F+C_2F_5l反应的动力学研究

本文用激光诱导荧光方法与分子束技术相结合,首次在R6G和DCM染料波段研究了反应 F+C_2F_5I→IF+C_2F_5(△H_0~0=-58kJ/mol)的动力学过程。由IF的荧光激发谱得到了IF(v’=3、4、5、6、7)五个振动能级的初生态布居,确定了反应机构,平均振动激发和总反应截面等动力学问题。     

可见光化学激光研究——Ⅱ.采用F-NH_3-IF化学反应体系实现IF化学激光的模型

本模型建立了采用F-NH_3-IF化学反应体系实现IF化学激光的机制,包括14个动力学过程.通过Gear自动积分法求得IF(B)和有关激发态粒子的数密度和IF(B,υ′=0,J′=21)→(X,υ″=5,J″=20)的增益系数,以及腔对以上参数的重要影响.计算表明当腔压大于6Torr时才有正的增益系数,大于1OTorr时有可能实现激射.还讨论了产生IF(B)的主要传能通道.     

红外激光引发CF_3CF=CF_2+O_2和CF_3CF=CF_2+C_2F_4+O_2反应

本文报道了在TEA CO_2激光P(28)线<00°1-02°0>照射时,红外激光引发CF_3CF=CF_3+O_2反应和CF_3CF=CF_2+C_2F_4+O_2反应。在反应中,得到的主要产物是CF_2O。根据反应产物可以推论在激光引发这二个体系反应过程中,存在着CF_2(~3B_1)卡宾,由于CF_2(~3B_1)卡宾和O_2反应生成CF_2O。当反应体系中存在C_2F_4时,由于C_2F_4参与CF_2O_2+C_2F_4→     

纯化学燃烧驱动的HBr化学激光

对以D_2为燃料、NF_3为氧化剂的纯化学燃烧驱动的HBr化学激光进行了研究。抽运反应为H+Br_2→HBr(v≤6,J)+Br,氢原子由F+H_2→HF+H反应提供,氟原子则由D_2/NF_3混合气体燃烧热解生成,激光提取所需的低温低压和快速流动条件由超音速流动系统完成。对由全反反射镜和部分反射(98%)输出镜组成的稳定腔进行了能量提取,获得了P_2(4)、P_2(5)、P_3(5)和P_3(6)的稳定激光输出,最大激光输出功率为14.3 W。     

氟化锂晶体F_2心光致电离及F_2和F_2~+心激光特性研究

室温下利用337nm脉冲激光照射着色LiF晶体,有效地将F_2心转变成F_2~+心,其浓度高于10~(16)cm~(-3)。利用消象散三镜折叠腔,研究了LiF晶体F_2和F_2~+心激光特性。实际工作表明,利用氮分子激光作为处理光束,可获得较长时间稳定的F_2~+心激光输出。     

色心激光晶体

本文报导近年来我们对碱卤晶体中色心研究的若干进展。主要内容有:(1)掺二价金属离子的NaF晶体中(F_2~+)心的一个可能的模型。(F_2~+)心可表示为一个F_2~+心位于一个正空位和二价金属离子的近邻(即F_2~++Ⅰ-Ⅴ对)。光谱学和热释发光的许多证据支持此种模型;(2)LiF晶体中F_3~+心的光学性质。对LiF晶体采用适当的着色条件,可得到比F_2     

印刷线路板快速翻版技术

染色方法是在清洁的线路上浇上染色剂.试验结果(见上表)表明,将线路化学镀银后,用硫化铵溶液染色效果良好,这是因为Na_2S染色效果差,因形成硫化物少,且Cu_2S暗灰色,只有CuS显棕色,但能生成两价铜的硫化物更少.为么什银和(NH-4)_2S反应效果良好,我们认为反应是分两步进行的.①银和(NH_4)_2S溶液中的NH_4OH形成银氨络合物:4Ag+8NH_4OH+O_2—→4Ag(NH_3)_2OH+6H_2O②银氨络合物与(NH_4)_2S形成黑色硫化银沉淀:2Ag(NH_3)_2OH+(NH_4)_2S—→Ag_2S↓+2NH_4OH+4NH_3↑ └→2NH_3↑+2H_O一天时间就可以做好双面黑白反差大的线路板,完全能满足制版要求,翻拍出的照相     

CO_2激光诱导NH_3的光化学

在用激光引发的反应体系中引入催化剂表面,目的在于探索实现高选择性皮应的新途径,本文简述在所建立的实验装置上观察到的一些实验现象。一、用连续 CO_2激光诱导 NH_3的光化学实验装置如图。CO_2激光功率15—50瓦连续可调,NH_3经液氮冷冻净化;白金(pt)可加热处理,反应器抽空到10~(-2)mmHg 柱。实验结果:①在一定的激光功率下,一定的 NH_3压力范围内,红外发射谱的强度随压力增加而增强。②在NH_3压力为60mmHg 柱时,测出了焦点处 NH_3     

着色LiF:OH~(-1)晶体F_2~+心再生及其激光实验

在液氮温度下利用电子束轰击LiF:OH-晶体,产生了密度高于10~(17)cm~(-3)的F_2~+心。室温下用氮分子激光(337nm)照射着色LiF:OH~-晶体,有效地将F_2心转变成F_2~+心,其浓度达10~(16)～10~(17)cm~(-3)。利用氮分子激光束作为处理光束,在室温下实现了稳定的F_2~+心激光运转。     

CF_2Cl_2十SF_6的激光裂解

本文采用CW CO_2激光器研究了SF_6+F_(12)在不同条件下的激光诱导化学反应,并与热反应进行了对照。证明SF_6在F_(12)的激光裂解中是一光敏剂,能使F_(12)的分解分数大大提高。整个反应为碰撞级联激发过程,而非多光子过程。     

F原子与胺类分子反应的可见化学发光研究

在交叉分子束装置上，进行了F原子与胺类分子（甲胺、乙胺、正丙胺、正丁胺）反应的可见化学发光实验研究，依次观察到了HF（3，0）、（4，0）、（5，1）、（6，2）、（7，3）、（8，4），HCF（A－X）和CN（A，B－X）的发射光谱．除F原子与甲胺的反应外，其余反应还观察到TCH（A－X）发射谱．依据产物光谱强度随反应物和反应压力的变化，对F原子与胺类分子反应的动力学过程进行了分析．     

BF_2~+,F~+ +B~+和Ar~++B~+注入硅快速退火剩余损伤及对浅P~+N结的影响(英文)

The residual damage is analysed by transmission electron microscopy (TEM) for BF2+, F+ + B+ and Ar+ + B+ implanted silicon after rapid thermal annealing(RTA). And the reverse leakage current of the implanted diodes is measured using a FJ-356 electrometer. The results show that 1 ) The residual damage due to BF2+ implantation is less than that of F+ + B + and Ar++ B+ implantation. 2) The reverse leakage current of BF2+ implanted diodes is less than that of F+ + B+ and Ar++ B + implanted diodes. 3) The reverse leakage current of F++B+ and Ar++ B+ implanted diodes increases with the increase of F+ and Ar+ energies, respectively. Therefore the physical behaviour of the interaction between molecular ion and silicon is different from that of the interaction between individual atom ion and silicon.     

sol-gel法制备表面改性纳米氧化锌

采用Zn(NO3)2.6H2O和NH3.H2O及合适的表面改性剂,通过sol-gel前驱体法,制备了高纯度的纳米ZnO粉体。采用激光粒度分析、SEM、XRD等手段,对所制备的粉体进行了表征。并研究了主盐浓度、反应温度、反应体系的pH值、表面改性剂等因素对ZnO晶体形成过程和显微结构的影响。结果表明:在Zn2+浓度为0.1mol/L、反应体系温度为50℃、pH值为6.0,采用聚乙二醇(PEG-2000)作为表面改性剂,将制得的前驱体在400℃分解2h,获得了纯度高、分散性好、结晶完整、粒度分布窄、粒状的纳米ZnO粉体。     

硅酸盐橙色荧光粉的发光性能研究

采用高温固相反应法制备了高效橙色荧光粉Sr3–xSiO5:xEu2+。通过X射线粉末衍射仪(XRD)、扫描电镜(SEM)及荧光分光光度计研究了Eu2+含量和不同助熔剂对荧光粉发光性能的影响,并分析了所制荧光粉的封装性能。研究表明,荧光粉Sr3–xSiO5:xEu2+的晶体结构属正方晶系。当Eu2+的摩尔分数为4%,并用质量分数为3%的NH4Cl作助熔剂时,制得的Sr3–xSiO5:xEu2+的发射光谱强度最大。荧光粉封装后可以有效降低白光LED的色温并提高其显色指数,这表明该荧光粉是一种适用于白光LED的光转化材料。     

An Active IF Balun for a Doubly Balanced Resistive Mixer

In this letter, we present a wideband active intermediate frequency (IF) balun for a doubly balanced resistive mixer implemented using a 0.5 mum GaAs pHEMT process. The 0.3 times 0.5 mm² IF balun was realized through a DC-coupled differential amplifier in order to extend IF frequency of the mixer to DC. The measured amplitude and phase imbalances were less than 1 dB and 5deg, respectively, from DC to 7 GHz. The output third order intercept (OIP3) and P1 dB of the IF balun were 18 dBm and 6 dBm, respectively at 1 GHz. The mixer with the IF balun is 1.7 times 1.8 mm² in size, has a conversion loss of 2 to 8 dB from 8 to 20 GHz RF frequency at a fixed IF of 1 kHz, which proves the mixer operates successfully at an IF frequency close to DC. The measured OIP3 were +10 to +15 dBm over the operating frequency with a DC power consumption of 370 mW.     

A high-IP3 RF receiver chip set for mobile radio base stations upto 2 GHz

We present a monolithically integrated high third-order intercept point (IP3) radio frequency (RF) receiver chip set for mobile radio base stations up to 2 GHz, in a 25-GHz f_T Si bipolar production technology. The chip set consists of a RF preamplifier, active mixer circuits, and an intermediate frequency (IF) limiter. The preamplifier gain is 12 dB, the noise figure is 5.5 dB at 900 MHz, and the output (OIP3) is up to +24 dBm depending on supply voltage. The two different mixers provide a conversion gain of 1.5 dB up to 3 dB, an OIP3 in the range of +21 dBm up to +29 dBm, and a minimal single sideband (SSB) noise figure of 13 dB. The IF limiter shows an excellent limiting characteristic at 10 dBm output power and has a high bandwidth of more than 1 GHz     

复合物p—C6H4F2...NH3（ND3）外部振动的共振双光子电离光谱

利用共振光电离技术和飞行时间质谱技术,观察到了复合物ｐ－Ｃ６Ｈ４Ｆ２．．．ＮＨ３（ＮＤ３）的共振双光子电离光谱。光谱分析表明,复合物分子间的伸 振动频率为８６．４ｃｍ＾－１;由复合物光解离机理以及伸缩模的失谐参数与键有的关系。获得了复合物电子激发态Ｓ１和基态Ｓ０的键能信息。Ａｂｉｎｉｔｉｏ计算表明,ｐ－Ｃ６Ｈ４Ｆ２．．．ＮＨ３（ＮＤ）复合物的几何结构是：ＮＨ３分子中的Ｎ原子位于垂直ｐ－Ｃ６Ｈ４Ｆ２     

亚稳态He（2^3S）原子与N2H4分子传能产物的发光研究

本文在流动余辉装置上,研究了亚稳态H2(2^3S）原子与N2H4分子碰撞传能,观察到了激发态产物NH（A^3п→X^3∑^ ）、NH（c^1п→a^1△）、NH2（A^~A1→X^2△B1)的发射光谱,由相对光谱强度求得了形成各产物的通道比;分析NH（A^3п,v′＝0）的转动分辨谱的结果表明,v′＝0能级上的转动布居是“双模”分布,激光态产物NH（A）、NH2（A）的形成机理可能是：He(2^3S) NH2H4 N2H4→NH2H4^*→NH(A) NH2(A) H。     

Discrete-time local polynomial approximation of the instantaneousfrequency

The local polynomial approximation (LPA) of the time-varying phase is used to develop a new form of the Fourier transform and the local polynomial periodogram (LPP) as an estimator of the instantaneous frequency (IF) Ω(t) of a harmonic complex-valued signal. The LPP is interpreted as a time-frequency energy distribution over the t-(Ω(t), Ω¹(t)),...,Ω^m-1(t) space, where m is a degree of the LPA. The variance and bias of the estimate are studied for the short- and long-time asymptotic behavior of the IF estimates. In particular, it is shown that the optimal asymptotic mean squared errors of the estimates of Ω^k-1(t) have orders O(N^-(2k+1)) and O(N^-/2(m-k+1)2m+3), k=1.2,...,m, respectively, for a polynomial Ω(t) of the degree m-1 and arbitrary smooth Ω(t) with a bounded mth derivative     

Broadband single- and double-balanced resistive HEMT monolithicmixers

A double-balanced (DB) 3-18 GHz and a single-balanced (SB) 2-16 GHz resistive HEMT monolithic mixer have been successfully developed. The DB mixer consists of a AlGaAs/InGaAs HEMT quad, an active LO balun, and two passive baluns for RF and IF. At 16 dBm LO power, this mixer achieves the conversion losses of 7.5-9 dB for 4-13 GHz RF and 7.5-11 dB for 3-18 GHz RF. The SB mixer consists of a pair of AlGaAs/InGaAs HEMT's, an active LO balun, a passive IF balun and a passive RF power divider. At 16 dBm LO power, this mixer achieves the conversion losses of 8-10 dB for 4-15 GHz RF and 8-11 dB for 2-16 GHz RF. The simulated conversion losses of both mixers are very much in agreement with the measured results. Also, the DB mixer achieves a third-order input intercept (IP₃) of +19.5 to +27.5 dBm for a 7-18 GHz RF and 1 GHz IF at a LO drive of 16 dBm while the SB mixer achieves an input IP ₃ of +20 to +28.5 dBm for 2 to 16 GHz RF and 1 GHz IF at a 16 dBm LO power. The bandwidth of the RF and LO frequencies are approximately 6:1 for the DB mixer and 8:1 for the SB mixer. The DB mixer of this work is believed to be the first reported DB resistive HEMT MMIC mixer covering such a broad bandwidth