基于C8051F410单片机的钨灯电源设计

针对光谱测试系统对光源稳定性越来越高的要求,介绍了一种以单片机为核心的高稳定性的钨灯电源系统.它以C8051F410单片机为核心,采用增量式PID控制算法,通过控制单片机的D/A输出来调整MOS场效应管的导通情况,从而达到稳定钨灯工作电流的目的,保证钨灯的发光稳定.通过实验验证,新设计的电源具有控制精度高、稳定性好、性能可靠等优点,可应用于光谱测试系统中.     

基于遗传算法的自寻优模糊控制器的研究与应用

针对矿山电力传动系统的特点和要求 ,根据遗传算法和模糊控制理论 ,研究和设计了一种基于遗传算法的自寻优模糊控制器。仿真研究和实时控制结果表明 ,该控制器设计的调速系统具有响应速度快、空载和负载情况下无静差、无超调、鲁棒性强等特点 ,且结构简单 ,易于实现实时控制。     

浅谈设计思维

设计的功能是以人为本,丰富和升华人们的生理体验和心理体验以提升生活品质,传递信息和新的思维方式;设计作品的优劣从某种角度来说是设计思维深入程度决定的;设计思维是以个人对世界的认识为基础的;人对世界认识的程度实际上也就是设计思维深入的程度,因此我们应弄清自己思维的渊源,树立正确的世界观。     

浅谈设计思维

设计的功能是以人为本,丰富和升华人们的生理体验和心理体验以提升生活品质,传递信息和新的思维方式;设计作品的优劣从某种角度来说是设计思维深入程度决定的;设计思维是以个人对世界的认识为基础的;人对世界认识的程度实际上也就是设计思维深入的程度,因此我们应弄清自己思维的渊源,树立正确的世界观。     

喷淋座垫的单片机智能控制

采用单片机进行智能控制 ,实现喷淋座垫智能化 ,克服了以往人工调整水杆和人工限时的弊病 ,提高了产品的性能和实用价值。     

Ultrastructural evidence for an innervation of epithelial enterochromaffine cells in the guinea pig duodenum

The innervation of the duodenal enterochromaffine cells (E.C.) of the guinea pig was studied at the electronmicroscopic level. Pretreatment with 5-OH-dopamine was performed to visualize catecholaminergic (CA) nervous elements. Near the basement membrane of all examined E.C. in the crypts, bundles of unmyelinated nerve processes were observed, only partly ensheathed in a Schwann cell cover. At least 4 types of processes could be observed. 1) Boutons containing only small clear vesicles, probably cholinergic fibres; 2) boutons with small clear vesicles, and in addition large (greater than 200 nm) granules with a dense matrix (P-type-fibres); 3) boutons with small electron-dense vesicles, probably CA-fibres; and 4) processes with few vesicles but having the appearance of dendrites. No typical synaptic arrangements were observed, but the minimal distance between the E.C. and the nerve bundles was 150 to 250 nm, thus well within the functional limits of the "autonomic gap". Thus epithelial E.C. may be influenced by several types of nervous elements, including CA-fibres.     

Therapy of hepatitis B. Practical implications

There is as yet no specific treatment for viral hepatitis, and in an uncomplicated course no further action apart from moderate bedrest is necessary. The patient should however, be isolated in a special ward. In fulminant hepatic failure the benefit of glucocorticoid therapy is still controverted and appears to depend on an early beginning. Treatment with HBsAg-rich human serum in fulminant hepatitis B is still under evaluation. In chronic active hepatitis the administration of azathioprine in combination with glucocorticoids is highly effective, and it appears to be irrelevant whether HBsAg is present in plasma or not; however, the best results have been achieved in "lupoid" hepatitis. The use of transfer factor, laevamisol or thymosin to suppress T-cell action on antibody production of the B-cells cannot yet be finally evaluated with respect to its effectiveness in chronic active hepatitis. Prevention is of major importance in solving the problems involved in hepatitis B infections. Recent experience with active immunization using HBsAg-rich sera or purified formalin inactivated HBsAg preparations suggest the possibility of successful vaccination against hepatitis B in the near future, but the precondition for obtaining sufficient quantities of vaccine is to find suitable culture media for the virus.     

冲积河流滩槽定量划分方法及应用

通过理论分析与数值计算,研究了冲积河流漫滩水流水力因子的变化特性。结果表明,断面平均流速在漫滩瞬间迅速减小,然后逐渐增大;断面综合动能修正系数、动量修正系数均随水深而缓慢增加,在漫滩瞬间迅速增大,随即快速减小。根据漫滩水流水力因子沿水深的变化特性,提出采用断面横向平均流速为判别因子以定量划分复式断面的滩与槽。此外,文中将其应用于黄河下游漫滩水流的水沙数值模拟,其结果与实际情况符合较好。     

沧州南部典型区近30年来气温演变特征分析

文中主要分析了沧州南部典型区近30年来气温演变情势,分析了其统计特征、年内变化趋势性和年代际变化、持续性、突变性和周期性,得出了一定的规律性,为深入研究本区域与气温有关的课题打下了基础。     

一种新的比相式电抗型距离继电器算法

对测量阻抗型和相量比较型两种类型的电抗距离继电器的抗稳态超越的能力进行了研究,主要包括负荷的影响和同相问题的研究。同时,构造了一个新的电抗型距离继电器判据和算法,该算法具有方向性,且不受负荷和同相问题的影响,解决了由于负荷和同相问题引起的稳态超越现象,提高了保护动作的可靠性。电磁暂态仿真结果证明该原理具有防止负荷和同相问题引起的稳态超越和保护范围不足的问题。