期刊文献+
共找到219篇文章
< 1 2 11 >
每页显示 20 50 100
Nasogastric tube syndrome:A Meta-summary of case reports
1
作者 Deven Juneja Prashant Nasa +1 位作者 Gunjan Chanchalani Ravi Jain 《World Journal of Clinical Cases》 SCIE 2024年第1期119-129,共11页
BACKGROUND Since its description in 1790 by Hunter,the nasogastric tube(NGT)is commonly used in any healthcare setting for alleviating gastrointestinal symptoms or enteral feeding.However,the risks associated with its... BACKGROUND Since its description in 1790 by Hunter,the nasogastric tube(NGT)is commonly used in any healthcare setting for alleviating gastrointestinal symptoms or enteral feeding.However,the risks associated with its placement are often underes-timated.Upper airway obstruction with a NGT is an uncommon but potentially life-threatening complication.NGT syndrome is characterized by the presence of an NGT,throat pain and vocal cord(VC)paralysis,usually bilateral.It is poten-tially life–threatening,and early diagnosis is the key to the prevention of fatal upper airway obstruction.However,fewer cases may have been reported than might have occurred,primarily due to the clinicians'unawareness.The lack of specific signs and symptoms and the inability to prove temporal relation with NGT insertion has made diagnosing the syndrome quite challenging.AIM To review and collate the data from the published case reports and case series to understand the possible risk factors,early warning signs and symptoms for timely detection to prevent the manifestation of the complete syndrome with life-threatening airway obstruction.METHODS We conducted a systematic search for this meta-summary from the database of PubMed,EMBASE,Reference Citation Analysis(https://www.referencecitation-analysis.com/)and Google scholar,from all the past studies till August 2023.The search terms included major MESH terms"Nasogastric tube","Intubation,Gastrointestinal","Vocal Cord Paralysis",and“Syndrome”.All the case reports and case series were evaluated,and the data were extracted for patient demographics,clinical symptomatology,diagnostic and therapeutic interventions,clinical course and outcomes.A datasheet for evaluation was further prepared.RESULTS Twenty-seven cases,from five case series and 13 case reports,of NGT syndrome were retrieved from our search.There was male predominance(17,62.96%),and age at presentation ranged from 28 to 86 years.Ten patients had diabetes mellitus(37.04%),and nine were hypertensive(33.33%).Only three(11.11%)patients were reported to be immunocompromised.The median time for developing symptoms after NGT insertion was 14.5 d(interquartile range 6.25-33.75 d).The most commonly reported reason for NGT insertion was acute stroke(10,37.01%)and the most commonly reported symptoms were stridor or wheezing 17(62.96%).In 77.78%of cases,bilateral VC were affected.The only treatment instituted in most patients(77.78%)was removing the NG tube.Most patients(62.96%)required tracheostomy for airway protection.But 8 of the 23 survivors recovered within five weeks and could be decannulated.Three patients were reported to have died.CONCLUSION NGT syndrome is an uncommon clinical complication of a very common clinical procedure.However,an under-reporting is possible because of misdiagnosis or lack of awareness among clinicians.Patients in early stages and with mild symptoms may be missed.Further,high variability in the presentation timing after NGT insertion makes diagnosis challenging.Early diagnosis and prompt removal of NGT may suffice in most patients,but a significant proportion of patients presenting with respiratory compromise may require tracheostomy for airway protection. 展开更多
关键词 Nasogastric tube Nasogastric tube syndrome Ryle’s tube sofferman syndrome Vocal cord paralysis
下载PDF
H_(2)S在线监测装置研发及在锅炉水冷壁高温腐蚀防治中的应用 被引量:2
2
作者 熊小鹤 谭厚章 +4 位作者 邱选兵 李传亮 王承亮 杨祖旺 郭古青 《电力科技与环保》 2024年第2期125-132,共8页
锅炉水冷壁高温腐蚀问题一直是影响锅炉安全运行的难题。为解决锅炉水冷壁高温腐蚀的主要媒介H_(2)S需要连续测量,但当前行业内缺乏能长期运行的H_(2)S在线监测装置问题,研发了基于可调谐二极管吸收光谱TDLAS原理测量锅炉水冷壁H_(2)S... 锅炉水冷壁高温腐蚀问题一直是影响锅炉安全运行的难题。为解决锅炉水冷壁高温腐蚀的主要媒介H_(2)S需要连续测量,但当前行业内缺乏能长期运行的H_(2)S在线监测装置问题,研发了基于可调谐二极管吸收光谱TDLAS原理测量锅炉水冷壁H_(2)S的监测装置,并使用装置在某300 MW等级电站锅炉上进行了示范应用,跟踪评估了该装置的性能。结果显示,基于TDLAS原理所研发的仪器在现场投运12个月以来保持稳定运行,装置在线监测结果显示炉内H_(2)S呈现脉冲式波动特点,H_(2)S浓度高时超过1600μL/L。监测中发现,炉内H_(2)S浓度与运行调整存在较密切的关系,在升负荷过程中,由2台磨转为3台磨运行时,前后墙23.60 m平台测点处H_(2)S浓度急剧增加,从46μL/L增至822μL/L,H_(2)S与脱硫塔入口SO_(2)没有显著的关联性。H_(2)S在线监测装置的成功研发可以实现锅炉主燃烧器区域关键参数的在线监测,并作为运行人员调整锅炉运行参数的主要依据,这对于锅炉高温腐蚀监测和锅炉数字化建设具有积极意义。 展开更多
关键词 锅炉 水冷壁 高温腐蚀 H_(2)s 还原性气氛
下载PDF
多因素影响下的S型管道冲刷腐蚀速率分析
3
作者 马忠贞 张友军 +1 位作者 吕雪飞 甘树坤 《吉林化工学院学报》 CAS 2024年第1期43-50,共8页
S型管道应用于输运过程中的复杂地形,在上下游弯头处,会形成不同程度的冲刷腐蚀,造成安全隐患。为分析其腐蚀影响因素,建立S型管道腐蚀模型,采用ANSYS的Workbench平台搭建Fluent模块对不同影响因素下的腐蚀模型进行研究,创建数据传输,... S型管道应用于输运过程中的复杂地形,在上下游弯头处,会形成不同程度的冲刷腐蚀,造成安全隐患。为分析其腐蚀影响因素,建立S型管道腐蚀模型,采用ANSYS的Workbench平台搭建Fluent模块对不同影响因素下的腐蚀模型进行研究,创建数据传输,进而研究流体在流入弯管后各因素与冲蚀速率的关系。结果表明,S型管道冲刷腐蚀受到多因素的影响,尤其是下游弯头处的冲刷腐蚀更为明显。适当减小颗粒物直径、颗粒物质量流量,增大管径和弯径比可以减缓腐蚀及减小腐蚀区域。研究可为管道安全稳定运行提供理论依据。 展开更多
关键词 DPM s型管 冲刷腐蚀 腐蚀速率 数值模拟
下载PDF
低比速水泵水轮机“S”形特性对尾水管最小压力敏感性研究
4
作者 王昭力 李远余 +3 位作者 樊红刚 郭连恒 邓清树 张美琴 《大电机技术》 2024年第5期58-65,共8页
水泵水轮机“S”形特性对机组的水力过渡过程有着要的影响,“S”形特性的优劣是判定模型转轮研发成功与否的关键指标之一,对低比速水泵水轮机显得更为重要。为更深入研究转轮“S”形特性、模型转轮优化设计、水力过渡过程三者间联系,本... 水泵水轮机“S”形特性对机组的水力过渡过程有着要的影响,“S”形特性的优劣是判定模型转轮研发成功与否的关键指标之一,对低比速水泵水轮机显得更为重要。为更深入研究转轮“S”形特性、模型转轮优化设计、水力过渡过程三者间联系,本文定义一种对“S”特性曲线定点定量的分析方法,利用不同试验特性曲线,通过水力过渡过程仿真分析加以判定,对“S”形曲线量化分析以探索三者之间的内在联系。研究表明全特性曲线中间等开度线“S”区弯曲程度对尾水管最小压力敏感性最强,等开度线在“S”区内单位流量与单位转速的比值越大,同一等开度线上飞逸单位流量越大,对提高尾水管进口最小压力越有利;叶片型式和活动导叶翼型优化设计可在一定程度上改善“S”形特性品质,提高甩负荷时尾水管最小压力值。本研成果在低比速水泵水轮机模型转轮研发和水力过渡过程优化计算方面均具有一定参考意义。 展开更多
关键词 低比速 水泵水轮机 s”形特性 过渡过程 尾水管最小压力
下载PDF
S型皮托管对向和非对向测量方法准确度实验研究
5
作者 张乐垚 张亮 +3 位作者 郭素娜 郭虎林 鲁贵祥 孔令彩 《计量学报》 CSCD 北大核心 2024年第6期864-872,共9页
S型皮托管的对向和非对向测量方法准确度在不同工况下有较大差异。通过风洞实流实验对风速、流速攻角和结构参数对S型皮托管对向和非对向测量方法准确度的影响进行了研究。结果表明:风速由5 m/s变化至30 m/s时,在不同流速攻角下S型皮托... S型皮托管的对向和非对向测量方法准确度在不同工况下有较大差异。通过风洞实流实验对风速、流速攻角和结构参数对S型皮托管对向和非对向测量方法准确度的影响进行了研究。结果表明:风速由5 m/s变化至30 m/s时,在不同流速攻角下S型皮托管对向和非对向测量准确度最大差异超过10%;对向和非对向测量中静压孔的压力变化是皮托管在较大流速攻角下造成测量误差的主因;外径较小、总静压孔距较大、测量端弯曲角度在15°至30°间、取压孔内径更小的S型皮托管在对向和非对向测量中都有更高的测量准确度;俯仰角取正值时对向测量准确度全面优于非对向测量,在俯仰角和偏航角同为45°时测量准确度差异达到最大值,大于70%。 展开更多
关键词 流量测量 s型皮托管 烟道流量 对向测量 非对向测量 测量准确度
下载PDF
水泵水轮机S特性对相继甩尾水最小压力的影响
6
作者 王皓臻 俞晓东 +2 位作者 林文雯 李朋宇 刘昌太 《水力发电学报》 CSCD 北大核心 2024年第6期113-122,共10页
为探究水泵水轮机全特性曲线S特性与尾水压力最小值的联系,基于新丰抽水蓄能电站的过渡过程数值仿真模型模拟了尾水最不利相继甩工况。通过调整机组运行轨迹线附近开度线斜率,对比分析并总结S区形状变化对相继甩工况尾水压力极值的影响... 为探究水泵水轮机全特性曲线S特性与尾水压力最小值的联系,基于新丰抽水蓄能电站的过渡过程数值仿真模型模拟了尾水最不利相继甩工况。通过调整机组运行轨迹线附近开度线斜率,对比分析并总结S区形状变化对相继甩工况尾水压力极值的影响规律,提出了一种图形指标,能够应用在抽蓄前期设计中评价S特性对尾水压力影响优劣,并验证其准确性。结果表明,相继甩工况后甩机组流量变化率第一波下降时,机组运行轨迹线呈现完整倒S形,S区形状变化改变了机组流量变化率的大小,导致出现在靠近轨迹线S形下拐点前的尾水压力极值发生变化,给出的图形指标形状越趋近于竖向细长的规则长方形,相应的尾水最小压力的改善效果越好。 展开更多
关键词 抽水蓄能电站 水泵水轮机全特性曲线 s特性 相继甩 尾水最小压力
下载PDF
海上热采油田H_(2)S成因机理研究
7
作者 尹洪超 张伟森 +1 位作者 冉兆航 张莹 《化学工程师》 CAS 2024年第6期46-50,共5页
随着我国海上稠油油田的深入开发,热采蒸汽驱规模逐步扩大,相应的H_(2)S系列问题也愈发凸显。H_(2)S不仅危害人的健康,还能腐蚀金属设备,严重影响生产的安全平稳运行。本文以L稠油油田为例,在调研目标油田储层概况和H_(2)S生成情况的基... 随着我国海上稠油油田的深入开发,热采蒸汽驱规模逐步扩大,相应的H_(2)S系列问题也愈发凸显。H_(2)S不仅危害人的健康,还能腐蚀金属设备,严重影响生产的安全平稳运行。本文以L稠油油田为例,在调研目标油田储层概况和H_(2)S生成情况的基础上,通过黄金管热模拟实验、色谱分析等方式,探究海上热采油田的H_(2)S的成因机理。实验结果表明,L稠油油田H_(2)S生成的物源主要为原油和地层水,岩屑能够起到催化作用;温度和时间是影响H_(2)S的主控因素,温度越高、时间越长,生成的H_(2)S量越高;L油田H_(2)S生成的主要原因是发生了地层水热裂解、硫酸盐还原反应。该研究成果能够为其他热采油田的H_(2)S成因研究提供探索思路,为油田H_(2)S治理指明方向。 展开更多
关键词 热采油田 H_(2)s 黄金管热模拟实验 物源 温度 机理
下载PDF
Predictive Model for Corrosion Rate of Oil Tubes in CO_2/H_2S Coexistent Environment Part Ⅰ: Building of Model 被引量:5
8
作者 李全安 白真权 +3 位作者 黄得志 张清 文九巴 李鹤林 《Journal of Southwest Jiaotong University(English Edition)》 2004年第2期141-147,共7页
Based on an analysis of the existing models of CO 2 corrosion in literatures and the autoclave simulative experiments, a predictive model of corrosion rate (r corr) in CO 2/H 2S corrosion for oil tubes has been ... Based on an analysis of the existing models of CO 2 corrosion in literatures and the autoclave simulative experiments, a predictive model of corrosion rate (r corr) in CO 2/H 2S corrosion for oil tubes has been established, in which r corr is expressed as a function of pH, temperature (T), pressure of CO 2 (P CO 2) and pressure of H 2S (P H 2S). The model has been verified by experimental data obtained on N80 steel. The improved features of the predictive model include the following aspects: (1) The influence of temperature on the protectiveness of corrosion film is taken into consideration for establishment of predictive model of the r corr in CO 2/H 2S corrosion. The Equations of scale temperature and scale factor are put forward, and they fit the experimental result very well. (2) The linear relationship still exists between ln r corr and ln P CO 2 in CO 2/H 2S corrosion (as same as that in CO 2 corrosion). Therefore, a correction factor as a function of P H 2S has been introduced into the predictive model in CO 2/H 2S corrosion. (3) The model is compatible with the main existing models. 展开更多
关键词 Predictive model CO 2/H 2s corrosion Corrosion rate scale temperature Oil tube
下载PDF
Safety of gastric lavage using nasogastric ryle’s tube in pesticide poisoning 被引量:1
9
作者 Uday Bhan Bhardwaj Anand Subramaniyan +2 位作者 Ashish Bhalla Navneet Sharma Surjit Singh 《Health》 2011年第7期401-405,共5页
Objective: Gastric lavage is mandatory irrespective of nature in all patients with acute poisoning in India. Present study was undertaken with aim whether lavage done using nasogastric Ryle’s tube and small aliquots ... Objective: Gastric lavage is mandatory irrespective of nature in all patients with acute poisoning in India. Present study was undertaken with aim whether lavage done using nasogastric Ryle’s tube and small aliquots of water or normal saline is safe. Patients and Methods: All the patients above 12 years of age admitted consecutively with pesticide ingestion or exposure between July 2004 to June 2005 were studied with respect to complications associated with lavage using Ryle’s tube. Forty five patients were admitted directly to our hospital and lavage was undertaken using Ryle’s tube (16F ) with 100 - 200 mL of aliquots till 1 - 1.5 liters of fluid was lavaged, with prophylactic endotracheal intubation in patients with Glasgow coma scale ( GCS) < 10 (group I). The incidence of complications related to lavage in group I was compared to that in 53 patients admitted during same period with pesticide poisoning but lavaged outside using nasogastric Ryle’s tube and referred to our institute (group II). Results: The significant complications observed in group I were significant drop in SaO2 (6 patients) laryngospasm, tachycardia, electrolyte imbalance and tube getting struck in throat (one each). In one patient in group I (had no prophylactic intubation though GCS 3) In group II, 7 had aspiration pneumonia (no prophylactic intubation). Other significant complication was drop in SaO2 during lavage. None of them had any serious life threatening complication. Conclusion: Gastric lavage carried out using nasogastric Ryle’s tube and small aliquots of water or normal saline is relatively safe in patients with pesticide poisoning when combined with prophylactic endotracheal intubation in patients with GCS < 10. In absence of prophylactic intubation, risk of aspiration is there. However aspiration pneumonia is generally mild and not life threatening. 展开更多
关键词 PEsTICIDE POIsONING GAsTRIC LAVAGE Nasogastric Ryle’s tube COMPLICATIONs
下载PDF
基于S-CO_(2)的强化壳管式蓄热单元传热性能优化 被引量:1
10
作者 方明惠 曹丽华 丛钰 《动力工程学报》 CAS CSCD 北大核心 2023年第2期275-282,共8页
为了了解壳管式蓄热单元的传热性能,提出了一种强化壳管式蓄热单元传热性能的优化方法。对不同的换热流体(HTF)进行优质选择,并基于回归正交试验对相变蓄热单元结构参数进行优化。结果表明:回归方程满足试验的显著性和失拟性检验,验证... 为了了解壳管式蓄热单元的传热性能,提出了一种强化壳管式蓄热单元传热性能的优化方法。对不同的换热流体(HTF)进行优质选择,并基于回归正交试验对相变蓄热单元结构参数进行优化。结果表明:回归方程满足试验的显著性和失拟性检验,验证结果与计算结果的相对误差在1%以内;采用800℃、20 MPa的超临界二氧化碳(S-CO_(2))和管径比为0.666 3的组合形式最优;优化后的蓄热单元获得的最高储热量为2 674.52 kJ,比优化前增加约39.5%,传热速率范围从1.76 kW降到0.007 kW。 展开更多
关键词 壳管式蓄热单元 s-CO_(2) 回归正交试验 数值模拟
下载PDF
Research on the inwall shot blasting of the S30432 high-pressure boiler tube
11
作者 XU Songqian1),ZHANG Yuehong1),JIANG Chuanhai2) and HUANG Yanpin1) 1) Special Steel Technology Center,Research Institute,Baoshan Iron & Steel Co.,Ltd.,Shanghai 200940,China 2) School of Materials Science and Engineering,Shanghai Jiaotong University,Shanghai 200240,China 《Baosteel Technical Research》 CAS 2012年第1期44-52,共9页
Inwall shot blasting is a method of improving the surface hardness and high temperature oxidation resistance of the S30432 high-pressure boiler tube.The differences on residual stress,sub-grain size,micro-hardness and... Inwall shot blasting is a method of improving the surface hardness and high temperature oxidation resistance of the S30432 high-pressure boiler tube.The differences on residual stress,sub-grain size,micro-hardness and structure between the S30432 inwall shot-blasting tube produced by Baosteel with six technological process parameters and the imported super 304H were studied systematically by contrast test research.It has been demonstrated that the S30432 obtains a higher residual stress,a deeper distributed layer and a better sub-grain size of the inwall field shot-blasting layer;the martensite content of the shot-blasting surface was low;and micro-hardness and structure refinement were better.After 2000 h’ oxidation test under the 650℃/26MPa steam condition,steam oxidation resistance of the Baosteel steel tube shot-blasting surface was higher,the oxide layer was thinner,and was well combined with bulk material. 展开更多
关键词 s30432 tube shot blasting residual stress sub-grain size micro-hardness
下载PDF
S型管束外空气-蒸汽冷凝传热特性数值分析
12
作者 肖家禹 高力 +2 位作者 孙中宁 景瑞涵 边浩志 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2023年第7期1242-1248,共7页
为追求非能动安全壳热量导出系统换热器更优异的管外空气-蒸汽冷凝传热性能,并为实验及换热器的拓展设计提供相应指导,本文对S型管束外含空气蒸汽冷凝传热特性进行了数值分析。结果表明:计算参数范围内,S型管束能有效强化管束外含空气... 为追求非能动安全壳热量导出系统换热器更优异的管外空气-蒸汽冷凝传热性能,并为实验及换热器的拓展设计提供相应指导,本文对S型管束外含空气蒸汽冷凝传热特性进行了数值分析。结果表明:计算参数范围内,S型管束能有效强化管束外含空气蒸汽冷凝传热能力,其平均冷凝传热系数为竖直管束的1.3~1.7倍。总结得出迎流面强化传热的管间冲刷效应和抑制传热的空气层堆叠效应的耦合作用机制。多排布置时,减小管排数、增大弯管半径、管间距及采用叉排布置均有利于提高S型管束外含空气蒸汽冷凝传热能力。 展开更多
关键词 空气-蒸汽冷凝 s型管束 强化换热 管间冲刷效应 空气层堆叠效应 管排布置 数值模拟
下载PDF
Surgical Management of Obstructive Urolithiasis in Small Ruminants by Tube Cystostomy in Chittagong, Bangladesh
13
作者 Bibek Chandra Sutradhar Tuli Dey +1 位作者 Saroj Kumar Yadav Mohammad Bayazid Bostami 《Journal of Agricultural Science and Technology(A)》 2018年第2期89-98,共10页
The present study was conducted to evaluate minimally invasive tube cystostomy technique in goats and calves suffering from obstructive urolithiasis having intact and ruptured urinary bladder. This clinical study was ... The present study was conducted to evaluate minimally invasive tube cystostomy technique in goats and calves suffering from obstructive urolithiasis having intact and ruptured urinary bladder. This clinical study was carried out on 84 clinical cases (61 goats and 23 calves) based on the history, clinical signs and physical examination along with common laboratory techniques at the Chittagong Veterinary and Animal Sciences University during January 2015-December 2016. Physical parameters like heart rate, respiratory rate, rectal temperature and dehydration status of animals were noted and corrected abnormality before surgery. Some cases had slightly higher haemoglobin (Hb), packed cell volume (PCV) and uric acid and epithelial casts in urine. The study revealed that abnormal calcium-phosphorus ratio was predisposing the animals to urolithiasis. It was found that young ruminants (3-5 months) were most commonly affected in both species. All affected animals were male in this study, in which calves were not castrated but in goats 95.08% animals were castrated. Rupture of bladder was more common in calves as compared to goats. Postoperatively all cases were administered with broad-spectrum antibiotic, anti-inflammatory agent and caliculolytic agents like ammonium chloride. Tube cystostomy with Foley’s catheter was the most satisfactory technique for the management of obstructive urolithiasis in small ruminants. Postoperative complications were recorded only in four animals and remaining 80 animals had a normal recovery from tube cystostomy. Tube cystostomy is a simple, inexpensive and very effective procedure for the treatment of urolithiasis in ruminants. 展开更多
关键词 small ruminants Foley’s catheter tube cystostomy UROLITHIAsIs
下载PDF
Preparation and Anti-coking Property of SiO_2/S Coating on HP40 Tube
14
作者 周建新 徐宏 +3 位作者 张莉 刘京雷 戚学贵 彭博 《过程工程学报》 EI CAS CSCD 北大核心 2007年第6期1243-1248,共6页
SiO2/S coating was prepared on the inner surface of an HP40 tube using dimethyldisulfide and tetraethylorthosilicate by atmospheric pressure chemical vapor deposition(APCVD) to alleviate catalytic coking on the inner ... SiO2/S coating was prepared on the inner surface of an HP40 tube using dimethyldisulfide and tetraethylorthosilicate by atmospheric pressure chemical vapor deposition(APCVD) to alleviate catalytic coking on the inner surface of radiant tube for ethylene production in petrochemical plants.The comparative coking experiments with the coated and uncoated HP40 tubes were carried out under the same cracking conditions.SiO2/S coating was compact and had excellent anti-coking property.The coke on the coated HP40 tube was about 22% of that on the uncoated HP40 tube,and only small granular coke was deposited on the coated HP40 tube.However,the filamentous coke formed on the uncoated HP40 tube.The thermal stability of SiO2/S coating was satisfactory at cracking temperature,and the anti-coking property of SiO2/S coating was still over 60% after 3 coking and decoking cycles. 展开更多
关键词 HP40管 焦炭 二氧化硅/硫被覆 大气压力化学汽相沉积 制备 抗成焦性
下载PDF
基于多注速调管的S波段9MeV能量可调加速管设计与研制
15
作者 郝聪慧 牛焕焕 +3 位作者 万知之 王麟 张子豪 张博鹏 《真空电子技术》 2023年第4期36-40,49,共6页
设计了一种S波段9 MeV驻波电子直线加速管。工作频率为2998 MHz,管长为780 mm。其使用3.1 MW多注速调管作为微波功率源,最大工作比可达到2‰,同时通过调节加速管输入功率及电子枪高压,可实现打靶电子束能量连续可调,可应用于无损检测领... 设计了一种S波段9 MeV驻波电子直线加速管。工作频率为2998 MHz,管长为780 mm。其使用3.1 MW多注速调管作为微波功率源,最大工作比可达到2‰,同时通过调节加速管输入功率及电子枪高压,可实现打靶电子束能量连续可调,可应用于无损检测领域,为工业探伤提供合适的能量、提高探伤效率。本文以工业领域常用的9 MeV/6 MeV能挡为例进行仿真设计及束流测试。 展开更多
关键词 s波段驻波加速管 多注速调管 工业无损检测
下载PDF
BT80S-5Cr抗CO_(2)/H_(2)S腐蚀油管的工业试制及性能评价
16
作者 石晓霞 张行刚 +2 位作者 詹飞 魏淼 贾冬梅 《钢管》 CAS 2023年第5期26-31,共6页
用10Cr5MoVRE钢试制了BT80S-5Cr抗CO_(2)/H_(2)S腐蚀油管。介绍了BT80S-5Cr抗CO_(2)/H_(2)S腐蚀油管的工业试制过程,分析了该油管的金相组织、力学性能和耐蚀性能以及全尺寸实物评价结果。分析认为:该油管的冶金质量、金相组织、力学性... 用10Cr5MoVRE钢试制了BT80S-5Cr抗CO_(2)/H_(2)S腐蚀油管。介绍了BT80S-5Cr抗CO_(2)/H_(2)S腐蚀油管的工业试制过程,分析了该油管的金相组织、力学性能和耐蚀性能以及全尺寸实物评价结果。分析认为:该油管的冶金质量、金相组织、力学性能、抗硫化物应力腐蚀开裂性能均满足技术要求,均匀腐蚀速率较同钢级3Cr低30%~50%;拉伸失效载荷高于技术要求55%以上,内压至失效载荷高于技术要求70%以上。 展开更多
关键词 油管 BT80s-5Cr CO_(2)/H_(2)s腐蚀 金相组织 力学性能 腐蚀性能
下载PDF
梨自交不亲和及其亲和突变品种花柱内S_4(S_4^(SM))基因的表达与作用的比较 被引量:26
17
作者 张绍铃 平塚伸 +2 位作者 徐国华 房经贵 刘友良 《Acta Botanica Sinica》 CSCD 2001年第11期1172-1178,共7页
提取梨 (PyrusserotinaRehd .)自交不亲和品种“二十世纪”(基因型为S2 S4 )、自交亲和的突变品种“奥嗄二十世纪”(S2 SSM4 ,SM =Stylar_partmutant;花柱部分突变 )及其亲和后代花柱的可溶性蛋白。经等电聚焦电泳 (IEF_PAGE)分析表明 ... 提取梨 (PyrusserotinaRehd .)自交不亲和品种“二十世纪”(基因型为S2 S4 )、自交亲和的突变品种“奥嗄二十世纪”(S2 SSM4 ,SM =Stylar_partmutant;花柱部分突变 )及其亲和后代花柱的可溶性蛋白。经等电聚焦电泳 (IEF_PAGE)分析表明 ,“奥嗄二十世纪”及其后代花柱仍存在SSM4 蛋白 ,但其含量逐代减少 ,同时发现“奥嗄二十世纪”的SSM4 基因仅在柱头表达 ,而“二十世纪”的S4 基因表达的部位除了柱头外 ,还包括花柱上部及花柱下部 ,且表达量呈现从柱头到花柱下部下降的趋势。S蛋白经等电聚焦电泳的凝胶板进行RNase活性染色处理 ,也得到相同的结果。从花柱 (包括柱头 )中纯化出的S蛋白经SDS_PAGE电泳后进行RNase活性染色的结果表明 ,S4 与SSM4 蛋白的分子量相近 (约 30kD) ,并且均具有RNase活性。进一步以酵母RNA为基质测定的比活性也基本相等 ,约为 2 75U·min-1·mg-1蛋白。在离体条件下 ,上述两种S蛋白 (S_RNase)也以相同的程度抑制S4 或SSM4 花粉发芽及花粉管伸长。研究证明 ,自交亲和突变品种“奥嗄二十世纪”的SSM4 基因也具有原始自交不亲和品种“二十世纪”S4 基因的功能。因此 ,其自交亲和的原因可归结为SSM4 基因的表达量较少及SSM4 基因仅在柱头中表达的缘故。 展开更多
关键词 自交不亲和性 s基因 s蛋白 花粉管伸长 花柱 突变品种
下载PDF
梨花柱S-RNase对花粉管超微结构的影响 被引量:10
18
作者 刘珠琴 张绍铃 +2 位作者 徐国华 赵彩平 吴俊 《西北植物学报》 CAS CSCD 北大核心 2005年第7期1357-1361,共5页
采用光学显微镜和透射电子显微镜研究了离体条件下不同品种梨花柱S-RNase对异花(亲和)及自花(不亲和)花粉萌发和花粉管生长及其超微结构的影响。结果表明,花柱S-RNase抑制不亲和花粉的萌发和花粉管的生长,对亲和花粉的萌发和花粉管的生... 采用光学显微镜和透射电子显微镜研究了离体条件下不同品种梨花柱S-RNase对异花(亲和)及自花(不亲和)花粉萌发和花粉管生长及其超微结构的影响。结果表明,花柱S-RNase抑制不亲和花粉的萌发和花粉管的生长,对亲和花粉的萌发和花粉管的生长基本没有影响。花粉生长初期,亲和及不亲和花粉管超微结构相似;但培养24h以后,亲和花粉管中充满细胞质和细胞器,而不亲和花粉管中只有靠近花粉管前端有少量细胞质,细胞壁增厚,细胞壁与细胞质之间有一层胼胝质和电子透明区间隔。 展开更多
关键词 自交不亲和 s-RNasc 花粉管 超微结构
下载PDF
类S型皮托管及其测量特性研究 被引量:10
19
作者 孙志强 郑剑武 +1 位作者 张宏建 周孑民 《传感器与微系统》 CSCD 北大核心 2007年第5期40-42,共3页
S型皮托管是工业过程中测量含尘气体最为常用的流速测量装置之一,但由于取压孔开口较大,对其测量会有一定的影响。为了减小取压孔引起的误差,并保持S型皮托管的优点,研究了一种新型的皮托管一类S型皮托管的测量特性。首先,根据对... S型皮托管是工业过程中测量含尘气体最为常用的流速测量装置之一,但由于取压孔开口较大,对其测量会有一定的影响。为了减小取压孔引起的误差,并保持S型皮托管的优点,研究了一种新型的皮托管一类S型皮托管的测量特性。首先,根据对置有皮托管的流场数值模拟的结果,确定了较优管型的开口斜度;其次,在流速范围为15-50m/s的DN100风管中对类S型皮托管进行了实流标定实验。结果表明:在实验范围内,类S型皮托管的校准系数都比较稳定,并非常接近1,其相对误差为±4%,能够满足大多数工业现场介质流速测量的要求。 展开更多
关键词 流速测量 皮托管 s 数值模拟
下载PDF
基于B/S模式的锅炉金属壁温在线监测系统 被引量:8
20
作者 高建强 陈聪 +3 位作者 李永华 陈鸿伟 王春波 廖丹 《中国电力》 CSCD 北大核心 2005年第12期68-71,共4页
在借鉴过程仿真和热力系统分析方法的基础上,开发了一套锅炉高温受热面金属壁温在线监测系统。该系统以一体化过程模型开发平台(IMMS)及其算法库为基础进行模型开发,利用火电厂已有的管理信息系统(MIS)采集机组运行数据,通过模型在线计... 在借鉴过程仿真和热力系统分析方法的基础上,开发了一套锅炉高温受热面金属壁温在线监测系统。该系统以一体化过程模型开发平台(IMMS)及其算法库为基础进行模型开发,利用火电厂已有的管理信息系统(MIS)采集机组运行数据,通过模型在线计算确定受热面管壁温度,并采用B/S结构显示实时监测信息。该系统已成功应用于某电厂200MW锅炉,有效减少了受热面超温爆管次数,延长了金属寿命,提高了机组安全经济运行水平。介绍系统的构成、功能及系统应用情况。 展开更多
关键词 锅炉 金属壁温 在线监测 B/s模式 模型开发平台
下载PDF
上一页 1 2 11 下一页 到第
使用帮助 返回顶部