过冷水滴撞击螺旋桨桨叶表面的数值模拟

本文介绍了某型螺旋桨在不同飞行状态下.求解桨叶水滴撞击特性的数值方法.该方法对桨叶运动模型进行简化,并在对绕桨叶运动的气流场计算的基础上,采用拉格朗日方法求解气流场中水滴运动方程,得到水滴运动轨迹.进而,确定了水滴对桨叶的撞击特性参数,为桨叶防冰系统设计提供条件.主要结论如下:(1)在巡航状态下,桨叶沿展向方向上总收集系数Em和局部收集系数β不断增大;(2)在爬升状态下,随着爬升高度H不断增大,飞行速度V0不断增大,水滴撞击在桨叶表面的范围有所增加,而且β随之增大;(3)随着水滴平均有效直径(MVD)的增大,水滴撞击在桨叶表面的范围明显增加同时,β在桨叶表面同一位置的值也随之增大.     

Clinical Analysis of Voice Change as a Parameter of Premenstrual Syndrome

We have evaluated the relationship between voice change and premenstrual syndrome (PMS) by comparing acoustic measurements made during the follicular phase and the premenstrual phase. Twenty-eight women were followed for 2 months for this study. Each participant was asked to produce an /a/ sound for 5 seconds at the midfollicular phase of the menstrual cycle and then 2-3 days before menstruation. Each voice sample was stored and analyzed by the Dr. Speech Science program. The voice data collected from all subjects during the two phases were compared. After that, the subjects were divided into a PMS-positive and PMS-negative group according to the criteria cited in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV); the voice data from each group were compared separately between the two phases. There was no significant difference in the acoustic parameters between the two phases in all subjects (N = 28). In the PMS-positive group (N = 16), jitter was significantly increased during the premenstrual phase compared to the follicular phase (p = 0.048). The patient's PMS score was not correlated with the severity of voice change. We conclude that the change of voice parameter was objectively identified in the PMS-positive group, therefore more careful voice habituation is required during the premenstrual phase in that group.     

Electromyography Activity of Vastus Medialis Obliquus and Vastus Lateralis Muscles During Lower Limb Proprioceptive Neuromuscular Facilitation Patterns in Individuals with and without Patellofemoral Pain Syndrome

Objective: Exercise therapy to strengthen quadriceps muscle is recommended in rehabilitation program for people with patellofemoral pain syndrome (PFPS). This study aimed to investigate the electromyography (EMG) activity of vastus medialis obliquus (VMO), vastus lateralis (VL) and VMO/VL ratio during PNF in individuals with and without PFPS. Methods: 26 persons with PFPS and 26 healthy subjects participated to study. All subjects performed PNF patterns (Flexion-Adduction-External Rotation (D₁FL), Extension-Adduction-External Rotation (D₂EX), D₁FL+ load, D₂EX+ load) and straight leg raise (SLR). The normalized EMG activity of VMO, VL and VMO/VL ratio were measured and analyzed using repeated measure ANOVA. Results: There were significant main effects of group and exercises for the both VMO and VL (p<0.05). It was found that except SLR and D₂EX, in the other motions PFPS group had lower VMO activity compared to healthy group (p<0.05). For VL except SLR, in the other motions PFPS group had lower VL activity too (p<0.05). The PNF patterns activated VMO more than SLR, however it was not significant (p>0.05). Also; there weren''t any significant difference between the two groups in VMO/VL activation ratios. Also, performing the PNF patterns with load increased VMO and VL muscles activity significantly (p<0.05). It also found that in PFPS group the VMO/VL ratio values in PNF patterns were significantly more than SLR and the highest VMO/VL ratio value (0.96) was found during D₂EX. Conclusion: The PNF patterns due to provide optimal VMO/VL ratio value than SLR and proper balance between these two muscles can be recommended in rehabilitation of individuals with PFPS.     

旋转状态半受限冲射流流动和换热特性研究

利用数值模拟的方法,通过改变冲击雷诺数Rej(20000-35000)、旋转数Ro(0-0．0117)等参数,分析旋转条件下半受限单孔冲击射流的流动和换热特性,讨论了旋转对冲击射流的流场结构和换热特性的影响．研究结果表明:冲击射流在离心力和哥氏力的共同作用下发生弯曲,造成冲击靶面上的冲击斑随着旋转数Ro的增加而不断偏移,显著影响了冲击的冷却效果．冲击靶面的平均Nu数随着冲击雷诺数Rej的增加而增加;当旋转数Ro增加时,冲击靶面的平均Nu数先增加,后减小,然后再增加．计算结果和试验结论基本一致．     

Nine absorbed components pharmacokinetic of raw and processed Moutan Cortex in normal and blood-heat and hemorrhage syndrome model rats

Raw Moutan Cortex (RMC) and Processed Moutan Cortex (PMC) have a long history of use in China and other Asian countries. In this study, a rapid and accurate ultra-high-pressure liquid chromatography coupled with diode array detector (UHPLC–DAD) method was developed and validated for the simultaneous determination of nine absorbed compounds of RMC/PMC. After extraction by protein precipitation with methanol from plasma, the analytes were separated on an Acquity UPLC® BEH Shield RP₁₈ column (2.1 × 100 mm, 1.7 μm, Waters, USA). Acetonitrile (A) and 0.1% (v/v) formic acid in water (B) were selected as the mobile phase to perform gradient elution. The linearity of nine analytes was >0.9915. The intra- and inter-assay precision (RSD) values were within 11.18%, and accuracy ranged from 91.32 to 101.29%. Suitable stability, matrix effect and extraction recoveries were also obtained. The validated method was applied to compare the pharmacokinetics of RMC and PMC in Blood-Heat and Hemorrhage Syndrome Model and normal rats. The results revealed that processing and the pathological state could influence the pharmacokinetic characteristics of compounds in RMC/PMC. The study willbe useful for further studies on pharmacokinetics and clinical application of raw and processed Moutan Cortex.     

高Pr数液体圆形自由射流局部恢复系数及换热特性的实验研究

1前言射流冲击对流换热具有非常高的换热系数山，按工质种类可分为气体射流和液体射流。射流冲击特别是以液体为工质的射流具有极高的换热率山。在实际应用中，空气射流一般都具有较高的流速。在射流速度极高，不能忽略粘性耗散的情况下，要用壁面温度见与射流的绝热壁温Ta。之差来定义对流换热系数h：h二q八Tw一见。）（1）式中绝热壁温定义为Taw一Ti＋，。‘／（iC）（z）其中，为恢复系数，。为射流出口流速，or为定压比热，Ti为射流静温。对于射流冲击换热，上述公式最先在Gardon和Cobonpue关于高流速空气射流的文章问中报道，并为…     

补肾调肝方治疗围绝经期综合征患者血清微量元素变化的观察

为观察补肾调肝方治疗围绝经期综合征38例的临床疗效及对血清微量元素的影响,采用经验方补肾调肝方加味治疗,疗程3个月,对血清中的微量元素作了临床分析。结果表明,治疗后血清微量元素锌、铁、锰明显高于治疗前(P<0.01),临床有效率94.7%。提示补肾调肝方有改善人体血清微量元素的作用,并取得临床明显的疗效。     

儿童多动症与微量元素关系的探讨

为了探讨儿童多动症与微量元素的关系，测定了７２例多动症患儿头发中的六种元素Ｚｎ、Ｃｕ、Ｐｂ、Ｃｒ、Ｆｅ、Ｃａ含量，并将其与正常儿童进行比较，结果表明：多动症组Ｃｕ显著低于正常组，Ｐ〈０．０１，多动症组Ｚｎ显著低于正常组，Ｐ〈０．０５，多动症组Ｐｂ显著高于正常组，Ｐ〈０．０５。提示调整患儿体内微量元素平衡可作为治疗儿童多动症的辅助方法。