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A new method of simultaneous determining Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) with a single sweep polarography
was developed. The experiment condition was studied and the results show that the optimum base solution is that the residue
got from evaporating 25 mL mixed solution, 2.5 mL 1.0 mol/L ethylenediamine, 3.0 mL 1.0 mol/L ammonia-ammonium chloride, 5.0
mL 10 % sodium sulfite and 0.5 mL 0.5 % gelatin were mixed and diluted to 25 mL with water. Under the condition of this base
solution, the polarography wave shapes of the six cations are ideal and without overlap of the peaks. In this base solution,
Cu(II), Zn(II), Fe(II), Mn(II), Co(II) and Ni(II) in synthetic samples were determined with relative errors 0.4–9.4% and relative
standard deviations 0.8%-12.2%. Under this experiment condition, one fold of Pb(II), Cr(VI) and Mo(VI) do not interfere with
the determination for Cu(II). This method has been used to the simultaneous determination of the amount of the six cations
in the samples of soil and Beiqi Tea. The relative standard deviations were 0. l%-2.1% and recoveries were 93.5%-99.0 %. 相似文献
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本文对乌鞘岭地区天然分布的中国沙棘和西藏沙棘果实生长与成熟期间维生素C,PP,E等含量的动态变化进行了系统的调查和分析测定。结果表明:V_C主要存在于果肉中,且随果实发育而增加,果实变色期(花后107—110天)达到最高值,随后急速下降。但完熟后果肉中V_C减少时种子内V_C却有所增加。中国沙棘V_C水平远较西藏沙棘为高(5倍以上)。果实发育前期果肉中V_(PP)含量很高,以后逐渐下降,完熟期中国沙棘果实内V_(PP)再度升高,其变化与呼吸速率的变化表现出相同的消长规律。V_E主要存在于种子里,总趋势是随成熟而增加。种子变色期V_E上升至第一高峰值,随后下降,果实完熟后达到第二高峰值。西藏沙棘V_E含量高于中国沙棘。本文对不同维生素可能起的生理作用也进行了讨论。 相似文献
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The effect of six plantation species in comparison to natural forest (NF) on soil organic carbon (SOC) and total nitrogen (TN) stocks, depth-wise distribution, biomass carbon (C), and N was investigated on plantations and cultivated lands on an Andic paleudalf soil in Southern Ethiopia. The SOC, N, and bulk density were determined from samples taken in 4 replicates from 10-, 20-, 40-, 60-, and 100-cm depth under each site. Similarly, the biomass C and N of the plantation species and understory vegetation were also determined. The SOC and N were concentrated in the 0- to 10-cm depth and decreased progressively to the 1-m depth. Next to the NF, Juniperous procera accrued higher SOC and N in all depths than the corresponding plantations. No evidence of significant difference on SOC and N distribution among plantations was observed below the 10-cm depth with minor exceptions. The plantations accrue from 133.62 to 213.73 Mg ha–1 or 59.1 to 94.5% SOC, 230.4 to 497.3 Mg ha–1 or 6.9 to 14.9% TBC and 420.37 to 672.80 Mg ha–1 or 12.5 to 20% total C-pool of that under the NF. The N stock under Juniperous procera was the highest, while the lowest was under Eucalyptus globulus and Cupressus lusitanica. We suggest that SOC and N sequestration can be enhanced through mixed cropping and because the performance of the native species Juniperous procera is encouraging, it should be planted to restock its habitat. 相似文献
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Hanqin Tian Guangsheng Chen Mingliang Liu Chi Zhang Ge Sun Chaoqun Lu Xiaofeng Xu Wei Ren Shufen Pan Arthur Chappelka 《Forest Ecology and Management》2010
The effects of global change on ecosystem productivity and water resources in the southern United States (SUS), a traditionally ‘water-rich’ region and the ‘timber basket’ of the country, are not well quantified. We carried out several simulation experiments to quantify ecosystem net primary productivity (NPP), evapotranspiration (ET) and water use efficiency (WUE) (i.e., NPP/ET) in the SUS by employing an integrated process-based ecosystem model (Dynamic Land Ecosystem Model, DLEM). The results indicated that the average ET in the SUS was 710 mm during 1895–2007. As a whole, the annual ET increased and decreased slightly during the first and second half of the study period, respectively. The mean regional total NPP was 1.18 Pg C/yr (525.2 g C/m2/yr) during 1895–2007. NPP increased consistently from 1895 to 2007 with a rate of 2.5 Tg C/yr or 1.10 g C/m2/yr, representing a 27% increase. The average WUE was about 0.71 g C/kg H2O and increased about 25% from 1895 to 2007. The rather stable ET might explain the resulting increase in WUE. The average WUE of different biomes followed an order of: forest (0.93 g C/kg H2O) > wetland (0.75 g C/kg H2O) > grassland (0.58 g C/kg H2O) > cropland (0.54 g C/kg H2O) > shrubland (0.45 g C/kg H2O). WUE of cropland increased the fastest (by 30%), followed by shrubland (17%) and grassland (9%), while WUE of forest and wetland changed little from the period of 1895–1950 to the period of 1951–2007. NPP, ET and WUE showed substantial inter-annual and spatial variability, which was induced by the non-uniform distribution patterns and change rates of environmental factors across the SUS. We concluded that an accurate projection of the regional impact of climate change on carbon and water resources must consider the spatial variability of ecosystem water use efficiency across biomes as well as the interactions among all stresses, especially land-use and land-cover change and climate. 相似文献
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松材线虫侵染对马尾松苯丙烷类代谢的影响 总被引:9,自引:1,他引:9
1.5年生马尾松植株接种松材线虫后,苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)的活性水平均高于对照,活性高峰通常出现在症状表现前夕,并在植株发病后下降.叶内PAL和POD活性高峰的出现晚于茎,与叶部病害发展一致.茎中酚类物质的含量随着线虫侵染时间的延长逐渐增加,至发病时达到高峰.酚类物质含量的变化与PAL、POD、PPO 3种酶活性的变化趋势基本一致.松材线虫的侵染明显影响寄主植物的苯丙烷类代谢,由此可知,松材线虫病的发生发展与松材线虫诱导感病寄主苯丙烷类代谢的异常变化有关. 相似文献
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两种卵蜂在舞毒蛾卵上的寄生动态 总被引:3,自引:0,他引:3
北京地区大蛾卵跳小蜂和舞毒蛾卵平腹小蜂在舞毒蛾卵上一年可以分别完成4-5代和2—3代。两种卵蜂对舞毒蛾的寄生率因采集时期不同而有差异,以8月采集的卵块寄生率最高。7月中旬至8月中旬采集的卵中大蛾卵跳小蜂的寄生率为2.26—4.18%。7月中下旬采集的,舞毒蛾卵平腹小蜂的寄生率为0.64—0.66%。大蛾卵跳小蜂当年羽化的占99.3%,次年羽化的占0.7%。舞毒蛾卵平腹小蜂当年羽化的占81.0%,次年羽化的为19.0%。为保护两种卵蜂,人工采摘卵块除治舞毒蛾的最好时期是9月下旬至次年3月下旬。 相似文献
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运用Cytb 和12s rRNA 基因鉴别梅花鹿(Cervus nippon)和马鹿(Cervus elaphus)的研究 总被引:2,自引:0,他引:2
本研究介绍了运用细胞色素b基因和12s核糖体RNA基因部分序列的系统学和核甘酸距离分析来鉴别降解的梅花鹿和马鹿样品。采用PCR和直接测序技术获得了8份嫌疑样品402bp细胞色素b基因序列,并与来自GenBank数据库27份同源的细胞色素b基因序列进行比对。3份嫌疑样品与梅花鹿的核甘酸距离值相同(0.026±0.006),小于梅花鹿与东部马鹿间最小的核甘酸距离值(0.036)。并且梅花鹿和马鹿的系统学分析表明这些样品与梅花鹿聚为一枝,因此可以推测它们来源于梅花鹿。同样的方法得出另3份嫌疑样品来源于马鹿。该结果被387bp12s核糖体RNA基因序列的系统学和核甘酸距离分析进一步证实。该方法是有效的,花费的时间少,能帮助减少同类野生动物案件的发生。图2表1参13。 相似文献
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This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin
Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based
on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites,
a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect,
vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems.
The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province.
Foundation item: This paper was supported by Chinese Academy of Sciences “100 people” project and the Open Research Station of Changbai Mountain
Forest Ecosystem.
Biography: XIAO Bao-ying (1974-), female, postgraduate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016,
P. R. China
Responsible editor: Zhu Hong 相似文献
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3S技术在中国湿地研究、调查与管理中的应用 总被引:10,自引:0,他引:10
CUI Li-juan Anna van Paddenburg ZHANG Man-yin 《林业研究》2005,16(4):317-322
This paper introduces the state of waterlands in China and discribes the applications of Remote Sensing (RS), Geographical Information System (G1S) and Global Positioning System (GPS) in wetland research, including land-coverclassification and change detection, wetland evolutionary processes, landscape-change analyses, channel migration, flood and wetlands resource monitoring and spatial quantitative analyses/modeling, ecosystem service evaluation, ecological processes and risk assessments, disease control, water quality monitoring/modeling, pollution monitoring/modeling, wetlands hydrology, wetland information systems and WebGIS. The limitations and needs for optimal use of these technologies are discussed, such as the limited advanced technical knowledge and skills, low awareness and capacity, unclear link between GIS output and policy making, lack of supporting policies and standards, lack of a wetlands geo-information networklimite, and the use of these techniques in wetland research. It is suggested that for realising true applications of RS, GIS and GPS technologies, the availability, accessibility, reliability, homogeneity, and continuity of wetlands-related geo-information enabling environment, policies and standards, and funding are needed. 相似文献
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结合离散型制造业的生产任务特点,探讨如何通过多种信息系统的集成和应用,提高企业信息化应用水平,提高传统制造业的技术水平和生产效率,提升产业核心竞争力。 相似文献
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株洲市生活污水污染特征研究 总被引:1,自引:0,他引:1
在一年中,分4个季度(每季度3天,每天4次)对株洲市区具有代表性的4个不同地点的生活污水水质进行了监测.结果表明生活污水中的主要污染物是BOD5和Inorg-P;污染物浓度有明显的时空变化规律,中午和傍晚前后的浓度较高,早晨和半夜则较低,冬、春季节的污水污染物浓度皆高于夏、秋两季,居民、餐饮业密集区的污水中污染物浓度显著高于商业区和混合区;污水中氮、磷主要以无机盐形式存在;目前株洲市生活污水排放量与主要工业污染源废水年排放量相当,CODcr、BOD 相似文献
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ACQ和CuAz防腐处理对木材力学性能的影响 总被引:9,自引:2,他引:9
采用水溶性铜防腐剂(ACQ)和铜唑类防腐剂(CuAz)加压浸注处理臭冷杉木材,研究了药液处理浓度和后期干燥条件对木材抗弯弹性模量和抗弯强度的影响。t检验表明,本试验条件下,经两种防腐剂处理后,木材的抗弯弹性模量保持不变或略微增加。通过分析与对照素材试件的t检验比较,表明两种防腐剂处理前、后木材的抗弯弹性模量差异不显著。ACQ和CuAz防腐处理对木材抗弯强度有一定影响,ACQ处理使得木材抗弯强度整体上略有下降,而CuAz处理由于保持量相对较低,对木材抗弯强度未见明显下降趋势。后期干燥方式对木材抗弯强度亦未见明显规律性的影响。 相似文献
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In Japan, ammoniacal copper quaternary wood preservatives type-1 (ACQ-1), which contains copper and benzalkonium chloride
as its active ingredients, is among the most widely used wood preservatives in the pressure treatment of wood. Benzalkonium
chloride (BAC) in commercial ACQ-1 products mainly comprises C12 and C14 homologues. In the present study, the leaching characteristics
of these BAC homologues were investigated using the heartwood and sapwood portions of Japanese cedar, Japanese larch, and
Sakhalin fir treated with ACQ-1 and 1% monoethanolamine (MEA) solution containing equimolar amounts of homologues. Distilled
water (DW) and artificial seawater (SW) were used as leaching media. Consequently, it was observed that the leaching rate
of the C12 homologue tended to be higher than that of the C14 homologue in DW. The leaching of C12 homologues was accelerated
by using SW, resulting in a significantly higher leaching rate than the C14 homologue using SW. It was thought that the difference
in the hydrophobicities based on alkyl chain lengths resulted in these phenomena. However, when the heartwood portion of Japanese
larch was treated with the homologues in MEA, the leaching rate of the C14 homologue was significantly higher than that of
the C12 homologue. 相似文献