定向红外对抗系统的激光源模拟研究

针对半实物仿真中定向红外对抗系统的有效模拟问题,在分析定向红外对抗激光源技术的基础上,依据实战应用,计算得到3 m~5 m波段定向红外对抗激光源的辐射能量为飞机红外辐射强度绝对值的8倍,结合波长4 m处简化的大气传输透过率随传输距离的变化,推导出实战应用中红外导引头上辐射照度随飞机导弹之间距离的变化规律。设计半实物仿真中定向红外对抗的模拟方案,依据逼真模拟的原则,计算得到模拟激光源能量随飞机导弹之间距离和飞机辐射强度的变化规律,据此将飞机导弹相互距离1 km时刻的红外干扰源辐射能量设置为波长4 m模拟激光源能量,其他距离的模拟能量通过衰减片来控制。为提高定向红外对抗模拟的通用性和智能性,设计了模拟激光源的闭环控制方案。     

原生质体诱变选育去甲基金霉素高产菌

采用紫外线、同平板梯度浓度亚硝基肌，纯铜蒸气激光诱变去甲基金霉素生产菌金霉素链霉菌的原生质体，结果表明原生质体对各种诱变剂的敏感性较高.正变幅度较大.原生质体经紫外线、同平板梯度浓度亚硝墓肌复合诱变后，筛选到一菌株，重新制备原生体，经激光诱变，选育出高产菌株S. A. HU02，去甲基金霉素效价从2831u/ml提高到4337u/ml，提高了53. 2，经多次传代产量性状非常稳定.     

掺铒光纤激光器自混合理论与微振动位移测量

利用线形掺铒光纤激光器搭建了一种新型光纤传感测量系统来测量微振动位移.采用条纹计数法分析自混合干涉信号,实验显示扬声器的振幅与驱动电压成很好的线性关系.该实验装置结构简单、成本低.实验结果表明,用该传感系统来进行振动位移测量,信号稳定,方法简单、迅速.     

脉冲激光法连续制备纳米钴乙醇溶胶的研究

纳米钴因其优异的磁性能在磁记录材料 [1]、超顺磁材料 [2 ]、巨磁材料 [3 ]和雷达吸波 [4 ]方面具有重要应用 .金属钴有面心立方、密排六方和非晶态 3种结构 [5] .目前 ,用等离子加热及碳电弧法制备的纳米钴粉基本上都是面心立方结构 [6] .Gibson等 [7]用超声化学方法获得了密     

CS—244／344红外碳硫测定仪计量检定中的几个问题

探讨CS-244/344红外碳硫测定仪检定规程在实际运用中存在的几个问题及相应的对策。     

Synthesis and photoreactions of polyesters containing triazene and cinnamylidene malonyl units

The synthesis and photoreactions of polyesters containing the photolabile triazene group (Ph NN NR₂) as well as photocrosslinkable units based on substituted cinnamylidene malonyl moieties are reported. The polyesters were obtained by reacting a triazene containing difunctional alcohol with different substituted cinnamylidene malonic acid dichlorides. Irradiation at λ > 395 nm enables selective photocrosslinking of the cinnamylidene malonyl ester units via [2+2]π‐cycloaddition without affecting the triazene units. The photocrosslinking reaction of the triazene containing polyesters as well as triazene‐free reference polyesters were investigated by UV and IR spectroscopy. After selective photocrosslinking the irradiated polymers became insoluble and no longer exhibited a T_g below decomposition temperature. The crosslinked triazene containing polyesters show strong absorption at λ = 308 nm and are therefore interesting candidates for applications using XeCl excimer laser ablation. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1903–1910, 2000     

Confocal microscopy study of uptake kinetics of α‐lactalbumin and β‐lactoglobulin onto the cation‐exchanger SP Sepharose FF

Confocal laser scanning microscopy (CLSM) was used to study single‐ and two‐component protein uptake for α‐lactalbumin (ALA) and β‐lactoglobulin (BLG), as models for whey proteins, to SP Sepharose FF at pH 3.7 during batch experiments in a finite bath. By coupling a fluorescent dye with the protein molecule, the penetration into individual adsorbent particles at different times during batch uptake was visualised. In a single‐component system, BLG penetrated fast into the adsorbent beads and gradually filled them in a shell‐wise fashion, while adsorption of ALA was mostly confined to the outer shells of the adsorbent. For the two‐component studies, the results showed that ALA was able to displace BLG despite its lower affinity to the adsorbent under the employed conditions. CLSM results were then compared both qualitatively and quantitatively to their counterparts obtained in traditional experiments by indirect measurements of the protein concentration in the fluid phase. A novel quantitative approach was undertaken by modifying the simple kinetic rate model traditionally used to determine the kinetic rate constant, k₁, for batch uptake experiments, in order to describe batch uptake kinetics based on CLSM data. Although BLG results were in good agreement, there was a discrepancy in ALA results.     

Photoinduced Oxidation Reaction of Benzotrifluoride with OH Radical by the Laser Flash Method

The optical transient and kinetics characterizations of the transients formed in the reaction of OH with benzotrifluoride (BTF) were performed by a laser flash photolysis technique. The results indicated that the formation of π‐type adduct of C₆H₅(OH)CF₃ was the major reaction channel, and the δ‐type adduct of C₆H₅CF₃OH formation was an additional minor process in the oxidation reaction of BTF attacked by OH radicals yielded from the photolysis of H₂O₂. Addition of OH to the CF₃ group led to the fluoride ion elimination to yield α,α‐difluorophenylcarbinol (C₆H₅CF₂OH). Trifluoromethylphenol (HOC₆H₄CF₃) of meta‐, para‐ and ortho‐substituted isomers resulted from the addition of OH to the BTF aromatic ring.     

Stability analysis for double-stranded DNA oligomers and their noncovalent complexes with drugs by laser spray

Laser spray, which is a newly developed ionization technique, can characterize the stability of noncovalent complexes in the solution phase. By using this advantage, laser spray has been applied to probe the intrinsic stability of double-stranded DNA (dsDNA) sequences and their binding affinities with various drugs in the solution phase. Systematic experiments were carried out using six 16-mer and three 22-mer dsDNA oligomers, together with the complexes of the 16-mer dsDNA with minor groove binders: berenil, Hoechst 33342, DAPI, and netropsin. Dissociation curves for each dsDNA or each complex were plotted as a function of laser power. The laser power (E50%), where 50% of each dsDNA or each complex was dissociated, was compared with its melting temperature (Tm) determined by UV spectroscopy. Linear correlations between E50% and Tm were obtained not only for the dsDNA oligomers (correlation factor r = 0.9835) but also for the 16-mer dsDNA complexes with minor groove binders (r = 0.9966). In addition, laser spray has successfully clarified the binding affinities of a 16-mer dsDNA with two intercalators: daunomycin and nogalamycin. In the case of the dsDNA-daunomycin complex, by changing the molar ratio of dsDNA : drug from 1 : 1 to 1 : 5, the concentration-dependent stability of the complex was confirmed by laser spray. The present results demonstrate that laser spray mass spectrometry can be a powerful and convenient method to investigate the relative binding affinities of dsDNA-ligand complexes in the solution phase, which could be applied to the early stage of high-throughput screening of drugs targeting for dsDNA.