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1.
The reactions of 4-carboxy-1,2-cyclohexanedionedioxime and nickel(II) were studied in alkaline media. Spectrophotometric studies indicate the presence of a 1:1 complex ion, NiD-. Magnetic susceptibility measurements on a series of solutions of varying ratios of vic-dioxime and nickel(II) showed that the 1:1 complex ion was diamagnetic and that two paramagnetic complexes, probably NiD24- and NiD37-, are present in solution. The stability constants for the three complexes were calculated from spectrophotometric and magnetic susceptibility data. The log K values were found to be log K1 = 28.74 ± 0.60, log K2 = 0.76 ± 0.15, and log K3 = 3.67 ± 0.73, respectively. 相似文献
2.
用ICP-AES法测定了东太平洋深海锰结核样品中二十多种主,次及微量元素,结果表明,表面瘤状和表面光滑两种类型锰结核的化学元素含量有较明显的区别,如表面光滑的锰结核TiO2含较高,而表面瘤状的锰结核Mn/Fe之值较高等。 相似文献
3.
用原子吸收光谱法测下了“东北水三七”根、茎、叶的21种化学元素,结果表明,不同部位的元素含量有一定差别。 相似文献
4.
CLIMATIC CHANGE SINCE LITTLE ICE AGE RECORDED BY DUNDE ICE CAP 总被引:21,自引:0,他引:21
The climatic change since the Little Ice Age recorded in the Dunde Ice Cap is presentedin this paper. There have been three cold periods and three warm periods since 1400AD.Among them, the coldest one was in the 17th century. Many evidences verified the three coldand warm variations recorded in the Dundc Ice Cap. But it was found from the comparison between the Dunde Icc Cap climatic record and thewinter temperature record in Shanghai that there was a temporal dfference in climatic changebetween East China and West China. The general trend is that the cooling and warmingprocesses in West China were earlier than that in East China. In the Dunde Ice Cap, it isnow in an anomalous warm period, while it is not as warm as in Dunde Ice Cap recordaccording to the winter temperature in Shanghai. In addition to the possible cause of temporaldifference in climatic change between West China and East China, another possible cause isthat the greenhouse effect of CO_2 may already be recognizable in the Dunde Ice Cap a 相似文献
5.
E.H. Appelman B. Beagley D.W.J. Cruickshank A. Foord S. Rustad V. Ulbrecht 《Journal of Molecular Structure》1976,35(1):139-148
The molecular structure of FBrO3 has been studied by gas-phase electron diffraction. Least-squares refinements of the molecular geometry using fixed spectroscopic amplitudes revealed two geometrical minima. Initially, the amplitudes employed were derived from diagonal force fields obtained by spectroscopic least-squares refinements to fit observed and calculated wave numbers; for each geometry there are two spectroscopic minima. In the lowest geometrical minimum the wave number agreement is poor, however, the introduction of the ∠OBrO/∠FBrO interaction force constant removed the discrepancies; the resulting force field is F(Br-O) = 6.92 ± 0.02 mdyn Å?1F(Br-F) = 3.22 ± 0.03 mdyn Å?1, F(∠OBrO) = 1.06 ± 0.02 mdyn Å, F(∠FBrO) = 0.81 ± 0.03 mdyn Å, F(∠OBrO/∠FBrO) = ?0.19 ± 0.02 mdyn Å. In the corresponding geometrical minimum rg(Br-O) = 1.582 ± 0.001 Å, rg(Br-F) = 1.708 ± 0.003 Å, rα(∠OBrO) = 114.9 ± 0.3°, rα(∠FBrO) = 103.3 ± 0.3°. Perpendicular amplitude correction coefficients, calculated for each force field employed, were used throughout to relate the interatomic distances through the rα-structure. The geometries of the rαo- and re-structures are estimated. 相似文献
6.
东海区海岸带景观格局变化对生态系统服务价值的影响 总被引:2,自引:0,他引:2
对大尺度、长时序的海岸带景观格局和生态系统服务价值(ecosystem services value,ESV)的研究,有利于更好地促进区域生态系统保护工作的开展。以1990,1995,2000,2005,2010,2015年6期遥感影像解译结果为基础,对东海区海岸带景观格局变化特征和ESV时空演变进行了分析,并探讨了ESV与景观格局变化二者间的关系。结果表明,1990—2015年的25 a间,受人类活动的影响,东海区海岸带农田和海域面积大量减少,建设用地面积大幅增加;在所研究的5类地貌类型中,除中起伏山地外,其余地貌类型景观面积转移都较为剧烈。25 a间东海区海岸带斑块数量、斑块密度、边界密度、shannon多样性指数等不断增加,景观破碎化、复杂化、多样化增强。农田景观的最大斑块指数、形态指数、边界密度等变化均较大。东海区海岸带ESV呈先增加后减小的趋势,其中森林景观对ESV总量贡献最大;水文调节、生物多样性维持、气候调节、土壤保持、废物处理和气体调节是东海区海岸带主要的生态系统服务功能;在空间上表现出以单位面积中、低ESV为主导的空间分布,高、极高和极低ESV分布较少。研究区ESV总量与农田和海域以及水域和建设用地面积显著相关;与斑块密度、边界密度和形态指数呈显著负相关。同时,食物生产、气体调节、气候调节、土壤保持和生物多样性维持的服务价值与景观指数间均显著相关。 相似文献
7.
国家类型学说源于欧美,是关于如何系统地区分和比较不同国家形式的学问,19世纪中叶以降伴随着西学东渐的潮流输入东亚文明圈。相较于中国的进程缓慢和规模有限,明治日本迅速形成了一套内涵丰富的以辨析国体政体关系为主旨的国家类型知识体系。国体政体是否有别、如何区分的争论,虽直接导源于西方的国家形式、政府形式异同问题,但根本症结在于日本以天皇总揽统治权之“体”行立宪政治之“用”后面临君权与民权的纠缠。清季朝野各方从日本引进各类国体政体理论探索改制问题,同样因君权、民权取向的互歧而衍生出彼此互异的国体政体观念。辛亥革命后,因缘君权时代的结束和民主共和的兴起,日本的国体政体学说在中国日趋失去活力,而民初议会政治的破产和主权所有者“民”背后阶级问题的出现,预示着新兴革命力量必须提出真正符合中国新的政治形势和需求的国家类型理论。 相似文献
8.
Afgan Aslanov 《Mathematical Methods in the Applied Sciences》2015,38(5):980-990
In this paper, we consider a class of second‐order initial value problems. We extend the family of second‐order initial value problems for which the existence and uniqueness of a solution is known. To handle the singularity, we introduce the more general Caratheodory type of restrictions. The solvability results of the Emden–Fowler type of equations is established as a special case.Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
9.
10.
S. Esposito 《International Journal of Theoretical Physics》2002,41(12):2417-2426
We present a method for reducing the order of ordinary differential equations satisfying a given scaling relation (Majorana scale-invariant equations). We also develop a variant of this method, aimed to reduce the degree of nonlinearity of the lower order equation. Some applications of these methods are carried out and, in particular, we show that second-order Emden–Fowler equations can be transformed into first-order Abel equations. The work presented here is a generalization of a method used by Majorana in order to solve the Thomas–Fermi equation. 相似文献