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赵寒  董军  夏添  梁雪  李文德 《中国环境科学》2021,41(4):1634-1641
利用氨基酸双子表面活性剂N,N'-双月桂酰基乙二胺二丙酸钠(DLMC)及其复配体系来提高四氯乙烯(PCE)在地下水中的溶解性,强化去除效果.测定了 DLMC的初级生物降解性并将其与短链醇(异丙醇IPA,乙醇)和传统表面活性剂十二烷基硫酸钠(SDS),辛基苯基聚氧乙烯醚(TX-100)和聚氧乙烯脱水山梨醇单油酸酯(Twe...  相似文献   

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遵义下寒武统黑色岩系Ni-Mo多金属矿的生物成矿作用   总被引:1,自引:0,他引:1  
贵州遵义地区黄家湾矿是黑色页岩型镍钼多金属元素矿床.镜下观察及电子探针分析首次发现了矿石中红藻囊果及其与各金属硫化物之间密切的共生关系,为生物参与成矿作用提供了证据.结合前人研究结果,认为镍、钼等金属元素的来源及富集可能与藻类生物作用有关.  相似文献   

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拟除虫菊酯对大鼠脑片谷氨酸递质释放的影响   总被引:4,自引:0,他引:4       下载免费PDF全文
应用脑片放射性同位素标记神经递质释放实验,体外观察拟除虫菊酯类杀虫剂对大鼠额叶皮层脑片兴奋性氨基酸递质谷氨酸释放过程的影响。结果显示,在20μmol/L剂量下,4种拟除虫菊酯(溴氰菊酯、北京菊酯Ⅱ号、Ⅲ号和氯菊酯)对脑片静息态谷氨酸基础释放无明显作用。而化学结构中含氰基的拟除虫菊酯可促进额叶皮层脑片在50mol/LKCL去极化状态下谷氨酸的释放,与溶剂对照比较,溴氰菊酯(20μmol/L)可使脑片谷氨酸释放增加28.8%。  相似文献   

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Intrauterine treatment of 4 fetuses with urethral obstruction was attempted in the third trimester of pregnancy. The fetuses displayed varying sonographic findings including pyelectasis, caliectasis, hydroureter, bladder dilatation, ascites, hydrops, missing kidneys and oligohydramnios. Ultrasonically guided aspiration from the dilated structures was carried out to relieve pressure on the kidney parenchyme and to collect fluid samples for diagnostic purposes. Amino acid concentrations in the fetal urine showed a pattern similar to plasma in 2 fetuses, a pattern almost like urine in 1 fetus and an intermediate pattern in the 4th fetus. Only the fetus with normal amino acid concentrations in the urine survived: the other 3 died in uremia shortly after birth. In 3 cases cells from the aspirated urine were cultured and used for chromosome analysis. The cell cultures grew fast and karyotyping was possible within 1 week. In 2 fetuses an intrauterine catheter was inserted to drain the kidney permanently into the amniotic cavity. In the first case the catheter was displaced to the fetal abdomen after some days of successful drainage. In the second case the catheter tore the placenta, and the child had to be delivered immediately.  相似文献   

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After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds (VOSCs): methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and dimethyl tetrasulfide (DMTeS). Even in the untreated control without a methionine addition, methionine and its catabolites (VOSCs, mainly DMDS) were found in considerable amounts that were high enough to account for the water’s offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine+glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS.  相似文献   

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针对当前乳化液膜法中关键步骤—破乳进行了实验性研究。对于煤油—LMA-1—NaOH膜体系,研究了化学法和交流低电压电破乳的可行性,重点研究了电破乳的方法及温度、液膜体系及电场强度对破乳的影响。结果表明:对本实验的膜体系,化学法破乳效果不佳,而低电压破乳效果较好,破乳后的LMA-1油相可重复使用,具有良好的工业化应用前景。  相似文献   

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Zr-based metal-organic frameworks(MOFs) have been developed in recent years to treat heavy metals,e.g.hexavalent chromium Cr6+ pollution,which damages the surrounding ecosystem and threaten human health.This kind of MOF is stable and convenient to prepare,but has the disadvantage of low adsorption capacity,limiting its wide application.To this end,a novel formic acid and amino modified MOFs were prepared,referred to as FormUiO-66-NH2.Due to the modification of formic acid,i...  相似文献   

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对废鱼肉、废禽畜肉及其加工过程产生的废弃物在近临界水中水解制备氨基酸和氨基酸水解液的脱色进行研究.反应器容积为200mL,反应温度为180~320 ℃,反应压力为5~26 MPa,反应时间为5~60 min.利用氨基酸分析仪对水解产物中的氨基酸进行定性和定量分析,实验结果发现,实验所用原料水解后可得到17种氨基酸.水解产物中不同种类氨基酸的产率随反应温度、反应压力和反应时间的变化规律各不相同.对其中8种含量较高、用途较广、附加值较高的氨基酸,分别进行了反应温度、反应压力、反应时间对水解液中氨基酸浓度的影响研究,得到了在较低的反应温度、合适的反应压力和一定的反应时间内获得较高氨基酸产率的水解条件.以颗粒状活性炭为脱色剂,对水解液在不同pH值、活性炭用量、吸附温度和吸附时间条件下进行脱色实验,并考察了脱色率和氨基酸损失率.结果表明,较好的吸附条件为:pH=4.0、活性炭用量为0.02g·mL-1、吸附温度40℃、吸附时间15min,脱色率96%;被活性炭吸附的氨基酸可以通过解吸附得到回收.  相似文献   

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