Optimization Design of Minimum Total Resistance Hull Form Based on CFD Method

In order to reduce the resistance and improve the hydrodynamic performance of a ship, two hull form design methods are proposed based on the potential flow theory and viscous flow theory. The flow fields are meshed using body-fitted mesh and structured grids. The parameters of the hull modification function are the design variables. A three-dimensional modeling method is used to alter the geometry. The Non-Linear Programming(NLP) method is utilized to optimize a David Taylor Model Basin(DTMB) model 5415 ship under the constraints, including the displacement constraint. The optimization results show an effective reduction of the resistance. The two hull form design methods developed in this study can provide technical support and theoretical basis for designing green ships.

Optimization of Extraction Process of Clerodendrum philippinum Schauer var. simplex Mlodenke Total Flavonoids(CPTF) by Central Composite Design-Response Surface Methodology

[Objectives] The research aimed to optimize extraction process of Clerodendrum philippinum Schauer var. simplex Mlodenke total flavonoids( CPTF),and provide reference for its development and utilization. [Methods] Based on single-factor test,ethanol concentration,extraction temperature and extraction time were taken as independent variables,and total flavonoids yield was taken as dependent variable. The test was conducted according to central composite design principle. Multivariate linear regression and binomial equation fitting of the result were conducted,and extraction process of CPTF was optimized by using response surface methodology. [Results]The optimal extraction process of CPTF was as below: ethanol concentration 54. 76%,extraction temperature 83. 92℃,extraction time 102. 64 min,solid-liquid ratio 1:20,extraction for twice. [Conclusions] The extraction process of CPTF by central composite design-response surface methodology was simple and feasible,with reliable prediction result,which was suitable for industrial production.

Extraction Process Optimization of Total Flavonoids from Mallotus apelta Stems by Central Composite Design/Response Surface Method

[Objectives] To optimize the extraction process of total flavonoids in stems of Mallotus apelta. [Methods]On the basis of singlefactor test,with volume fraction of ethanol,extraction time and ratio of solvent as independent variables,the content of total flavonoids as dependent variables,the completely secondary response surface regression fitting was conducted on the independent and dependent variables,and the Response Surface Method was used to optimize the optimum extraction process of total flavonoids in Mallotus apelta stems and predict the optimum process. [Results] The optimum extraction process of total flavonoids in Mallotus apelta was determined as follows: ethanol concentration of 71. 5%; extraction time of 154. 6 min; solid-liquid ratio of 1∶19. 2; total flavonoids content of 7. 060 mg/g; fitted binomial squared correlation coefficient R^2= 0. 8751.[Conclusions]Composite Design/Response Surface Method could be used in the extraction process optimization of total flavonoids in Mallotus apelta stems,the mathematical model established had high prediction accuracy,the method was simple and operability was good.

采用Box-Behnken Design优化玉米须总黄酮提取工艺

为获取玉米须中总黄酮的最佳提取工艺,采用Box-Behnken Design对微波辅助法进行了优化研究。通过建立二次多项式的预测模型,对影响总黄酮提取率的微波功率、提取时间、液固比分别进行研究。结果表明,微波功率240 W,提取时间11 min和液固比14 m L/g的参数条件下,实际提取率1.401%与模型理论预测值1.432%很接近。采用Box-Behnken Design优化后的工艺不仅总黄酮提取率高,而且省时、操作简单。

非对称型假体设计及全膝关节置换后的力学分析

背景:全膝关节置换是治疗膝关节晚期病症的有效手段,但假体衬垫容易因内部应力变化而产生磨损失效,寿命有限且术后患者的活动能力降低。如何对假体进行改进设计来满足患者更多的需求是假体研究的重要方向。目的:基于半月板的形态设计一种非对称型假体,并与对称设计的后稳定型假体进行比较,分析2种假体的应力分布情况和衬垫的接触面积变化,以探究非对称型假体设计是否存在优势。方法:通过有限元方法对1例膝骨关节炎患者进行模拟截骨和假体装配,建立基于非对称型假体及对称设计的后稳定型假体的全膝关节置换术后膝关节模型。在0°,10°,20°,30°的屈膝条件下,探究股骨假体、胫骨假体以及衬垫上的Mises应力,并通过对比衬垫内外侧的接触面积,分析全膝关节置换后膝关节生物力学变化和运动行为的改变。结果与结论:(1)在0°-30°的屈膝过程中,2种假体衬垫上的Mises应力峰值均表现出先减小后增大的趋势,且内侧始终大于外侧。(2)非对称型设计的假体与后稳定型假体相比,应力峰值更低;在屈膝30°时,非对称型假体衬垫内外侧的Mises应力峰值分别为15.81 MPa和11.95 MPa,后稳定型衬垫为16.70 MPa和13.76 MPa,两者内侧差值约为5.33%,而外侧则相差13.15%;对比股骨假体和胫骨假体上的Mises应力峰值,非对称型假体在屈膝过程中始终低于后稳定型假体。(3)在0°站立位时,后稳定型假体衬垫的内侧接触面积为17.96 mm^(2)、外侧为34.10 mm^(2);而非对称型假体衬垫的内外侧接触面积分别为105.47 mm^(2)和107.80 mm^(2),具有更大的接触面积且两侧差距更小。(4)结果表明,非对称型假体的生物力学表现更好,且能够对维持膝关节稳定性、提升关节活动度有所帮助。这种设计能够在一定程度上还原膝关节以内侧髁为轴进行外旋的运动机制,是一种更为有效的膝关节假体选择方案。

Application of Ecological Engineering Method in Urban Waterscape Design

According to the concept of three-dimensional design and landscape function,this paper used TD(Total Design)to analyze ecological engineering method in urban riverfront landscape projects,by taking landscapes of Chuhe River in Liuhe District,Nanjing City for example.

ANALYSES OF ENERGY LOSSES AND ACCUMULATOR AND PARAMETERS DESIGN METHOD OF HYDRAULIC IMPACTOR MECHANISM

ＡＮＡＬＹＳＥＳＯＦＥＮＥＲＧＹＬＯＳＳＥＳＡＮＤＡＣＣＵＭＵＬＡＴＯＲＡＮＤＰＡＲＡＭＥＴＥＲＳＤＥＳＩＧＮＭＥＴＨＯＤＯＦＨＹＤＲＡＵＬＩＣＩＭＰＡＣＴＯＲＭＥＣＨＡＮＩＳＭ￥Ｈｅ，Ｑｉｎｇｈｕａ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｃｈａｎｉｃａｌＥｎ...

The Effects of Design Parameters on the Resistance of High Speed Monohull

The paper puts forward a method of predicting the calm water total resistance of the high speed displacement ship with transom stern.The hull surface is defined by mathematical function and design parameters.The effects of design parameters on the total resistance are discussed.

Changes in Femoral Stem Geometry Reduce Intraoperative Femoral Fracture Rates in Total Hip Replacement

Intraoperative fracture rates in total hip arthroplasty (THA) have been associated with uncemented stems, anterolateral surgical approach, diagnoses other than osteoarthritis, and female gender. The purpose of this study was to investigate if changes in stem design would influence intraoperative fracture rates. 1497 THA with Bi-Metric stems were compared to 1277 THA with Echo Bi-Metric Full Proximal Profile stems and 366 THA with Echo Bi-Metric Reduced Proximal Profile stems. The intraoperative fractures rates were 5.48%, 1.41% and 1.37% for Bi-Metric and Echo Bi-Metric with standard and reduced proximal geometry stems, respectively. Stem survivorship with aseptic loosening as an endpoint was 100% in all cohorts at the final follow-up. We conclude that changes in femoral stem geometry in uncemented THA reduce intraoperative fracture rates while preserving fixation.

Central-Composite Design响应面实验设计用于金盏菊提取工艺的研究

目的:确定金盏菊最佳提取工艺条件。方法:以金盏菊中总黄酮含量及浸膏得率为考察指标,应用中心组合(Central composite design,CCD)响应面实验设计,考察药材与提取溶剂的比例(料液比)、乙醇浓度、提取时间对金盏花提取效率的影响。结果:根据二项式拟合方程,确定金盏花最佳提取工艺条件为药材与溶剂的比例为1∶12,乙醇浓度为68%,提取时间为1.8 h,提取两次。结论:中心组合响应面实验设计能够对金盏菊的提取工艺进行优化筛选。

Central Composite Design响应面法优化厚裂凤仙花总黄酮提取工艺研究

为厚裂凤仙花中总黄酮资源的开发利用,本文采用单因素与星点-效应面法相结合的方式,考察提取溶剂浓度、料液比、提取时间、提取次数对厚裂凤仙花中总黄酮提取率的影响。优选出厚裂凤仙花总黄酮最佳提取方法为:甲醇体积分数80%,料液比为1︰64,提取时间为50 min;提次数为3次;验证实验结果表明,总黄酮平均提取率为5.51 mg/g,与实验模型RSD值为0.79%。建立的模型与实际方案有较高拟合度,可作为苗药厚裂凤仙花总黄酮提取工艺参数。

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and orthogonal design were adopted to study the extraction technology for total phenols of leaves in Acanthopanax giraldii Harms. [Results]The optimum extraction conditions were determined as follows: extraction solvent( 70% methanol),solid-liquid ratio( 1∶ 35),and reflux extraction time( 60 min). Under these conditions,the yield of crude extract from total phenols of leaves in Acanthopanax giraldii Harms was 38. 67 mg/g.[Conclusions] The technology was simple,and of low cost and high extraction rate,suitable for the extraction of total phenols of leaves in Acanthopanax giraldii Harms.

大亳菊总黄酮的提取及其颗粒剂制备工艺研究

优选大亳菊总黄酮的提取及其颗粒剂制备工艺。采用正交试验,以总黄酮提取率为判断标准,优选大亳菊总黄酮的提取工艺;以成型率为判断标准,优选大亳菊总黄酮颗粒剂的制备工艺。结果表明,优选的大亳菊总黄酮提取工艺为:液料比为25∶1,乙醇体积分数75%,提取温度85℃,回流时间1.25h;优选的制粒工艺为:可溶性淀粉∶糊精=1∶1,浸膏粉∶辅料=1∶3,干燥温度60℃,干燥时间2h。该工艺简便、稳定,可以用于大亳菊总黄酮的提取及其颗粒剂的制备。

基于胆碱类低共熔溶剂高效提取香附总黄酮的研究

目的:采用胆碱类低共熔溶剂高效提取香附药效组分总黄酮。方法:通过中心组合设计法,对胆碱类低共熔溶剂的性质(种类、组分摩尔比、含水量)、提取温度、提取时间、液料比等因素进行分析。结果:研究发现,香附总黄酮的最佳提取条件为:以氯化胆碱为氢键供体,以丙三醇为氢键受体,摩尔比1∶2,含水量20%,配比1∶4,水比例30%,提取温度80℃,提取时间40 min,液固比为15 mL/g。结论:本研究提示可将胆碱类低共熔溶剂作为可持续、高效的天然提取介质应用于香附药效组分的提取。

基于总安全系数法的喷射混凝土支护承载能力的试验研究

为验证总安全系数法中喷层的荷载结构模型及其安全系数计算方法,研制大型隧道结构模型试验系统,采取结构试验的方法,开展毛洞、不同厚度喷层以及二次衬砌的加载破坏试验。通过围岩和细砂材料的三轴试验明确模型试验中各材料的物理与力学参数,模拟毛洞、不同厚度喷层以及二次衬砌的加载破坏全过程,依据破坏状态明确喷层与二次衬砌的设计承载能力,试验中监测围岩应力应变、喷层内外侧应变和喷层位移,结合监测结果分析喷层与二次衬砌在承载过程中的变形特征与受力特征,明晰喷层与二次衬砌的承载机制,并与总安全系数法理论计算结果进行对比分析。结果表明:1)在试验断面条件下喷层受力状态为小偏心受压,喷层与围岩之间的粘结能有效传递剪力,从而减少了喷层的弯矩,有利于充分发挥喷层的抗压强度,同厚度情况下喷层的设计承载力要高于二次衬砌;2)试验得到的厚度为2 cm和4 cm喷层的设计承载力比总安全系数法理论计算结果分别大27.0%和22.9%,表明总安全系数法的喷层承载力计算模型是合理的,并具有合适的安全性。

Influence of the Different Prosthesis Designs on Subjective Functional Evaluation after TKA: Medium-Term Outcome Using the 2011 Knee Society Score

Background: Patient-reported outcome (PRO) has become the focus of increased attention in the assessment of total knee arthroplasty (TKA). The purpose of this study was to investigate whether different prosthesis designs affected postoperative patient-reported performance. Materials and Methods: We reviewed 216 patients (234 knees) implanted with the Press-Fit Condylar Sigma prosthesis at our institution between January 2009 and December 2011. This study included 76 knees with fixed-bearing cruciate-retaining (FB-CR), 78 knees with fixed-bearing posterior-stabilized (FB-PS), and 80 knees with mobile-bearing posterior-stabilized (MB-PS) designs. The mean follow-up was 8.0 ± 0.74 years. Preoperative and follow-up ratings according to the 2011 Knee Society Score (2011 KSS), range of motion (ROM), and standing femoro-tibial angle (FTA) were obtained for all patients. Additionally, Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were collected at last follow-up. Results: Three separate subscales of the 2011 KSS of the three cohorts were significantly improved post-operatively compared to the pre-operative values (p < 0.05), except for expectation scores. At the time of follow-up, significantly higher the 2011 Knee Society Functional Scores <2011 KSFS> (P = 0.016) were found in the PS group. In particular, there were significant differences in advanced activities of the 2011 KSFS among the three groups (P = 0.017). Satisfaction scores showed no difference among the three groups (P = 0.251). On the other hand, WOMAC and expectation scores were significantly better in the PS groups. (P = 0.003, P = 0.004). ROM in the MB-PS group (124.0°) was better than that in FB-PS (119.4°) and FB-CR (118.9°) (P = 0.005). On the other hand, additional surgery was needed in five PS knees. Conclusion: The PS prostheses had superior 2011 KSFS, expectation scores, WOMAC scores and ROM than the CR prostheses. In contrast, the postoperative prosthesis-related complication rates were lower with CR prostheses. Further detailed evaluation is necessary to determine whether the characteristics of the different prostheses affect PRO.

雾水葛总黄酮的提取工艺优化及其对线虫应激能力的影响

目的 正交法优化雾水葛总黄酮的提取工艺,探究其对秀丽隐杆线虫抗应激能力的影响。方法采用NaNO_(2)-Al(NO_(3))_(3)-NaOH显色法测定雾水葛中总黄酮的质量分数,以雾水葛总黄酮提取率为指标,通过单因素考察及正交试验考察时间、温度、料液比、乙醇体积分数对总黄酮提取率的影响,优选出最佳提取工艺。设立给药组和空白组,通过观察线虫头摆动次数、H_(2)O_(2)氧化应激、抗热应激试验探究总黄酮对秀丽隐杆线虫抗应激能力的影响。结果最佳提取工艺:提取时间为40 min,提取温度为70℃,乙醇体积分数为60%,料液比为1∶40 (g∶mL),总黄酮提取率实测值为1.31%。给药组线虫头摆动次数明显多于空白组(P<0.01)。雾水葛总黄酮质量浓度为0.300 mg/mL时,给药组在氧化应激和热应激实验中平均寿命比空白组分别延长32.28%、42.96%。结论超声法操作简单、便捷、提取率高,提取所得总黄酮能增强秀丽隐杆线虫应激能力。

重型燃气轮机侧向进气蜗壳参数化设计方法研究

重型燃气轮机侧向进气蜗壳会带来额外进气损失并产生进气畸变,这将会影响压气机的效率和稳定性,进而影响整机效率。目前侧向进气蜗壳的设计仍以经验设计为基础,并未形成系统化的侧向进气蜗壳参数化设计方法,尚无各关键无量纲参数的推荐取值范围。该文基于传统的蜗壳设计理论,针对侧向进气道蜗壳进行简化设计,并通过数值模拟方法研究其内部流动机理,明确进气蜗壳内的流动损失主要来自导流锥两侧的剪切涡、支板绕流涡和收缩段边界层。在此基础上,提出一种参数化设计方法,研究几何结构对进气蜗壳总压损失和出口气流不均匀性的影响。结果表明,收缩段入口直径、锥底直径和锥角对进气蜗壳气动性能影响较大。最后,该文给出各设计参数的推荐取值范围,可为未来高性能侧向进气蜗壳设计准则制定提供基础。

Box-Behnken Design响应面法优化银杏叶总黄酮柱层析纯化工艺

为得到质量分数较高的银杏叶总黄酮提取物,在单因素试验基础上,以上样质量浓度、乙醇体积分数、洗脱液接收体积和洗脱流速为考察因素,以银杏叶总黄酮质量分数、收率为考察指标,采用BBD(Box-Behnken Design)响应面法对银杏叶总黄酮柱层析纯化工艺进行优化。得到最佳工艺为上样质量浓度3.1 mg/mL,乙醇体积分数71%,洗脱液接收体积2 BV(BV为装柱体积)及洗脱流速2 BV/h。在最佳工艺条件下,完成三批验证实验,银杏叶总黄酮平均质量分数可达到35.77%,收率为93.30%,银杏总内酯质量分数达到《中国药典》标准。利用BBD响应面法优化银杏叶总黄酮柱层析纯化工艺是科学、合理、可行的,可为工业化大生产提供参考。

芩莲正积方水提物中总黄酮提取工艺的优化

本文旨在研究芩莲正积方水提物中的总黄酮提取工艺。实验采用水提法,以芩莲正积方总黄酮提取率为指标,通过单因素实验和正交实验考察浸泡时间、提取温度、提取次数、提取时间和料液比对方中总黄酮提取率的影响。芩莲正积方水提物中总黄酮的最佳提取工艺为:浸泡时间0h、提取次数1次、提取温度90℃、提取时间60min、料液比1∶20,在该提取工艺下得到的芩莲正积方水提物中总黄酮提取率最高为6.76%。