994 resultados para Bin


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This paper describes the design of an interference imaging spectrometer. A static Polarization Imaging Spectrometer (PIS) based on a single Savart polariscope has been developed. It produces the interferogram and target's image in the spatial domain which are recorded by using a two-dimensional (2D) CCD detector. Imaging lens localizes the interference fringes and target's image coincident with the plane of detector, thereby facilitating an extremely compact design. The spectrum of the input light is reconstructed through the Fourier-transform of the interferogram. The total optics is as small as 20 x 6 cm phi in size and the spectral resolution of the prototype system is 97.66 cm(-1) between 25,000 and 10, 000 cm(-1). The polarization interference imaging device has advantages of ultra-compact size, wide field of view, high throughput and without any moving parts. (C) 2002 Published by Elsevier Science B.V.

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Based on the data processing technologies of interferential spectrometer, a sort of real-time data processing system on chip of interferential imaging spectrometer was studied based on large capacitance and high speed field programmable gate array( FPGA) device. The system integrates both interferograrn sampling and spectrum rebuilding on a single chip of FPGA and makes them being accomplished in real-time with advantages such as small cubage, fast speed and high reliability. It establishes a good technical foundation in the applications of imaging spectrometer on target detection and recognition in real-time.

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A novel Nd3+-doped lead fluorosilicate glass (NPS glass) is prepared by a two-step melting process. Based on the absorption spectrum a Judd-Ofelt theory analysis is made. The emission line width of NPS glass is 44.2nm. The fluorescence decay lifetime of the 4F3/2 level is 586±20μsec, and the stimulated emission cross-section is 0.87×10-20cm2 at 1056nm. A laser oscillation is occurred at 1062nm when pumped by 808nm Diode Laser. The slope efficiency is 23.7% with a 415mJ threshold. It is supposed that NPS glass is a good candidate for using in ultra-short pulse generation and amplification by the broad emission bandwidth and long fluorescence lifetime.

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近年来,随着脉冲傅里叶变换核磁共振波谱仪灵敏度的提高及计算机技术的进步,使NMR技术在生物领域的应用有了飞速的发展。论文应用NMR技术研究了稀土化合物(硝酸镧)对大鼠体内代谢产物的影响。对Wistar种大鼠按不同剂量给药(灌胃和腹腔注射两种方式)后的尿液和血清中的代谢物质的~1H NMR谱数据进行研究,并结合血清、尿液中生化指标的检测结果,指出稀土作用后大鼠肾脏的肾小管及肝脏线粒体均受到一定程度的损害,随稀土摄入量的增多,损害程度越严重。并提出代谢物中尿素、Suc、Kg、Cit、DMA、DMG、TMAO和氨基酸等可以作为肾脏受损伤的NMR markers,而乙醇、Lac和Tau可作为肝脏受损伤的NMR markers。实验中最小剂量为0.05 mg La(NO_3)_3/kg体重,仍有机体受损的NMR信号,说明稀土的安全剂量小于这一数值。在临床磁共振成像中,造影剂是医学诊断中的一种重要辅助试剂。本文采用NMR水弛豫分析法研究了GdDTPA及Gd(cycle-DTPA-1,2-PN)、Gd(DTPA-BIN)在水溶液和BSA溶液中的弛豫性质,为研究顺磁性金属配合物与蛋白质间相互作用情况提供了有效方法;对配体cycle-DTPA-1,2-pn、DTPA-BIN做了~1H NMR滴定研究,得出其质子解离过程和解离常数,并采用半经验量化计算方法计算了两种配体的质子化过程,得到了与~1H NMR滴定一致的结果。结果表明将NMR实验和量化计算方法结合,是考察复杂配体热力学稳定性的有效方法。

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近年来,随着高场傅里叶变换核磁共振波谱仪灵敏度的提高、分辨率的增加、化学位移的扩展、多脉冲实验技术的发展以及计算机技术的不断进步,使NMR技术和MRI技术在生物和医学领域的应用有了飞速的发展。论文工作围绕新型MRI造影剂的研制和稀土对动物体液代谢产物的影响及作用,进行了较系统的研究。合成了四种稀土配合物:K_(11)[Gd(PW_(11)o_(39)]_2]、K_9GdW_(10)O_(36)、Gd_2(P_2W_(18)O_(62)、K_(15)[(GdO)_3(PW_9O_(34)_2]和四种中性的多竣多胺类稀土配合物:Gd(DTPA-BDEA)、Gd(DTPA-BDMA)、Gd(DTPA-BIN)和Gd(cyclic-DTPA-1,2-pn),从对造影剂临床应用的一般要求出发,对其进行了表征和溶解性、稳定性及体外的弛豫实验,指出它们是潜在的较好的MRI造影剂。在此基础上,通过大鼠体内的MRI实验考察了/又种造影剂侯选化合物的体内弛豫效率、选择性及体内滞留时间和代谢情况,并与目前临床普遍运用的造影剂GdDTPA进行了比较。并结合动物急性毒性实验(LD_(50)测定)对其进行综合评价,且对其应用于临床的可能性进行了探讨。结果表明,K_(11)[Gd(PW_(11)O_(39)_2]、K_9GdW_(10)O_(36)、K_(15)[GdO)_3(PW_9O_(34)_2]和Gd(DTPA-BDMA), Gd(DTPA-BIN), Gd(cyclic-DTPA-1,2-pn)是良好的具有肝脏选择性的MRI造影剂,K_(15)[(GdO_3(PW_9O_(34)_2]、Gd(cyclic-DTPA-1,2-pn)Gd(DTPA-BDMA)具有良好的肾脏代谢性能,另外KgGdW10036有可能对病理状态的诊断有一定的作用。首次运用高分辨'H NMR技术,检测了大鼠长期服用不同剂量硝酸斓(0,0.05, 0.2, 2.0, 10, 20 mg/kg体重)和农用稀土微肥常乐(La203: 30.48%, Ce02: 54.67,Pr6011: 6.05%, Nd203: 8.8%) (0, 0.1, 0.2, 2.0, 10, 20 mg/kg体重)后血清及尿液中的代谢物如柠檬酸、酮体、肌酸酚、二甲胺、二甲基甘氨酸、TMAO、氨基酸和乳酸、唬拍酸、牛磺酸等的浓度、物种的变化,并用ICP-MS法测定了长期口服常乐后大鼠各组织及脏器中的稀土含量,并结合一些生化指标的测试,对稀土在体内与细胞、组织和器官的作用机理及在动物体内的积累、排泄和远期毒性进行了有意义的探讨。结果表明,高剂量稀土在体内长期作用,可能导致动物肝脏和肾脏特定部位(如肾小管、'肾乳头、肝脏线粒体)受到选择性的损伤,且损害程度与剂量成正比关系。并发现,不同的稀土离子在体内有不同的作用方式,不同的稀土离子在体内有不同的代谢和累积速率,而且动物对稀土的毒性可能有一个适应过程。低剂量稀土对代谢没有明显影响,并建议了一个较安全剂量,但仍需对稀土的农用安全性进行进一步研究。