橡胶活性官能团对增韧环氧树脂动态力学性能的影响

用动态扭摆法测试聚丙烯酸丁酯橡胶增韧环氧树脂的动态力学行为,研究在环氧树脂低固化度和高固化度时,橡胶活性官能团种类(环氧基官能团与羧基官能团)和数量(官能度)对其影响。研究体系中橡胶玻璃化转变温度(Tg)的移动大小,与橡胶和基体树脂健合程度之间的关系。     

Human balance and posture control during standing and walking

The common denominator in the assessment of human balance and posture is the inverted pendulum model. If we focus on appropriate versions of the model we can use it to identify the gravitational and acceleration perturbations and pinpoint the motor mechanisms that can defend against any perturbation.

We saw that in quiet standing an ankle strategy applies only in the A/P direction and that a separate hip load/unload strategy by the hip abd/adductors is the totally dominant defence in the M/L direction when standing with feet side by side. In other standing positions (tandem, or intermediate) the two mechanisms still work separately, but their roles reverse. In the tandem position M/L balance is an ankle mechanism (invertors/evertors) while in the A/P direction a hip load/unloading mechanism dominates.

During initiation and termination of gait these two separate mechanisms control the trajectory of the COP to ensure the desired acceleration and deceleration of the COM. During initiation the initial acceleration of the COM forward towards the stance limb is achieved by a posterior and lateral movement of the COP towards the swing limb. After this release phase there is a sudden loading of the stance limb which shifts the COP to the stance limb. The COM is now accelerated forward and laterally towards the future position of the swinging foot. Also M/L shifts of the COP were controlled by the hip abductors/adductors and all A/P shifts were under the control of the ankle plantar/dorsiflexors. During termination the trajectory of both COM and COP reverse. As the final weight-bearing on the stance foot takes place the COM is passing forward along the medial border of that foot. Hyperactivity of that foot's plantarflexors takes the COP forward and when the final foot begins to bear weight the COP moves rapidly across and suddenly stops at a position ahead of the future position of the COM. Then the plantarflexors of both feet release and allow the COP to move posteriorly and approach the COM and meet it as quiet stance is achieved. The inverted pendulum model permitted us to understand the separate roles of the two mechanisms during these critical unbalancing and rebalancing periods.

During walking the inverted pendulum model explained the dynamics of the balance of HAT in both the A/P and M/L directions. Here the model includes the couple due to the acceleration of the weight-bearing hip as well as gravitational perturbations. The exclusive control of A/P balance and posture are the hip extensors and flexors, while in the M/L direction the dominant control is with the hip abductors with very minor adductor involvement. At the ankle the inverted pendulum model sees the COM passing forward along the medial border to the weight-bearing foot. The model predicts that during single support the body is falling forward and being accelerated medially towards the future position of the swing foot. The model predicts an insignificant role of the ankle invertors/evertors in the M/L control. Rather, the future position of the swing foot is the critical variable or more specifically the lateral displacement from the COM at the start of single support. The position is actually under the control of the hip abd/adductors during the previous early swing phase.

The critical importance of the hip abductors/adductors in balance during all phases of standing and walking is now evident. This separate mechanism is important from a neural control perspective and clinically it focuses major attention on therapy and potential problems with some surgical procedures. On the other hand the minuscule role of the ankle invertors/evertors is important to note. Except for the tandem standing position these muscles have negligible involvement in balance control.     

政策反馈理论视域：中国医疗卫生政策钟摆式变迁及其逻辑

新中国成立以来,党和国家不断强化医疗卫生建设,70余年来医疗卫生政策演进呈钟摆式变迁的特征,即从公益导向的福利性医疗卫生政策摆向效率导向的市场化政策,再摆向公益为主兼顾效率的民生导向政策,在公益与效率间发生三次摆动。本文借助政策反馈理论分析医疗卫生政策钟摆式变迁的内在逻辑,发现政策变迁过程中原有政策通过资源效应、解释效应、演化效应和学习效应影响新政策的制定,使得新政策留有原政策的烙印,呈现出摆动式变迁而非剧烈或范式变迁。政策反馈理论为医疗卫生政策制定提供新视角,制定医疗卫生政策需注重原政策的历史影响力,以公共价值引领医疗医保医药政策,从多重政策反馈效应视角出发优化卫生政策的制定。     

基于多成分含量测定和化学计量学的不同基原白芷药材质量评价研究

目的 采用指纹图谱、多成分含量测定结合化学计量学方法分析和比较不同基原白芷药材（白芷Angelica dahurica和杭白芷Angelica dahurica var. formosana）的化学成分,为白芷药材的质量控制提供技术方法及数据支撑。方法 采用高效液相色谱法对白芷和杭白芷药材化学成分进行分析,建立不同基原白芷药材化学指纹图谱;在此基础上,对白芷和杭白芷药材中的花椒毒酚、水合氧化前胡内酯、白当归素、花椒毒素、佛手柑内酯、氧化前胡素、欧前胡素、珊瑚菜素和异欧前胡素9种香豆素类成分进行含量测定;进一步应用聚类分析、主成分分析及偏最小二乘判别分析等化学计量学方法对白芷与杭白芷进行区分与比较,寻找差异化合物。结果 建立了不同基原白芷药材的化学指纹图谱,共标定了11个共有峰,所建立的化学指纹图谱专属性良好,可用于白芷药材的质量评价;多成分含量测定和化学计量学结果表明,白芷和杭白芷药材中所含香豆素类成分种类无差异,但香豆素类成分含量有明显差异;佛手柑内酯、珊瑚菜素、异欧前胡素、氧化前胡素和花椒毒素为白芷和杭白芷药材间的差异性化合物,可以作为区分和鉴别二者的质量标志物。结论 基于指纹图谱...     

安国引种黄芪的质量初步评价

测定安国县１０个村引种黄芪药材中黄芪甲苷含量,平均值为０．１９９％,比传统道地黄芪高２倍,比《中国药典》标准（不得少于０．０４％）高近４倍,但外观质量难以相比,１０个村黄芪药材中砷、汞、铅、镉、镍、钴等 ６种元素的平均值分别为 ０． ２４４、０． ００９、１．７３１、０． ０３６、０． ２１４、０． ３０２ μｇ／ｇ,与土壤中６种元素的比值即富集系数≤０．５。     

榛子叶化学成分研究(Π)

目的　对榛子叶中的鞣质成分进行了研究 ,开发利用黑龙江省榛子叶资源。方法　利用 1 H- NMR,1 3C- NMR,FAB- MS,CD谱及 1 H- 1 HCOSY二维谱与化学方法鉴定。结果　从中得到 4个化学成分 :榛叶素 B(heterophylliin B, ) ,tellimagrandin ( ) ,casuarictin ( ) ,casuarinin ( )。结论　榛叶素 B是一个新的鞣花二聚体成分     

玉仁丰乳丸质量标准研究

采用薄层色谱法对制剂中的黄芪、王不留行、川芎进行了鉴别，采用双波长薄层扫描法以人参皂苷Rg1为指标进行了含量测定。方法回收率为97．54％，RSD=3．43％，玉仁丰乳丸中人参皂苷Rg1测定含量为0．55％（n=3）。方法准确，专属性强，可有效地控制该制剂的质量。     

大孔吸附树脂富集小蓟中咖啡酸酯类成分的研究

目的通过对23种大孔吸附树脂筛选,寻找适用于纯化小蓟中咖啡酸酯类成分的大孔吸附树脂,为从小蓟中工业化生产咖啡酸酯类成分提供依据。方法采用23种大孔吸附树脂对小蓟提取物进行吸附纯化,以总咖啡酸酯收率和纯度作为指标综合评价。结果23种吸附树脂中,以树脂HPD-100吸附洗脱的总咖啡酸酯的收率最高为87.6%、纯度为52.2%。结论HPD-100树脂综合性能良好,适用于小蓟中咖啡酸酯类成分的纯化。     

乌拉尔甘草叶挥发油的化学成分分析

 目的分析乌拉尔甘草叶挥发油的化学成分。方法采用水蒸气蒸馏法提取,运用毛细管气相色谱-质谱联用法结合计算机检索对其化学成分进行分析和鉴定,用气相色谱面积归一化法测定各组分的相对百分含量。结果经毛细管色谱分离出76个峰,并且确认了其中的61种化合物。化学成分主要为十九烷(12.89%),廿烷(12.23%),1-十七烯(12.05%),2,6,11-三甲基-十二烷(7.54%),十八烷(7.46%),E-蒎烷(5.54%),二十二烷(5.30%),二十三烷(4.92%),十六烷基-环氧乙烷(3.09%) 等,上述9种化合物的含量占挥发油总量的71.02%。结论首次报道了乌拉尔甘草叶挥发油的化学成分,为进一步开发利用提供了科学依据。     

梁外半野生甘草最佳采收期研究

目的:研究甘草中甘草酸的积累动态,确定内蒙古梁外地区育苗移栽的半野生甘草最佳采收期.方法:用HPLC法测定不同时间采集的不同株龄的半野生甘草中甘草酸含量.结果:甘草中甘草酸含量6～7月份最高,8月份开始逐渐降低,11～12月最低,翌年3～4月份开始逐渐增加,直到6～7月份达最高峰;甘草在移栽后的前三年,甘草酸含量无明显增加,第四年的各个月份的甘草酸含量均远大于头三年.结论:育苗移栽的半野生甘草的最佳采收期为移栽后的第四年7～8月份.