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31.
本文通过3,6-二肼基-1,2,4,5-四嗪(DHT)分别与高氯酸和硝酸反应得到2种高氮含能离子盐,并通过X-射线单晶衍射技术对它们的结构进行了表征。(DHT)(NO3)2(1)属于单斜晶系,C2/c空间群,晶胞参数:a=1.3000(6)nm,b=0.8349(3)nm,c=1.0187(5)nm,β=118.89(5)°,Z=4;(DHT)(ClO4)2(2)属于正交晶系,P21212空间群,晶胞参数:a=0.9804(4)nm,b=1.0747(4)nm,c=0.5325(2)nm,Z=2。采用DSC和TG-DTG技术研究了这两种含能离子盐的热分解机理,并对这两种含能离子盐的非等温动力学、爆热及感度进行了测试分析。研究表明这两种含能离子盐在敏感型含能材料领域具有潜在的应用前景。 相似文献
32.
本文通过3,6-二肼基-1,2,4,5-四嗪(DHT)分别与高氯酸和硝酸反应得到2种高氮含能离子盐,并通过X-射线单晶衍射技术对它们的结构进行了表征。(DHT)(NO3)2(1)属于单斜晶系,C2/c空间群,晶胞参数:a=1.300 0(6) nm,b=0.834 9(3) nm,c=1.018 7(5) nm,β=118.89(5)°,Z=4;(DHT)(ClO4)2(2)属于正交晶系,P21212空间群,晶胞参数:a=0.980 4(4) nm,b=1.074 7(4) nm,c=0.532 5(2) nm,Z=2。采用DSC和TG-DTG技术研究了这两种含能离子盐的热分解机理,并对这两种含能离子盐的非等温动力学、爆热及感度进行了测试分析。研究表明这两种含能离子盐在敏感型含能材料领域具有潜在的应用前景。 相似文献
33.
Shuo Gu Tingting Mou Jian Chen Jing Wang Ying Zhang Meirong Cui Wenqian Hao Yue Sun Chengqin Zhang Tiantian Zhao Binbin Wei 《Journal of separation science》2022,45(10):1656-1671
Baihe-Dihuang Tang is a commonly prescribed remedy for depression. In this study, component screening with untargeted and targeted metabolomics was used to identify potential biomarkers for depression in chronic unpredictable mildly stressed rats. Using this novel identification method, the screening of organic acids, lily saponins, iridoids, and other ingredients formed the basis for subsequent metabolomics research. Baihe-Dihuang Tang supplementation in chronic unpredictable mild-stress-induced depression models, increased their body weight, sucrose preference, brain-derived neurotrophic factor deposition, and spatial exploring. Untargeted metabolomics revealed that Baihe-Dihuang Tang exerts its antidepressant effects by regulating the levels of lipids, organic acids, and its derivatives, and benzenoids in the brain, plasma, and urine of the depressed rats. Moreover, it also modulates the d -glutamine and d -glutamate metabolism and purine metabolism. Targeted metabolomics demonstrated significant reduction in l -glutamate levels in the brains of depressed rats. This could be a potential biomarker for depression. Baihe-Dihuang Tang alleviated depression by regulating the levels of l -glutamate, xanthine, and adenine in the brains of depressed rats. Together, these findings conclusively established the promising therapeutic effect of Baihe-Dihuang Tang on depression and also unraveled the underlying molecular mechanism of its potential antidepressant function. 相似文献
34.
15N/14N Isotopic Exchange in the Dissociative Adsorption of N2 on Tantalum Nitride Cluster Anions Ta3N3-
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Adsorption and activation of dinitrogen (N2) is an indispensable process in nitrogen fixation. Metal nitride species continue to attract attention as a promising catalyst for ammonia synthesis. However, the detailed mechanisms at a molecular level between reactive nitride species and N2 remain unclear at elevated temperature, which is important to understand the temperature effect and narrow the gap between the gas phase system and condensed phase system. Herein, the 14N/15N isotopic exchange in the reaction between tantalum nitride cluster anions Ta314N3- and 15N2 leading to the regeneration of 14N2/14N15N was observed at elevated temperature (393-593 K) using mass spectrometry. With the aid of theoretical calculations, the exchange mechanism and the effect of temperature to promote the dissociation of N2 on Ta3N3? were elucidated. A comparison experiment for Ta314N4-/15N2 couple indicated that only desorption of 15N2 from Ta314N415N2- took place at elevated temperature. The different exchange behavior can be well understood by the fact that nitrogen vacancy is a requisite for the dinitrogen activation over metal nitride species. This study may shed light on understanding the role of nitrogen vacancy in nitride species for ammonia synthesis and provide clues in designing effective catalysts for nitrogen fixation. 相似文献
35.
In this study, flexible silk fibroin protein and biocompatible barium hexaferrite (BaM) nanoparticles were combined and electrospun into nanofibers, and their physical properties could be tuned through the mixing ratios and a water annealing process. Structural analysis indicates that the protein structure of the materials is fully controllable by the annealing process. The mechanical properties of the electrospun composites can be significantly improved by annealing, while the magnetic properties of barium hexaferrite are maintained in the composite. Notably, in the absence of a magnetic field, cell growth increased slightly with increasing BaM content. Application of an external magnetic field during in vitro cell biocompatibility study of the materials demonstrated significantly larger cell growth. We propose a mechanism to explain the effects of water annealing and magnetic field on cell growth. This study indicates that these composite electrospun fibers may be widely used in the biomedical field for controllable cell response through applying different external magnetic fields. 相似文献
36.
Weidong Shang Sheng‐Nan Su Rong Shi Ze‐Dong Mou Guo‐Qiang Yu Xia Zhang Dawen Niu 《Angewandte Chemie (International ed. in English)》2021,60(1):385-390
We here report glycosyl sulfoxides appended with an aryl iodide moiety as readily available, air and moisture stable precursors to glycosyl radicals. These glycosyl sulfoxides could be converted to glycosyl radicals by way of a rapid and efficient intramolecular radical substitution event. The use of this type of precursors enabled the synthesis of various complex C‐linked glycoconjugates under mild conditions. This reaction could be performed in aqueous media and is amenable to the synthesis of glycopeptidomimetics and carbohydrate‐DNA conjugates. 相似文献
37.
Nan Zhao Huawei Mou Yuguang Zhou Xinxin Ju Shoujun Yang Shan Liu Renjie Dong 《Molecules (Basel, Switzerland)》2021,26(4)
Developing a green and sustainable method to upgrade biogas wastes into high value-added products is attracting more and more public attention. The application of solid residues as a performance enhancer in the manufacture of biofilms is a prospective way to replace conventional plastic based on fossil fuel. In this work, solid digestates from the anaerobic digestion of agricultural wastes, such as straw, cattle and chicken manures, were pretreated by an ultrasonic thermo-alkaline treatment to remove the nonfunctional compositions and then incorporated in plasticized starch paste to prepare mulching biofilms by the solution casting method. The results indicated that solid digestate particles dispersed homogenously in the starch matrix and gradually aggregated under the action of a hydrogen bond, leading to a transformation of the composites to a high crystalline structure. Consequently, the composite biofilm showed a higher tensile strength, elastic modulus, glass transition temperature and degradation temperature compared to the pure starch-based film. The light, water and GHG (greenhouse gas) barrier properties of the biofilm were also reinforced by the addition of solid digestates, performing well in sustaining the soil quality and minimizing N2O or CH4 emissions. As such, recycling solid digestates into a biodegradable plastic substitute not only creates a new business opportunity by producing high-performance biofilms but also reduces the environmental risk caused by biogas waste and plastics pollution. 相似文献
38.
Phases of nonlinear double tearing modes are studied numerically. The first two phases lead to the formation and growth of magnetic islands and are followed by a fast reconnection phase to complete the process, driven by a process of neighboring magnetic separatrices merging and magnetic islands coupling. The fast growth can be understood as a result of the island interaction equivalent to a steadily inward flux boundary driven. Resistivity dependences for various phases are studied and shown by scaling analysis for the first time. It is found that after an early Sweet-Parker phase with a eta(1/2)-scale, a slow nonlinear phase in a Rutherford regime with a eta(1)-scale is followed by the fast reconnection phase with a eta(1/5)-scale. 相似文献
39.
高效阴离子交换色谱分离-脉冲安培检测法测定烟草料液中的糖、糖醇和醇类化合物 总被引:6,自引:0,他引:6
建立了高效阴离子交换色谱分离-脉冲安培检测法测定烟草料液中的糖、糖醇以及醇类化合物的方法。以NaOH为淋洗液,在CarboPac MA1阴离子交换柱上等度分离了肌醇、甘油、丙二醇、半乳糖醇、木糖醇、山梨醇、甘露醇、葡萄糖、果糖、蔗糖、甘露糖和半乳糖等12种化合物。对影响分离和检测的条件进行了优化,并在此优化条件下分析了烟草料液中的糖、糖醇以及醇类化合物。12种化合物的检出限为2.0~216μg/L(25.0μL进样,以3倍信噪比计算检出限)。12种化合物浓度为1~5mg/L的标准溶液连续7次进样的RSD为0.7%~4.3%。方法对烟草料液中12种化合物的加标回收率为80%~108%。方法灵敏、高效、简便、快捷。 相似文献
40.
烟叶和烟草料液中氨基酸的直接检测及碳水化合物的去除 总被引:3,自引:0,他引:3
建立了高效阴离子交换色谱-积分脉冲安培法(HPAEC-IPAD)直接检测烟叶和烟草料液中氨基酸的方法。利用离线除糖的方法,去除烟叶和烟草料液中大量干扰糖类,包括葡萄糖、果糖和蔗糖及麦芽低聚糖等。采用AminoPac PA10阴离子交换柱,以NaOH和NaAc的强碱性溶液为淋洗液,采用梯度洗脱,流速为0.25 mL/min;积分脉冲安培法对氨基酸进行检测,回收率可达76%~105%。此方法可以有效的解决烟叶、烟草料液等含糖量高的样品中糖类化合物的干扰,对氨基酸实现灵敏、准确的定量分析。 相似文献