金属硫氰酸根配合物FeHg(SCN)_4,MnHg(SCN)_4的合成、晶体结构与非线性光学性质的研究

合成了配合物晶体FeHg(SCN)_4和MnHg(SCN)_4用单晶X射线衍射方法测定了这两个晶体的结构.以尿素为标准样品用粉末晶体倍频1064nm的Nd:YAG激光,测得其倍频光强度分别为:FeHg(SCN)_4,0.6倍于尿素;MnHg(SCN)_4,50倍于尿素.后者显示了作为新的非线性光学材料的发展前景.     

Synthesis, Structure and Non-linear Optical Properties of Manganese Mercury Tetrathiocyanate

IntroductionRecently,ourresearchinterestshavefocusedonMHg(SCN).seriesofcrystallinecomplexesbecauseoftheirstrikingnonlinearopticalproperties.Inthepreviouspaper"',wehavereporedthesynthesis.structureandnonlinearoptical(NLO)propertiesofCdHg(SCN).andFeHg...     

Elastic media with randomly distributed defects

In this paper, the elastic field in a solid with randomly distributed defects is derived. These defects are composed of cavities and microcracks, whose locations, orientation and size are random variables. The Random Point Field Model is proposed to describe the random defects, and the basic equations for elastic field in a random defect medium are developed. Two examples are studied in detail. One is a solid with random microcracks and the other is a solid with ellipsoidal cavities.     

一个Саульев型格式及其对二维粘性不可压缩流的应用

在本文中,我们提出了一个稳定的求解扩散——对流方程的Саульев型格式,并提出了它的单调性和自调性。最后将其应用于二维粘性不可压缩圆柱绕流的计算,与已发表的数值结果和实验结果相比较表明我们的计算结果是好的。     

N-β-羟乙基乙二胺在铜催化剂上的反应机理

1　前言哌嗪是一种重要的化工原料和医药中间体 ,应用十分广泛 [1] ,数十年来国内外对其合成工艺进行了大量的研究 ,其中以醇胺为原料在一定催化剂作用下脱水环合生成哌嗪的研究最为引人注目 [2～ 4 ]。我们研究开发了以 N-β-羟乙基乙二胺 (以下简称羟乙 )为原料 ,在铜催化剂作用下合成哌嗪的工艺。通过醇制备胺的反应是由 Sabatier和 Mail-he在 1 90 9年研究发现的 ,称为醇催化胺化反应[5] 。随后人们对于此类醇催化胺化反应的历程进行了大量的研究。Schwegler和 Adkins认为反应是一个脱氢 /加氢历程 [6 ] ,有机胺是通过烯胺(雪弗碱 )中…     

基于SiPM读出的塑料闪烁体探测器时间性能研究

研究了基于硅光电倍增管(SiPM)双端读出的面积为10 cm ×10 cm的薄塑料闪烁体探测器的时间性能。239Pu放射源测试结果显示:(1)在多支SiPM串连读出方式下,随着SiPM数量的增加,探测器时间分辨逐渐变好;(2)在固定12支SiPM数量不变的情况下,并联支路越多,探测器时间分辨越差;(3)采用快时间塑料闪烁体并增加其厚度,可有效提高探测器时间分辨;(4)采用比束斑尺寸更大的塑料闪烁体,可有效提高探测器时间分辨的位置均匀性;(5)对于1 mm厚的EJ232塑料闪烁体探测器,在单端12支SiPM串行连接的情况下,可获得好于131 ps的时间分辨。这一研究对RIBLL2起始时间探测器的升级改造具有重要的指导意义。     

川西平落雷口坡组海相碳酸盐的锶同位素地球化学特征

通过对平落4井雷口坡组段的岩心进行锶同位素组成的实验分析,研究了含卤碳酸盐地层物源贡献与沉积环境的演化,以及后期深部热液活动可能对富钾卤水形成所施加的影响.结果表明,区内海相碳酸盐w(87Sr)/w(86 Sr)值的变化,主要受二叠纪末峨眉山玄武岩浆喷发和印支期隆升导致四川盆地由"洋盆"向"孤盆"演化的地质构造背景所制...     

钝感炸药直径效应实验研究

钝感炸药爆轰波的传播与波阵面曲率密切相关 ,为研究这种非理想行为 ,通过光电联合测试方法测量了常温下直径为 10、12 .5、15、30mm的钝感药柱的定态爆速和波形 ,根据拟合的爆轰波形 ,分析了波阵面法向速度Dn与当地曲率之间的关系。结果表明 ,定态爆速随药柱直径的增大而增大 ,当较小时 ,Dn只与有关 ,当较大时 ,Dn不仅与有关 ,而且还与药柱直径有关。     

Surface-Enhanced Raman Spectroscopy-Based Optical Biosensor for Liquid Biopsy: Toward Precision Medicine

Liquid biopsy is regarded as a promising strategy for assisting precision medicine because of its convenience, noninvasiveness, and ability to overcome tumor heterogeneity and achieve early detection. Recently, impressive advancements in plasmonic biosensors, artificial intelligence, and portable Raman equipment have yielded unprecedented progress in surface-enhanced Raman spectroscopy (SERS)–based point-of-care testing (POCT) systems for liquid biopsy. The development of these systems presents a paradigm shift in on-site liquid biopsy applications by leveraging the unique benefits of efficiency, fast analysis, portability, affordability, and user-friendliness. Herein, these advances are introduced over the last 3 years in the field of SERS-based POCT systems for labeled and label-free biomarker analysis in body fluids, including tumor circulating proteins and cells, exosomes, micro-RNA, and circulating tumor DNA. Additionally, powerful machine learning algorithms (including deep learning algorithms) are integrated with SERS to effectively extract potential data features and generate precise diagnostic models. The review highlights the use of handheld and portable Raman devices in significantly promoting the application of SERS-based POCT in clinical scenarios. Finally, the review outlines the challenges and future perspectives of this technology.     

SPECTROSCOPIC STUDIES OF SEVERAL MESO-SUBSTITUTED ZINC TETRABENZOPORPHYRINS

The electronic spectroscopic properties of severalmeso-substituted zinc tetrabenzoporphyrins(ZnTBP,ZnTMTBP,ZnTPTBP,ZnTTTBP and ZnTNTBP)have been investigated intoluene.The lifetimes determined showed that the fluorescenceof these compounds decay with good double exponentials.