Composition and digestibility during ageing of Italian ryegrass leaves of consecutive insertion levels

Organic matter digestibility (OMD) is determined from the proportion of indigestible cell wall (ICW) in the total plant organic matter. To improve understanding of processes governing the proportion of ICW, plant morphological development, and leaf composition and digestibility were studied for Italian ryegrass (Lolium multiflorum Lam). Since grass is usually grown in swards, a comparison was made between spaced and sward grown plants. The time course of ICW accumulation in individual leaves on the main stem (MS) could be described by a negative exponential saturation curve. Remarkably, the curvature and the asymptotic ICW as a proportion of total leaf cell wall mass were the same for all leaves in both the spaced and the sward plants. Under both conditions, leaves consecutively formed on the MS had lower cell wall digestibility (CWD) at leaf appearance and lower rate of CWD decline during ageing, which could be explained from the longer period between the estimated start of ICW formation and the moment of leaf appearance. The higher cell wall content for consecutively formed leaves and for leaves of the sward plants enhanced the effect of lower CWD on OMD at leaf appearance, but counteracted the lower CWD decline rate, so that all leaves had the same rate of OMD decline with age. The observed trends clearly demonstrate the close link between morphological development and leaf composition and digestibility. © 1997 SCI.     

动态共乘系统中一种高效的插入操作方法

针对现有插入操作方法因时间复杂度高而降低动态共乘系统的运行效率,设计了一种以最小化车辆绕行距离为优化目标的线性时间插入操作方法,考虑乘客上车、下车时间约束和车辆容量限制等条件的动态共乘路线优化问题.建立共乘路线模型,采用动态规划技术和固定源节点插入位置的策略,以及利用位置向量的计算结果,可在常量时间内找到车辆绕行距离最小的目标节点的插入位置.理论分析表明:方法能够在线性时间内找到源节点和目标节点的最佳插入位置.仿真结果表明,基于线性时间的插入操作方法能够迅速地得到共乘优化路线,显著提高了动态共乘系统的运行效率.     

混合流水车间插单重调度的超启发式遗传算法

针对带有紧急订单的混合流水车间插单重调度问题,提出了一种双层编码的超启发式遗传算法。针对混合流水车间具有的订单排序和机器选择的双决策特征,在算法低层设计双层编码方案,在个体中表示订单排序和机器选择两类信息,对应一个唯一调度解,进而提出了12种排序和选择启发式对个体进行迭代优化;在算法高层采用自适应遗传算法,用来确定订单排序启发式和机器选择启发式的操作组合以及各组合执行的次序,并设计了自适应变异算子来优化算法的有效性。大规模数据实验的结果表明,所提算法具有很好的求解质量和求解效率。     

波分交叉连接结构的一种简单评估方法

提出了一种评估各种波分交叉连接（WXC）结构的简单分析方法，定性讨论了几种常用WXC结构在阻塞、模块性、广播发送能力和扩展能力的特性。利用线性方程组建立数学模型，并对几种常见WXC方案做出了定量分析插入损耗、硬件成本和灵活性的比较结果。对比几种实现方案得出，基于解复用／空间光开关矩阵／复用的WXC结构（DSM）具有最小的传输损耗，且其成本和灵活性均表现较好。     

Molecular Insertion: A Master Key to Unlock Smart Photoelectric Responses of Covalent Organic Frameworks

Covalent organic frameworks (COFs) show potentials in prominent photoelectric responses by judicious structural design. However, from the selections of monomers and condensation reactions to the synthesis procedures, the acquisition of photoelectric COFs has to meet overmuch high conditions, limiting the breakthrough and modulation in photoelectric responses. Herein, the study reports a creative “lock-key model” based on molecular insertion strategy. A COF with suitable cavity size, TP-TBDA, is used as the host to load guests. Merely through the volatilization of mixed solution, TP-TBDA and guests can be spontaneously assembled via non-covalent interactions (NCIs) to produce molecular-inserted COFs (MI-COFs). The NCIs between TP-TBDA and guests acted as a bridge to facilitate charge transfer in MI-COFs, unlocking the photoelectric responses of TP-TBDA. By exploiting the controllability of NCIs, the MI-COFs can realize the smart modulation of photoelectric responses by simply changing the guest molecule, thus avoiding the arduous selection of monomers and condensation reactions required by conventional COFs. The construction of molecular-inserted COFs circumvents complicated procedures for achieving performance improvement and modulation, providing a promising direction to construct late-model photoelectric responsive materials.     

基于低电压驱动MEMS的可调光衰减器的设计与性能分析

研制了一种低成本、小体积的静电驱动微电机系统（MEMS）可调光衰减器（VOA）。该器件采用了静电驱动微反射镜和光纤光准直器，它具有良好的光学性能，克服了传统VOA的缺点。它的驱动电压范围是0～8V，工作范围是0～25dB。给出了器件的衰减量和驱动电压的关系、光学性能的分析和试验结果。     

电极插入不同深度下稀土电解槽电热场耦合模拟

运用数值模拟软件COMSOL研究了不同电极插入深度下3kA钕电解槽的电热场。结果表明,电解槽槽电压随着阴阳极插入深度的递增而降低,槽体的整体温度随着阴阳极插入深度的增加而下降。结合实际生产经验与本研究结果,认为电极插入深度220mm比较适宜,且整个电解过程相对稳定,能够达到槽体电压、温度分布等方面的要求。     

AV3611网络分析仪应用

文中介绍了一种利用国产ＡＶ３６１１分析仪和ＨＰ８３５０Ｂ扫频信号源配置成一套网络分析仪的方法及其使用说明。     

LMS CADA-X中声强分析软件及其应用

介绍了ＬＭＳ ＣＡＤＡ－Ｘ中声强分析软件的主要功能和使用方法，利用该软件对一构件的隔声量进行了测量。     

Homogeneous Intercalation Chemistry and Ultralow Strain of 1T’’’ MoS2 for Stable Potassium Storage

Intercalation anodes usually exhibit better cyclability than conversion and alloying anodes for lithium or sodium storage due to the robust layered structure. However, for larger-sized potassium accommodation, these intercalation anodes usually undergo huge layer expansion and structural distortion, triggering severe capacity fading. Herein, the novel 1T’’’ MoS₂ is revealed the intercalation anode for stable K⁺ storage, in which metallic Mo─Mo bonds and puckered S layers accelerate the charge transfer and homogeneous K⁺ insertion. Moreover, the ultralow strain (3.5%) induced by the non-detachable potassium ions pillar sustains the layered structure. Consequently, 1T’’’ MoS₂ achieves a reversible capacity of 125 mA h g⁻¹ at 0.2 C and keeps nearly 100% capacity retention at 1 C over 500 cycles. In situ characterizations and density functional theory simulations reveal the in-depth intercalation reaction accompanied by the MoS₂ phase transformation between 1T’’’ and 1T’ during cycling. Furthermore, a 1T’’’ MoS₂//MCMB K-dual ion battery displays a superior cycling lifespan with 98% capacity retention over 250 cycles. This study provides a new intercalation anode and contribute to the electrode design for stable potassium ion storage.