Frontiers in Ultrashort Pulse Generation: Pushing the Limits in Linear and Nonlinear Optics

Optical pulses in the 5-femtosecond range are produced by a variety of methods. Although different in technical detail, each method relies on the same three key components: spectral broadening due to the nonlinear optical Kerr effect, dispersion control, and ultrabroadband amplification. The state of the art of ultrashort pulse generation is reviewed with a focus on direct laser oscillator schemes.     

Protons and Electrons in Jupiter's Magnetic Field: Results from the University of Chicago Experiment on Pioneer 10

Fluxes of high energy electrons and protons are found to be highly concentrated near the magnetic equatorial plane from distances of ~ 30 to ~ 100 Jovian radii (R(J)). The 10-hour period of planetary rotation is observed as an intensity variation, which indicates that the equatorial zone of high particle fluxes is inclined with respect to the rotation axis of the planet. At radial distances [unknown] 20 R(J) the synchrotron-radiation-producing electrons with energies greater, similar 3 million electron volts rise steeply to a maximum intensity of ~ 5 x 10(8) electrons per square centimeter per second near the periapsis at 2.8 R(J). The flux of protons with energies greater, similar 30 million electron volts reaches a maximum intensity of ~ 4 x 10(6) protons per square centimeter per second at ~ 3.5 R(J) with the intensity decreasing inside this radial distance. Only for radial distances [unknown] 20 R(J) does the radiation behave in a manner which is similar to that at the earth. Burst of electrons with energies up to 30 million electron volts, each lasting about 2 days, were observed in interplanetary space beginning approximately 1 month before encounter. This radiation appears to have escaped from the Jovian bow shock or magnetosphere.     

非线性光子晶体中腔场的平均光子数分布研究

考虑腔模与Mollow峰的中心峰共振的情况,通过解析稳态方程,讨论了处于非线性光子晶体微腔中的二能级原子在外加相干场的驱动下腔场平均光子数的分布情况。研究结果表明,当光子晶体的态密度很大时,腔场的平均光子数随着驱动场拉比频率的增加而增加,最终达到饱和。     

激光加电场处理水稻幼苗POD及CAT同工酶酶谱分析

比较了激光加电场处理及未处理的水稻幼苗过氧化物酶（POD）、过氧化氢酶（CAT）同工酶酶谱。结果表明,激光加电场处理过的POD与对照组没有明显区别,CAT与对照组有明显区别,且处理过的GS-1 CAT同工酶与其后代GS-2水稻CAT同工酶酶谱没有变化。说明激光处理后,水稻中与CAT相关的某些基因发生了变化,且在一定时间内可以稳定遗传。     

MATLAB在光学教学中的应用

探讨在基础物理光学教学中,应用MATLAB软件模拟光的双缝干涉、单缝衍射和光栅衍射,以获得良好的课堂教学效果。     

四夸克态质量的一相对论夸克模型研究

考虑四夸克态是双夸克和双反夸克的束缚态, 在一相对论夸克模型下利用变分法计算了轻重四夸克态的质量. 采纳夸克-夸克及双夸克-双反夸克之间的相互作用为单胶子交换势与标量和矢量线性禁闭混合势的总和, 使用拟合基态介子质量得到的参数作为输入, 计算了0++的轻、重四夸克态的质量. 计算的结果支持X(3872), Y(3940)是含有粲夸克的0++重四夸克态;f0(600), κ(800), f0(980)和a0(980)是0++的轻四夸克态.     

加速优质小麦品种推广 走产业化发展之路

本文通过对优质小麦推广意义的论述、现状、问题的分析,提出了今后发展优质小麦的对策是:加强优质小麦新品种选育;优化品种,品质结构,实行良种良法配套;实行区域化布局,规模化生产;实行订单生产,提高产业化经营水平,提高加工转化能力,创造名牌产品。     

基于Visual Basic的电子干涉、衍射模拟

根据杨氏双缝干涉、光栅的强度分布函数以及德布罗意物质波的理论,采用蒙特卡罗中的舍选法对大量电子进行舍选,并在Visual Basic中的图片框中输出显示,从而达到在Visual Basic的环境下对电子双缝干涉、光栅衍射的模拟.通过此模拟,可以更加形象地理解电子的波粒二象性以及电子波是概率波,为教学提供方便.     

Wake collapse in stratified fluid: experimental exploration of scaling characteristics

Passage of a submerged self-propelled body or other mixing device produces a region of more or less homogeneous fluid, in a fluid having a stable vertical density gradient (stratified), which initially expands vertically and then falls back (collapses). Maximum expansion Z(2) at time t(2) after the start of mixing are dependent variables related to the diameter Z(1) of propeller or mixer and to the V?is?l?-Brunt period T by T/t(2) = 2.5 and Z(2)t(2)/Z(1)T = 1.3. These scaling relations are first-order approximations.     

信息技术对蚕桑产业发展的推动作用

从蚕桑产业发展现状和信息技术应用趋势方面,分析了信息技术在蚕桑产业的需求、研究、应用和实施,提出在蚕桑产业里引入现代信息技术,开展蚕业信息化研究工作,促进蚕桑产业与现代信息技术相结合.     

Acceleration of emergence of bacterial antibiotic resistance in connected microenvironments

The emergence of bacterial antibiotic resistance is a growing problem, yet the variables that influence the rate of emergence of resistance are not well understood. In a microfluidic device designed to mimic naturally occurring bacterial niches, resistance of Escherichia coli to the antibiotic ciprofloxacin developed within 10 hours. Resistance emerged with as few as 100 bacteria in the initial inoculation. Whole-genome sequencing of the resistant organisms revealed that four functional single-nucleotide polymorphisms attained fixation. Knowledge about the rapid emergence of antibiotic resistance in the heterogeneous conditions within the mammalian body may be helpful in understanding the emergence of drug resistance during cancer chemotherapy.     

加快推进江苏省农业产业化的若干思考

论述了江苏省在发展农业产业化进程中取得的成效和存在的问题,并提出了相关对策和建议。     

李树日光温室促成栽培技术

介绍了适宜李树栽培的日光温室的基本结构及建造此类日光温室应注意的问题 ,并从品种选择、高标准定植、肥水管理、整形修剪、化学控制、环境调控、花果管理、病虫害防治等方面提出了李树日光温室促成栽培技术     

近红外激光云高仪与微脉冲激光雷达比对分析

云在气象领域扮演着重要的角色,因此准确测量云高有助于分析天气系统未来的变化,为气象等领域提供依据。为了比较CL51激光云高仪和微脉冲激光雷达(MPL)这2个云高仪的性能,对位于南京信息工程大学的2台仪器2012年9—11月这3个月的数据进行分析,得出如下结论:CL51和MPL第一层云底高度的相关性很高,相关系数为0.89;CL51的所有数据平均高度为3.879 km,MPL的所有数据平均高度为3.587 km,说明这2台仪器的一致性很高。     

新农村建设中城乡统筹规划的推动

在新的历史时期,新农村建设中城乡统筹规划不能割断历史,只能在先行国家的历史教训和成功经验中汲取营养,并从我国的国情和变化了的形势出发,尽量在现有的规划手段、制度的基础上进行创新,探索新的推动路径,才能有效地指导社会主义新农村建设。     

激光在现代农业及生物科学中的应用

激光自诞生以来，其在农业和生物科学以及其它诸多领域中得到了日益广泛的应用，并获得了巨大的成功。本文对激光进行了概述并从激光作用于生物有机体的效应这个角度阐述了应用于农业领域的激光技术。     

Bacterial Methanogenesis and Growth from CO2 with Elemental Iron as the Sole Source of Electrons

Previous studies of anaerobic biocorrosion have suggested that microbial sulfur and phosphorus products as well as cathodic hydrogen consumption may accelerate anaerobic metal oxidation. Methanogenic bacteria, which normally use molecular hydrogen (H(2)) and carbon dioxide (CO(2)) to produce methane (CH(4)) and which are major inhabitants of most anaerobic ecosystems, use either pure elemental iron (Fe(0)) or iron in mild steel as a source of electrons in the reduction of CO(2) to CH(4). These bacteria use Fe(0) oxidation for energy generation and growth. The mechanism of Fe(0) oxidation is cathodic depolarization, in which electrons from Fe(0) and H(+) from water produce H(2), which is then released for use by the methanogens; thermodynamic calculations show that significant Fe(0) oxidation will not occur in the absence of H(2) consumption by the methanogens. The data suggest that methanogens can be significant contributors to the corrosion of iron-containing materials in anaerobic environments.     

Acceleration of nitrogen ions to 7.4 gev in the princeton particle accelerator

Nitrogen ions in charge states N(5+) and N(6+) have been accelerated in the Princeton Particle Accelerator to 4 and 7.4 billion electron volts (Gev), respectively. An external N(5+) beam of 1 x 10(6) particles per second has been obtained and focused to a 6-millimeter-diameter spot. The N(6+) beam was about 2 x 10(5) particles per second. The total charge-changing collision cross section of N(5+) in water vapor was determined as a function of ion energy. The improvement in vacuum necessary to increase the N(5+) beam at least tenfold was calculated. The N(6+) total cross section is probably smaller than that of N(5+) at the higher energies.