硅元素对甘蔗的增产和增糖作用

<正> 我校化学系以季明德同志为首的含硅植物生长素课题组于1985年研究成功8501含硅植物生长素(简称8501),在盆栽试验的基础上进行了三年连续的田间小区试验。研究结果表明、8501可使甘蔗含糖分提高8%左右、产量增加10%左右。根据小区试验结果估算、每亩净增     

熵增加原理在求最大功问题中的应用

热力学中有一类关于最大功的问题．解决这类问题，通常有两种方法：一种是利用卡诺定理求解；另一种是利用熵增加原理结合熵的态函数性质求解．本文试图通过几个的题说明用后一种方法有时可使问题大大简化．     

ON THE FRACTAL NATURE OF INCREMENTS OF THE INFINITE SERIES OF OU PROCESSES RELATED TO THE CHUNG LIL

The author proves that the set of points where the Chung type LIL fails for the path of the infinite series of independent Ornstein-Uhlenbeck processes is a random fraetal, and evaluates its Hausdorff dimension.     

镧增加铝合金熔体氢含量的实验分析

采用第一滴气泡法和减压凝固法分析测量了一定量的稀土镧加入前后的铝硅合金熔体氢含量和铝硅合金凝固试样剖面的针孔和气孔的变化，发现镧的加入量超过一定量(0．3％)时，铝合金熔体中的氢含量增加，铝合金凝固试样的针孔和气孔增多。可以认为：一定量的稀土镧引起铝合金增氢现象的原因是镧中含有氢。同时，讨论了镧中氢的来源和含量对铝合金中氢的影响。     

Numerical study on the performance of nozzle flow for supersonic chemical oxygen–iodine lasers

Laser performance is greatly dependent on its operating conditions due to the strong coupling among multi- physics such as gas-dynamics, chemical reaction kinetics and optics in the mixing nozzle of COIL. In this paper, 3D CFD technology is used to simulate the mixing and reactive flow of subsonic cross jet scheme at different conditions. Results obtained show that the jet penetration depth plays a dominant role in the spatial distribution of small signal gains. In the case of over-penetration, unsteady flow structures are induced by impinging between the opposing jets. The optimum spatial distribution of the chemical performance cannot be obtained even if the full penetration condition is achieved through the subsonic transverse jet mixing scheme in the COIL nozzle flow.     

Optimum fluorescence emission around 1.8 μm for LiYF4 single crystals of various Tm3＋-doping concentrations

In this paper, optical spectra of LiYF4 single crystals doped with Tm3＋ ions of various concentrations are reported. The emission intensity at 1.8 ktm first increases with increasing Tm3＋ concentration, and reaches a maximum value when the concentration of Tm3＋ is about 1.28 mol%, then it decreases rapidly as the concentration of Tm3＋ further increases to 3.49 mol%. The emission lifetime at 1.8 p.m also shows a similar tendency to the emission intensity. The maximum lifetime of 1.8 μm is measured to be 17.68 ms for the sample doped with Tm3＋ of 1.28 mol%. The emission cross section of 3F4 level is calculated. The maximum reaches 3.76 × 10 -21 cm2 at 1909 nm. The cross relaxation （3H6, 3H4 →3 F4, 3F4） between Tm3＋ ions and the concentration quenching effect are mainly attributed to the change of emission with Tm3＋ concentration. The largest quantum efficiency between Tm3＋ ions is estimated to be ,-147% from the measured lifetime and calculated radiative lifetime. All the results suggest that the Tm3＋/LiYF4 single crystal may have potential applications in 2 μm mid-infrared lasers.     

基于结构方程的城市轨道交通建设项目后评价研究

随着我国城市轨道交通建设项目的快速发展,其在效益、影响、成功度等各方面的项目后评价越来越受到重视.但目前国内在这方面的研究不多,根据建设项目后评价的目的和内容,结合城市轨道交通的特点,通过文献调研与专家访谈等方法建立了城市轨道交通建设项目后评价指标体系,并通过实地调研与统计分析对指标体系的科学性进行了客观检验,在此基础上利用结构方程对后评价模型进行了实证研究.     

高维辅助的普适量子线路优化

受到Lanyon等(Lanyon B P et al 2008 Nature Physics. 5 134)利用高维Hilbert空间成功简化Toffoli门的启发, 本文将辅助维度应用到普适量子线路中, 结合Cosine-Sine Decomposition(CSD), Quantum Shannon Decomposition(QSD)等矩阵分解方法, 优化了两比特和三比特普适幺正量子线路, 给出了计算n比特普适量子线路复杂度的公式, 并利用线性光学和腔QED系统设计了实验方案. 结果表明, 两比特和三比特量子线路的复杂度已分别接近和优于目前最优结果, 且随着比特数的增加, 本方案的优势愈加明显.     

Natural Connectivity of Complex Networks

The concept of natural connectivity is reported as a robustness measure of complex networks. The natural connectivity has a clear physical meaning and a simple mathematical formulation. It is shown that the natural connectivity can be derived mathematically from the graph spectrum as an average eigenvalue and that it changes strictly monotonically with the addition or deletion of edges. By comparing the natural connectivity with other typical robustness measures within a scenario of edge elimination, it is demonstrated that the naturM connectivity has an acute discrimination which agrees with our intuition.     

设备更新的最佳年限的决策模型

作为一个企业的管理者和工程技术人员，对企业所使用的设备除了要了解设备的的运转状况之外，同时更应了解设备何时要更新，对这些问题要认真对待，更新过早，老设备的生产潜力未得到充分的发挥而抛弃，造成损失；更新过晚，老设备生产效率低下，维护费用增加，也会造成损失，于是产生了生产设备更新最佳年限的决策问题。