15 research outputs found

    Application of MALDI-Tof-MS and FT-ICR-MS in Study on Schiff Base Nickel Complexes

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    本研究对基质辅助激光解吸电离飞行时间质谱(MAldI-TOf-MS)的原理和应用做了简要介绍,并概括了常用基质的应用特点和适用范围。通过基质的选择及测试条件的优化,分别对3种席夫碱镍配合物进行质谱分析,实验结果表明,[M+H]+峰的分子质量以及同位素丰度都与理论计算值十分吻合。采用此法不仅能准确地测定席夫碱镍配合物的分子质量,为席夫碱镍配合物结构的鉴定奠定基础,也是金属有机化合物分子质量测定的有效方法,是快速分析金属有机化合物的工具之一。为了进一步说明质谱在金属配合物测定中的可靠性,辅以傅里叶变换离子回旋共振质谱仪(fT-ICr-MS)进行确证。The principle and applications of matrix-assisted laser desorption ionization time of flight mass spectrometry(MALDI-Tof-MS) were briefly introduced.The characteristics and scope of the application of matrixes were summarized.Three Schiff base nickel complexes were respectively analyzed by MALDI-Tof-MS.The results showed that the molecular weight + peak and the isotopic abundance were very consistent with the theoretical value.By this method not only the molecular weight of Schiff base complexes was accurately determined,providing important assistance for the structural identification,but also it would be an effective and rapid tool for identification of metal organic complexes,and supplemented by Fourier transform ion cyclotron resonance mass spectrometer(FT-ICR-MS) for confirmation.国家自然科学基金(2077309820973136)资

    扭曲椭圆管内降膜蒸发特性研究

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    高效换热管有利于提高降膜蒸发器的传热性能,通过FLUENT软件对扭曲椭圆管内降膜蒸发过程进行研究,分析了液膜在扭曲椭圆管内的流动以及分布情况。研究结果表明:液膜在扭曲椭圆管内为螺旋流动,因离心力的作用会在垂直于主流方向产生二次流,从而增强对传热边界层的扰动;从壁面到液膜表面,液膜速度及压力都在逐渐增大,速度的变化率在逐渐地减小;相比于圆管,扭曲椭圆管内的液膜流动更为平稳,且液膜厚度的分布因扭矩的存在而具有一定的周期性变化规律;在扭曲椭圆管内,流体速度场与温度场的协同性相对来说比圆管的好,而速度场与压力场的协同性比圆管的差

    A study of optimum fertilization model for plastic-mulched wheat on newly built terrane land in North Shaanxi Province

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    采用田间正交旋转试验设计 ,于 1999年在延安市燕沟进行了小麦产量与氮肥 (N)、磷肥 (P2 O5)和有机肥 (M) 3因子 5水平的新修梯田地膜小麦试验。通过对试验结果数学建模及模型分析得出 ,本区影响产量的因子效应为 N >P≈ M,N肥产量效应约为磷肥、有机肥的 3倍 ,有机肥增产趋势在低肥力时最低 ,随着肥力水平提高 ,其增施肥料的增产能力增加 ,而氮肥、磷肥肥效均呈递减趋势 ,即肥效随施肥量增加而减小。还分析了本区小麦单位面积产量≥ 2 5 0 0 kg/ hm2 的优化施肥组合 ,筛选的施肥方案为 N 2 5 1.8~ 2 72 .5 kg/ hm2 ,P2 O510 8.9~136 .5 kg/ hm2 ,有机肥 12 80 0~ 16 40 0 kg/ hm2。均值依次为 2 6 1.1,12 5 .1和 146 0 0 kg/ hm2

    三维变形管MVR蒸发器的强化传热数值研究

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    蒸发器的换热性能对MVR(mechanical vapor recompression)系统有着重要影响。利用FLUENT软件,以水为介质,在雷诺数13000<Re<110000,研究了三维变形管的不同结构参数对管内传热与压降性能的影响,拟合出了计算准则关联式。模拟结果显示:由于受到离心力的作用,流体在三维变形管内产生了垂直于主流方向上的二次流,促进了边界层与主流区的径向混合,强化了传热;三维变形管的扭距S越小,长短轴比A/B值越大,强化传热效果越好,但同时压降也会增大;综合换热性能在13000<Re<60000随着雷诺数Re的增大迅速减小,在60000<Re<110000随雷诺数Re增大而逐渐趋于平稳,但仍然优于光滑直圆管,减小扭距S值比增大长短轴比A/B值更有利于提高管内综合强化传热性能。将三维变形管应用于MVR蒸发器中,节材效益显著

    新疆阿热勒托别地区遥感化探综合找矿研究

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    以新疆阿热勒托别地区为例进行遥感化探综合分析研究。由于新疆阿热勒托别工作区图像上的植被和云严重影响了矿化蚀变信息的特征谱带的识别,使得应用Crosta法提取矿化蚀变信息效果不理想,因此采用掩膜技术剔除植被和云的影响。选择Crosta法对掩膜后图像进行羟基和铁氧化物蚀变信息提取,以μ+1.64σ-μ+2σ、μ+2σ-μ+3σ及>μ+3σ3级阈值分割遥感异常信息,并用不同色彩叠加到遥感与化探融合图像上,结合地质构造信息进行综合分析,圈定成矿有利地段,经野外检查,验证了多处地表岩石蚀变的存在并新发现铜矿点一处,证实了该方法的有效性

    中文科技期刊四封编排规范性调研分析——基于中国科学院主管的中文科技期刊

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    【目的】通过对中国科学院主管的中文科技期刊四封的编排规范性进行调研,找出科技期刊四封标注项目现存问题,为提升我国科技期刊四封编排质量提供依据。【方法】在文献调研及对照国家有关四封编排格式规定的基础上,初拟了中文科技期刊四封编排规范性审核表;之后采用专家咨询法对该表进行优化,最终确定中文科技期刊四封审核表的各项内容,并使用该表对中国科学院主管的2019年出版的中文科技期刊四封编排规范性进行调研和分析。【结果】中文科技期刊四封编排的不规范主要表现为封一未标注出版单位,版权块中CN号字号不规范,刊有广告的期刊未标注"广告发布登记"或标注错误等。【结论】通过对中国科学院科技期刊全样本调研,可以推断我国科技期刊四封编排,尤其是封一和版权块标注内容的规范性亟待全面提升,以充分发挥期刊的整体功能

    Electrochemical Performance of Sodium Difluoro(oxalato)borate as the Additive of Non-aqueous Electrolytes for Sodium-ion Batteries

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    引入电解液添加剂是提升钠离子二次电池电化学性能的重要途径.本论文制备了二氟草酸硼酸钠(NaDFOB)并作为NaClO4/碳酸乙烯酯(EC)/碳酸丙烯酯(PC)( EC:PC体积比=1:1)非水电解液的添加剂,分别考察了其加入量对于电导率特性、电化学氧化分解电压的影响,以及应用于NaNi0.5Mn0.5O2半电池的电化学性能. 结果表明,NaDFOB作为添加剂时对于NaClO4/EC/PC电解液电导率提升不明显,但是显著提升了电解液的氧化分解电压;以添加0.025 mol&middot;L-1 NaDFOB的电解液应用于NaNi0.5Mn0.5O2半电池时,首周不可逆比容量由22 mAh&middot;g-1下降到9 mAh&middot;g-1,同时0.2C倍率下循环200周容量保持率由44.4% 提升到89.5%,平均每周容量衰减为0.06 mAh&middot;g-1. 因此,NaDFOB可以作为钠离子电池非水电解液的一种有效添加剂.Sodium ion battery has attracted worldwide and intensive attention recently, while the adoption of electrolyte additives has been considered as one effective strategy to promote the cell performance. Within this work sodium difluoro(oxalato)borate (NaDFOB) was prepared and adopted as an additive for the general non-aqueous electrolyte formula of 1 mol&middot;L-1 NaClO4/EC/PC (Vol: Vol=1:1), and the effects of the additive concentration on ionic conductivity and oxidization decomposition voltage were investigated in detail. In addition, the cell performance evaluated by NaNi0.5Mn0.5O2 as the cathode was also studied. It reveals that the addition of NaDFOB into the NaClO4/EC/PC electrolyte resulted in the significantly increased oxidation decomposition voltages from 4.6 V to 4.85 V, in spite of the slightly increased ionic conductivity, attributed to extra dissociated sodium salt NaDFOB. When the 0.025 mol&middot;L-1 NaDFOB added electrolyte was used to support the operation of NaNi0.5Mn0.5O2 cathode, the initial irreversible capacity decreased from 22 mAh&middot;g-1 to 9 mAh&middot;g-1, and the capacity retention upon 200 cycles at 0.2 C-rate increased from 44.4% to 89.5%, with an average capacity fade of 0.06 mAh&middot;g-1 per cycle. Therefore, the NaDFOB was proved to be an effective electrolyte additive for non-aqueous sodium ion batteries.国家自然科学基金(No.21506141),山西省自然科学基金(No.2015021131, No.201601021040)资助项目作者联系地址:1. 太原理工大学化学化工学院,山西 太原 030024; 2. 山东玉皇新能源科技有限公司,山东 菏泽 274000Author's Address: 1 College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi Province, 030024, P. R. China; 2 Shandong Yuhuang New Energy Technology Co. Ltd. Heze274000, Shandong Province, P. R. China通讯作者E-mail:[email protected]
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