基于ZigBee的智慧温室蓄电池监测节点设计

针对传统温室监测节点蓄电池剩余电量问题,提出一种改进的基于ZigBee无线通信技术的温室节点无线监测方案,设计一个经济实用的低功耗ZigBee无线监测节点;以CC2530为主控芯片,通过控制不同的传感器和电池智能管理芯片DS2438及其外围电路,实现温室环境参数和各节点蓄电池电压、电流以及剩余电量的精确测量并实时显示;测试结果表明,系统运行稳定,数据检测精度达到0.001。     

梳状波导结构中石墨烯表面等离子体的传播性质

理论上研究了介质/石墨烯/介质梳状波导结构中表面等离子体的传播性质. 波导中表面等离子体模的有效折射率随着石墨烯费米能级的提高而减小, 随着介质折射率的增加而增加. 分析和仿真结果表明, 基于这种梳状波导可以在中红外波段实现新型的纳米等离子体滤波器, 器件的尺度在几百纳米的范围. 通过改变梳状分支的长度, 石墨烯的费米能级, 介质的折射率和波导中石墨烯的层数, 很容易来调节带隙的位置. 另外, 滤波带隙的宽度随着梳状分支数的增加而增加. 这种滤波性质将在可调的高集成光子滤波器件中具有潜在的应用.     

细胞外钾离子浓度延迟恢复对螺旋波的影响研究

在Luo-Rudy相I心脏模型中考虑了细胞外钾离子浓度的频率依赖性,并研究了细胞外钾离子浓度的延迟恢复对螺旋波动力学的影响.数值模拟结果表明,在螺旋波态下,细胞外钾离子浓度的延迟恢复会导致细胞外钾离子浓度周期振荡,其振荡周期和振幅随延迟恢复时间的增加而增加,进而导致出现呼吸螺旋波、多螺旋波共存、螺旋波做Lévy飞行式漫游、螺旋波通过不同方式消失等现象,这些结果与实验结果一致.     

Simultaneous intracavity optical parametric oscillation and stimulated Raman scattering pumped by a doubly passively Q-switched Nd:GGG laser

By using a doubly passively Q-switched Nd:Gd₃Ga₅O₁₂(Nd:GGG) laser with Cr⁴⁺:YAG and GaAs as saturable absorbers as pump laser, simultaneous intracavity optical parametric oscillation and stimulated Raman scattering based on a single X-cut KTiOPO₄ (KTP) crystal have been realized. Under an incident diode pump power of 10.5 W, the output powers at the signal wave near 1,569 nm and the first Stokes emission near 1,094 nm were 218 and 72 mW, corresponding to the optical-to-optical conversion efficiencies of 2.08 and 0.69 %, respectively. The measured shortest pulse duration at the signal wave near 1,569 nm was 580 ps, generating a pulse peak power of 43.7 kW, while the minimum pulse duration at the first Stokes emission near 1,094 nm was 1.61 ns. By adjusting the tilt angle of the KTP crystal, up to the third Stokes scattering was also obtained.     

实Clifford分析中,双正则函数向量的非线性边值问题

研究实Clifford分析中关于多个未知函数的双正则函数向量的一个非线性边值问题     

A pair of epimeric cassane-type diterpenoids and a new labdane-type derivative from Caesalpinia decapetala

Caesaldecins A and B (1a/1b), a pair of epimeric cassane-type diterpenoids containing an ether linkage between C-6 and C-20 and an α,β-butenolide ring in the northern hemisphere, were isolated from the leaves of the medicinal plant Caesalpinia decapetala (Roth) Alston, along with a new labdane-type diterpenoid, termed as 8(17),11(Z),13(E)-trien-15,18-dioic acid (2). Structures of 1 and 2 were established by extensive spectroscopic analyses, including HRESIMS, 1D and 2D NMR, and electronic circular dichroism (ECD) calculations. The in vitro antibacterial and inhibitory activities against a panel of bacteria and cancer cell lines were evaluated, respectively. Compound 2 displayed moderate antibacterial activity against the methicillin-resistant Staphylococcus aureus subsp. aureus (MRSA) with an MIC₅₀ value of 5.99?μg?mL^?1.     

Facile construction of trifluoromethyl-azirines via one-pot metal-free Neber reaction

A Et₃N-mediated Neber reaction of aryl/alkyl-2,2,2-trifluoroethylketoximes has been developed. This one-pot metal-free protocol enables the facile construction of an array of trifluoromethyl-substituted azirines in moderate to high yields under mild reaction conditions. Further transformations of azirines to CF₃-containing pyrrole and amino-alcohol derivatives are also demonstrated.     

采用有限单元法计算梁任意形状截面特性

采用将梁截面离散化的方式,用数值积分计算截面的几何特性,并根据梁剪切变形和扭转理论,利用变分原理建立截面的有限元法方程,求解任意形状截面的扭转常数、剪切中心以及剪切面积修正系数等特性.本方法适用于各种形式的截面,具有计算精度高及适应性强的特点.根据上述理论编制了相应程序,按照不同的单元划分方式,分别计算出矩形截面截面特性,与理论解进行比较;又对舟山市定海长峙至岙山预应力混凝土连续箱梁截面进行了计算,并与Ansys结果进行比较,均证明采用本文的计算方法能得到满意的结果,且该方法适用于各种形状的截面形式.     

Spinodal surface instability of soft elastic thin films

When the thicknesses of thin films reduce to microns or even nanometers, surface energy and surface interaction often play a significant role in their deformation behavior and surface morphology. The spinodal surface instability induced by the van der Waals force in a soft elastic thin film perfectly bonded to a rigid substrate is investigated theoretically using the bifurcation theory of elastic structures. The analytical solution is derived for the critical condition of spinodal surface morphology instability by accounting for the competition of the van der Waals interaction energy, elastic strain energy and surface energy. Detailed examinations on the effect of surface energy, thickness and elastic properties of the film show that the characteristic wavelength of the deformation bifurcation mode depends on the film thickness via an exponential relation, with the power index in the range from 0.749 to 1.0. The theoretical solution has a good agreement with relevant experiment results.     

预应力对LY12铝层裂强度的影响

通过过盈配合的热装配方法和机械夹紧方法对LY12铝合金平面样品施加了径向预应变,采用平面飞片撞击方法获得了预应力对层裂特性的影响。结果表明:当飞片以500 m/s的速度撞击样品,预应变为0（无预应变）、25110-6、1 10810-6、1 88610-6时,层裂强度分别为1.130、0.935、0.755、0.643 GPa,初始预应力（变）明显降低了LY12铝层裂强度,证实了材料的层裂强度与初始应力状态密切相关,可为以后的非一维平面应变下的层裂研究提供参考。