High-speed penetration of ogive-nose projectiles into thick concrete targets:Tests and a projectile nose evolution model

The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 mm.This study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic penetration.In the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/s.Severe erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered projectiles.By examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration tests.Furthermore,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation mechanism.Finally,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present study.Depending upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or hemispherical.Due to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.

Investigation on taste characteristics and sensory perception of soft-boiled chicken during oral processing based on electronic tongue and electronic nose

The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.

Stability Analysis of Nonlinear Models of Nose Landing Gear Shimmy

Shimmy can reduce the service life of the nose landing gear, affect ride comfort, and even cause fuselage damage leading to aircraft crashes. Taking a light aircraft as the research object, the torsional freedom of landing gear around strut axis and lateral deformation of tire are considered. Since the landing gear shimmy is a nonlinear system, a nonlinear mechanical model of the front landing gear shimmy is established. Sobol index method is proposed to analyze the influence of structural parameters on the stability region of the nose landing gear, and Routh-Huritz criterion is used to verify the reliability of the analysis results of Sobol index method. We analyse the effect of torsional stiffness of strut, caster length, rated initial tire inflation pressure, rake angle, and vertical force on the stability region of theront landing gear. And the research shows that the optimization of the torsional stiffness of the strut and the caster length of the nose landing gear should be emphasized, and the influence of vertical force on the stability region of the nose landing gear should be paid attention to.

DRGs下的腹腔镜结直肠癌NOSES手术改进

目的:探讨在(疾病)诊断相关分类(diagnosis related groups,DRGs)形势下,腹腔镜结直肠癌经自然腔道取标本(NOSES)手术方式改进及其可行性。方法:回顾性分析安阳市肿瘤医院2019年2月至2021年2月实施DRGs的42例改进后的腹腔镜结直肠癌NOSES术,并与同期进行常规腹腔镜结直肠癌手术的238例患者在费用、治疗结果、并发症等方面相比较。结果:NOSES改进组42例患者DRGs控费成功率为95.2%(40/42),与常规腹腔镜组在DRGs费用及近期并发症发生率方面无显著性差异(P>0.05)。结论:腹腔镜结直肠癌NOSES改进手术可以达到DRGs费用标准,手术安全可靠,应用双7号丝线代替部分直线切割闭合器是可行的。

常规腹腔镜手术与NOSES术对结直肠癌患者术后康复对比观察

目的分析结直肠癌患者采用常规腹腔镜手术和NOSES术(经自然腔道取标本手术)治疗的临床效果,及对患者术后康复状态的影响。方法选取我院治疗结直肠癌46例患者进行分组,对照组采用常规腹腔镜手术治疗,研究组实施NOSES术进行医治,观察两组手术不同时段的应激反应指标[丙二醛(MDA)、超氧化物歧化酶(SOD)]、疼痛程度(VAS)、生活质量(EORTC QLQ-C30)改善状况,对比两组患者术后并发症发生情况。结果两组间术前SOD、MDA水平、VAS、EORTC QLQ-C30评分与术后并发症发生率对比差异不明显(P>0.05),研究组术后MDA水平,及1 w的VAS评分、EORTC QLQ-C30评分与对照组对比均较低,但术后SOD水平则比对照组高,组间差异比较显著(P<0.05)。结论结直肠癌患者采用经自然腔道取标本手术治疗,可改善患者的应激反应,缓解患者疼痛症状,提高患者的生活质量水平,治疗效果良好,有助于患者术后康复。

Analysis of the changes of volatile flavor compounds in a traditional Chinese shrimp paste during fermentation based on electronic nose,SPME-GC-MS and HS-GC-IMS

Traditionally fermented shrimp paste has a long fermentation period and is susceptible of external factors,which leads to unstable quality and limits its development and application.Therefore,the purpose of this study is to analyze the flavor changes in the shrimp paste fermentation process and screen out the key volatile aroma components in the shrimp paste to control the flavor quality of the shrimp paste products.The overall odor profile was detected by the electronic nose.A total of 106 volatile flavor compounds in the shrimp paste samples at different fermentation stages were identified by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)and headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS).The main aroma components alcohols,aldehydes,pyrazines and other substances in the fermentation process showed an overall upward trend.A total of 17 key volatile aroma components in shrimp paste at different fermentation stages were identified by the relative aroma activity value(ROAV)method.The combination of electronic nose,SPME-GC-MS and HS-GC-IMS could comprehensively reflect the changes of volatile components in shrimp paste at different fermentation stages,which helps to further understand the mechanism of shrimp paste flavor formation and provides a basis for the regulation of the flavor quality of shrimp paste products.

机器人NOSES手术在直肠癌治疗中的应用现状

机器人手术操作系统在直肠癌治疗中的应用在国内外逐渐开展,但仍需要通过辅助切口取出标本。随着经自然腔道取标本手术(NOSES)的兴起,机器人手术操作系统与NOSES结合在直肠癌外科治疗领域取得了良好的临床疗效。该文就机器人NOSES手术在直肠癌治疗中的应用现状作一综述。

Revision rhinoplasty for contracted nose:A systematic review and meta-analysis

Background:This study aimed to review treatments and evaluate the aesthetic outcomes,complications,and reoperation rates regarding surgical correction for a postoperative contracted nose.Methods:PubMed,MEDLINE,and Embase databases were searched for studies detailing aesthetic outcomes and complications of surgical correction of a contracted nose.Surgical procedures,adjuvant treatment,outcomes,and complications were synthesized and analyzed.Results:Nine articles encompassing 376 patients were included in the systematic review,and six articles(198 participants)were included in the meta-analysis.The most frequently used graft material was the autologous rib cartilage(61.1%).Surgical procedures were heterogeneous in these studies.The nasolabial angle reduced by 9.52°(95%confidence interval(CI):(-11.95,-7.09),P<0.0001),and the nasal length increased significantly(standardized mean difference(SMD)=2.25,95%CI:(1.26,2.23),P<0.00001).However,the evidence was insufficient to determine a significant change in the columellar-labial angle(SMD=-0.95,95%CI:(-2.19,0.29),P=0.13)and columellar-lobular angle(SMD=2.39,95%CI:(-1.20,5.97),P=0.19).Aesthetic dissatisfaction(12.5%)and infection(4.5%)were the most commonly reported complications.Reoperation was performed in 5.3%of patients.Conclusion:Surgical correction can increase the nasal length,reduce the nasolabial angle,and have a low reoperation rate.No significant improvement in the columellar-labial or columellar-lobular angle was observed.

Acute Mastoiditis Clinical Course and Management in Patients Presented to Khartoumar Ear, Nose and Throat Hospital during the Period from November 2017 to November 2019

Introduction: Acute mastoiditis is the most common complication of Acute Otitis Media (AOM) and it’s the cause of serious morbidity. There is no standard universally agreed-upon management approach to acute mastoiditis. This study aims to view the clinical presentation and management approaches in Khartoum Ear, Nose and Throat Hospital. Methodology: This is a prospective case series and a hospital-based study conducted at Khartoum Ear, Nose and Throat Hospital during the period from November 2017 to November 2019. A total of 61 patients were included in the study. Results: The median age at presentation is 5 years old, males are more affected than females with a ratio of 1.35:1, and the mean duration of symptoms prior to hospital admission was 9.6 days. The most common presenting symptoms were otalgia (83.3%), ear discharge (83.3%) and post-auricular swelling (83.3%), and the most common signs at admission were tenderness over the mastoid (95.1%), retroauricular swelling and protrusion of the auricle (82%), and redness over the mastoid (77%). The abnormal tympanic membrane was found in all patients with central perforation being the commonest finding (73.8%), and bulging tympanic membrane (21.3%). 34.4% of patients received oral antibiotics before admission and the mean duration of symptoms prior to admission increased significantly in those who received antibiotics 12.7 days in comparison to those who didn’t 8.3 days. Only 52.5% of patients had a past history of recurrent acute otitis media, and 8.2% had a past history of acute mastoiditis. All the patients with recurrent mastoiditis had a past history of recurrent acute otitis media. Computed Tomography (CT) scans were obtained for 50.8% and 83.9% of those scans showed coalescent mastoiditis. Further evidence of intracranial extension was found in 6.5% and Magnetic Resonance Imaging (MRI) was obtained for them. Of the study group, 67.2% presented with subperiosteal abscess, 4.9% with facial nerve palsy and 3.3% with brain abscess. Thirteen patients with no complications were managed initially with injectable and topical antibiotics and were successful in only 6 of them (46%), abscess incisions and drainages were needed in 46 patients and were successful in 34 of them (73.9%). Eighteen patients (29.5%) needed mastoidectomy and all of them were managed successfully (100%). One patient (1.6%) was referred for intracranial abscess drainage in a specialized hospital, also one patient (1.6%) initially presented with intracranial abscess died on the second day of admission and 96.8% were discharged in good condition. The mean duration of hospital stay was 7.5 days. Conclusion: Patients present to the hospital after a prolonged period with a higher rate of complications, and the delayed presentation increased significantly in patients who received oral antibiotics prior to admission. Conservative medical treatment in non-complicated acute mastoiditis was ineffective in more than half of the patients and abscess incision and drainage and/or mastoidectomy are often necessary for the management.

经直肠NOSES手术对结直肠癌的疗效

探讨经直肠经自然腔道取出标本手术(NOSES)手术对结直肠癌的影响。方法 共需为研究确立80例参与者,在选取阶段,需要注意两个要素,一个是需要对患者的患病情况进行确定,也就是说每一位都必须是结直肠癌患者,另一个就是针对时间而设置的限制,2017.8~2022.8是可纳入区间,上述工作完成后,根据方案,设置组别,数量为2,人数平分。对照组:腹腔镜下直肠癌根治术,观察:经直肠NOSES手术。结果 观察组结直肠癌患者的首次排气天数、切口长度、首次下地天数和术后VAS评分明显低于对照组(P<0.05);术后1个月,两组结直肠癌患者的RRP和MSP均明显降低(P<0.05),且两组结直肠癌患者的RRP和MSP无明显差异(P>0.05);术后1周,两组结直肠癌患者的胃泌素和前列腺素E2水平均明显降低(P<0.05),且观察组结直肠癌患者的胃泌素和前列腺素E2水平明显低于对照组(P<0.05);两组结直肠癌患者术后1周的不良反应发生情况比较接近(P>0.05)。结论 经直肠NOSES手术对结直肠癌患者有较好的疗效。

基于E-nose、HS-SPME-GC-MS和GC-IMS检测三种草莓鲜榨汁的香气

不同草莓品种鲜榨汁风味存在较大区别,风味特征会直接影响草莓鲜榨汁消费者接受度和经济价值。本研究以妙香3号草莓、红颜草莓和黔莓2号草莓为研究对象,利用电子鼻(Electronic nose,E-nose)、顶空固相微萃取-气相色谱-质谱联用(Headspace Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry,HS-SPME-GC-MS)和气相色谱-离子迁移谱(Gas Chromatography-Ion Mobility Spectrometry,GC-IMS)对三种草莓鲜榨汁的挥发性风味物质进行定性和定量分析。结果表明,三种草莓鲜榨汁中挥发性风味物质含量和种类有明显差别。电子鼻可以有效区分三种草莓鲜榨汁;HS-SPME-GC-MS检测出89种挥发性风味物质,包括55种酯类、9种醛类、7种醇类、13种酮类和5种酸类。其中22种挥发性风味物质是三种草莓鲜榨汁共有的,包括11种酯类、4种醛类、芳樟醇、5种酮类及壬酸。妙香3号鲜榨汁中5-己基二氢-2(3H)-呋喃酮含量较高,红颜草莓鲜榨汁中乙酸己酯和(Z)-乙酸-2-己烯-1-醇酯含量较高,黔莓2号草莓鲜榨汁中乙酸甲酯、丁酸甲酯、己酸甲酯、己醛、(E)-2己烯醛、芳樟醇和4-甲氧基-2,5-二甲基-3(2H)-呋喃酮含量较高。GC-IMS检测出60种挥发性风味物质,包括24种酯类、12种醛类、7种醇类、10种酮类、2种呋喃和5种其他物质。丁酸乙酯、乙酸异丙酯、2-己烯醛、1-戊烯-3-醇含量在三种草莓鲜榨汁中含量均较高,是形成草莓风味特性的关键物质。

腹腔镜下结直肠癌NOSES术中保留左结肠动脉的中远期疗效观察

目的观察腹腔镜下结直肠癌经自然腔道取标本手术(NOSES)中保留左结肠动脉(LCA)的中远期临床疗效。方法回顾性分析2016年7月至2021年12月于四川省肿瘤医院行NOSES的155例直肠、乙状结肠癌患者的临床资料,根据术中是否保留LCA将其分为保留LCA组(80例)和不保留LCA组(75例),比较两组术后复发、转移及中远期生存情况。结果保留LCA组随访4~65个月,不保留LCA组随访7~71个月。在随访期间发生局部复发或远处转移保留LCA组4例(5.1%),不保留LCA组7例(9.5%)。两组无病生存期(DFS)比较差异无统计学意义(P>0.05)。进一步以TNM分期进行分层分析,两组Ⅰ、Ⅱ、Ⅲ期患者的DFS比较差异亦无统计学意义(P>0.05)。保留LCA组死亡2例(2.5%),不保留LCA组死亡2例(2.7%),两组总生存期(OS)比较差异无统计学意义(P>0.05)。以TNM分期进行分层分析,两组Ⅰ、Ⅱ、Ⅲ期患者的OS比较差异均无统计学意义(P>0.05)。结论腹腔镜结直肠癌NOSES中严格遵守肿瘤外科手术原则,在保留LCA的同时彻底清扫肠系膜下动脉根部的淋巴结不会影响结直肠癌患者的中远期治疗效果。

NOSES在ERAS理念下对左半结肠癌患者术后应激与康复的影响

目的探讨在加速康复外科(enhanced recovery after surgery concept,ERAS)理念下经自然腔道取标本手术(natural orifice specimen extraction surgery,NOSES)对左半结肠癌患者术后应激指标及恢复的影响。方法选取2019年10月~2020年8月大连大学附属中山医院收治的60例左半结肠癌患者,采用随机数字表法将其分为NOSES+ERAS组(n=31)和ERAS组(n=29)。NOSES+ERAS组患者采用在ERAS理念下的NOSES,ERAS组患者采用在ERAS理念下的腹腔镜结肠癌根治术。比较两组患者的术后临床恢复指标(术后首次排气时间、进流食时间、首次排便时间、术后住院时间),实验室检查指标[白细胞计数(white blood cell,WBC)、C反应蛋白(C-reactive protein,CRP)、白细胞介素-6(interleukin-6,IL-6)、血清淀粉样蛋白A(serum amyloid A protein,SAA)],术后并发症的发生情况以及术后疼痛数字分级评分(numerical rating scale,NRS)。结果与ERAS组比较,NOSES+ERAS组患者的术后首次排气时间、进流食时间、首次排便时间及住院时间均缩短(P均<0.05);术后第3天的WBC降低(P<0.05),术后第1、3、5天的CRP、IL-6、SAA水平降低(P<0.05);术后并发症发生率降低(P<0.05);术后12、24、48h的疼痛NRS评分降低(P<0.05)。结论NOSES在ERAS理念下可以有效减少左半结肠癌患者术后疼痛、住院时间、首次排气时间、首次排便时间、进流食时间,降低机体炎症,减少瘢痕,促进患者恢复。

基于HS-SPME-GC-O-MS和E-nose解析不同热加工方式下西瓜籽特征性香气差异

目的:解析不同热处理下西瓜籽风味差异.方法:借助顶空固相微萃取—气相色谱—嗅闻—质谱技术(HS-SPME-GC-O-MS)和电子鼻(E-nose)分析技术.结果:热加工使西瓜籽由浅淡的清香向浓郁的烤香转变;基于HS-SPME-GC-O-MS共检测到18类115种挥发性化合物,其中吡嗪类、醇类和醛类分别占总挥发性物质含量的34.25%,21.07%,10.99%;微波处理后西瓜籽中挥发性化合物高达63种,且吡嗪类物质占挥发性物质含量的53.31%.结论:热加工方式对西瓜籽香气影响显著,对比空气油炸和烘制加工,微波处理后西瓜籽香气更为浓郁.

Nose-to-nose校准技术的理论分析

Nose- to- nose校准技术的理论基础是 :kick -out脉冲正比于取样示波器系统的冲激响应 .Janverspecht博士和美国国家标准技术研究院 (NIST)用S参数法对此进行了详尽的分析 .本文从电路理论分析入手 ,对kick- out脉冲产生的机理重新进行了分析 ,得出了十分有用的数学表达式和结论 :kick out脉冲不仅与电路参数有关 ,而且与选通脉冲有关 .这一结论并被计算机的仿真所证实 ,这用以前的理论是无法解释的 .

用于宽带取样示波器的Nose-to-nose校准技术

介绍一种宽带系统校准的新方法 ,对比几种传统的校准方法 ,这种称为nose to nose的校准方法是目前校准精度最高的一种 .这项技术所基于的一个基本事实是 :当示波器的取样电路对直流电压取样时 ,会产生一个极窄的脉冲到输入端 ,这个脉冲正比于系统的冲激响应 ,称为kick out脉冲 ,这样将两台示波器的输入端对接就在第二台示波器上得到了含有两台示波器冲激响应的卷积输出 ,应用反卷积算法可以得到这两台示波器的冲激响应函数 .

基于Nose-to-Nose校准法的取样示波器冲激响应的一种算法

本文根据时变电路概念和信号与电路系统理论 ,利用Nose to Nose(NTN)校正法 ,对取样示波器的双二极管平衡型取样电路建立了时变线性电路模型 ,导出了kick out脉冲和取样系统冲激响应的时域表达式 ,证明了该脉冲是NTN校正中的零输入响应而非冲激响应 ,提出了从kick out脉冲中提取时间常数从而确定取样器冲激响应的新的数据处理方法与公式 ,有效地解决了NTN校正中取样管结电容变化对校正精度的影响问题 .

取样示波器nose-to-nose校准技术中kick-out脉冲的研究

研究了nose-to-nose校准技术中关键信号kick-out脉冲产生的机理以及影响因素,并通过将两台Agilent86100系列的50GHz的取样示波器对接,获得了kick-out脉冲的响应波形.

Using an Electronic Nose to Rapidly Assess Grandlure Content in Boll Weevil Pheromone Lures

Samples of pheromone lures used in boll weevil, Anthonomus grandis （Boheman）, eradication programs are routinely analyzed by Gas Chromatography （GC） to ensure lures are adequately dosed with grandlure, the synthetic aggregation phero- mone produced by male weevils. However, preparation of GC samples is tedious, time consuming, and requires a moderate level of experience. We examined the use of a commercially-available electronic nose （e-nose） for rapidly assessing the grandlure contents of lures. The e-nose was trained to recognize headspace collections of grandlure emitted from new lures and after lures were aged under field conditions for 4 d, 7 d, 10 d, and 14 d. Based on cross-validation of the training set, the e-nose was 82% accurate in discriminating among the different age classes of lures. Upon sampling headspace collections of pheromone from a different set of field-aged lures, the e-nose was 〈50% accurate in discriminating 4 d, 7 d, and 10 d aged lures from the other age classes of lures. However, the e-nose identified new and 14 d aged lure samples with 100% accuracy. In light of these findings, e-nose technology shows considerable promise as an alternative approach for rapidly assessing the initial grandlure contents of lures used in boll weevil eradication programs.

Nose-to-Nose校准技术的仿真研究

N ose-to-nose校准技术可以对任意带宽的取样示波器进行自校准.早期的研究工作集中在对关键信号k ick-ou t脉冲的仿真.本文从不同的角度对微波二极管取样头电路进行了全面的仿真,得到了结论:k ick-ou t脉冲是由于在取样电路的不平衡时选通脉冲的泄漏造成的.并对NTN校准技术从仿真实验到物理实验做了介绍.