known about seasonal changes in burrowing activity and burrow architecture in subterranean African mole-rats (Bathyergidae, Rodentia). The solitary genus Heliophobius is the least known genus of this family. We examined burrow systems of the silvery mole-rat ( Heliophobius argenteocinereus) in Malawi in two periods of the dry season. Burrow pattern was influenced by the time of the year, becoming more reticulated at the peak of the dry season when soil was dry and hard. Overall digging activity did not cease during the dry season; yet burrowing strategy changed and the soil was deposited in tunnels rather than transported to mounds. The length of burrow systems was correlated with the body mass of the respective occupants. In spite of their solitary habits – and contrary to the prediction of the aridity food-distribution hypothesis – silvery mole-rats are able to occupy poor habitats with low food supply.     

Recycling plant wax constituents for chemical defense: hemi-biosynthesis of triterpene saponins from β-amyrin in a leaf beetle

Several species of Doryphorina leaf beetles from Central- and South America produce oleanane triterpene glycosides in their defensive glands. The presence of pentacyclic triterpenes in insects is intriguing since they lack the key enzymes necessary to synthesize these compounds. Since -amyrin is a common constituent of leaf waxes, we hypothesized that these leaf beetles use this compound as a precursor to their oleanane glycosides. To test this hypothesis we first confirmed the presence of -amyrin in Ipomoea batatas, the food plant of Platyphora kollari. Next, adults of P. kollari were fed for 10 days with I. batatas leaf disks painted with a solution of [2,2,3-²H₃]-amyrin ([2,2,3-²H₃]-1). The secretion from their defensive glands was collected and analyzed by HPLC-ESIMS. The results demonstrated that the secretion of beetles fed with an amount of [2,2,3-²H₃]-amyrin corresponding to the quantity of unlabeled (natural) -amyrin present in the leaf disks contained on average 5.1% of [2,2,3-²H₃]-3-O--d-glucopyranosyl-(1-->4)--d-glucuronopyranosyl-hederagenin ([2,2,3-²H₃]-2), whereas the secretions of beetles fed with 10 times this amount of [2,2,3-²H₃]-amyrin contained on average 23.9% of [2,2,3-²H₃]-2. In both series of experiments, the percentage of labeled versus unlabeled triterpene glycoside in the secretion was positively correlated with the amount of deuterated -amyrin ingested. These results demonstrate for the first time that some leaf beetles are able to metabolize a widespread triterpenic constituent of leaf wax into more complex glycosides that are stored in their defensive glands.