ON THE REGULARITY AND EXISTENCE OF SOLUTIONS FOR SEMILINEAR ELLIPTIC EQUATIONS OF SECOND ORDER

Let Ω(?)R~n be a bounded domain with a smooth boundary (?)Ω L a strictly elliptic operator and c(x)≥0 in Ω. In this paper we are concerned with the following Dirichlet problem with the growth condition (P_1): a<2, for n=2. It is proved that if p(x, t) has all derivatives up to order l which are locally Hlder continuous in (?)×R. and if a_(ij)(x) ∈C_(l 1,α)(Ω) and c(x)∈C_(l,α)(Ω), then any weak solution in W_0~(1,2) of (1) lies in C_(l 2,α)(Ω). Moreover, under the growth condition (P_1) and some additional assumptions, the existence of nontrivial solution of (1) is proved. The main difficulity here is that the simple bootstrapping procedure fails to apply directly to the case of the growth condition (P_1).     

二机器流水作业排序问题全部最优解的结构

排序问题F2||Cmax,Johnson条件只是最优解的充分条件，不是必要的．本文绘出一个充分必要条件，由此得到生成全部最优解的算法．主要理论是基于一种序论方法．     

由三氯丙烷粗馏分制取三醋酸甘油酯

三醋酸甘油酯工业上历来是用甘油与醋酸酯化制得[1],三醋酸甘油酯用作纤维素树脂和乙烯基聚合物、共聚物的增塑剂。主要用于增塑醋酸纤维素作卷烟过滤嘴,可提供良好的弹性、透气性和合适的硬度。工业上由氯丙烯生产环氧氯丙烷过程中,生产相当量的三氯丙烷(以下简称ＴＣＰ),1,3二氯2丙醇等副产品[2]。以齐鲁石化公司氯碱厂3.2×104ｔ/ａ环氧氯丙烷装置为例,副产物ＴＣＰ达2000ｔ/ａ。它们在生产中成为一个馏分分离出来。这一馏分没有什么用处,用燃烧法处理时还生成ＨＣｌ等废气污染环境[3],我们考虑将它转化为三醋酸甘油酯,既可以变废为宝又…     

LIA组元的脉冲功率调制系统研制

本文介绍一种以加速组元为终端负载的纳秒脉冲功率系统。获得的加速间隙电压为350kV，90ns(半高宽)，波形上升时间为30ns；Blumlein主开关工作电压大于280kV，抖动小予1.5ns(均方根值)。对同轴场畸变开关性能的进一步改善作了必要的讨论，提出了用等场强原则偏置触发极，比通常采用自然中位面方法，可使开关工作电压提高8．7％。     

制导光缆中光纤寿命预期

介绍了光纤寿命预期的疲劳实验方法和筛选实验方法。采用这两种方法，利用电子万能材料试验机和光纤筛选复绕机对室温下光纤进行了疲劳性能实验。实验得出，在张力小于850g的情况下，制导光纤的寿命可以达到10年以上；光纤的韦伯参数md和疲劳参数nd的大小影响光纤寿命。实验表明，当光纤的使用状态受力较大时，或使用贮存状态相差较大时，宜选用动态方法进行寿命预期；当贮存和使用状态受力变化不大时，宜选用筛选复绕方法预期光纤寿命。制导光纤寿命模型宜选用动态疲劳模型，通信光纤可选用筛选实验模型。实验还表明，提高光纤的抗疲劳因子nd和减小光缆中光纤的应变，可以更好地保持光缆中光纤的使用寿命和可靠性。     

Characterization of inner layer thickness change of a composite circular tube using nonlinear circumferential guided wave:A feasibility study

The feasibility of using the nonlinear effect of primary circumferential guided wave (CGW) propagation for characterizing the change of inner layer thickness of a composite circular tube (CCT) has been investigated. An appropriate mode pair of the fundamental and double-frequency CGWs (DFCGWs) has been selected to enable the second harmonics of primary wave mode in the given CCT to accumulate along the circumferential direction. When changes in the inner layer thickness (described as the equivalent inner layer thickness) take place, the corresponding nonlinear CGW measurements are conducted. It is found that there is a direct correlation between change of equivalent inner layer thickness of the CCT and the relative acoustic nonlinearity parameter (Δβ) measured with CGWs propagating through one full circumference, and that the effect of second-harmonic generation (SHG) is very sensitive to change in the inner layer thickness. The experimental result obtained demonstrates the feasibility for quantitatively assessing the change of equivalent inner layer thickness in CCTs using the effect of SHG by primary CGW propagation.     

How Does van der Waals Confinement Enhance Phonon Transport?

We study the mechanism of van der Waals(vdW)interactions on phonon transport in atomic scale,which would boost developments in heat management and energy conversion.Commonly,the vdW interactions are regarded as a hindrance in phonon transport.Here we propose that the vdW confinement can enhance phonon transport.Through molecular dynamics simulations,it is realized that the vdW confinement is able to make more than two-fold enhancement on thermal conductivity of both polyethylene single chain and graphene nanoribbon.The quantitative analyses of morphology,local vdW potential energy and dynamical properties are carried out to reveal the underlying physical mechanism.It is found that the confined vdW potential barriers reduce the atomic thermal displacement magnitudes,leading to less phonon scattering and facilitating thermal transport.Our study offers a new strategy to modulate the phonon transport.     

氧化钙改性高岭土对垃圾渗滤液中氨氮的去除研究

采用氧化钙对高岭土进行改性,并用XRD、SEM和FT-IR对改性高岭土进行了表征。将改性高岭土应用于垃圾渗滤液的处理,考察了改性高岭土投加量、渗滤液初始pH、时间等因素对氨氮去除效果的影响,并对其吸附机理进行了研究。结果表明,氧化钙改性高岭土的产物主要是胶凝材料水化物(硅铝酸钙和含Al的C-S-H凝胶),形貌为蜂窝状;向氨氮含量为3520mg/L、pH为7.53~7.80的垃圾渗滤液中投加160g/L吸附剂,吸附60min,氨氮的去除率达82.66%,吸附量为18.19mg/g。氧化钙改性高岭土对氨氮的吸附符合Langmuir等温模型,动力学上符合准二级动力学方程,其相关系数分别为0.9678,0.9989。同时,该吸附过程包含了膜扩散和颗粒内扩散。