949 resultados para 2,4,6,8-tetraoxaadamantanes


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In the title compound, C12H10FN7S, the dihedral angles made by the plane of the thione-substituted triazole ring with the planes of the other triazole ring and the benzene ring are 74.55 (2) and 11.50 (3)degrees, respectively. The structure shows a number of N - H center dot center dot center dot N intermolecular hydrogen-bonding interactions, and weak C - H center dot center dot center dot S intra- and intermolecular interactions.

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The title compound, 2-(methoxybenzoyl)-N-phenyt-2-(1,2,4-triazol-1-yl)thioacetamide was synthesized by several reactions from 4-methoxyacetophenone, triazole and phenyl isothiocyanate. The structure was identified by elemental analysis, H-1 NMR, MS and IR. The single crystal structure of 2-(methoxybenzoyl)-N-phenyl-2-(1,2,4-triazol-1-yl)thioacetamide was determined with X-ray diffraction. The preliminary bioassays show that the title compound exhibits weak antifungal activities and plant-growth regulatory activity.

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In the title compound, C12H10ClN7S, the dihedral angles made by the plane of the thione-substituted triazole ring with the planes of the other triazole ring and the benzene ring are 73.57 (3) and 46.65 (2)degrees, respectively. Inter-and intramolcular hydrogen bonds and pi-pi stacking interactions stabilize the structure.

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In order to find leading compounds with an excellent fungicidal activity, the tide compound 2-(1,3-dithiolan-2-yl-idene) -1-phenyl-2-(1,2,4-triazol-1-yl) ethanone was synthesized according to the biological isosterism and its structure was confirmed by means of IR, MS, H-1 NMR and elemental analysis. The single crystal structure of the tide compound was determined by X-ray diffraction. The preliminary biological test shows that the synthesized compound exhibits some biological activities.

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The title compound, N'-(4-methoxybenzylidene)-2-(1H-1,2,4-triazol-1-yl)acetohydrazide, was synthesized and its structure was confirmed by means of IR, MS,H-1 NMR and elemental analysis. The single crystal structure of the title compound was determined by X-ray diffraction. The preliminary biological test shows that the synthesized compound has a low antifungal activity.

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In the title compound, C12H10FN7S, the dihedral angles made by the plane of the thione-substituted triazole ring with the planes of the other triazole ring and the benzene ring are 71.94 (3) and 40.10 (2)degrees, respectively. Inter- and intramolecular hydrogen-bond and pi-pi stacking interactions stabilize the structure.

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N'-(4-fluorobenzylidene)-2-(1H-1 2,4-triazole-1-yl) acetohydrazide was synthesized by the reaction of 4-fluorobenzaldehyde with 2-(1H-1 2,4-triazole-1-yl) acetohydrazide. The structure was confirmed via elemental analysis, MS, H-1 NMR, IR, and X-ray diffraction. It crystallized in a monoclinic system with space group P2 (1) a = 0.4905 (1) nm, b = 0.8160 (2) nm, c = 1.4105 (3) nm, beta = 93.33 (3)degrees, Z = 2, V = 0.5636 (2) nm(3), D-c = 1.457 Mg/m(3), mu = 0.112 mm(-1), F(000) = 256, and final R-1 = 0.0685. Several intermolecular hydrogen-bond interactions existed in the crystal structure, facilitating the stabilization of the compound.

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采用水蒸气蒸馏法提取了冷蒿挥发油,气相色谱-质谱联用结合计算机检索对其化学成分进行了分析和鉴定,共分离出106个峰,确定了101种化合物,它们主要是二甲基-甲撑基环庚(17.67%)、3,3,6-三甲基-1,5-庚二烯醇-2(16.40%)、3,3,6-三甲基-1,4-庚二烯醇-6(8.55%)、桉树脑(5.57%)、3,7-二甲-基2,6-辛二烯醇-1(3.85%)、神圣亚麻三烯(3.73%)、1-甲基-3-异丙基苯(3.26%)、桥环[2,2,1]萜烯(2.91%)、樟脑(2.26%)、香叶烯(2.20%),以上10种化合物占挥发油总量的66.40%。

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建立并检测印度獐牙菜和川西獐牙菜中獐牙菜苦苷、龙胆苦苷、芒果苷、异荭草苷4种苷类成分含量的反相高效液相色谱分析方法.结果表明,该方法简单,准确,快速,可作为獐牙菜类药材的质量控制依据.

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受高原抬升所致的水系变迁及人类活动的影响,分布于南门峡河流的裂腹鱼亚科鱼类与黄河干支流种群间的基因交流受到长期限制.作为孤立小群体,探讨其分类学地位及其在小生境中的进化机制对了解青藏高原鱼类多样性和物种的形成、进化具有重要意义.本文采用聚合酶链式反应(PCR)和直接测序方法获得了南门峡裂腹鱼亚科鱼类(n=29)及其近缘种(n=19)共48个个体的线粒体DNA(mtDNA)细胞色素b(cyt b)基因的全序列(1 140 bp),并以厚唇裸重鱼和尖裸鲤为外群构建了MP和Bayesian系统进化树.南门峡裂腹鱼亚科鱼类29个个体的序列经排序后,发现有100个(8.77%)多态性位点,共定义了16个单倍型,在系统进化树上分布于截然不同的两个族群中.其中5个单倍型(NMX3、6、7、13、15)与其近缘种花斑裸鲤和青海湖裸鲤形成单系群(MP 99%,Bayesian 98%),而其余11个单倍型(NMX1、2、4、5、8、9、10、11、12、14、16)与黄河干支流的黄河裸裂尻鱼形成另一个单系群(MP 99%,Bayesian 99%).序列差异分析显示,分布于不同族群的南门峡裂腹鱼亚科鱼类之间存在较大的碱基差异(平均为7.42%),显示出种间差异水平,表明分布于南门峡河流的裂腹鱼亚科鱼类可能是花斑裸鲤和黄河裸裂尻鱼形态相似种的复合体.结合青藏高原隆升所致的气候环境变化和高原北部水系变迁的事件,推断形态趋同进化可能导致了南门峡河流裂腹鱼亚科鱼类形态相似种的共存,而小生境自然选择压力是引发适应性形态趋同进化的主要原因.

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合成了新的荧光衍生试剂1-[2-(对甲苯磺酸酯)乙基]-2-苯基咪唑[4,5-f]9,10-菲(TsEPIP),并将其作为柱前衍生化试剂,在Eclipse XDB-C:色谱柱上采用梯度洗脱实现了11种长链(C_(20)~C_(30))游离脂肪酸(FFA)衍生物的基线分离。利用柱后在线的串联质谱并以大气压化学电离源(APCI)的正离子模式实现了各组分的质谱定性。对土壤及3种苔醉(东亚毛灰鲜、锦丝鲜、羽平鲜)中FFA组分的定量结果表明,苔鲜植物从土壤中富集了大量的长链游离脂肪酸。荧光检测的激发波长和发射波长分别为260 nm和380 nm。线性回归系数大于0.9996,检测限为26.19~76.67 fmol。所建立的方法具有良好的重现性,对实际样品的测定结果令人满意。

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按照青藏公路建设和整修的不同阶段,利用样方调查植被空间分布变化,得出高寒草原植被的自然演替进程遵循以下规律。在工程结束2年,8年,26年后,群落植被覆盖度和生物多样性指标分别达到原生植被的2%~4%,6%一23%;32%~54%,46%~50%:95%以上和100%左右.青藏公路沿线高寒草原植被的人为破坏影响是明显的,植被的自然恢复需要20年左右的时间.工程建设破坏面积大于1500m~2,植被难以恢复,土壤沙化和水土流失,影响周边地区生态环境质量.因此,在青藏铁路工程建设中首先应当减少对地形地貌的破坏,其次应当重视对地表土壤的保护并辅助人工植被恢复措施,促进植被的自然恢复.

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目的:对红花岩黄芪化学成分进行研究。方法:用溶剂法、色谱法提取、分离红花岩黄芪化学成分,用波谱法鉴定其结构。结果:从红花岩黄芪中分离得到7 个化合物,碳三十醇(1) ,二十四碳酸( 2) ,5 ,7-二羟基-4′-甲氧基-6 ,8-二异戊烯基异黄酮(3) ,对香豆酸二十二酯( 4) ,豆甾醇( 5) , 5 ,7-二羟基-4 ,-甲氧基- 6-异戊烯基异黄酮( 6) ,咖啡酸二十四酯( 7) 。结论:化合物3 和4 为新天然产物,其它化合物均为首次从该植物中获得。

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The exploration in recent years shows that the Yanchang Formation in the southwest of Ordos Basin is of great resource potential and good exploration and exploitation prospect. In the thesis ,sedimentary source analysis,sedimentary system,sedimentary microfacies,sandstones distribution and reservoir characteristic are studied and favorable oil area are forecasted in Chang6-Chang8 of Yanchang formation in HuanXian region, by mainly study on the data of field section observation ,core observation, well logging explaination and routine microscope slice identification,scanning Electron Microscope and reservoir analysis of lithology and physical property , Under the guidance of such advanced theories and methods as sedimentology,reservoir sedimentology,lithological oil pool and so on. The stratum of Chang6-Chang8 of Yanchang formation could be divided into pieces of member following the principles that firstly contrasting the big segments, then contrasting the small segments, being controlled by cycle and consulting the thickness etc.And the characteristic of stratum are detailed discussed , respectively. Based on the source direction of the central basin, heavy and light minerals are used to analyse source direction of Chang6 and Chang8 member, in HuanXian area. Research result shows that the source of Chang6 and Chang8 member is mixed provenance,including west-south,west and east-north. By the study of rock types、 sedimentary conformation、lithology and electromotive curve combination and palaeo-biology,lake、delta and braided delta mianly developed in study area are recognized, Subaqueous distributary channels in delta front and in braided delta front, and sand body in deep-lake turbidite, are the main reservoir.forthermore,the characteristic of depositional system and sandy body in space are discussed. Applied with routine microscope slice identification, Scanning Electron Microscope, reservoir lithology and physical property analysis and other analytic machinery, Feldspar-lithic fine-sandstone and feldspar fine-sandstone are mainly sandstone of Y Chang6-Chang8 in Huanxian area, small pore and tiny pore are the main pore types, tiny throat type and micro-fine throat type are widely developed , secondary dissolution porosity, intercrystal porosity, tiny pore and micro-crack are main pore types.Intergranular porosity and dissolution porosity secondary is the main pore secondary. The dominant diagenesis types in the area are compaction, cementation, replacement and dissolution. Chlorite films cementation facies, carbonate cementation facies ,mud cementation compaction facie, compaction 、pressure solution facies are the main diagenetic facies,in which Chlorite films cementation facies is the best diagenetic facies in study area. Reservoir influence factor analysis ,rock types are the main factor forming this low-pore and low-permeability of Chang6-Chang8 member in study area,and relatively higher permeability area are cortrolled by sedimentary facies distribution, diagenesis improved reservoir physical property. According to the distributing of sedimentary micro-facies and sandy body , and the test oil, favorable region in Chang6-Chang8 are forecasted.

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贵州的乌江流域属典型的喀斯特地貌,也是我国严重的酸雨区之一。酸沉降可以导致土壤中盐基离子的流失并释放出具有植物毒性的元素,对植被和生态造成破坏。即使在酸沉降停止后,土壤的退化也会持续,pH值仍可继续降低。因此,加强乌江流域的酸沉降对土壤及生态系统破坏的研究十分必要。乌江中上游地区广泛分布高硫煤和矿床硫化物,煤中的还原态硫化物(主要是黄铁矿)和矿床硫化物经过氧化风化会产生大量的溶解态金属和H2SO4,在污染环境的同时会大大加速碳酸盐岩的化学侵蚀。 本研究在导师刘丛强研究员主持的中国科学院知识创新工程重要方向重大项目(喀斯特地区(贵州乌江流域)物质的水文地球化学循环及其环境效应,批准号:KZCX2-105;乌江流域典型喀斯特土壤-植被生态系统生源要素生物地球化学研究,批准号:KZCX3-SW-140)课题的支持下,选择贵州喀斯特地区的典型河流为研究对象,利用化学质量平衡、同位素地球化学研究手段,探讨了硫酸风化碳酸盐岩对河水化学组成的影响,溶解硫酸盐的来源及硫同位素组成的时空变化,定量计算了丰水期乌江流域硫酸风化碳酸盐岩的侵蚀速率及其对大气CO2释放的影响,并对土壤总硫和硫酸盐的生物地球化学循环进行了同位素示踪研究。获得的主要结论揭示了水-岩作用和人类活动对硫的生物地球化学循环的控制机理,以及硫循环在碳酸盐岩化学风化中的作用,为了解喀斯特地区硫的循环演化及其环境效应提供了重要的基础科学依据。主要结论如下: 硫酸侵蚀碳酸盐岩对河水化学组成的影响 乌江枯、丰水期河水SO42−平均浓度分别为0.65mmol/L和0.48mmol/L,占阴离子总量的25%以上。干流河水SO42−浓度具有从上游到下游逐渐降低的趋势,支流河水SO42−浓度具有明显的区域性差异特征,枯水期上游和下游地区支流的SO42−平均浓度分别为0.80mmol/L和0.26mmol/L,丰水期河水也有类似的特征。SO42−、NO3−、Cl−与Na+浓度比值的相互关系表明河水SO42−具有人为来源。沅江水系河水SO42−含量远低于乌江河水,枯水期平均浓度0.22mmol/L,丰水期平均0.14mmol/L。 乌江流域不同来源H2SO4参与下的碳酸盐岩风化是影响河水化学组成最主要的因素。舞阳河水中的溶质主要来自H2CO3风化白云岩,不存在硫酸风化碳酸盐岩的迹象。清水江河水离子组成则同时受到H2CO3、H2SO4风化碳酸盐岩和H2CO3风化硅酸盐的影响。由此可见,喀斯特地区不同河流的河水化学组成受H2SO4风化碳酸盐岩的影响是不同的。 水-岩作用模拟表明:乌江枯水期河水的CSI在−0.2 ~ 1之间,绝大多数河水处于对CaCO3过饱和状态,丰水期河水的CSI较枯水期平均高0.3,CaCO3全部过饱和。河水PCO2,river相对大气PCO2,atm一般是过饱和的。因此,喀斯特地区河水即具有沉积性又具有向大气释放CO2的趋势。舞阳河水方解石和白云石在枯、丰水期全部过饱和,DSI平均值在两季均远高于CSI,这与舞阳河流域分布着大量的白云岩有关。而清水江大部分河水的方解石和白云石处于不饱和状态。流域不同的地质背景决定了河水中方解石和白云石的饱和状态,在同一地质背景条件下又取决于河水中的CO2分压。 扣除乌江丰水期河水化学组成中H2SO4溶解碳酸盐岩的贡献之后,部分河水由对方解石和白云石过饱和变为不饱和,溶解沉淀性质发生了根本的改变。由此可见,H2SO4风化碳酸盐岩通过改变河水的化学组成,对河水的化学稳定性也存在很大影响。 河水硫同位素地球化学与碳酸盐岩侵蚀 枯水期乌江河水硫同位素δ34S值的变化范围为−15.7‰ 到18.9‰,宽广的δ34S值范围反映了不同河段汇入的SO42−来源于流经具有不同同位素组成特征地质背景的支流。丰水期δ34S值的变化范围小于枯水期,在−11.5‰ 到8.3‰之间。两个季节河水SO42−的δ34S值均随着SO42−浓度的增加而降低。乌江硫酸盐的硫同位素组成具有明显的季节性变化,丰水期干流河水的δ34S值在−6.7‰ ~ −3.9‰之间,平均值较枯水期低3‰。支流河水的硫同位素组成具有明显的区域性差异。舞阳河河水富集34S,清水江河水富集32S,硫同位素组成的季节变化和支流差异远不如乌江明显。 硫同位素示踪显示:乌江上游河水硫酸盐主要来自煤中黄铁矿的氧化、矿床硫化物氧化及雨水;下游河水硫酸盐的硫同位素组成主要介于雨水和蒸发岩端元之间,煤中黄铁矿氧化的贡献较少。不同端元的硫同位素组成表明:丰水期水量增加时,煤中黄铁矿氧化来源的硫酸盐的贡献增加,导致了乌江河水δ34S值的降低。雨水δ34S值季节性变化对河水硫同位素组成的季节性变化的影响是次要的。 乌江河水向贵州省外输出的SO42−通量为170×1010g/a,丰水期占全年SO42−输出总量的72%,上游地区输出的SO42−占年输出总量的80%。煤中黄铁矿风化、雨水、矿床硫化物风化、蒸发岩溶解对丰水期乌江河水SO42-的贡献分别为45%、27%、24%和4%。硫化物氧化产生H2SO4,而后H2SO4侵蚀碳酸盐岩,这是研究区内两个非常重要的硫循环过程。丰水期H2SO4侵蚀碳酸盐岩的速率为35.1t/ (km2•a),约合17.5mm/ka。总的CO2释放通量约为8.1 t/ (km2•a)。通过推导丰水期乌江流域碳酸盐岩侵蚀方程可知,丰水期乌江流域碳酸盐岩的侵蚀有52%是由H2SO4风化造成的。 喀斯特流域土壤硫的生物地球化学 黄壤的总硫含量一般小于0.1%,而石灰土的总硫含量全部大于0.1%, 同一剖面同样深度黄壤总硫含量夏季生长期高于冬季休眠期,但是石灰土则恰恰相反。一般情况下,土壤总硫含量首先与土壤类型有关,其次可能受到植被的影响。即使是同一土壤类型,随着剖面深度的增加总硫含量变化趋势也并不一致。 土壤无机硫酸盐的含量与土壤类型密切相关,黄壤SO42−含量明显高于石灰土。黄壤表层土硫酸盐形态硫占总硫的2.4% ~ 6.4%,随着剖面加深土壤硫酸盐形态硫的含量出现先增加后降低的趋势,最高可占总硫的20%以上,这种现象应该是铁、铝氧化物或氢氧化物对硫酸盐的吸附造成的。同样是黄壤,也可能由于上覆植被的不同造成不同剖面土壤硫酸盐在含量上的差异,或同一剖面不同季节含量上的差异。石灰土硫酸盐形态硫在总硫中的百分含量不超过3%,而且易受淋溶而流失,即使在有植被覆盖的情况下也是如此。 所有样品总硫的δ34S值均为正值且总是大于同层SO42−的δ34S值。随着黄壤剖面的加深δ34S值呈逐渐增加的趋势,有机硫循环过程不断富集34S可能是产生这种现象的原因。 硫同位素组成表明黄壤剖面表层土SO42−应来源于大气沉降。夏季表层土SO42−的δ34S值稍高于冬季,明显高于贵阳夏季大气降水的硫同位素组成,可能是大气总沉降的反映,也可能是不同季节土壤有机硫的矿化水平的不同造成的。黄壤剖面无论冬季还是夏季SO42−均随剖面的加深逐渐富集34S。在剖面上层SO42−的δ34S值与SO42−含量正相关,可能是有机硫矿化生成的SO42−加入的结果。下层土壤硫酸盐δ34S值与含量明显反相关,可能是硫酸盐还原菌发生作用导致了较大的同位素分馏。 从乌江上游至下游,石灰土表层土壤SO42−的硫同位素逐渐富集32S。硫同位素组成表明中、下游石灰土SO42−的来源很可能是大气降水,而上游样品还存在矿山硫的来源。 土壤无机硫酸盐对乌江河水硫酸盐的贡献还不明确,但它不应是乌江河水硫酸盐的主要来源。