长白山次生蒙古栎林细根生物量及其季节动态

通过对长白山次生蒙古栎林细根生物量及动态的研究发现:4月末～9月末细根总生物量介于4.023 3～4.916 3 t/hm2,随时间逐渐增加;各月平均有67.2%的细根生物量集中于土壤表层0～10 cm,仅7月末0～10 cm土层细根生物量的比例(59.3%)偏低.细根表现为向深土层生长,不同土层内活细根所占比例的变化与活细根总生物量的季节变化规律基本相同,最低值出现在4月末;该群落细根年生长量为2.228 0 t/hm2,年死亡量为0.782 0 t/hm2,年分解量为0.119 0 t/hm2,年周转率为0.54次/a.     

栀子中黄酮类化合物的提取和含量测定

为了进一步开发和利用我地区丰富的蒙药材资源,研究了栀子中总黄酮的提取条件,以亚硝酸钠—硝酸铝—氢氧化钠为体系,用分光光度法测定总黄酮的含量.结果表明,超声提取的最佳条件是使用70％乙醇、超声提取二次、超声对间30min;总黄酮的含量为3.5mg·g-1,样品的回收率在96.0％～ 101.7％.此结果为栀子药效功能的进一步研究、资源开发和利用提供了科学的依据.     

Preserving Coherence of Coherent State Studied via Weyl-Wigner Correspondence

By means of the Weyl correspondence and the explicit normally ordered expression of the Wigner operator we convert the time evolution equation of coherent states, governed by some Hamiltonian operators, into seeking for consistent solution of a set of evolution equtions of classical variables which can meet the requirment that an initial coherent state remains coherent all the time.     

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提出了一种用于高功率微波武器的等离子体通道天线(PCA),计算了该天线的辐射方向图。推导出了一般性天线的辐射方向函数;建立了PCA的近似电磁模型;给出了圆坐标系下PCA和周围空气中的电磁场,利用边界条件得出了PCA的色散方程,求出PCA的表面波波矢。重点讨论了PCA的辐射场随等离子体密度、天线长度、半径的变化,证实了PCA方向图的可控性。     

Lie Algebra and Lie Super Algebra for Integrable Couplings of C-KdV Hierarchy

Based on the constructed Lie algebra and Lie super algebra, the integrable couplings and super-integrable couplings of the C-KdV hierarchy are obtained respectively. Furthermore, its super-Hamiltonian structures are presented by using super-trace identity.     

Generation of Broadband High Harmonics through Linear Mode Conversion in Inhomogeneous Plasmas

The generation of high order harmonics from an inhomogeneous ovderdense plasma target irradiated by an ultrashort intense laser pulse is studied by numerical simulation. During such interaction, ultrafast electron bunches are generated and excite electron plasma oscillations as they pass through the overdense target. These plasma oscillations will emit high-frequency electromagnetic emission by linear mode conversion. Instead of the integer harmonies generation, the emission appears with a broadband and even continuous spectrum corresponding to the electron plasma frequency range of the inhomogeneous plasma density.     

Finite dimensional modules over quantum toroidal algebras

For all generic q\mathrm{\in }{C}^{*}, when g is not of type A₁; we prove that the quantum toroidal algebra U_q(g_tor) has no nontrivial finite dimensional simple module.     

序半群Quantale完备化的进一步结果

本文给出了序半群上幂集Quantale的最大拓扑闭包的具体形式,即序半群的最小Quantale完备化.在此基础上,证明了Quantale范畴Quant是序半群范畴OSGrp*的满的反射子范畴.最后,给出了序半群Quantale完备化的一个应用.     

求解二次分配问题的新的流量模型

二次分配问题是具有广泛应用背景的经典组合优化难题之一。本文在二次分配问题已有线性化模型的基础上,提出了一种新的基于流量的线性化模型。数值试验结果表明,新模型无论从时间上还是计算节点数都更具有优势。     

低气压下长间隙工频放电试验平台研究

为研究极高海拔低气压下工频放电特性,搭建了包括真空试验腔、真空泵、真空计、工频电源、高速摄像机等仪器的低气压长间隙工频放电试验平台,并对其气密性和放电性能进行测试。该平台可实现23 Pa~100 k Pa范围内气压调节和600mm以内放电间隙调节。测试结果表明:试验平台能够模拟海拔20 km以上的长间隙工频放电,且对于试验周期较短的工频放电特性研究具有良好的气密性和放电性能。研究成果对高海拔低气压下长间隙放电特性研究具有重要参考价值。