毛竹及其变种叶片化学计量与养分重吸收效率

【目的】评价毛竹(Phyllostachys edulis)及其变种叶片养分重吸收效率,旨在揭示主要养分元素的生态适应机制,以期为毛竹及其变种的可持续经营提供科学依据。【方法】以毛竹及其变种[黄槽毛竹(P. edulis cv. Luteosulcata)、花毛竹(P. edulis cv. Tao Kiang)、厚壁毛竹(P. edulis cv. Pachyloen)、金丝毛竹(P. edulis cv. Gracilis)]为研究对象,分析不同竹龄(1、3、5 a)叶片化学计量特征与养分重吸收效率。【结果】毛竹及其变种C、N 含量差异较小,P含量波动性较大。不同竹种相同竹龄立竹间成熟叶和凋落叶C、N、P含量差异性较大,1年生竹种叶片养分含量较高,随着竹龄增加,竹种适应能力逐渐下降。毛竹及其变种相同年龄立竹间、同一变种不同年龄立竹间叶片化学计量比存在一定差异性。1、3、5年生花毛竹叶片N、P重吸收效率较高,年龄对除厚壁毛竹外的其他毛竹及其变种叶片N重吸收效率影响呈现先升后降趋势,而不同年龄毛竹及其变种叶片P重吸收效率波动性较大。【结论】研究区毛竹及其变种生长受P元素的限制,毛竹及其变种随竹龄的增加适应能力有所变化,花毛竹适应性较强,厚壁毛竹则对土壤的依赖性较大。     

一种HEVC样点自适应补偿快速算法

为解决高性能视频编码标准H.265/HEVC中引入的样点自适应补偿技术的计算复杂度极高导致严重影响编码效率的问题,提出一种HEVC样点自适应补偿快速算法.首先根据编码单元(coding unit, CU)的划分深度确定亮度树形编码块(coding tree block, CTB)中需要提取边缘方向的区域,然后利用边缘方向提取算法获得亮度CTB的边缘方向列表,并根据此列表减少亮度CTB在模式判别过程中遍历的模式数量,最后利用亮度和色度CTB之间的相关性进一步简化色度CTB的模式判别过程.实验结果表明,在性能损失较小的情况下,本算法可以在全I帧(AI)、随机访问(RA)、低延时B帧(LB)、低延时P帧(LP)四种配置下分别节省31.75%、 56.85%、 52.81%、 51.51%的样点自适应补偿编码时间.     

基于模型的汽油机电子节气门控制器设计

摘要： 建立了电子节气门系统模型，并通过系统辨识方法得出模型参数.根据被控电子节气门的摩擦力和非线性回位弹簧模型，设计了前馈非线性补偿控制器.将经过前馈非线性补偿后的电子节气门系统简化成线性系统，并对该线性系统进行H无穷控制器的设计.对设计的H无穷控制器进行离散化，并加入比例控制环节来弥补控制器离散化导致的性能下降.经过试验验证，在前馈非线性补偿器、H无穷控制器和比例控制的作用下，被控电子节气门的性能达到了设计需求.     

梯度网络平稳点集合的Hopfield稳定性与吸引域

给出梯度神经网络模型的电路实现 ,证明了网络平稳点集合的全局 Hopfield稳定性。对各个平稳点吸引域的几何估计得到了相关结果 ,这为网络初始输入的数量与方向判定提供了基本的量度参数准则。     

农机报表管理系统的设计与实现

以新疆生产建设兵团农机报表管理系统为例，介绍了基于C／S和B／S模式的农机报表管理系统的设计与实现，并对其系统开发中的关键技术等内容进行了探讨。     

ICP-AES光谱仪的研制及其分析软件的设计

目前,市场上的ICP光谱仪仍以国外仪器为主,国内仪器的开发与研制始终未能有所突破,在仪器分析软件上仍属空白,这极大限制了国内ICP光谱仪的发展.本文主要针对单道顺序扫描型ICP-AES光谱仪的硬件及分析软件的开发提供了思路.     

Regulation of insulin receptor function

Resistance to the biological actions of insulin contributes to the development of type 2 diabetes and risk of cardiovascular disease. A reduced biological response to insulin by tissues results from an impairment in the cascade of phosphorylation events within cells that regulate the activity of enzymes comprising the insulin signaling pathway. In most models of insulin resistance, there is evidence that this decrement in insulin signaling begins with either the activation or substrate kinase activity of the insulin receptor (IR), which is the only component of the pathway that is unique to insulin action. Activation of the IR can be impaired by post-translational modifications of the protein involving serine phosphorylation, or by binding to inhibiting proteins such as PC-1 or members of the SOCS or Grb protein families. The impact of these processes on the conformational changes and phosphorylation events required for full signaling activity, as well as the role of these mechanisms in human disease, is reviewed in this article. Received 3 August 2006; received after revision 1 December 2006; accepted 8 January 2007     

Homology Priority Task Scheduling in μC/OS-Ⅱ Real-Time Kernel

μC/OS-Ⅱ is an open source real-time kernel adopting priority preemptive schedule strategy. Aiming at the problem of μC/OS-Ⅱ failing to support homology priority tasks scheduling, an approach for solution is proposed. The basic idea is adding round-robin scheduling strategy in its original scheduler in order to schedule homology priority tasks through time slice roundrobin. Implementation approach is given in detail. Firstly, the Task Control Block （TCB） is extended. And then, a new priority index table is created, in which each index pointer points to a set of homology priority tasks. Eventually, on the basis of reconstructing μC/OS-Ⅱ real-time kernel, task scheduling module is rewritten. Otherwise, schedulability of homology task supported by modified kernel had been analyzed, and deadline formula of created homology tasks is given. By theoretical analysis and experiment verification, the modified kernel can support homology priority tasks scheduling, meanwhile, it also remains preemptive property of original μC/OS-Ⅱ.