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1.
荆马河区域土壤和蔬菜中氟化物的污染及其特征 总被引：1，自引：0，他引：1
荆马河区域土壤中氟化物总量与浸提态量之间存在良好的线性关系，因此，以浸提态为评价因子。调查结果表明，该区域土壤已不同程度地受到氟化物的污染，其中以朱庄乡污染尤为突出；氟化物在污染严重的土壤中有明显的向下迁移趋势。该区域污染源附近氟含量相当多，表现为叶菜类氟含量大大高于根菜类，并已超过食品卫生标准近１０倍，氟化物在蔬菜中的积累主要来自于大气氟化物，很少来自于土壤。 相似文献
2.
满洲里市环境中氟的迁移转化 总被引：2，自引：0，他引：2
满洲里市地表水体和地下水中氟含量已超过水质标准，土壤中的氟也超过全国平均水平。在分析氟环境表征的基础上，探讨了氟在环境中的迁移转化及其影响因素，指出环境中氟化物的富集既有自然条件的控制，也有人类非理性的环境行为所致。并根据氟在环境中的 多转化的规律，提出相应的治理对策。 相似文献
3.
大气氟污染对蚕叠生产的影响 总被引：1，自引：0，他引：1
综述了大气氟污染对蚕桑生产影响的研究结果，蚕区大气氟化物主要来自砖瓦厂，等排氟工厂。工厂排出的氟物化可被桑叶吸收，积累，家蚕食用这种被氟污染的桑叶会发生急性或慢性中毒。 相似文献
4.
本文论述了地热水开发利用及地热尾水排放过程中对环境造成的氟污染问题。实验结果表明：国内许多地热井点地热水中氟含量偏高，一般在０．５－１７ｍｇ／ｌ之间，最高可达４０ｍｇ／ｌ（国家饮水水质氟含量标准为１．０ｍｇ／ｌ）；利用地热水养鱼，当地热水中氟含量高于１．０ｍｇ／ｌ时，鱼体内氟化物含量高于２．０ｍｇ／ｋｇ，超过了国家食品卫生标准的要求；地热水灌溉能引起土壤氟含量增高，但高氟土壤对农作物品质影响不明显。 相似文献
5.
土壤作为氟的环境化学体系枢纽,有着极其重要的作用。土壤中的氟污染不仅会对人类造成直接的危害,还会因水源、动植物的富集而对人类的健康造成不利的影响。氟污染是目前环境热点问题之一。我国是高氟地区分布广泛的国家,地方性氟中毒的研究表明饮用水是地方性氟中毒的主要传播途径,氟中毒的发病率与饮用水含量之间是否存在相关性,已有的研究结论不尽相同。现有的土壤氟污染修复技术主要有植物修复技术、固化/稳定化修复技术、电动力学修复技术和化学淋洗修复技术等。目前土壤氟的研究还存在部分地区土壤氟污染的来源、土壤微生物与土壤中氟化物的相互作用机制不明确。因此,对土壤氟污染与修复方法的研究十分必要。论文参考大量的国内外有关氟污染的相关文献,系统总结了土壤氟污染的现状、土壤氟污染修复方法的最新研究进展,重点比较了各种土壤氟污染修复方法的优势和缺陷,并探究在实际修复应用中的可行性,指出了今后土壤氟污染修复的发展方向。 相似文献
6.
为阐明茶树高富集土壤氟的化学机制,采用动力学方法研究了茶树根系分泌柠檬酸对茶园土壤氟形态及其在土壤固一液相分配的影响。结果表明,土壤溶出液的pH和电导率随溶出时间的增加而逐渐减小。土壤氟的释放存在快速释放和慢速释放两个阶段,呈现初始（0～6h）溶出浓度较高,而后（6～10h）逐渐减缓的趋势。一级动力学方程、Elovich方程、扩散方程、双常数方程均对土壤氟的溶出过程有较好的拟合,决定系数（R^2）均大于0．91。土壤溶出液中的游离态氟和总氟的释放量随柠檬酸浓度的升高而增加,反应开始前2h的高浓度柠檬酸溶出液中A1-F络合物的浓度较大,反应开始前1h的A1-F络合物主要以A1F3为主,占氟溶出总量的90％左右;随着溶出时间的延长,A1FI的溶出量逐渐增大,并逐渐超过A1F3。高浓度柠檬酸促进土壤氟的溶出释放,有利于A1-F络合物向AlP、AlE形态转化。 相似文献
7.
污灌土壤中氟及硫的形态分布特征 总被引：4，自引：0，他引：4
以乌鲁木齐雅马里克山的石灰性土壤为研究对象,采用连续提取法和分步提取法对土壤氟和硫的化学形态进行了测定,研究了不同水质及外源对土壤氟和硫各形态的含量及其分布的影响.结果表明土壤氟主要以残渣态为主,占全氟含量99.5%以上.各形态氟呈残余态氟>有机束缚态氟>水溶态氟>可交换态氟>铁锰结合态氟的趋势.不同水质浇灌后,土壤硫主要以有机硫为主,占71.5%～81.2%.并且呈现有机硫>盐酸可溶性硫>水溶性硫>吸附性硫的趋势.外源物质对土壤理化性质及对土壤中氟和硫各形态有不同程度的影响.土壤氟和硫各形态之间以及各形态与土壤理化性质之间的相关性分析表明,全氟与残余态氟极显著相关.土壤全硫与有机硫之间具有十分密切的相关性.土壤pH值、有机质和CaCO3含量是影响土壤中氟及硫赋存形态的主要土壤因子. 相似文献
8.
金华地区氟污染成因,危害及对策（Ⅲ）——人发氟和若干元素含量？… 总被引：1，自引：0，他引：1
研究结果表明：氟斑牙患者体内氟含量高于正常人体；同年龄组男性发氟含量高于女性；随年龄增加，人发氟含量也不断增加；发中钙含量女性略高于男性；和正常人体相比，氟斑牙患者发Ｃｕ，发Ｆｅ含量无明显差异。 相似文献
9.
氟对家蚕血液及中肠磷酸酶活性的影响 总被引：7，自引：0，他引：7
运用人工饲料中定量添加氟化物的方法，探讨了氟对家蚕中肠碱性磷酸酶（AKP）、血液酸性磷酸酶（ACP）活性的影响。结果表明，氟对家蚕中肠AKP、血液ACP的活性有明显的抑制作用，并随着添氟浓度的增加而增强，间隔添氟、停止添氟不能减轻这种抑制作用。添食石灰能减轻氟对中肠AKP、血液ACP活性的影响。 相似文献
10.
辽宁省柳绕地区的氟状况及磷石膏施用对土壤氟的影响 总被引：1，自引：0，他引：1
柳绕地区北部为新构造振荡上升的倾斜平原，沉积盖层较薄，地下水垂直排泄强烈，造成土壤盐渍化。潜水在碱性条件下氟的浓度增加，使本区北部成为氟中毒区，局部为重度病害工。酸性物料改良碱性氟中毒区土壤，可以抑制氟的活动性，即使施用含氟的磷石膏也不增加土壤的水溶性氟和速效性氟。 相似文献
11.
Nondestructive quantification of organic compounds in whole milk without pretreatment by two-dimensional NMR spectroscopy 总被引：2，自引：0，他引：2
In this study, various organic compounds in commercial whole milk were quantified simultaneously by 1H 1D and 1H - 13C HSQC 2D NMR spectra without any pretreatment. 2D NMR spectroscopy was applied to quantification of milk compounds for the first time. Milk fat content was easily determined to be 3.6 +/- 0.1%, and the lactose content was 47.8 +/- 1.0 mg/mL by 1H NMR spectra. From 1H-13C HSQC spectra, the concentrations of citrate, N-acetylcarbohydrates, and trimethylamine were determined to be 3.2 +/- 0.2, 2.9 +/- 0.1, and 4.0 +/- 0.6 mM, respectively. The latter two compounds were quantified in milk for the first time. Butyric acid, total monounsaturated fatty acids, and total polyunsaturated fatty acids of triacylglycerols were 6.2 +/- 0.5, 9.1 +/- 0.9, and 2.9 +/- 0.3 mM, respectively. The fatty acid compositions (mol %) of triacylglycerols were then calculated and were observed to be in good agreement with reference values. The results indicated that 1H 1D and 1H-13C HSQC 2D NMR spectroscopy is useful for the rapid and nondestructive determination of various compounds in milk. 相似文献
12.
Srivastava A Harish R Shivanandappa T 《Journal of agricultural and food chemistry》2006,54(3):790-795
Roots of Decalepis hamiltonii are consumed as pickles and as a health drink in southern India for their health benefits. The antioxidant properties of the root extracts have been shown previously; this paper reports the isolation of antioxidant compounds from the aqueous extract of the roots of D. hamiltonii. Five novel antioxidant compounds were isolated and characterized by NMR and MS. The compounds exhibited free radical scavenging activity in vitro and inhibited low-density lipoprotein oxidation. This study demonstrates that the root extract of D. hamiltonii is a cocktail of several antioxidant compounds with health implications. 相似文献
13.
Rastrelli L Caceres A De Simone F Aquino R 《Journal of agricultural and food chemistry》1999,47(4):1537-1540
Our research program on the Central American fooder plant Gliricidia sepium led to the discovery of two new triterpene saponins (1 and 2) and known aromatic compounds. The new compounds possess 3beta,21beta, 24-trihydroxy-22-oxoolean-12-ene as an aglycon. The oligosaccharide moiety linked to C-3 of the aglycon contained two pyranoses (glucuronic acid and xylose); in addition the glucose residue of both 1 and 2 is also linked to C-21. Structure elucidation of these new compounds through the extensive use of 1D and 2D NMR techniques have provided detailed information about the sapogenin and the saccharide chains, inclusive of sugar sequence and the position of glycosylation. 相似文献
14.
Chung CP Hsu CY Lin JH Kuo YH Chiang W Lin YL 《Journal of agricultural and food chemistry》2011,59(4):1185-1194
Two new lactams, coixspirolactam D (1) and coixspirolactam E (2), and a new spiroenone, coixspiroenone (3), together with seven known compounds, coixspirolactam A (4), coixspirolactam B (5), coixspirolactam C (6), coixlactam (7), coixol (8), ethyl dioxindole-3-acetate (9), and isoindol-1-one (10), and two neolignans, zhepiresionol (11) and ficusal (12), were isolated from the bioactive subfraction of adlay bran ethanolic extract (ABE). Compounds 9 and 10 are the first isolates from natural resources. The structures of new compounds were identified by spectroscopic methods, including infrared (IR) spectrum, 1D and 2D nuclear magnetic resonance (NMR), and mass spectrum (MS). All of the isolated compounds were tested for antiproliferative effects on MCF-7, MDA-MB-231, and T-47D cells. Results showed that compounds 1, 3, 4, 6, and 7 at 50 μM significantly inhibited MCF-7 cell proliferation by 30.2, 19.2, 21.0, 13.5, and 32.4%, respectively; compounds 2, 4, and 7 significantly inhibited T-47D cells at 50 μM by 20.7, 24.8, and 28.9%; and compounds 1, 2, and 12 significantly inhibited MDA-MB-231 cells at 50 μM by 47.4, 25.3, and 69.3%, respectively. In conclusion, ABE has antiproliferative activities, and this effect is partially related to the presence of lactams and spiroenone. 相似文献
15.
Dammarane-type glycosides from steamed notoginseng 总被引：1，自引：0，他引：1
Notoginseng, the root of Panax notoginseng (Burk.) F. H. Chen (Araliaceae), is a Chinese traditional medicine, which is used in both raw and processed forms due to their different pharmacological activities. Detailed chemical investigation on steamed notoginseng led to the isolation of 27 dammarane-type triterpenoids (1-27), including 4 new glycosides, namely, notoginsenosides ST-1-ST-3 and ST-5 (1-4), in addition to 3 other known compounds. Of the new compounds, 1-3 possess new aglycones. Their structures were elucidated on the basis of detailed analyses of their 1D and 2D NMR spectra and chemical reactions. The known compounds, koryoginsenoside-R1 (19), yesanchinoside D (20), 6'-O-acetylginsenoside Rg3 (24), and 3beta,6alpha,12beta-trihydroxydammar-20(21),24-diene ( 25), were isolated from notoginseng for the first time. 相似文献
16.
Namibian chewing stick, Diospyros lycioides, contains antibacterial compounds against oral pathogens
The twigs of Diospyros lycioides, a plant commonly known as "muthala", are frequently used as chewing sticks for the cleaning of teeth by rural and urban people in Namibia. Preliminary studies showed that a methanol extract of D. lycioides inhibited growth of selected oral pathogens. Subsequent bioassay-guided fractionation led to the isolation of four novel bioactive naphthalene glycosides, diospyrosides A, B, C, and D (1-4), and two known bioactive naphthoquinones, juglone (5) and 7-methyljuglone (6). The structures of the new compounds were elucidated using spectroscopic techniques including 1D and 2D NMR. These compounds inhibited the growth of oral cariogenic bacteria (Streptococcus mutans and Streptococcus sanguis) and periodontal pathogens (Porphyromonas gingivalis and Prevotella intermedia) at minimum inhibitory concentrations ranging from 0.019 to 1.25 mg/mL. Juglone exhibited the strongest inhibitory activity among these compounds. 相似文献
17.
不同酶和酵母对干红葡萄酒香气影响的差异分析 总被引：2，自引：2，他引：0
为提高甘肃河西产区蛇龙珠干红葡萄酒的香气品质,优化酿酒工艺,该文采用顶空固相微萃取和气相色谱-质谱联用技术,分析比较了添加不同浸渍酶和酵母发酵的蛇龙珠干红葡萄酒的香气构成。结果显示:蛇龙珠干红葡萄酒中初步定性香气化合物75种,主要为酯、醇、酸、萜烯和酚类物质。比较酯类、萜烯类等香气成分质量浓度和香气物质释放总量,EX-V酒样明显高于EX和HC酒样,D254酒样明显高于BDX酒样。各组酒样主要香气成分构成相似,但微量香气成分差异显著。果香是香气强度最高的香气系列,植物香、脂肪香、花香次之,其香气强度EX-V酒样高于EX和HC酒样,D254酒样高于BDX酒样。浸渍酶和酵母对甘肃河西产区蛇龙珠干红葡萄酒香气品质的影响评价显示,浸渍酶EX-V优于EX和HC,酵母D254优于BDX。研究结果可为甘肃河西产区蛇龙珠干红葡萄酒香气品质的提高及酿造工艺研究提供科学数据参考。 相似文献
18.
Léon F Van Boven M de Witte P Busson R Cokelaere M 《Journal of agricultural and food chemistry》2004,52(5):1207-1211
A mixture of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC) has been isolated by column chromatography from a jojoba meal (Simmondsia chinensis) extract. The molecular species of both classes could be separated and isolated by C18 reversed phase HPLC. The two major compounds were identified by 1D and 2D (1)H and (13)C NMR, by MS, and by GC-MS as 1-oleoyl-3-lysophosphatidylcholine and 1,2-dioleoyl-3-phosphatidylcholine. Eight other molecular species of LPC and four other molecular species of PC could be assigned by comparison of the mass spectra of the isolated compounds with the spectra of the two major compounds. Complete characterization of the individual molecular species was achieved by GC and GC-MS analysis of the fatty acyl composition from the isolated compounds. The PC/LPC proportion in the phospholipid mixture from three different samples is 1.6 +/- 0.1. LPC is considered to be an important bioactive compound; the results of this study suggest further research for the evaluation of potential health benefits of jojoba meal phospholipids. 相似文献
19.
Vrhovsek U Guella G Gasperotti M Pojer E Zancato M Mattivi F 《Journal of agricultural and food chemistry》2012,60(10):2507-2516
Although the composition of strawberry fruit has been extensively studied, especially for the most abundant phenolic compounds, agrimoniin has never been univocally identified as one of the most abundant phenolic compounds in the fruit. In this study agrimoniin was isolated in the fruit of Fragaria vesca and its structure characterized. Furthermore, its presence was definitively established to be the main ellagitannin in both F. vesca and Fragaria ananassa D. fruit. The presence of sanguiin H-6 and lambertianin C as minor compounds was confirmed in both F. vesca and F. ananassa D. samples. For the first time here is reported the full NMR assignments for agrimoniin. These data should represent a point of reference for NMR analysis of this and other structurally related ellagitannins. Finally, the establishment of an HPLC protocol for separation provided information making it possible to avoid confusion with sanguiin H-6, the main ellagitannin in Rubus species, which is also present in strawberries but at a much lower concentration. 相似文献
20.
Chen D Yu S van Ofwegen L Proksch P Lin W 《Journal of agricultural and food chemistry》2012,60(1):112-123
Fifteen new guaiazulene-based terpenoids designated anthogorgienes A-O (1-15) were isolated from a Chinese gorgonian Anthogorgia sp., together with eight known analogues (16-23). The structural patterns were classified into monomers, dimers, and trimers, which were supposed to be generated from a precursor guaiazulene and followed by side-chain and nucleus oxidation and oxidative rearrangement. The structures of new compounds were elucidated on the basis of extensive spectroscopic (IR, MS, and 1D and 2D NMR) data analysis. A possible biogenetic relationship of the isolated compounds was postulated. Some of the compounds showed potent antifouling activities against the larval settlement of barnacle Balanus amphitrite , whereas their antibiotic activities were also evaluated. 相似文献