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消除管尾三角的一种新方法
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作者 孙斌煜 张洪 +2 位作者 路锁柱 程力 孙航临 《钢管》 CAS 1998年第3期1-4,共4页
从原理、结构、使用等方面详细介绍了消除管尾三角的新方法,指出新方法的成功主要在于设置在支撑顶头和顶杆的支挡装置上的快速推进控制系统。当轧制临近管尾时,系统的压力传感器便发出信号,启动液压系统的换向阀,同时快推油缸快速... 从原理、结构、使用等方面详细介绍了消除管尾三角的新方法,指出新方法的成功主要在于设置在支撑顶头和顶杆的支挡装置上的快速推进控制系统。当轧制临近管尾时,系统的压力传感器便发出信号,启动液压系统的换向阀,同时快推油缸快速向前推动,迅速穿透管坯,改变顶头相对于轧辊的位置,增大D/S值,从而消除管尾三角。工业性试验表明,这是一种简单而有效的消除管尾三角的方法。 展开更多
关键词 无缝钢管 管尾三角 轧制 轧管机
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热轧钢管尾部内折产生的原因及控制措施
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作者 高建学 王庆伟 杨梁才 《天津冶金》 CAS 2019年第5期37-39,共3页
热轧无缝钢管的管尾内折缺陷严重影响了产品合格率和成材率指标。天津钢管公司采用460PQF连轧管机组生产无缝钢管所产生的管尾内折缺陷主要出现在294孔型系列,其产生的主要原因与穿孔机变形区的椭圆度有关,也与导卫装置的稳定性和穿孔... 热轧无缝钢管的管尾内折缺陷严重影响了产品合格率和成材率指标。天津钢管公司采用460PQF连轧管机组生产无缝钢管所产生的管尾内折缺陷主要出现在294孔型系列,其产生的主要原因与穿孔机变形区的椭圆度有关,也与导卫装置的稳定性和穿孔参数的调整有关。分析了管尾内折的成因,通过采用优化设计穿孔顶头、改造导卫锁紧装置、动态调整轧制参数等方法有效地消除了管尾内折缺陷,460机组的生产指标得到大幅度提高。 展开更多
关键词 无缝钢管 管尾内折 椭圆度 顶头设计 参数调整
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涂敷钢管尾端反吹气加压装置设计与实现
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作者 张国广 《机械工程师》 2011年第8期104-105,共2页
钢管涂敷是管类生产中的一个重要的生产工序。传统工作方式为人工手持压缩气管尾随钢管一起缓慢移动并不断地对管内吹风,这种方式效率低,工作强度较大,最重要的是存在较大的安全隐患。管尾反吹气加压装置,采用电磁自动控制,有效地保证... 钢管涂敷是管类生产中的一个重要的生产工序。传统工作方式为人工手持压缩气管尾随钢管一起缓慢移动并不断地对管内吹风,这种方式效率低,工作强度较大,最重要的是存在较大的安全隐患。管尾反吹气加压装置,采用电磁自动控制,有效地保证了生产中钢管涂敷质量,提高了生产效率。 展开更多
关键词 钢管涂敷 管尾反吹 自动控制
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葡萄害虫—蓟马
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作者 傅望衡 邢开基 杜立权 《中外葡萄与葡萄酒》 1989年第4期22-25,共4页
缨翅目昆虫种类很多,通称为蓟马,一般成虫体长只有1—2毫米(也有个别更短或更长者)。仔细用肉眼观察才能见到。因此往往容易被人们所忽视。蓟马在我国葡萄产区一直有着广泛的分布,由于造成的损害不太严重,未引起人们注意,近年来对葡萄... 缨翅目昆虫种类很多,通称为蓟马,一般成虫体长只有1—2毫米(也有个别更短或更长者)。仔细用肉眼观察才能见到。因此往往容易被人们所忽视。蓟马在我国葡萄产区一直有着广泛的分布,由于造成的损害不太严重,未引起人们注意,近年来对葡萄的为害有日益增长之势,据1989年在辽宁省盖县葡萄集中产区13个乡镇的调查。 展开更多
关键词 成虫体 集中产区 缨翅目 昆虫种类 纹蓟马科 触角节 虫口密度 喷布 管尾亚目 虫态
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带管端探伤的全管体自动超声波探伤系统 被引量:1
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作者 高光旭 崔二炜 +3 位作者 刘忠魁 陈开云 李久营 胡建华 《无损检测》 2010年第7期524-527,共4页
设计了一种带管端探伤的全管体自动超声波探伤系统。系统由超声波探头、超声波探伤仪器、图像跟踪系统、PLC电气控制系统和全管体探伤机械装置组成,把焊缝探伤和母材探伤合为一体,实现螺旋管全管体的自动化超声波探伤。在全管体探伤机... 设计了一种带管端探伤的全管体自动超声波探伤系统。系统由超声波探头、超声波探伤仪器、图像跟踪系统、PLC电气控制系统和全管体探伤机械装置组成,把焊缝探伤和母材探伤合为一体,实现螺旋管全管体的自动化超声波探伤。在全管体探伤机械装置中的焊缝管端检测装置后增加焊缝跟踪装置,在母材管端检测装置后依次增加管尾检测装置、母材管端探头体和管头检测装置,实现了管端自动探伤,解决了管端盲区问题,提高了探伤速度,保证了螺旋管探伤的可靠性和准确性,降低了人力资源成本。 展开更多
关键词 管尾 管头 管端 全管体自动超声波探伤
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The genus Bolothrips(Thysanopfera: Idolothripinae)—a new record to China, with two new record species
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作者 郭付振 曹少杰 冯纪年 《Entomotaxonomia》 CSCD 北大核心 2014年第2期90-96,共7页
Bolothrips icarus (Uzel) and B. bicolor (Heeger) are newly recorded from China. This represents the first record of the genus Bolothrips (Uzel) in China. Examined specimens are deposited in the Entomological Mus... Bolothrips icarus (Uzel) and B. bicolor (Heeger) are newly recorded from China. This represents the first record of the genus Bolothrips (Uzel) in China. Examined specimens are deposited in the Entomological Museum, Northwest A&F University, Yangling, Shaanxi, China (NWAFU). 展开更多
关键词 Tubulifera Phlaeothripoidea TAXONOMY
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A newly recorded genus Smilothrips Bhatti(Thysanoptera:Thripidae) in China
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作者 马吉德 杨淑兰 童晓立 《Entomotaxonomia》 CSCD 北大核心 2013年第3期179-184,共6页
A newly recorded species Smilothrips productus Bhatti, 1976 (Thripidae: Thripinae), collected on sedges from Sichuan is described and illustrated using SEM. This is also the first report of a member of the genus Sm... A newly recorded species Smilothrips productus Bhatti, 1976 (Thripidae: Thripinae), collected on sedges from Sichuan is described and illustrated using SEM. This is also the first report of a member of the genus Smilothrips in China. Larvae and two different wing morphs of the species (micropterous and brachypterous) are also described for the first time herein. 展开更多
关键词 Yubulifera Thripoidea wing morphs taxonomy
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On the genus Nesothrips Kirkaldy(Thysanoptera: Phlaeothripidae) with two newly recorded species from China
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作者 Shaojie CAO Yang WANG +1 位作者 Jinian FENG Fuzhen GUO 《Entomotaxonomia》 CSCD 2019年第3期220-225,共6页
Two species in the genus Nesothrips are first recorded from China.N.doulli&N.fodinae are described in detail and an identification key of the species among genus Nesothrips currently recorded from China is provided.
关键词 Tubulifera Idoiothripinae TAXONOMY key
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Effect of fin attachment on thermal stress reduction of exhaust manifold of an off road diesel engine 被引量:4
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作者 Ali Akbar Partoaa Morteza Abdolzadeh Masoud Rezaeizadeh 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第3期546-559,共14页
The effect of fin attachment on the thermal stress reduction of exhaust manifold of an off road diesel engine(Komatsu HD325-6) was investigated.For doing this,coupled thermo-fluid-solid analysis of exhaust manifold of... The effect of fin attachment on the thermal stress reduction of exhaust manifold of an off road diesel engine(Komatsu HD325-6) was investigated.For doing this,coupled thermo-fluid-solid analysis of exhaust manifold of the off road diesel engine was carried out.The thermal analysis,including thermal flow,thermal stress,and the thermal deformation of the manifold was investigated.The flow inside the manifold was simulated and then its properties including velocity,pressure,and temperature were obtained.The flow properties were transferred to the solid model and then the thermal stresses and the thermal deformations of the manifold under different operating conditions were calculated.Finally,based on the predicted thermal stresses and thermal deformations of the manifold body shell,two fin types as well as body shell thickness increase were applied in the critical induced thermal stress area of the manifold to reduce the thermal stress and thermal deformation.The results of the above modifications show that the combined modifications,i.e.the thickness increase and the fin attachment,decrease the thermal stresses by up to 28% and the contribution of the fin attachment in this reduction is much higher compared to the shell thickness increase. 展开更多
关键词 MANIFOLD EXHAUST simulation MODIFICATION thermal stress deformation diesel engine
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Comparison of mechanical and column flotation performances on recovery of phosphate slimes in presence of nano-microbubbles 被引量:1
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作者 Fatemeh Taghavi Mohammad Noaparast +1 位作者 Ziaeddin Pourkarimi Fardis Nakhaei 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第1期102-115,共14页
Fine particle flotation has been one of the main problems in many mineral processing plants.The bubble particle collision rate is very low for fine particles,which reduces flotation efficiency.Also,the existence of sl... Fine particle flotation has been one of the main problems in many mineral processing plants.The bubble particle collision rate is very low for fine particles,which reduces flotation efficiency.Also,the existence of slimes is,generally,detrimental to the flotation process,affecting the selectivity and the quality of the concentrates.Besides,it causes an increase in reagents consumption.Hence,in most of processing plants,some of these particles are transmitted to the tailing ponds to reduce the effects of these problems and increase the selectivity of the process.Esfordi phosphate plant in Iran loses more than 30%of its capacity as particles with d 80 finer than 30μm.These fine particles with 15.9%P_(2)O_(5)content are transferred to tailing dam.Processing of fine particles is very important for phosphate industry from economic and environmental aspects.This study addressed the processing of fine tailings(slimes)from a phosphate ore concentrator via flotation,despite the traditional view that ultrafine particles do not float.Phosphate flotation performances in the presence and absence of nanobubbles(NBs)in both mechanical and column cells were compared according to the metallurgical results of the process.NBs(generated by hydrodynamic cavitation)have interesting and exclusive properties such as high stability,durability and high surface area per volume,leading to increase of their utilization in mining-metallurgy and environmental areas.The results of this study revealed that,in the absence of NBs,a concentrate containing 26.9%P_(2)O_(5)with a recovery of 29.13%was obtained using mechanical cells in comparison to 31.6%P_(2)O_(5)with a recovery of 32.74%obtained using column flotation.In the presence of NBs,the recoveries of the concentrate of the mechanical and column flotation increased to 40.49%and 41.26%with 28.47%and 30.43%P_(2)O_(5)contents,respectively.Comparative study showed that the column flotation was almost more efficient for processing the phosphate ore in the presence of the NBs,and had thicker froth layer compared to the mechanical flotation. 展开更多
关键词 column flotation mechanical cell PHOSPHATE TAILINGS SLIME NANOBUBBLE Venturi tube hydrodynamic cavitation
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早寒武世澄江化石库中鳃曳形目的早期祖先 被引量:6
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作者 韩健 舒德干 +1 位作者 张志飞 刘建妮 《科学通报》 EI CAS CSCD 北大核心 2004年第16期1644-1652,共9页
对澄江化石库中鳃曳虫科的最古老的直接祖先Xiaoheiqingella peculiaris以及Yunnanpriapulus halteroformis 进行深入研究, 认为二者很可能为同物异名, 其躯干之后存在一对而不是一个尾附肢, 肛前区发现可能的生殖管. 另外报道了一个... 对澄江化石库中鳃曳虫科的最古老的直接祖先Xiaoheiqingella peculiaris以及Yunnanpriapulus halteroformis 进行深入研究, 认为二者很可能为同物异名, 其躯干之后存在一对而不是一个尾附肢, 肛前区发现可能的生殖管. 另外报道了一个极为稀有的化石鳃曳动物新属种Paratubiluchus bicaudatus gen. nov., sp. nov. (双尾拟管尾虫), 其特征为: 25列吻突, 明显的颈区, 无环纹的躯干以及一对尾附肢, 虫体各部分的比例与现生鳃曳动物的兜甲幼虫以及幼虫型鳃曳动物Palaeopriapulitidae科比较接近, 推测为Tubiluchidae科的直接祖先之一, 双肢型的尾附肢可能为Priapulidae科和Tubiluchidae科的共祖衍征. Paratubiluchus gen. nov. 很可能起源于具25列吻突的幼虫型鳃曳动物, 而且恰好处于兜甲幼虫型鳃曳动物与成虫型鳃曳动物的中间环节. 展开更多
关键词 早寒武世 澄江化石库 鳃曳形目 小黑箐虫 管尾 系统古生物学 古生态学
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Efficiency and therapeutic effect of modified pigtail probe in anastomosing lacerated lacrimal canaliculus 被引量:7
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作者 梁涛 赵桂秋 +3 位作者 李英兰 杨珊珊 张凌云 吴媛 《Chinese Journal of Traumatology》 CAS 2009年第2期87-91,共5页
Objective: To investigate the necessity of modification to the traditional pigtail probe and evaluate its efficiency and therapeutic effect in searching the nasal cut ends and anastomosing the lacerated lacrimal cana... Objective: To investigate the necessity of modification to the traditional pigtail probe and evaluate its efficiency and therapeutic effect in searching the nasal cut ends and anastomosing the lacerated lacrimal canaliculus. Methods: Eighty-seven patients (including 87 eyes) suffering from canalicular laceration were randomized into two groups: 41 patients treated with traditional pigtail probes (Group A) and 46 with modified pigtail probes (Group B). During the reconstruction of the lacerated canaliculi, the traditional pigtail probe and the modified pigtail probe were used respectively to seek for the nasal cut ends of lacerated lacrimal canaliculi. Peripherally inserted central catheter (PICCTM) silicone tube with diameter of 0.95 mm was intubated as a stent for 4-6 months. The surgical outcomes were retrospectively analyzed after stent removal. Results: In Group B, the primary success rate of searching the nasal cut ends of lacerated lacrimal canaliculi was 93.48% (43/46) and the final success rate was 97.83% (45/46). No false passage formed in Group B. Statistical sig- nificance was found between Group A and Group B as the primary success rates of searching the nasal cut ends ( x^2 = 10.522, P〈0.01) and the false passage forming rates were concerned ( x^2=4.704, P〈0.05), whereas no significance was found between the two groups as the final success rates were concerned ( x^2=0.007, P〉0.05). The mean time of searching the nasal cut ends of lacerated lacrimal canaliculi in Group B was (5.02±2.73) minutes and the mean time of operation was (33.90±4.84) minutes, and both were significantly shorter than those of Group A (t1=9.779, t2=10.700, P〈0.01). The cure rate of Group B was 95.65%, though higher than that of Group A, no statistical significance was found (Z=-1.007, P〉0.05). Totally, 2 patients (2.30%) were found to be absent of common canaliculus and underwent bicanalicular nasal intubation in the two groups. Conclusions: Pigtail probes are efficient and convenient apparatus for searching the nasal cut ends of the lacerated lacrimal canaliculi in the reconstruction of canalicular laceration. Necessary or proper modifications to the pigtail probes can minimize the risk of iatrogenic damages or complications and enhance the efficiency and therapeutic effect of canalicular repair. 展开更多
关键词 LACERATIONS INTUBATION Lacrimal apparatus Anastomosis surgical
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Mechanism of the Reversal Effect of Acupuncture on the Fall of Blood Pressure Induced by Angiotensin-(1-7)in the Caudal Ventrolateral Medulla of Rats
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作者 王锦 沈霖霖 +2 位作者 曹银祥 朱大年 朱忠春(Translator) 《Journal of Acupuncture and Tuina Science》 2006年第4期201-205,共5页
Objective:To investigate the mechanism of the reversal effect of acupuncture on the fall of blood pressure induced by angiotensin (1-7)[Ang-(1 7)] in the caudal ventrolateral medulla (CVLM) of rats. Methods: A... Objective:To investigate the mechanism of the reversal effect of acupuncture on the fall of blood pressure induced by angiotensin (1-7)[Ang-(1 7)] in the caudal ventrolateral medulla (CVLM) of rats. Methods: Ang-(1-7) and its selective receptor antagonist (DAla7), Ang(1-7) and Ang(779) were microinjected into the CVLM respectively to induce the change of blood pressure, during which, the concentrations of amino acid neurotransmitters were detected by means of microdialysis and high performance liquid chromatography (HPLC)combined with fluorescent detector, on the other hand, the effects of electro-acupuncture (EA) on the level of blood pressure and the concentrations of amino acid neurotransmitters were also observed. Results: Unilateral microinjection of Ang(1 7) into the CVLM could decrease the blood pressure (BP), which was accompanied by an increase in the release of Glu and a decrease in the release of Tau in the same site; Whereas microinjection of Ang-779 into the CVLM could elevate BP, which was accompanied by a decrease in the release of Glu and an increase in the release of Tau; EA at acupoint Zusanli (ST 36) for 20 min could inhibit the fall of blood pressure induced by microinjection of Ang-(1-7) into the CVLM and the elevation of blood pressure induced by microinjection of Ang-779 into the CVLM, and in the meantime, it could inhibit the changes of the release of Glu and Tau induced by microinjection of Ang-(1-7) and Ang-779 into the CVLM. Conclusion: The reversal effect of EA on the fall or elevation of blood pressure induced by microinjection of Ang-(1-7) or Ang-779 into the CVLM might be related to the changes of Glu and Tau release. 展开更多
关键词 Caudal Ventrolateral Medulla ELECTRO-ACUPUNCTURE Blood Pressure Amino Acid Neurotransmitters
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Assessment of food supplementation and surveillance as techniques to reduce damage caused by black capuchin monkeys Sapajus nigritus to forest plantations
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作者 Sandra Bos MIKICH 《Current Zoology》 SCIE CAS CSCD 2014年第5期581-590,共10页
Black capuchin monkeys Sapajus nigritus are among several mammalian species that damage forest plantations, pri- marily plantations of pine trees (Pinus spp.) in South Brazil. Management practices to reduce these da... Black capuchin monkeys Sapajus nigritus are among several mammalian species that damage forest plantations, pri- marily plantations of pine trees (Pinus spp.) in South Brazil. Management practices to reduce these damages include supplemen- tary food offerings and plantation surveillance. To assess the efficiency of these techniques, four treatments were evaluated: feeding (F, with supplementary bananas and maize), surveillance (S, in situ, wherein men patrolled the plantations, deterring the monkeys), feeding + surveillance (FS) and control (no procedures) (C). The efficiency assessment of each treatment involved the number of recorded primate sightings in the treatments with the presence of guards (S and FS) and a damage inventory of the outskirts of the experimental points immediately before and after the experiment. These data were complemented by a simulta- neous study of the availability of fruit, the primary item in the diet of this primate species, in the remnant native forest in the study area. Most sightings of S. nigritus occurred early in the morning, and in general, sightings were inversely proportional to the availability of native fruits. This trend was most evident in treatment FS, most likely due to the presence of food. Treatments F and FS exhibited higher percentages of damage, indicating that these are inefficient management techniques. Treatment S exhi- bited the lowest damage rate, but at a high cost, making this technique difficult to apply over large expanses. The development of other management techniques, such as environmental enrichment and the use of deterrents, is recommended to minimize the damage caused by capuchins in forest plantations [Current Zoology 60 (5): 581-590, 2014]. 展开更多
关键词 CEBUS Damage control Wildlife management PINUS Food provisioning
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