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Chyle leak following root of mesentery dissection in pancreaticoduodenectomy with inferior infracolic superior mesenteric artery first approach
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作者 Prabir Maharjan Sujan Regmee +5 位作者 Spandan D Adhikari Rabin Pahari Roshan Ghimire Dhiresh K Maharjan Suman K Shrestha Prabin B Thapa 《World Journal of Clinical Cases》 SCIE 2025年第8期8-14,共7页
BACKGROUND The root of mesentery dissection is one of the critical maneuvers,especially in borderline resectable pancreatic head cancer.Intra-abdominal chyle leak(CL)including chylous ascites may ensue in up to 10%of ... BACKGROUND The root of mesentery dissection is one of the critical maneuvers,especially in borderline resectable pancreatic head cancer.Intra-abdominal chyle leak(CL)including chylous ascites may ensue in up to 10%of patients after pancreatic resections.Globally recognized superior mesenteric artery(SMA)first approaches are invariably performed.The mesenteric dissection through the inferior infracolic approach has been discussed in this study emphasizing its post-operative impact on CL which is the cornerstone of this study.AIM To assess incidence,risk factors,clinical impact of CL following root of mesentery dissection,and the different treatment modalities.METHODS This is a retrospective study incorporating the patients who underwent dissection of the root of mesentery with inferior infracolic SMA first approach pancreat-oduodenectomy for the ventral body and uncinate mass of pancreas in the Department of Gastrointestinal and General Surgery of Kathmandu Medical College and Teaching Hospital from January 1,2021 to February 28,2024.Intraop-erative findings and postoperative outcomes were analyzed.RESULTS In three years,ten patients underwent root of mesentery dissection with inferior infracolic SMA first approach pancreatoduodenectomy.The mean age was 67.6 years with a male-to-female ratio of 4:5.CL was seen in four patients.With virtue of CL,Clavien-Dindo grade Ⅱ or higher morbidity was observed in four patients.Two patients had a hospital stay of more than 20 days with the former having a delayed gastric emptying and the latter with long-term total parenteral nutrition requirement.The mean operative time was 330 minutes.Curative resection was achieved in 100%of the patients.The mean duration of the intensive care unit and hospital stay were 2.55±1.45 days and 15.7±5.32 days,respectively.CONCLUSION Root of mesentery dissection with lymphadenectomy and vascular resection correlated with occurrence of CL.After complete curative resection,these were managed with total parenteral nutrition without adversely impacting outcome. 展开更多
关键词 Chyle leak Chylous ascites Clavien-Dindo Pancreatoduodenectomy Root of mesentery dissection superior mesenteric artery first approach Total parenteral nutrition Uncinate mass Vascular resection Ventral body mass
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Colossal well-differentiated liposarcoma of the small bowel mesentery:A case report
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作者 Yong Tian Guo-Qin Liu +2 位作者 Chuan-Fang Li Qing-Ming Tian Song Qiao 《World Journal of Gastrointestinal Oncology》 2026年第1期263-272,共10页
BACKGROUND Well-differentiated small bowel mesenteric liposarcoma(LPS)is rare,with high malignancy,poor prognosis,and high preponderance to local recurrence.CASE SUMMARY Here we described a 71-year-old male,who compla... BACKGROUND Well-differentiated small bowel mesenteric liposarcoma(LPS)is rare,with high malignancy,poor prognosis,and high preponderance to local recurrence.CASE SUMMARY Here we described a 71-year-old male,who complains of persistent abdominal distension for a month.The clinical manifestation is a huge abdominal mass occupying almost the entire abdomen.Physical examination indicated palpable massive mass in the abdomen,hard texture,indefinable boundary,poor mobility.The abdominal enhanced computed tomography at another hospital scan showed multiple abdominal masses originating from the small bowel mesentery.Abdominal and pelvic magnetic resonance imaging at our hospital showed multiple masses in the abdominal and pelvic cavities,indicating that the tumor originated from the mesentery or peritoneum.Results of exploratory laparotomy indicated that the tremendous mass primarily results from the mesentery of the small intestine,occupying the entire abdominal cavity in a polymorphic and lobulated shape.The patient underwent complete surgical resection of the tumor,and the weight of the tumor was approximately 11 kg.The histopathological examination of the resected specimens confirmed the diagnosis of well-differentiated LPS of the small bowel mesentery.CONCLUSION Completed surgical resection was cornerstone,and histopathological and molecular confirmations were crucial.The necessity of adjuvant therapy should be phrased as a potential consideration to improve patient’s survival time. 展开更多
关键词 Well-differentiated liposarcoma Small bowel mesentery Colossal liposarcoma MDM2 gene amplification Case report
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Superior mesenteric venous thrombosis after laparoscopic radical resection of rectal cancer: a report of a rare case and literature review 被引量:9
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作者 Xinliang Jin Weijie Xue +5 位作者 Yixiu Wang Qinkai Xue Zhiqi Gong Yongke Liu Zhaojian Niu Chengzhan Zhu 《Oncology and Translational Medicine》 2018年第6期266-269,共4页
Mesenteric venous thrombosis(MVT) is rare, but life-threatening. MVT is often characterized by occult and nonspecific signs and symptoms. Diagnosis requires a high index of clinical suspicion, and emergency surgery is... Mesenteric venous thrombosis(MVT) is rare, but life-threatening. MVT is often characterized by occult and nonspecific signs and symptoms. Diagnosis requires a high index of clinical suspicion, and emergency surgery is necessary to optimize patient survival, especially in people aged more than 70 years. MVT is a rare but fatal complication after laparoscopic radical surgery for rectal cancer. This study reports a case of extensive intestinal ischemic infarction caused by acute MVT after laparoscopic radical surgery for rectal cancer in a 70-year-old male. 展开更多
关键词 VENOUS thrombosis mesentery radical RESECTION of RECTAL cancer intestinal NECROSIS
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Dedifferentiated liposarcoma of the small bowel mesentery presenting as a submucosal mass 被引量:3
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作者 Eun-Jung Cha 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2011年第7期116-118,共3页
Dedifferentiated liposarcoma(DDLPS) is a variant of liposarcoma but with a more aggressive course.It occurs most commonly in the retroperitoneum and rarely in any other anatomical location.We describe a case of DDLPS ... Dedifferentiated liposarcoma(DDLPS) is a variant of liposarcoma but with a more aggressive course.It occurs most commonly in the retroperitoneum and rarely in any other anatomical location.We describe a case of DDLPS arising from the small bowel mesentery presenting as submucosal mass of the small bowel.The current case is unusual as the tumor originated from the small bowel mesentery and a dedifferentiated component transmurally invaded the small bowel wall,including the small bowel submucosa. 展开更多
关键词 Dedifferentiated LIPOSARCOMA Small BOWEL mesentery
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Tuberculosis versus non-Hodgkin's lymphomas involving small bowel mesentery:Evaluation with contrast-enhanced computed tomography 被引量:5
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作者 Peng Dong Bin Wang Quan-Ye Sun Hui Cui 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第24期3914-3918,共5页
AIM: To evaluate the specific computed tomography (CT) imaging criteria for differentiating tuberculosis involving the small bowel mesenteric lymph nodes from lymphomas. METHODS: We retrospectively reviewed the anatom... AIM: To evaluate the specific computed tomography (CT) imaging criteria for differentiating tuberculosis involving the small bowel mesenteric lymph nodes from lymphomas. METHODS: We retrospectively reviewed the anatomic distribution,CT enhancement patterns of lymphoma in 18 patients with mesenteric tuberculosis and 22 with untreated non-Hodgkin’s lymphomas (NHL) involving small bowel mesentery (SBM). Of the 18 patients with tuberculosis,9 had purely mesenteric tuberculous lymphadenopathy (TL),and 9 had mesenteric TL accompanied with tuberculous mesenteritis (TLM). RESULTS: CT showed that tuberculosis and NHL mainly affected lymph nodes in the body and root of SBM. Homogeneously enhanced lymph nodes in the body and root of SBM were found more often in the NHL (P < 0.05). Homogeneously mixed peripheral enhanced lymph nodes in the body of SBM were found more often in mesenteric TL and TLM (P < 0.05). Peripheral enhanced lymph nodes in the root of SBM were found more often in mesenteric TL and TLM (P < 0.01). "Sandwich sign" in the root of SBM was observed more often in NHL (P < 0.05). CONCLUSION: Anatomic lymph node distribution,sandwich sign and specific enhancement patterns of lymphadenopathy in SBM on CT images can be used in differentiating between tuberculosis and untreated NHL involving SBM. 展开更多
关键词 TUBERCULOSIS LYMPHOMA mesentery X-ray Computed tomography
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Glytan decreases portal pressure via mesentery vasoconstriction in portal hypertensive rats 被引量:1
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作者 Qing-Hong Du Lin Han +5 位作者 Jun-Jie Jiang Ya Xu Wei-Hong Li Peng-Tao Li Xin-Yue Wang Xu Jia 《World Journal of Gastroenterology》 SCIE CAS 2014年第44期16674-16682,共9页
AIM: To investigate the effects of Glytan on splanchnic hemodynamics and its reduction of portal pressure in portal hypertensive rats.
关键词 Glytan Portal hypertension HEMODYNAMICS mesentery ENDOTHELIN-1 Receptor Sensitivity
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Successful treatment of a giant ossified benign mesenteric schwannoma 被引量:1
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作者 Ying-Sheng Wu Shao-Yan Xu +3 位作者 Jing Jin Ke Sun Zhen-Hua Hu Wei-Lin Wang 《World Journal of Gastroenterology》 SCIE CAS 2018年第2期303-309,共7页
Primary benign schwannoma of the mesentery is extremely rare. To date, only 9 cases have been reported in the English literature, while mesenteric schwannoma with ossified degeneration has not been reported thus far. ... Primary benign schwannoma of the mesentery is extremely rare. To date, only 9 cases have been reported in the English literature, while mesenteric schwannoma with ossified degeneration has not been reported thus far. In the present study, we present the first giant ossified benign mesenteric schwannoma in a 58-year-old female. Ultrasound, computed tomography and magnetic resonance imaging were used, but it was still difficult to determine the definitive location and diagnose the mass. By laparotomy, a 10.0 cm × 9.0 cm × 9.0 cm giant mass was found in the mesentery and was then completely resected. Microscopically, the tumour located in the mesentery mainly consisted of spindleshaped cells with a palisading arrangement. Some areas of the tumour were ossified, and a true metaplastic bone formation was observed, with the presence of bone lamellae and osteoblasts. Immunohistochemical investigation of the tumour located in the mesentery showed that the staining for the S-100 protein was strongly positive, while the stainings of SMA, CD34, CD117 and DOG-1 were negative. The cell proliferation index, measured with Ki67 staining, was less than 3%. Finally, a giant ossified benign mesenteric schwannoma was diagnosed. After surgery, the patient was followed up for a period of 43 mo, during which she remained well, with no evidence of tumour recurrence. 展开更多
关键词 SCHWANNOMA mesentery OSSIFICATION LAPAROTOMY S-100
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An unusual presentation of sclerosing mesenteritis as pneumoperitoneum: Case report with a review of the literature 被引量:3
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作者 Sumita Chawla Satheesh Yalamarthi +2 位作者 Irshad A Shaikh Veena Tagore Paul Skaife 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第1期117-120,共4页
Sclerosing mesenteritis is a rare condition that involves the small or large bowel mesentery. An unusual presentation of this condition, which led to difficult preoperative assessment and diagnosis, is described. This... Sclerosing mesenteritis is a rare condition that involves the small or large bowel mesentery. An unusual presentation of this condition, which led to difficult preoperative assessment and diagnosis, is described. This report is followed by a comprehensive review of the literature. 展开更多
关键词 Mesenteritis PANNICULITIS Small bowelobstruction mesentery
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Relationship between abdominal trauma or surgery and mesenteric panniculitis 被引量:1
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作者 Taylan Kara Murat Canyigit 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第48期6139-6139,共1页
Mesenteric panniculitis is a rare disease characterized by chronic non-specific inflammation of mesenteric fat tissue.Several etiologic and/or associated factors have been reported in the literature so far.Although tr... Mesenteric panniculitis is a rare disease characterized by chronic non-specific inflammation of mesenteric fat tissue.Several etiologic and/or associated factors have been reported in the literature so far.Although trauma or surgery is one of the potential etiologic factors for mesenteric panniculitis,to the best of our knowledge,no strong correlation has been shown in the literature until now. 展开更多
关键词 mesentery PATHOLOGY Mesenteric panniculitis TRAUMA suRGERY
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SENP1通过PPARY去SUMO化修饰调控NF⁃κB信号通路参与糖尿病肾病进展的作用
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作者 陈淑娟 周丽明 +1 位作者 刘雪婷 李明政 《解剖学研究》 2025年第3期230-237,共8页
目的探讨小泛素样修饰体特异性肽酶1(SENP1)通过过氧化物酶体增殖物激活受体γ(PPARγ)去小泛素样修饰体(SUMO)化修饰调控核因子⁃κB(NF⁃κB)信号通路参与糖尿病肾病(DN)进展的作用和机制。方法取肾小球系膜细胞,分为肾小球系膜细胞(NC... 目的探讨小泛素样修饰体特异性肽酶1(SENP1)通过过氧化物酶体增殖物激活受体γ(PPARγ)去小泛素样修饰体(SUMO)化修饰调控核因子⁃κB(NF⁃κB)信号通路参与糖尿病肾病(DN)进展的作用和机制。方法取肾小球系膜细胞,分为肾小球系膜细胞(NC)组、高糖诱导的肾小球系膜细胞(HGMC组)、高糖诱导的肾小球系膜细胞+SENP1沉默质粒对照(si⁃NC1组)、高糖诱导的肾小球系膜细胞+SENP1沉默质粒(si⁃SENP1)组、高糖诱导的肾小球系膜细胞+SENP1过表达对照(mimic⁃NC1组)、高糖诱导的肾小球系膜细胞+SENP1过表达质粒(mimic⁃SENP1组)、高糖诱导的肾小球系膜细胞+PPARγ沉默对照(si⁃NC2组)、高糖诱导的肾小球系膜细胞+PPARγ沉默质粒(si⁃PPARγ组)、高糖诱导的肾小球系膜细胞+PPARγ过表达对照(mimic⁃NC2组)、高糖诱导的肾小球系膜细胞+PPARγ过表达质粒(mimic⁃PPARγ组)、高糖诱导的肾小球系膜细胞+SENP1过表达质粒+PPARγ过表达质粒(mimic⁃SENP1+mimic⁃PPARγ)。以qRT⁃PCR法检测各组SENP1、PPARγ表达;采用免疫印迹法检测NF⁃κB信号通路蛋白表达;TUNEL法检测细胞凋亡;免疫共沉淀验证SENP1可对PPARγ去SUMO化修饰。结果与NC组比,HGMC组SENP1及PPARγmRNA表达均显著降低(P<0.05),NF⁃κB1、IKKα1、IκBα蛋白1表达、细胞凋亡率均显著增加(P<0.05),与HGMC组或si⁃NC1组比,si⁃SENP1组的SENP1及PPARγmRNA表达均显著降低(P<0.05),NF⁃κB、IKKα、IκBα蛋白表达、细胞凋亡率均显著增加(P<0.05),与HGMC组或mimic⁃NC1组比,mimic⁃SENP1组的SENP1及PPARγmRNA表达均显著增加(P<0.05),NF⁃κB、IKKα、IκBα蛋白表达、细胞凋亡率均显著降低(P<0.05),与HGMC组或si⁃NC2组比,si⁃PPARγ组的PPARγmRNA达显著降低(P<0.05),NF⁃κB、IKKα、IκBα蛋白表达、细胞凋亡率均显著增加(P<0.05),与HGMC组或mimic⁃NC2组比,mimic⁃PPARγ组的PPARγmRNA表达显著增加(P<0.05),NF⁃κB、IKKα、IκBα蛋白表达、细胞凋亡率均显著降低(P<0.05),与mimic⁃SENP1组或mimic⁃PPARγ组比,mimic⁃SENP1+mimic⁃PPARγ组的SENP1及PPARγmRNA表达均显著增加(P<0.05),NF⁃κB、IKKα、IκBα蛋白表达、细胞凋亡率均显著降低(P<0.05)。结论SENP1可能通过PPARγ去SUMO化修饰抑制NF⁃κB信号通路参与DN进展。 展开更多
关键词 糖尿病肾病 小泛素样修饰体特异性肽酶1 过氧化物酶体增殖物激活受体Γ su⁃MO化修饰 核因子⁃κB信号通路
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SUS301L不锈钢电阻点焊接头的微观组织和力学性能研究
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作者 杨亮 揣荣岩 +4 位作者 薛丹 刘芳 刘昆霖 刘畅 蔡桂喜 《材料研究学报》 北大核心 2025年第6期435-442,共8页
使用显微硬度仪、电子拉伸剪切试验机、SEM和IBIS等手段表征SUS301L不锈钢电阻点焊接头不同区域的微观组织、微区性能、断口形貌并研究其力学性能。结果表明,接头的熔核形貌呈椭圆形,分为母材区、热影响区和熔核区。接头熔核的边缘至核... 使用显微硬度仪、电子拉伸剪切试验机、SEM和IBIS等手段表征SUS301L不锈钢电阻点焊接头不同区域的微观组织、微区性能、断口形貌并研究其力学性能。结果表明,接头的熔核形貌呈椭圆形,分为母材区、热影响区和熔核区。接头熔核的边缘至核心区域的组织分布依次为柱状枝晶和等轴枝晶,接头的主要缺陷有熔核边缘的飞溅、熔核心部的缩孔和微裂纹,飞溅与缩孔的发生密切相关。熔核的直径是影响接头力学性能的关键因素,其力学性能与熔核直径呈正相关。随着双层板厚度的增加,单位熔核直径的增量产生的最大拉剪力增量随之显著增大。热影响区的硬度和强度均低于母材区和熔核区,导致在塑性环形成了一个软化区。这种软化区的强度较低,能承载的拉剪力较小,因此成为拉剪开裂的起始区域。拉剪断裂形式分为穿核断裂和沿核断裂,熔核的直径影响接头的断裂形式。 展开更多
关键词 金属材料 suS301L不锈钢 电阻点焊 力学性能 断裂机理 显微组织
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固体氧化物燃料电池用Ti_(3)SiC_(2)/SUS430复合双极板材料直接扩散焊接连接性能
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作者 韦守李 徐斌 +7 位作者 时婧 孙明月 程强 赵经香 常修亮 戴作强 李希超 郑莉莉 《材料科学与工程学报》 北大核心 2025年第1期62-67,共6页
本研究提出将一种Ti_(3)SiC_(2)/SUS430复合双极板材料的金属放置于阳极一侧,陶瓷放置于阴极一侧,从而避免“阴极毒化”现象。研究利用Gleeble 3500热模拟试验机在850~1150℃下对SUS430和Ti_(3)SiC_(2)进行直接扩散焊接,通过观察接头界... 本研究提出将一种Ti_(3)SiC_(2)/SUS430复合双极板材料的金属放置于阳极一侧,陶瓷放置于阴极一侧,从而避免“阴极毒化”现象。研究利用Gleeble 3500热模拟试验机在850~1150℃下对SUS430和Ti_(3)SiC_(2)进行直接扩散焊接,通过观察接头界面的微观形貌,研究了焊接温度对接头结构和组织的影响。研究结果表明,当焊接温度低于950℃时,基体元素并未发现明显的互扩散,难以获得可靠接头;当焊接温度为1050℃时,SUS430与Ti_(3)SiC_(2)陶瓷界面之间已经实现了紧密贴合,呈现出不连续的锯齿状;当焊接温度高于1150℃时,Si挥发向SUS430基体扩散,使得Ti_(3)SiC_(2)产生拓扑分解,同时Fe、Cr向Ti_(3)SiC_(2)基体扩散,界面处产生了反应层,两种材料基本实现了有效连接。由于两种材料的热膨胀性能不匹配,会出现焊接裂缝,可考虑添加中间层进行扩散焊接,以获得结合更紧密的复合双极板材料。 展开更多
关键词 固体氧化物燃料电池 Ti_(3)SiC_(2) suS430 扩散焊接 界面反应
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SUS304不锈钢极薄带电脉冲辅助拉伸试验研究
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作者 刘红艳 范婉婉 +3 位作者 杨亚玉 王炳超 和东平 王涛 《锻压技术》 北大核心 2025年第11期200-208,共9页
为了定量分析非热效应对SUS304不锈钢极薄带拉伸变形的影响,通过拉伸至相同应变(ε_(en)=30%),进行了室温拉伸、电脉冲辅助拉伸和相同温度下的加热拉伸试验。基于上述试验探究了SUS304不锈钢极薄带在不同脉冲电流下力学性能和微观组织... 为了定量分析非热效应对SUS304不锈钢极薄带拉伸变形的影响,通过拉伸至相同应变(ε_(en)=30%),进行了室温拉伸、电脉冲辅助拉伸和相同温度下的加热拉伸试验。基于上述试验探究了SUS304不锈钢极薄带在不同脉冲电流下力学性能和微观组织的变化规律。结果表明,非热效应可以使试样的加工硬化效果减弱。随着脉冲电流的增加,试样的屈服强度、抗拉强度和显微硬度逐渐降低。同时,非热效应可以使试样变形均匀,降低位错堆积,试样内晶粒尺寸逐渐增大,小角度晶界逐渐减少,孪晶界逐渐增加,促进了织构聚集。当脉冲电流增大至2.5 A时,变形晶粒的体积分数相比室温拉伸试样减少了57.5%,表明脉冲电流加速了变形晶粒在较低温度下的动态回复。 展开更多
关键词 suS304不锈钢 极薄带 脉冲电流辅助成形 非热效应 相同应变
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基于DBO-LSTM的磁粒研磨SUS304细长管内表面工艺参数优化研究
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作者 唐嘉斌 郭龙文 +3 位作者 王天 肖春芳 矫彦婷 韩冰 《电镀与精饰》 北大核心 2025年第7期64-73,共10页
利用磁粒研磨技术对SUS304不锈钢细长管内表面光整加工时,由于影响研磨效果的因素众多,导致最佳工艺参数难以确定。本文设计4因素4水平正交试验,分析主轴转速、磁极进给速度、粗精加工磨粒粒径组合和粗精加工时间比对表面粗糙度值的影... 利用磁粒研磨技术对SUS304不锈钢细长管内表面光整加工时,由于影响研磨效果的因素众多,导致最佳工艺参数难以确定。本文设计4因素4水平正交试验,分析主轴转速、磁极进给速度、粗精加工磨粒粒径组合和粗精加工时间比对表面粗糙度值的影响。并构建蜣螂算法(DBO)优化长短期记忆神经网络(LSTM)的表面粗糙度预测模型,预测模型的拟合优度R^(2)为0.9769,均方根误差(RMSE)为0.0179,平均绝对误差(MAE)为0.0162。再次利用DBO算法进行全局寻优,得到最佳工艺参数组合为:主轴转速2715 r/min,外部磁极进给速度为4 mm/s,粗精加工磨粒粒径组合为80目和100目,粗精加工时间比为1.35∶1,预测的表面粗糙度Ra为0.080μm。对上述工艺参数进行微调并进行试验,结果表明:得到的表面粗糙度Ra为0.078μm,与预测值的相对误差RE约为2.56%。应用最佳工艺参数组合进行试验,在降低SUS304细长管内表面粗糙度值的同时,还能改善其表面微观形貌,提升加工效率。 展开更多
关键词 磁粒研磨 suS304细长管 DBO-LSTM预测模型 表面粗糙度值 工艺参数
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统一视角下的几个物理概念:SU(1,1)群的启示
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作者 张仁 谢吉坤 +2 位作者 马胜利 吕辰威 张威 《物理与工程》 2025年第2期67-73,共7页
通过统一的视角重新审视物理学中看似不相关的多个概念,不仅为科学研究提供了新的思路,也可以极大促进物理教学的深度和广度。本文以SU(1,1)群为例,探讨了如何将这一数学工具应用于物理学的不同领域,从而揭示其在不同物理现象中的核心... 通过统一的视角重新审视物理学中看似不相关的多个概念,不仅为科学研究提供了新的思路,也可以极大促进物理教学的深度和广度。本文以SU(1,1)群为例,探讨了如何将这一数学工具应用于物理学的不同领域,从而揭示其在不同物理现象中的核心作用。采用对比分析的研究方法,本文首先通过狭义相对论中的洛伦兹变换展示了SU(1,1)群如何帮助我们更加深刻地理解这一变换的物理本质。然后,本文转向量子力学,探讨了SU(1,1)群在描述简谐振子问题中的应用,揭示了其在量子态演化中的关键作用。在凝聚态物理领域,文章讨论了波戈留波夫变换的统一描述,强调了SU(1,1)群在理解凝聚态系统相变中的重要性。最后,文章还探讨了量子光学中的压缩态,展示了SU(1,1)群在描述光场压缩态特性中的应用,进一步揭示了其在量子信息处理中的潜力。通过SU(1,1)群的视角,本文总结了这些物理概念共同的数学基础和普适的物理规律,不仅使学生加深了对这些物理概念的理解,也促进了他们对物理对称性思想的深入认识,从而为物理教育和研究提供了新的视角和方法。 展开更多
关键词 su(1 1)群 洛伦兹变换 简谐振子 波戈留波夫变换
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不同焊丝激光-MIG复合焊接SUS301L/Q450NQR1异种钢接头的组织及性能 被引量:1
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作者 邱培现 邓鸿剑 +4 位作者 陈北平 张纹源 孙中文 朱宗涛 何绍雄 《电焊机》 2025年第1期101-107,共7页
为了降低成本,采用ER309LSi和CHW-55CNH两种不同焊丝,利用激光-MIG复合焊对Q450NQR1和SUS301L钢板进行对接焊,对比研究了两种焊丝接头的组织与性能。结果表明:两种焊丝接头均无未焊透、未熔合等缺陷,焊缝表面呈明显的鱼鳞纹;ER309LSi焊... 为了降低成本,采用ER309LSi和CHW-55CNH两种不同焊丝,利用激光-MIG复合焊对Q450NQR1和SUS301L钢板进行对接焊,对比研究了两种焊丝接头的组织与性能。结果表明:两种焊丝接头均无未焊透、未熔合等缺陷,焊缝表面呈明显的鱼鳞纹;ER309LSi焊丝接头焊缝中心区主要为树枝状结晶的奥氏体以及少量铁素体组成;CHW-55CNH焊丝接头焊缝中心区主要由先共析铁素体以和珠光体组成;CHW-55CNH焊丝接头焊缝硬度(374 HV)大于ER309LSi焊丝接头(217 HV);ER309LSi焊丝接头平均抗拉强度(632.3 MPa)略大于CHW-55CNH焊丝接头(608.6 MPa);两种焊丝接头的中性盐雾腐蚀试验结果相差不大,电化学分析试验结果表明ER309LSi焊丝接头的耐蚀性优于CHW-55CNH焊丝接头。综上,当构件受力或耐蚀性要求不严格的时候,可以用价格较低的CHW-55CNH焊丝替代ER309LSi焊丝。 展开更多
关键词 激光-MIG复合焊 Q450NQR1钢 suS301L不锈钢 力学性能 耐蚀性
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冷变形SUS304奥氏体不锈钢再结晶行为
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作者 飞尚才 蒋小霞 《锻压技术》 北大核心 2025年第1期215-219,共5页
为了提高SUS304奥氏体不锈钢的加工性能、消除加工硬化、防止在冷轧过程中开裂,利用拉伸试验、金相观察等试验方法和手段,研究了不同退火工艺条件下,冷变形SUS304奥氏体不锈钢组织和性能的变化。研究发现:在同一退火时间下,随着退火温... 为了提高SUS304奥氏体不锈钢的加工性能、消除加工硬化、防止在冷轧过程中开裂,利用拉伸试验、金相观察等试验方法和手段,研究了不同退火工艺条件下,冷变形SUS304奥氏体不锈钢组织和性能的变化。研究发现:在同一退火时间下,随着退火温度的增加,强度下降,伸长率先升后降,晶粒尺寸逐渐增加;退火温度为1050℃时,随着退火时间的增加,碳化物逐渐溶入基体,材料的强度和伸长率不断增加;退火温度为1080℃时,随着退火时间的增长,屈服强度、抗拉强度有下降的趋势,而伸长率呈先升后降的趋势。在所有退火工艺中,1050℃×180 s条件下SUS304奥氏体不锈钢的综合性能最佳。 展开更多
关键词 suS304奥氏体不锈钢 退火工艺 强度 伸长率 孪晶
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New fossil materials of Sus lydekkeri from the Early Pleistocene Shanshenmiaozui site in Nihewan Basin of North China 被引量:1
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作者 TONG Hao-Wen CHEN Xi +1 位作者 ZHANG Bei SUN Ji-Jia 《古脊椎动物学报(中英文)》 北大核心 2025年第3期210-241,共32页
Suid is one of the most common taxa among the Pleistocene mammalian fauna in China.However,its phylogenetic taxonomy and evolution are far from clear.The newly recovered suid fossil materials from the Early Pleistocen... Suid is one of the most common taxa among the Pleistocene mammalian fauna in China.However,its phylogenetic taxonomy and evolution are far from clear.The newly recovered suid fossil materials from the Early Pleistocene Shanshenmiaozui site in Nihewan Basin in North China provide new insight into the evolution of its kind in North China.The new materials include partial skulls and mandibles of males,and most of their teeth were preserved in situ.The specimens can be referred to the species Sus lydekkeri,which is the only species of Sus found in North China from the Early Pleistocene.The fossils of the once reported Pleistocene species“Potamochoerus chinhsienensis”should also be provisionally included in the species S.lydekkeri according to its form and size,which at least now excludes it from Potamochoerus.The species S.lydekkeri is very close to the extant species S.scrofa,and even was combined into the latter as a chronological subspecies by some authors,while its larger size,prominent preorbital fossa,backwardly positioned infraorbital foramen,frequently appearing verrucosic type(at least the intermediate type of the male lower canine),and simple crown structures support its validness as an independent species.The Early Pleistocene forms are characterized by a larger size,lower L/W ratio of cheekteeth,both upper and lower M3s having no more than three lobes,and the male lower canine is exclusively of a verrucosic type.Suid fossils are a very good indicator of paleoenvironments and paleoclimate.Both the northern and the southern faunas in China contain suid fossils throughout the Pleistocene Epoch,while the southern fauna has prominently more diversified taxa and more abundant fossil collections;whether that is caused by different origins or by environmental modifications is still not clear. 展开更多
关键词 Shanshenmiaozui of Nihewan North China Early Pleistocene sus lydekkeri
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SUS304极薄带剪切过程中的包申格效应研究
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作者 魏晶磊 周存龙 +4 位作者 魏东 常泽斌 王天翔 廖席 段浩杰 《塑性工程学报》 北大核心 2025年第11期124-132,共9页
针对包申格效应可能会导致对材料性能的预测出现偏差,进而在制造过程中引发缺陷,降低生产效率的问题,选择SUS304极薄带作为研究对象,系统分析了不同晶粒尺寸的SUS304极薄带在循环剪切状态下包申格效应对其力学性能的影响。结果表明,随... 针对包申格效应可能会导致对材料性能的预测出现偏差,进而在制造过程中引发缺陷,降低生产效率的问题,选择SUS304极薄带作为研究对象,系统分析了不同晶粒尺寸的SUS304极薄带在循环剪切状态下包申格效应对其力学性能的影响。结果表明,随着预剪应变的增加,包申格系数逐渐增大,包申格效应因子逐渐减小,包申格效应随着预剪应变的增加而增强。随着晶粒尺寸的增大,SUS304极薄带在正向剪切过程中的屈服剪切强度和流动剪应力逐渐降低,包申格系数先增大后减小,包申格效应因子先减小后增大,包申格效应随着晶粒尺寸的增大呈现先减小后增大的趋势。 展开更多
关键词 suS304极薄带 包申格效应 循环剪切 预剪应变 晶粒尺寸
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喷丸表面强化对地铁端部底架用SUS301L不锈钢疲劳裂纹扩展行为的影响
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作者 杨莉 张勇 +2 位作者 张月莹 郑儒宏 崔耕 《热加工工艺》 北大核心 2025年第8期73-77,共5页
为了研究喷丸强化对材料疲劳裂纹扩展行为的影响,以地铁端部底架用SUS301L不锈钢为研究对象,采用紧凑拉伸试样进行了SUS301L不锈钢不同时间喷丸处理后的疲劳裂纹扩展试验。通过断口形貌特征、显微硬度、金相组织和残余应力分析,探讨了... 为了研究喷丸强化对材料疲劳裂纹扩展行为的影响,以地铁端部底架用SUS301L不锈钢为研究对象,采用紧凑拉伸试样进行了SUS301L不锈钢不同时间喷丸处理后的疲劳裂纹扩展试验。通过断口形貌特征、显微硬度、金相组织和残余应力分析,探讨了喷丸时间对其疲劳裂纹扩展行为的影响机制。结果表明:疲劳裂纹扩展速率随喷丸时间的延长而降低,尤其在ΔK(应力强度因子范围)较小时,喷丸20 min的裂纹扩展速率较喷丸5 min降低至25%,较未处理试样降低至20%。裂纹扩展速率的降低主要归结于喷丸处理在SUS301L不锈钢表面引起马氏体转变、晶粒细化和引入残余压应力。 展开更多
关键词 喷丸 疲劳裂纹扩展 suS301L不锈钢 马氏体转变 晶粒细化 残余压应力
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