High Beam Quality Green Generation with Output 140W Based on a Thermally-Near-Unstable Flat-Flat Resonator

By using a diode-side-pumped Q-switched Nd:YAG rod laser based on a thermally-near-unstable fiat-fiat resonator, an intracavity-frequency-doubled green beam generation is investigated. Output power 140 W is obtained at a repetition rate of 10kHz and a pulse width of 110ns. The green beam quality factors Mx^2 and My^2, which are measured by a laser beam analyser, are 10.65 and 10.85, respectively, at output power of 124W.     

复合深度神经网络在直升机声目标识别中的研究

针对直升机探测中目标运动过程连续识别的鲁棒性问题,提出了一种基于复合深度神经网络的直升机声学特征提取和识别框架。复合深度神经网络由卷积神经网络和长短时记忆神经网络以并行结构组合,进行直升机声学特征的优化,完成直升机类型识别。针对直升机声信号特性,对卷积神经网络进行了改进,使得该复合深度神经网络在信号短时谱基础上优化声信号特征表征并提取前后帧之间的相关信息,弥补通常声目标识别方法不能充分利用目标信号时间历程信息的缺陷。真实外场实验数据测试结果显示:相较于传统识别方法,该算法显著提升了直升机进入有效探测范围后连续识别的鲁棒性和目标识别正确率。     

基于噪声谱结构特性的谱减法

提出了基于噪声谱结构特性的谱减法,在不增加语音失真的情况下,抑制传统谱减法的“音乐噪声”。首先,依据噪声谱结构特性在频带间自适应平滑周期图,减小谱估计方差的同时,避免噪声非连续谱的能量泄露;其次,依据噪声谱的结构特性,对增益函数进行自适应调整以更有效的抑制有调噪声。测试结果表明,不论对宽带噪声还是对窄带噪声,本文算法在信噪比提高和噪声抑制量等客观评价指标上都明显优于传统谱减法。非正式主观测听进一步验证了本文算法的有效性。      

一种用于立体声声学回波消除的新型鲁棒梯度法格梯形自适应滤波算法

立体声声学回波消除的梯度法格梯形算法对脉冲干扰不具鲁棒性。针对这个问题,引入了鲁棒M-估计方法,并从理论上予以了论证。由此产生的双通道M-估计梯度法格梯形算法具有显著提升的抗脉冲干扰鲁棒稳定性,从而也具有了更高的实际应用价值。      

块菌的傅里叶变换红外光谱研究

块菌是珍稀野生食用菌,其蛋白质和糖类含量较高,块菌多糖具有潜在的药用价值。文章利用傅里叶变换红外光谱技术(FTIR)对五种云南野生块菌作了研究。结果表明,块菌属真菌有其独特的光谱特征,全谱最强峰为出现在1 042和1 077 cm-1附近的强双峰。在脂分子的羰基峰1 742 cm-1及糖类异构体的指纹区1 200～750 cm-1,不同种类、不同产地块菌的光谱有明显差异,另外,正常块菌和霉变块菌的光谱亦有明显差异,主要体现在谱峰吸收强度的变化上,部分谱峰吸收强度比的变化表明,块菌样品变质前后,其蛋白质和糖类物质的含量发生了变化。FTIR光谱提供了块菌成分的有关化学信息,为鉴别块菌和区分块菌的种类、质量提供了简便快捷的手段。     

一个HBsAg基因在大肠杆菌中的强表达系统

利用筛选启动基因的载体系统,从大肠杆菌染色体DNA中获得一个启动基因片段。在它的控制下HBsAg基因在大肠杆菌中有较强的表达。通过抗-HBs亲和层析柱分离纯化了表达产物。用琼脂糖双扩散免疫分析法和聚丙烯酰胺——SDS凝胶电泳对分离纯化的表达产物进行了鉴定。     

双闭环光纤陀螺控制回路研究

本文讨论了采用数学据齿波和方波调制方案的闭光纤陀螺系统的实现。在此基础上,进一步研究了针对消除由于斜坡复位幅度２π不精确给系统带来的误差而设计的第二闭环回路（幅值回路）。结果表明：第二闭环回路的加入能很好地在短时间内消除由复位幅度２π不精确带给系统的偏差。     

CLONING AND RESTRICTION MAPPING OF HUMAN HBV GENOME SEROTYPE adr

A Bam HI cleaved 3.2 Kb fragment from the HBV adr genome was cloned in E. coli, using pBR322 as vector. sixteen restriction sites from the action of Bam HI, Hind Ⅲ, Bgl Ⅰ, Bgl Ⅱ, Ava Ⅰ, Hinc Ⅱ, Sph Ⅰ, Xba Ⅰ, Xho Ⅰ and Sst Ⅱ were determined and mapped. No cleavage sites were found for Eco RI, Pst Ⅰ, Sma Ⅰ, Hpa Ⅰ, Kpn Ⅰ, Pvu Ⅱ and Sst Ⅰ.The restriction map for HBV adr is significantly different from those reported for the subtypes adw, ayw and adyw.     

A CLONE OF HEPATITIS B VIRUS (SUBTYPE adr) DNA WITH A NEW HINDIII SITE

We have cloned the HBV genome subtype adr through its HindⅢ site into plasmid pBR.322. Twelve recombinant plasmids each with an insert of the HBV genome were obtained. The restriction map of one of the recombinants, plasmid pADR-H1, was analyzed. The location of the sites for BamHⅠ, BglⅠ, BglⅡ, SstⅡ, XbaⅠ and XhoⅠ in pADR-HⅠ were found to be the same as that in pADR-1, but the HindⅢ site of pADR-H1 is distinctly different from that of pADR-1. The BamHⅠ-HindⅢ fragment is 316 bp long in the gcnome of pADR-1. However, it is only 82 bp in pADR-Hl. No deletion of sequence between BamHⅠ and HindⅢ sites has been found in the HBV genome of pADR-H1, The sequencing data around the HindⅢ site of pADR-H1 in both pADR-H1 and pADR-1 show that there is a stretch of AAGTTT in pADR-1 compared to an AAGCTT in pADR-H1. In addition, other differences were found. There are three sites for AvaⅠ, four for HincⅡ, one for HpaⅠ and none for SphⅠ in the genome of pADR-H1 compared to four sites for AvaⅠ, three f