用于图像检索的连通直方图方法

本文提出了一种用于图像检索的连通直方图（CRH：Connected-Region histogram)方法。连通直方图是图像中连通区域面积的统计函数，反应了图像中连通区域的概率分布，是图像内容的一种简洁表达。它具有灰度、旋转、平移等不变性，并可通过权函数来强调某些连通区域。另外，还可以根据连通区域的其他特征（如连通区域的形状、所处的相对位置等）来优化、改进连通直方图，提高图像的检索效率。实验证明，连通直方图具有一定的图像检索能力。     

我国廉租房的制度困境与法律矫正

作为解决我国低收入者住房问题的重要举措,廉租房制度发挥了重要作用。然而,我国廉租房制度基本框架在立法上其层级较低,并反映了廉租房制度尚未融入社会保障体系的观念与制度设计。而在实践中,廉租房制度在法律上的缺陷主要表现为对农民工的排斥、违法成本较低并导致实施成本高昂。因此,在廉租房制度的法律完善过程中,政府有义务发挥主导性的作用,并提升法律制度的位阶和完善其具体内容。对廉租房制度进行法律的检讨与完善,有助于我国廉租房制度的完善与廉租房制度功能的释放。     

CRH3动车轮对压装选配

轮对的压装质量与其性能有着直接的关系。传统的轮对压装多是依据经验来进行轮轴的选配,没有明确的参考标准,因而导致压装合格率较低。文章以CRH3型动车组轮对为例,利用Ansys软件建立了二维轴对称模型对轮对压装过程进行模拟仿真,通过非线性接触分析得出过盈量、摩擦因数、公差等因素对轮对压装应力分布及压装曲线的影响。结果表明,过盈量对轮对应力及压装曲线均有较大的影响;摩擦因数对应力值影响较小,对压装曲线则影响较大;公差对轮对应力影响比较明显,对压装曲线的影响则比较微弱。最后在满足国家标准要求的前提下给出一个范围,以此作为轮对压装的参考标准,可提高轮对压装的质量,保证机车安全平稳运行。     

CRH3型动车组牵引传动系统的直接转矩控制研究

为了研究高速动车组的具体模型结构及其牵引传动控制系统,采用直接转矩控制(DTC)系统控制异步牵引电机,建立了CRH3型高速动车组牵引传动系统的Matlab/simulink仿真模型,整流部分由四象限脉冲整流器输出3 000 V左右平滑的直流电压,逆变部分由直接转矩控制系统驱动牵引电机。该系统能根据CRH3型动车组的牵引、制动曲线模拟动车组牵引、惰行、制动等各种运行工况。整个运行过程中系统的谐波较小,电压/电流相位差基本能保持在同相或反相运行,功率因数基本接近1;在网压波动和突然失电情况下,机车也基本能保持恒速运行。最后,将该模型仿真结果与京津城际高速铁路的部分数据进行了对比验证。研究结果表明,该模型建模基本正确,同时系统具有良好的稳态和动态性能,验证了直接转矩控制方法的有效性。     

Hypothalamic regulatory peptides and their receptors: Cytochemical studies of their role in regulation at the adenohypophyseal level

Hypothalamic regulatory peptides bind to specific receptors on target cells in the pituitary and control secretion. They in turn can be regulated at the pituitary level by steroid and peptide modulators. Affinity cytochemical techniques are important tools for the identification of specific target binding sites for these regulatory peptides. This presentation reviews the work in which potent, biotinylated ligands of gonadotropin releasing hormone (bio-GnRH), corticotropin releasing hormone (bio-CRH), and arginine vasopressin (bio-AVP) were applied to study the target cell responses. Bio-GnRH, bio-CRH, and bio-AVP bind to membrane receptors on specific anterior pituitary cells. Dual labeling for either gonadotropin or adrenocorticotropin (ACTH) antigens further identified the target cells. After 1–3 minutes, the label was in patches or capped on the surface. After 3 minutes, it was internalized in small vesicles and sent to receptosomes and vacuoles in the Golgi complex. Eventually the biotinylated peptides, or a metabolite, was found in the lysosomes (multivesicular bodies) and a subpopulation of secretory granules. The route and rate of uptake was similar to that described for the classical receptor-mediated endocytosis process. In contrast, intermediate lobe corticotropes internalized the bio-CRH in less than 1 minute. The route through the Golgi complex appeared to be bypassed. Instead the labeled peptide was in vesicles, on the membranes of scattered vacuoles, and in multivesicular bodies. Modulation of ligand binding by steroids showed that changes in receptor numbers correlated with changes in the number of cells that bound the ligand. In male rats, dihydrotestosterone reduced the percentage of GnRH-bound cells by 50%. Most of the reduction appeared in cells that stored luteinizing hormone (LH) antigens. In diestrous female rats, estradiol increased the percentage of bio-GnRH-bound cells. However, the steroid decreased the percentage of GnRH-bound cells in cells from proestrous rats. Glucocorticoids decreased the percentage of CRH-bound corticotropes in as little as 10 minutes. Potentiation of secretion by these ligands was correlated with increases in the percentage of ligand-bound cells. AVP pretreatment of corticotropes increased the percentage of cells that bound bio-CRH. It also increased the rate of receptor-mediated endocytosis of CRH and changed the route so that the Golgi complex was bypassed. This effect could be mimicked by activation of its second messengers (calcium and protein kinase C). Similarly, CRH pretreatment increased the percentage of corticotropes that bound AVP. Thyrotropin releasing hormone (TRH) pretreatment also increased the percentage of thyrotropes that bound AVP. Finally, calcium or sodium channel blockers altered CRH binding so that fewer cells were labeled. This binding by CRH was not dependent on extracellular calcium and tests with a calcium channel agonist showed that it was related to activation of calcium channels. To summarize, these affinity cytochemical studies have identified specific target cells in the pituitary for GnRH, CRH, and AVP. They have also identified heterogeneity in the population. They have demonstrated new information about the direct modulatory effects of steroids, ion channels, and neuropeptides on neuropeptide binding by subpopulations of these target cells.     

基于IADRC的多CRH5型车网耦合系统低频振荡抑制方法

近年来国内相继出现多起高速铁路车网耦合系统低频振荡,振荡严重时甚至导致动车组牵引封锁。针对多列CRH5型动车组升弓整备投入牵引网时发生低频振荡提出了一种有效抑制方法。首先,分析了多列CRH5型动车组同时升弓接入牵引网的多车网电气耦合系统特性。其次,基于改进自抗扰控制策略对车网系统负载CRH5型动车组整流器的控制器进行优化设计来抑制系统低频振荡。最后,相比原有动车整流器PI控制和传统自抗扰控制技术,在Matlab/Simulink平台下测试验证了基于改进自抗扰控制的多CRH5动车组升弓整备投入牵引网的车侧电气量发生低频振荡抑制的正确性和有效性。     

动车组高速列车用6005A铝合金车体型材挤压工艺

为适应我国高速铁路发展的需要,开发了动车组高速列车用6005A铝合金车体型材,通过试验研究,优化了合金成分配比,确定了公司内部合金成分控制标准,优化了挤压工艺参数和模具设计、制造方案.生产出了内部组织和力学性能合格的高速列车用的6005A铝合金车体型材.     

基于ANSYS分析某型号动车组M车固有振动特性对人的影响

对某型号动车组M车首先进行谐响应分析,确定车体结构在作用0~100Hz简谐载荷时的响应特性,得出与乘客乘座舒适性直接相关的车体部位的响应值与频率的关系曲线,将其与人体各部位或系统的固有频率对比后得出人体在M车车体结构受简谐载荷时的固有振动特性的敏感程度。然后以轨道轨距不平顺为例,对M车进行随机振动（PSD）分析,预测车体在受到基础激励的实际运行过程中结构响应情况,分析车体运行时影响乘客乘座舒适性的主要频率范围及原因。     

和谐号动车座椅的人因学改善研究

以和谐号动车座椅为研究对象,以人因学为理论依据,以人因学软件Jack为研究工具,建立数字人,对动车座椅进行建模仿真,通过舒适度检验发现其存在的问题。结果表明：通过对动车座椅座面高度、座面倾角以及靠背高度的重新设计,可以显著提高旅客乘坐的舒适度。     

Stress Adaptation and the Brainstem with Focus on Corticotropin-Releasing Hormone

Stress adaptation is of utmost importance for the maintenance of homeostasis and, therefore, of life itself. The prevalence of stress-related disorders is increasing, emphasizing the importance of exploratory research on stress adaptation. Two major regulatory pathways exist: the hypothalamic–pituitary–adrenocortical axis and the sympathetic adrenomedullary axis. They act in unison, ensured by the enormous bidirectional connection between their centers, the paraventricular nucleus of the hypothalamus (PVN), and the brainstem monoaminergic cell groups, respectively. PVN and especially their corticotropin-releasing hormone (CRH) producing neurons are considered to be the centrum of stress regulation. However, the brainstem seems to be equally important. Therefore, we aimed to summarize the present knowledge on the role of classical neurotransmitters of the brainstem (GABA, glutamate as well as serotonin, noradrenaline, adrenaline, and dopamine) in stress adaptation. Neuropeptides, including CRH, might be co-localized in the brainstem nuclei. Here we focused on CRH as its role in stress regulation is well-known and widely accepted and other CRH neurons scattered along the brain may also complement the function of the PVN. Although CRH-positive cells are present on some parts of the brainstem, sometimes even in comparable amounts as in the PVN, not much is known about their contribution to stress adaptation. Based on the role of the Barrington’s nucleus in micturition and the inferior olivary complex in the regulation of fine motoric—as the main CRH-containing brainstem areas—we might assume that these areas regulate stress-induced urination and locomotion, respectively. Further studies are necessary for the field.