78 research outputs found

    Current Status and Expectation on Research for Ellobiid

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    耳螺(EllObIId)是一类特殊的原始有肺类软体动物,大多嗜盐,主要分布于海陆过渡区的高潮带和潮上带。耳螺在软体动物进化史上具有特殊地位,并且因其对环境变迁和人为干扰十分敏感,可作为环境评估的重要指标种。过去2个多世纪,众多学者已经对耳螺的形态学、解剖学、分类学和生态学等开展了系统的研究。本文概述了耳螺研究的3个阶段:起步阶段(18世纪末至20世纪30年代初)、发展阶段(20世纪30年代初至70年代末)和成熟阶段(20世纪80年代至今),最后总结了耳螺研究中存在的不足,并对未来研究方向进行展望。Ellobiid is a special group of mollusks with primitive lung.Most of them are halophilic and mainly found in high tidal and supratidal zone in the transitional zone between land and sea.Ellobiid has a unique position in the mollusk evolutionary history.They can be used as indicators in environmental assessments due to their sensitivity to environmental changes and to human disturbances.During the past two centuries,many scholars had carried out systematic research on Ellobiid,including morphology,anatomy,taxonomy and ecology.This article outlined the three study stages on the Ellobiid: initial stage(from late 18th century to early 1930s),development stage(from early 1930s to late 1970s) and mature stage(1980s to present).Finally,this paper points out the insufficiency of those studies and some prospects for future research on this group.国家自然科学基金项目(No.40876046

    Video-assisted Thoracoscopic 3D Mode Operation for Solitary Pulmonary Nodules

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    目的探讨三维胸腔镜手术(3d VIdEO-ASSISTEd THOrACIC SurgEry,3d-VATS治疗孤立性肺结节(SOlITAry PulMOnAry nOdulE,SPn)的效果。方法回顾性分析2013年3月~2014年3月50例SPn的资料,采用3d-VATS手术模式楔形切除结节,根据快速病理结果决定是否行肺叶切除加淋巴结清扫术。统计手术时间(去除快速冰冻时间)、术后24 H引流量、总引流量、引流管拔除时间、淋巴结清扫数及术后并发症等。结果 3d-VATS模式下,50例均行肺结节楔形切除,其中23例病理为恶性,继续行肺癌根治术,手术顺利。肺癌根治术手术时间(62±12)MIn,术中出血量(35±5)Ml,清扫淋巴结(19±3)个,术后24 H引流量(120±20)Ml,术后胸管引流时间(4±1)d,术后住院时间(7±2)d。并发症3例,其中术后肺炎2例,阵发性心房纤颤1例,均治愈。无围手术期死亡。随访2~12个月,平均6.3月。1例术后3个月脑转移,1例术后5个月肺癌复发。结论胸腔镜3d模式下治疗SPn是一种新的选择方式,安全可行,值得推广应用。Objective To evaluate the effects of surgical treatment for solitary pulmonary nodules under thoracoscopic 3D mode(3D-VATS).Methods A total of 50 cases of solitary pulmonary nodules from March 2013 to March 2014 were retrospectively analyzed.Intraoperative wedge pulmonary resection with 3D-VATS was utilized.According to intraoperative pathological findings,lobectomy plus lymph node dissection was given or not.Intraoperative time( minus fast freezing time),drainage volume for 24 h,total drainage volume,drainage tube removal time,number of lymph node dissected,and postoperative complications were recorded.Results Under 3D-VATS mode,50 cases of solitary pulmonary nodules were treated with wedge resection,including 23 cases of malignant pathology receiving radical resection, which was smoothly.The radical resection time( lung lobectomy plus lymphadenectomy) was(62 ± 12) min,the bleeding volume was(35 ± 5) ml,the lymphadenectomy number was 19 ± 3,the drainage volume for 24 h was(120 ± 20) ml,the postoperative chest tube removal time was(4 ± 1) days,and the postoperative hospital stay was(7 ± 2) days.Postoperative complications occurred in 3 cases,including 2 cases of pneumonia and 1 case of paroxysmal atrial fibrillation.No perioperative deaths were observed.All the cases were followed up for 2- 12 months,with an average of 6.3 months.Brain metastases was found in 1 case at the third postoperative month and recurrence of lung cancer was noted in 1 case at the fifth postoperative month.Conclusion Thoracoscopic 3D mode treatment for solitary pulmonary nodules is a new,safe,and feasible alternative and should be widely applied

    Combined Use of Thoracoscopy and Laparoscopy in Total Laryngectomy for Cervical Esophageal Carcinoma

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    目的探讨胸、腹腔镜联合全喉切除治疗颈段食管的可行性和疗效。方法 2009年1月~2014年7月胸、腹腔镜联合全喉切除治疗33例颈段食管癌。胸腔镜下分离食管、腹腔镜下管胃成形、全喉切除、气管永久造口、胃咽吻合术。结果胸部手术时间40~66 MIn,平均53 MIn;腹部手术时间35~51 MIn,平均44 MIn;颈部手术时间128~150 MIn,平均139 MIn。术中出血量130~270 Ml,平均150 Ml。术后住院时间8~14 d,平均12 d。病理均为鳞状细胞癌,其中高分化2例,中分化19例,中-低分化7例,低分化5例。切缘病理学检查无癌组织残留。31例淋巴结转移。并发症:吻合口漏2例,喉返神经损伤3例,肺部感染6例,胃排空障碍2例,吻合口狭窄1例,无死亡病例。33例随访1个月~5年,术后1、3、5年生存率分别为87.9%、54.5%、45.5%。结论颈段食管癌应采取积极的手术治疗,胃咽吻合术是颈段食管癌切除后较为理想的修复手段。Objective To investigate clinical feasibility and efficacy of combined use of thoracoscopy and laparoscopy in total laryngectomy for cervical esophageal carcinoma.Methods Clinical data of 33 patients with cervical esophageal carcinoma undergoing surgical treatment in our department from January 2009 to July 2014 were analyzed retrospectively.The esophagus was separated under thoracoscopy.And laparoscopic gastroplasty,total laryngectomy,tracheal permanent colostomy,and gastric pharyngeal anastomosis were performed.Results The thoracoscopic operation time was 40- 66 min( mean,53 min),the laparoscopic operation time was 35- 51 min( mean,44 min),and the cervical operation time was 128- 150 min( mean,139 min).The blood loss was 130- 270 ml( mean,150 ml).The postoperative hospital stay was 8- 14 d( mean,12 d).Pathological examinations showed squamous cell carcinoma in all the cases,including 2 cases of highly differentiated carcinoma,19 cases of moderately differentiated carcinoma,7 cases of moderately or lowly differentiated carcinoma,and 5 cases of lowly differentiated carcinoma.No residual cancer was found at cutting edges pathologically.Among the 33 cases,lymph node metastasis was found in 31 cases.Complications included 2 cases of anastomotic fistula,3 cases of recurrent laryngeal nerve injury,6 cases of pulmonary infection,2cases of delayed gastric emptying,and 1 case of anastomotic stenosis.There was no death.All the patients were followed up for 1months to 5 years.The survival rates at 1,3,and 5 postoperative year were 87.9%,54.5%,and 45.5%,respectively.Conclusions Cervical esophageal carcinoma should be surgically treated actively.Gastric pharyngeal anastomosis is an ideal option for the repair of cervical esophageal cancer resection

    1978~2008年中国湿地类型变化

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    分别基于美国陆地卫星(Landsat MSS/TM/ETM+)和中巴资源卫星(CBERS-02B)影像数据,以人工目视解译为主,完成了中国1978~2008年4期(基准年分别为1978,1990,2000和2008年)湿地遥感制图,并进行了大量的室内外验证.在此基础上,对我国湿地现状及近30年来湿地变化进行了初步分析,得到以下主要结论:(ⅰ)截止2008年,中国湿地面积约为324097km2,其中以内陆沼泽(35%)和湖泊湿地(26%)为主.(ⅱ)1978~2008年,中国湿地面积减少了约33%,而人工湿地增加了约122%.过去30年里湿地减少的速度大幅降低,由最初5523km2/a(1978~1990年)降为831km2/a(2000~2008年).(ⅲ)减少的自然湿地(包括滨海湿地和内陆湿地),其类型变化由湿地向非湿地转化的比例逐渐降低.初期(1978~1990年)几乎全部(98%)转换为非湿地;在1990~2000年间减少的自然湿地约有86%转化为非湿地,而在2000~2008年,这一比例下降为77%.(ⅳ)气候变化和农业活动是中国湿地变化的主要驱动因素,湿地变化在中国分为三大不同特征区域,即西部三省/自治区(西藏、新疆和青海)、北部两省/自治区(黑龙江和内蒙古)和其他省市区.其中西部区域尤其是青藏高原,湿地变化的驱动因子以气候增温为主;新疆湿地由于气候增温和农业活动共同作用造成变化不大.北部省/自治区的湿地变化则主要由农业活动引起;而其他省市区的湿地变化几乎完全受控于人类的农业经济活动

    Preprocessing Technology to Weld Seam for Tailored Blank Laser Welding

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    激光焊接作为激光加工的重要组成部分,其应用范围几乎涵盖了所有的焊接领域,其中的激光拼焊技术更是在汽车制造领域中处于举足轻重的地位,激光拼焊是采用激光作为能源,将若干不同材质、不同厚度、不同涂层的钢材或铝材进行自动焊接而形成一块整体板材,以满足零部件对材料性能的不同要求。焊接质量的保证是激光拼焊最关键的技术难点,引起激光焊接缺陷的因素很多,主要有光束质量、母材性能、焊接工艺参数、焊接工件参数及保护气体等。焊接工件参数主要是指焊接前两被焊板材边缘的配合精度,由于采用激光焊接时激光能量集中,光束直径很小,如果两被焊板材边缘配合精度不高使焊缝间间隙过大,激光将无功透过间隙而影响焊接质量。由于普通剪板机的剪切误差使剪切的板材边缘不可能精确平直,另外还有焊机本身的定位对中误差等因素使两板装配后的配合精度很难达到焊接要求。这就要求焊接前对板材边缘进行预处理以使其达到焊接要求。 本文提出了长焊缝激光拼焊焊缝碾压预成型技术,即通过碾压轮对被焊板材厚板焊缝边缘进行碾压使其发生向焊缝方向的塑性变形来填补两板间的间隙以降低激光拼焊对板材边缘直线度及焊机定位对中精度的要求,从而提高激光拼焊的质量和速度。文章主要针对激光拼焊焊缝碾压预成型技术中需要解决的几个关键问题展开研究。 首先,通过建立数学模型分析了板材在碾压过程中的受力模型,给出了板材顺利进入碾压和进行碾压需要满足的条件;其次,通过利用数值分析模拟和实验相结合的方法分析了两板间力的作用规律,给出了板材在碾压过程中不发生窜动需要满足的力学条件;再次,通过利用有限元计算和实验验证的方法分析了影响板材塑性变形规律、板材发生一定塑性变形所需要碾压力的各种因素及其影响规律,这些影响因素包括碾压轮的几何参数、碾压工艺参数、板材的厚度及同一板材的不同位置;最后利用Kriging近似优化模型对碾压轮的几何参数即碾压轮的直径、宽度和边缘形状进行了最优化设计。 依据本文理论所搭建的长焊缝激光拼焊焊缝碾压预成型试验台的试验结果显示焊缝碾压预成型技术能有效降低激光拼焊对板材边缘质量及焊机定位对中精度的要求,有效提高激光拼焊焊接质量和焊接速度

    Design and Research of Missile General Assembly Automatic Docking Platform

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    提出了导弹舱段的自动对接系统。该自动对接系统利用舱段调整机构及基于激光测距传感器测量的位姿测量系统来实现舱段的自动对接。针对调整机构的结构进行了运动学分析,得到其运动学模型及逆运动学解。另外研究对接过程机构设计方法,建立自动对接系统的误差模型,对其调整误差进行分析与研究,并进行仿真来验证设计方法的正确性

    一种特种合金铝锭熔炼的配料方法

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    本发明涉及一种特种合金铝锭熔炼过程的配料优化方法,包括以下步骤:根据特种铝合金熔炼过程配料工艺,初始化配置参数;以特种合金铝锭熔炼过程的配料方案为解,建立特种合金铝锭熔炼过程配料的多目标优化模型;设计融入分布式估计的多目标非支配排序优化算法用于求解该模型;通过迭代计算对配料方案进行优化,最终得到多个符合生产实际的优化配料方案。本发明与传统的人工配料相比,大幅度提高了特种合金铝锭的配料效率和准确率,降低了配料技术员和配料工人的工作强度,有效地合理利用废旧料,减少库存积压,降低生产成本,实现企业的降耗增效

    Vertical Weightless Movement Method Based on Equivalent Dynamics

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    针对航天器高精度地面微重力仿真试验实现难题,提出了一种基于等效动力学原理的垂向失重运动实现方法。通过对该实现方法的原理分析,指出了该方法实现高精度垂向失重运动模拟的等效动力学条件及其适用条件,并分析了基于该实现方法的模拟器构型要求。对模拟误差精度进行仿真分析,结果显示其失重运动模拟精度可达99%,满足高精度微重力仿真试验的要求

    Design of tailored blank laser welding system for long seam based on rolling process

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    提出基于焊缝碾压预成型的长焊缝激光拼焊系统,其通过焊前对较厚板材边缘进行碾压使材料向焊缝方向塑性变形来填补焊缝间隙,极大地降低了长焊缝激光拼焊对板材直线度的要求。系统结构简便,成本较低,可有效提高焊接速度和焊接质量。介绍了系统组成结构、工作原理及控制方法。焊接结果表明,对于焊前间隙0.5mm板材的焊接,系统能大大提高焊接速度并保证焊接质量
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