基于新旧共同规范的主要支撑构件曲形面板结构强度对比分析

为明确共同规范对主要支撑构件曲形面板有效面积计算公式更新后主要支撑构件曲形面板有效系数的变化,通过实例分析规范修改对主要支撑构件曲形面板有效性的影响,认为规范修改对于非对称曲形面板的影响远大于对称曲形面板,可通过设置径向肘板、将非对称曲形面板改为对称曲形面板、改变面板尺度比,使得有效系数最大,可采用细网格进一步分析,进...     

MEASUREMENT OF NASAL FIGURE BY MAGNETIC RESONANCE IMAGING

Restoring the nasal figure is an important stepin facial reconstruction and medicolegally recon-structing skull because of the special characteris-tics of nose position and construction on face.Some researches have proved that nasal figure hadnot only racial, also sexual characteristics, and itcould change' as the increase of the individuals'age. In order to get the basic materials of nasal fig-ure of the Han nationality in Xi'an area, we havemeasured noses of 3l3 cases of the Han nationality…     

THE DIAGNOSIS OF MAGNETIC RESONANCE IMAGING FOR SPINAL CAVERNOUS ANGIOMAS

Ｓｐｉｎａｌｃａｖｅｒｎｏｕｓａｎｇｉｏｍａｉｓａｋｉｎｄｏｆｖａｓｃｕｌａｒｄｅｆｏｒｍｉｔｙｏｆｓｐｉｎａｌｃｏｒｄ .Ｓｏｆａｒ ,ｉｔｉｓｕｓｕａｌｌｙｒｅｇａｒｄｅｄａｓｔｈｅｏｃｃｕｒｒｅｎｃｅａｔｃａｐｉｌｌａｒｙｌｅｖｅｌ[1,2 ] .Ｗｉｔｈｔｈｅｄｅ ｖｅｌｏｐｍｅｎｔｏｆｍａｇｎｅｔｉｃｒｅｓｏｎａｎｃｅｉｍａｇｉｎｇ (ＭＲＩ)ｔｅｃｈｎｉｑｕｅ,ｍｏｒｅａｎｄｍｏｒｅｃａｓｅｓｏｆｓｐｉｎａｌｃａｖｅｒｎｏｕｓａｎｇｉｏｍａｓｗｉｌｌｂｅｆｏｕｎｄ .Ｉｎｔｈｉｓｓｔｕｄｙ ,3ｃａｓｅｓ…     

充填型岩溶突水突泥灾害源的核磁共振表征与泥水识别方法

隧道穿越富水岩溶地层时,为预报可能遭遇的突水突泥灾害类型、水量以及突出物信息,需提前探明掌子面前方地层含水量、渗透系数、导水系数等水文地质参数,从而对灾害源进行泥水识别。核磁共振探测（Magnetic Resonance Sounding,MRS）是一种能够直接探明地层水文地质特征的物探方法,基于MRS方法的这一优势,提出一种针对充填型岩溶突水突泥灾害源的核磁共振表征与泥水识别的方法,以期对突水突泥灾害进行预报并加以区分。通过引入Log-Gauss分布函数构建MRS弛豫时间的时空分布函数,用以表征不同灾害所对应的充填物特征;并对掌子面前方电阻率、含水量以及MRS弛豫时间分布进行三维离散,实现了对充填型岩溶突水突泥灾害源的核磁共振表征与建模。在此基础上,正演模拟了不同类型突水突泥灾害源的MRS响应信号,并分析了其响应特征与影响因素。基于灾害源的MRS响应信号特征,利用充填物含水量和MRS弛豫时间的时空分布函数建立了以充填型岩溶突水突泥灾害源的泥水识别因子作为对灾害源进行泥水识别的判据。     

Parametrical studies of a new numerical model for controlled ship motions in extreme astern seas

Parametrical studies based on numerical simulations were carried out for very steep regular waves to assess possible improvements in the state-of-the art numerical modelling of the control and capsizing behaviour of ships in following and quartering seas. A nonlinear 6-DOF numerical model has been developed with the inclusion of frequency-dependent terms, the so called memory effects, and a flexible axis system that allows straightforward combination of seakeeping and manoeuvring models while accounting for extreme motions. The previously undertaken validation analyses using extensive model test data provided qualitatively good agreement, whereas the comparison with numerical models without coupling of the vertical motions and frequency-dependent hydrodynamic terms embodied in radiation forces identified improvements in the accuracy. However, to broaden the assessment of the numerical model, further parametrical numerical analyses were carried out using two ships, which had previously been tested in the validation analyses, for various operational and environmental conditions. These parameters were changed in accordance with the recommendations from international organisations and experience from model tests to realise and avoid dangerous conditions that often result in capsizing, such as broaching associated with surf riding and low-cycle resonance. As a result of the parametric analysis, we discuss the sensitivity of the improvements in the numerical model for various critical operational and design parameters and its possible use to provide a link between the ship's behavior and these parameters.     

簧间质量质心位置对机车运行平稳性的影响

C0-C0轴式机车的转向架簧间质量质心位置与转向架几何中心位置不重合,在轨道方向上发生偏移,会影响机车的动力学性能。文章以一台6轴架悬机车为例,建立转向架簧间质量质心偏移的机车计算模型,对其运行平稳性进行研究。计算结果表明,质心偏移量对机车横向平稳性和垂向平稳性的影响是相互矛盾的。在转向架设计时应合理安排簧间质量质心的位置以协调机车的横向、垂向动力学性能。     

雁门关隧道富水段软弱围岩初期支护开裂变形控制技术

结合北同蒲铁路取直线雁门关隧道软弱围岩初期支护开裂变形控制施工实例,介绍施工地质揭示情况,分析围岩与初期支护开裂变形原因,提出针对富水段软弱围岩初期支护开裂变形控制施工技术方法,创新了钢拱架锁脚锚管施工新工艺。     

基于共振解调的铁路货车轴承故障诊断

以铁路货车轴箱双列圆锥滚子轴承为研究对象,基于共振解调技术研究了早期故障精密诊断方法。首先在轮对跑合实验台上,采用压电加速度传感器、信号调理器和INV36DF型信号采集处理仪等搭建轴承故障测试系统,测量该类型轴承外圈和滚子存在轻微故障时的振动信号,然后通过带通滤波、包络解调和频谱分析等方法,准确提取出了轴承外圈和滚子的故障特征频率。研究结果表明,利用这种方法可以消除系统噪声干扰,能有效诊断出轴承外圈和滚子的轻微损伤。该方法对于铁路货车轴承的早期故障诊断具有较好的理论意义和实际应用价值。     

树突状细胞介导的T淋巴细胞对肝癌细胞的特异性杀伤效应

目的通过体外诱导高效特异的抗肝癌细胞系免疫反应,制备一种以树突状细胞(DC)为基础的肝癌疫苗。方法分离人外周血单核细胞,经IL4和GMCSF联合刺激诱导DC分化。培养第4天,DC用人肝癌细胞系SMMC7721的冻融抗原致敏。培养第7天,将肝癌冻融抗原致敏的DC和未经肝癌冻融抗原致敏的DC分别与T淋巴细胞混合培养24h作为效应细胞,以人SMMC7721肝癌细胞、MCF7乳腺癌细胞和PC3前列腺癌细胞作为靶细胞,用MTT法检测细胞毒活性。结果经肝癌冻融抗原致敏的DC对SMMC7721细胞有高效而特异的杀伤活性,对其他肿瘤细胞系也有一定的杀伤活性,但无明显特异性;未经肝癌冻融抗原致敏的DC对3种肿瘤细胞系均有一定的杀伤活性,但无明显特异性;各组效应细胞对靶细胞的杀伤率随效靶比(EC/TC)的升高而增强。结论以肝癌细胞冻融抗原冲击致敏的DC刺激T淋巴细胞增殖在体外可诱导产生高效特异性的抗肝癌免疫反应,为肝癌的主动特异性免疫治疗提供了可靠的理论依据。     

弱磁性介质谐振腔的品质因数特性

以有机高分子磁性材料作为金属壁谐振腔的填充材料，根据腔体内的场结构，分析材料的相对磁导率和介质损耗对谐振腔的品质因数的影响．分析表明，在介质损耗相同的情况下，谐振腔的品质因数随相对磁导率呈增加趋势，且介质损耗越小，增加趋势越明显．