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QP980淬火-配分钢热模拟激光焊接热影响区性能
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作者 王金凤 郭亿 +4 位作者 苏文超 车亚军 蔡笑宇 李文娟 徐肖飞 《焊接学报》 北大核心 2025年第7期1-8,共8页
文中采用Gleeble-3500热模拟系统对QP980淬火-配分钢激光焊接热影响区(heat affected zone,HAZ)不同亚区进行热模拟,通过研究HAZ不同亚区的组织和性能,并与焊接接头HAZ相同区域进行比较.结果表明,热模拟获得的焊接HAZ各亚区组织与激光... 文中采用Gleeble-3500热模拟系统对QP980淬火-配分钢激光焊接热影响区(heat affected zone,HAZ)不同亚区进行热模拟,通过研究HAZ不同亚区的组织和性能,并与焊接接头HAZ相同区域进行比较.结果表明,热模拟获得的焊接HAZ各亚区组织与激光焊接接头相同区域的组织一致.力学性能分析表明,在热模拟试样中,亚临界热影响区(sub-critical heat affected zone,SCHAZ)抗拉强度和硬度都最低,断后伸长率在整个焊接HAZ中最大.拉伸试验中SCHAZ发生了明显的伸长,表明延展性能相对较好.焊接接头横截面硬度分析表明,焊接接头的临界热影响区(inter-critical heat affected zone,ICHAZ)硬度低于母材(base metal, BM),为焊接接头的软化区.焊接接头的拉伸性能及横截面硬度分布表明焊接接头的薄弱区域位于焊接HAZ的ICHAZ,与模拟焊接HAZ的性能吻合.通过对SCHAZ的组织进行分析,相比BM的几何必须位错密度(geometrically necessary dislocations,GND)减少,平均晶粒尺寸增大,小角度晶界晶粒含量下降. 展开更多
关键词 qp980淬火-配分钢 激光焊接 模拟焊接热影响区 接头软化
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预淬火处理对超高强QP钢显微组织和力学性能的影响研究
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作者 朱娜琼 许明珠 +1 位作者 沈超 李麟 《热加工工艺》 北大核心 2025年第15期105-110,共6页
采用定量金相、SEM、TEM及XRD等检测技术结合室温拉伸试验,研究了预淬火处理对淬火-配分处理后超高强QP钢组织演变和力学性能的影响。结果表明:与未经预淬火的样品相比,经950℃预淬火的样品呈现细化的层片状组织,残余奥氏体以薄膜状为... 采用定量金相、SEM、TEM及XRD等检测技术结合室温拉伸试验,研究了预淬火处理对淬火-配分处理后超高强QP钢组织演变和力学性能的影响。结果表明:与未经预淬火的样品相比,经950℃预淬火的样品呈现细化的层片状组织,残余奥氏体以薄膜状为主并有少量块状,该组织有利于TRIP效应的发挥,同时可阻碍裂纹扩展,提高了实验钢的强塑性,在抗拉强度超过1200 MPa的情况下伸长率接近20%;当预淬火温度为990℃时,实验钢的组织呈等轴状特征,马氏体回火程度较高,造成残余奥氏体多呈块状分布而不利于TRIP效应发挥,加之组织内贝氏体及二次马氏体含量减少导致其强塑积下降。 展开更多
关键词 预淬火处理 qp 显微组织 力学性能 TRIP效应
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QP1180淬火-配分钢激光焊接接头微观组织及力学性能
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作者 李文娟 王金凤 +4 位作者 苏文超 郭亿 车亚军 蔡笑宇 王海林 《精密成形工程》 北大核心 2025年第2期85-93,共9页
目的对QP1180淬火-配分超高强钢的激光焊接工艺进行研究,以获得没有缺陷、能满足汽车零部件使用要求的焊接接头。方法将1.6 mm厚的QP1180钢板作为母材,对其进行激光焊接,通过改变焊接速度和激光输出功率的方式改变焊接热输入;利用扫描... 目的对QP1180淬火-配分超高强钢的激光焊接工艺进行研究,以获得没有缺陷、能满足汽车零部件使用要求的焊接接头。方法将1.6 mm厚的QP1180钢板作为母材,对其进行激光焊接,通过改变焊接速度和激光输出功率的方式改变焊接热输入;利用扫描电子显微镜(SEM)、液压拉伸试验机和维氏硬度计等手段,研究热输入对接头宏观成形、界面组织演变规律及接头力学性能的影响。结果在调整激光焊接工艺参数的条件下,在焊缝表面均未发现明显缺陷,焊缝表面成形良好。随着热输入的增加,QP1180钢激光焊接接头焊缝金属区上下表面以及最窄区域的宽度均有所增加,并且在同样热输入条件下,激光输出功率对焊缝宽度的影响大于焊接速度的影响。母材平均硬度约为375HV,软化区位于亚临界热影响区,软化区宽度随着热输入的增加而变宽。与母材相比,软化区平均硬度下降17HV~52HV,细晶区硬度最高为536HV,较母材硬度大幅增加。在所有能实现焊透的热输入下,工艺参数对焊接接头的强度和塑性影响较小,且均能获得性能良好的焊缝。结论获得了没有缺陷并能满足汽车零部件使用要求的焊接接头。 展开更多
关键词 qp1180淬火-配分钢 激光焊接 工艺参数 微观组织
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不等厚异质QP1180/DP1180钢板激光拼焊接头组织及性能研究
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作者 李文娟 王金凤 +5 位作者 苏文超 车亚军 王晶 郭亿 王海林 张元好 《精密成形工程》 北大核心 2025年第7期69-78,共10页
目的解决高强度钢QP1180和DP1180在汽车轻量化应用方面存在的热影响区软化等问题,进行了不等厚异质QP1180/DP1180钢板激光拼焊接头组织及性能研究。方法对1.6 mm厚QP1180钢和1.2 mm厚DP1180钢进行激光拼焊,通过扫描电子显微镜、液压拉... 目的解决高强度钢QP1180和DP1180在汽车轻量化应用方面存在的热影响区软化等问题,进行了不等厚异质QP1180/DP1180钢板激光拼焊接头组织及性能研究。方法对1.6 mm厚QP1180钢和1.2 mm厚DP1180钢进行激光拼焊,通过扫描电子显微镜、液压拉伸试验机和维氏硬度计等设备研究热输入对焊接接头微观组织和力学性能的影响。结果在不同焊接工艺参数下,激光焊接接头均为全焊透状态且表面成形良好。随着热输入的增大,焊缝金属区向母材区的过渡逐渐平缓、凹陷变小,上下表面宽度均有所增大,焊缝金属区板条马氏体束随着热输入的增加而变长,条束间距亦变宽,且宽度分布不均匀。热输入对QP1180侧和DP1180侧热影响区晶粒大小变化的影响规律基本一致,即热输入越大,粗晶区和细晶区的晶粒尺寸越大,临界热影响区铁素体含量也越多,QP1180侧亚临界热影响区析出的碳化物颗粒越多,但对DP1180侧亚临界热影响区微观组织的影响不明显。焊接接头两侧都存在明显的软化区,DP1180侧软化更为显著。在本研究所用焊接热输入条件下,单向拉伸试验中试样均断裂在母材区,由断口分析可知,所有工艺参数下的试样均为韧性断裂。结论在能形成全焊透的焊接工艺窗口内,均获得抗拉强度达到母材强度95%以上、断后伸长率达到母材断后伸长率30%以上的焊接接头。 展开更多
关键词 qp1180钢 DP1180钢 激光拼焊 微观组织 力学性能
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汽车用QP980钢模拟火灾后的组织与力学性能变化
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作者 李文通 亓海全 +5 位作者 笪仲钟 万宇 王为民 姚小凤 李欣欣 谢盈盈 《材料热处理学报》 北大核心 2025年第3期160-170,共11页
采用热处理模拟车辆受火的方法,设定不同的受热温度和保温时间及冷却方式,研究了车身结构钢QP980受热后组织及力学性能的变化。结果表明:在100~700℃受热冷却后,QP980钢的组织主要为铁素体和马氏体,铁素体略有长大。高于500℃后,其强度... 采用热处理模拟车辆受火的方法,设定不同的受热温度和保温时间及冷却方式,研究了车身结构钢QP980受热后组织及力学性能的变化。结果表明:在100~700℃受热冷却后,QP980钢的组织主要为铁素体和马氏体,铁素体略有长大。高于500℃后,其强度显著下降,伸长率略有提高;800℃加热空冷时,QP980钢的组织由铁素体及马氏体和少量贝氏体组成,马氏体含量略有增加,强度升高,但伸长率下降;水冷时,组织转变为马氏体和铁素体,马氏体体积分数显著升高,故而强度增加,伸长率急剧下降。900~1000℃奥氏体相区加热空冷时,QP980钢的组织主要为铁素体、马氏体以及贝氏体,受晶粒长大的影响,综合力学性能均发生不同程度的下降;水冷后则由马氏体与贝氏体构成,强度较高,伸长率极低。QP980车辆结构件在100~1000℃受火后,性能均将出现不同程度的劣化,无法继续满足车辆服役条件。 展开更多
关键词 qp980钢 先进高强钢 力学性能 显微组织 模拟火灾
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Interleukin-17A facilitates tumor progression via upregulating programmed death ligand-1 expression in hepatocellular carcinoma 被引量:1
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作者 Zhong-Xia Yang Li-Ting Zhang +2 位作者 Xiao-Jun Liu Xue-Bin Peng Xiao-Rong Mao 《World Journal of Gastrointestinal Oncology》 SCIE 2025年第1期176-198,共23页
BACKGROUND Hepatocellular carcinoma(HCC)is an inflammation-associated tumor with a dismal prognosis.Immunotherapy has become an important treatment strategy for HCC,as immunity is closely related to inflammation in th... BACKGROUND Hepatocellular carcinoma(HCC)is an inflammation-associated tumor with a dismal prognosis.Immunotherapy has become an important treatment strategy for HCC,as immunity is closely related to inflammation in the tumor microenvir-onment.Inflammation regulates the expression of programmed death ligand-1(PD-L1)in the immunosuppressive tumor microenvironment and affects im-munotherapy efficacy.Interleukin-17A(IL-17A)is involved in the remodeling of the tumor microenvironment and plays a protumor or antitumor role in different tumors.We hypothesized that IL-17A participates in tumor progression by affe-cting the level of immune checkpoint molecules in HCC.The upregulation of PD-L1 expression in HCC cells by IL-17A was assessed by reverse transcription PCR,western blotting,and flow cytometry.Mechanistic studies were conducted with gene knockout models and pathway inhibitors.The function of IL-17A in immune evasion was explored through coculture of T cells and HCC cells.The effects of IL-17A on the malignant biological behaviors of HCC cells were evaluated in vitro,and the antitumor effects of an IL-17A inhibitor and its synergistic effects with a PD-L1 inhibitor were studied in vivo.RESULTS IL-17A upregulated PD-L1 expression in HCC cells in a dose-dependent manner,whereas IL-17A receptor knockout or treatment with a small mothers against decapentaplegic 2 inhibitor diminished the PD-L1 expression induced by IL-17A.IL-17A enhanced the survival of HCC cells in the coculture system.IL-17A increased the viability,G2/M ratio,and migration of HCC cells and decreased the apoptotic index.Cyclin D1,VEGF,MMP9,and Bcl-1 expression increased after IL-17A treatment,whereas BAX expression decreased.The combination of IL-17A and PD-L1 inhibitors showed synergistic antitumor efficacy and increased cluster of differentiation 8+T lymphocyte infiltration in an HCC mouse model.CONCLUSION IL-17A upregulates PD-L1 expression via the IL-17A receptor/phosphorylation-small mothers against decapenta-plegic 2 signaling pathway in HCC cells.Blocking IL-17A enhances the therapeutic efficacy of PD-L1 antibodies in HCC in vivo. 展开更多
关键词 INTERLEUKIN-17A programmed death ligand-1 Interleukin-17A receptor Small mothers against decapentaplegic 2 Hepatocellular carcinoma IMMUNOTHERAPY
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QP980钢的连续冷却转变曲线及显微组织 被引量:1
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作者 易寒 彭立培 +3 位作者 蔡周彦 夏玉琳 白佳鑫 刘腾轼 《上海金属》 2025年第2期50-53,共4页
利用DIL805A热膨胀仪测定了QP980钢以不同速率冷却时的热膨胀曲线。采用切线法结合显微组织及硬度检测绘制了该钢的连续冷却转变曲线。结果表明:QP980钢的临界点Ac1和Ac3分别为707和891℃;以≤1℃/s的速率冷却后QP980钢的组织为铁素体... 利用DIL805A热膨胀仪测定了QP980钢以不同速率冷却时的热膨胀曲线。采用切线法结合显微组织及硬度检测绘制了该钢的连续冷却转变曲线。结果表明:QP980钢的临界点Ac1和Ac3分别为707和891℃;以≤1℃/s的速率冷却后QP980钢的组织为铁素体、珠光体和贝氏体,以2℃/s的速率冷却后为铁素体、贝氏体和马氏体,以≥5℃/s的速率冷却后为全马氏体。 展开更多
关键词 qp980 显微组织 硬度 CCT 曲线
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Relationship between Helicobacter pylori infection and programmed death-ligand 1 in gastric cancer:A meta-analysis 被引量:1
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作者 Hong-Chang Yang Cheng-Feng Fu +3 位作者 Li-Jun Qiao Gen-He Long Li-Fen Yang Biao Yao 《World Journal of Clinical Oncology》 2025年第4期280-290,共11页
BACKGROUND Gastric cancer(GC)is one of the most common malignancies worldwide,and Helicobacter pylori(HP)infection is a well-established risk factor for its development.Programmed death-ligand 1(PD-L1)expression is a ... BACKGROUND Gastric cancer(GC)is one of the most common malignancies worldwide,and Helicobacter pylori(HP)infection is a well-established risk factor for its development.Programmed death-ligand 1(PD-L1)expression is a crucial biomarker for predicting the efficacy of immune checkpoint inhibitors in cancer treatment.While HP infection and PD-L1 expression in GC may be linked,the relationship between them remains unclear,in part because there have been conflicting results reported from various studies.AIM To perform a meta-analysis to assess the relationship between HP and PD-L1 expression in patients with GC.METHODS A systematic literature review was conducted using PubMed,Embase,Cochrane Library,and Web of Science databases.Observational studies that examined the association between HP infection and PD-L1 expression in patients with GC were included.Odds ratios and 95%confidence intervals were calculated to estimate the association.Heterogeneity was assessed using Cochrane’s Q test and I²statistic.A random-effects model was used due to significant heterogeneity across studies.RESULTS Fourteen studies involving a total of 3069 patients with GC were included.The pooled analysis showed a significant association between HP infection and increased PD-L1 expression in GC tissues(odd ratio=1.69,95%confidence interval:1.24-2.29,P<0.001,I^(2)=59%).Sensitivity analyses confirmed the robustness of these findings.Subgroup analyses did not show significant variation based on geographic region,sample size,or method of PD-L1 assessment.Publication bias was minimal,as shown by funnel plots and Egger’s regression test.CONCLUSION HP infection is associated with increased PD-L1 expression in GC,suggesting that HP status may influence the response to programmed cell death protein 1/PD-L1 blockade therapy. 展开更多
关键词 Helicobacter pylori Gastric cancer programmed cell death protein 1/programmed death-ligand 1 Immune checkpoint blockade therapy PATHOGENESIS
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Glia-to-neuron reprogramming to the rescue?
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作者 Jack W.Hickmott Cindi M.Morshead 《Neural Regeneration Research》 SCIE CAS 2025年第5期1395-1396,共2页
Over the last two decades,the dogma that cell fate is immutable has been increasingly challenged,with important implications for regenerative medicine.The brea kth rough discovery that induced pluripotent stem cells c... Over the last two decades,the dogma that cell fate is immutable has been increasingly challenged,with important implications for regenerative medicine.The brea kth rough discovery that induced pluripotent stem cells could be generated from adult mouse fibroblasts is powerful proof that cell fate can be changed.An exciting extension of the discovery of cell fate impermanence is the direct cellular reprogram ming hypothesis-that terminally differentiated cells can be reprogrammed into other adult cell fates without first passing through a stem cell state. 展开更多
关键词 programming PASSING proof
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Neurocircuit regeneration by extracellular matrix reprogramming
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作者 Shengzhang Su Ian N.Levasseur Kimberly M.Alonge 《Neural Regeneration Research》 SCIE CAS 2025年第8期2300-2301,共2页
The brain's extracellular matrix(ECM),which is comprised of protein and glycosaminoglycan(GAG)scaffolds,constitutes 20%-40% of the human brain and is considered one of the largest influencers on brain cell functio... The brain's extracellular matrix(ECM),which is comprised of protein and glycosaminoglycan(GAG)scaffolds,constitutes 20%-40% of the human brain and is considered one of the largest influencers on brain cell functioning(Soles et al.,2023).Synthesized by neural and glial cells,the brain's ECM regulates a myriad of homeostatic cellular processes,including neuronal plasticity and firing(Miyata et al.,2012),cation buffering(Moraws ki et al.,2015),and glia-neuron interactions(Anderson et al.,2016).Considering the diversity of functions,dynamic remodeling of the brain's ECM indicates that this understudied medium is an active participant in both normal physiology and neurological diseases. 展开更多
关键词 MATRIX programMING
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Cytoplasmic and nuclear programmed death ligand 1 expression in peritumoral stromal cells in breast cancer:Prognostic and predictive value 被引量:1
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作者 Evgeniya Yu Zubareva Marina A Senchukova Natalia V Saidler 《World Journal of Experimental Medicine》 2025年第2期150-170,共21页
BACKGROUND Breast cancer(BC)continues to occupy a leading position in terms of morbidity and mortality from malignant neoplasms among the female population.One of the promising markers associated with BC progression i... BACKGROUND Breast cancer(BC)continues to occupy a leading position in terms of morbidity and mortality from malignant neoplasms among the female population.One of the promising markers associated with BC progression is programmed death ligand 1(PD-L1).Previously,we investigated PD-L1 expression in BC via a new antibody against programmed cell death protein 1 ligand 1(PDCD1 LG1)and reported that high PDCD1 LG1 expression in tumor cells is an independent factor for a high risk of regional metastasis in patients with BC.However,the prognostic significance of PDCD1 LG1 expression in BC stromal cells has not been adequately studied.AIM To study the features of PDCD1 LG1 expression in BC stromal cells and its relationship with BC clinicopathological characteristics.METHODS In a prospective single-center observational study,tumor samples from 148 patients with newly diagnosed BC were examined.The tumor sections were immunohistochemically stained with antibodies against PDCD1 LG1.In the tumor samples,the PDCD1 LG1-positive lymphocyte(PDCD1 LG1+LF)score,presence of nuclear PDCD1 LG1 expression in the LFs,PDCD1 LG1 expression in polymorphic cell infiltrates(PDCD1 LG1+polymorphic cell infiltrates[PCIs]),and cells of the fibroblastic stroma and endothelial cells of the tumor microvessels were assessed.Statistical analyses were performed using Statistica 10.0 software.RESULTS A PDCD1 LG1+LF score≥3 was detected more often at stages N0 and N3 than at N1 and N2(P=0.03).Moderate and pronounced PDCD1 LG1+PCIs and the presence of PDCD1 LG1+fibroblastic stroma were associated with negative estrogen receptor status(P=0.0008 and P=0.03,respectively),human epidermal growth factor receptor 2-positive(HER2+)BC(P<0.00001 and P=0.0005),and luminal B HER2+,non-luminal HER2+and triple-negative BC(P<0.00001 and P=0.004).The risk of metastasis to regional lymph nodes(RLNs)depend on lymphovascular invasion(LVI)and the PDCD1 LG1+LF score.In the absence of LVI and a PDCD1 LG1+LF score<3 or≥3,metastases in RLNs were absent in 66.6%and 93.9%of patients with BC,respectively.In the presence of LVI and a PDCD1 LG1+LF score<3 or≥3,metastases in RLNs were detected in 82.6%and 92.7%of patients with BC,respectively.CONCLUSION The results indicated that the combined assessment of the PDCD1 LG1+LF score and LVI can improve the accuracy of predicting the risk of metastasis to RLNs in patients with BC. 展开更多
关键词 Breast cancer programmed death-ligand 1 Regional metastasis Tumor stroma
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Safe flight corridor constrained sequential convex programming for efficient trajectory generation of fixed-wing UAVs 被引量:2
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作者 Jing SUN Guangtong XU +2 位作者 Zhu WANG Teng LONG Jingliang SUN 《Chinese Journal of Aeronautics》 2025年第1期537-550,共14页
Generating dynamically feasible trajectory for fixed-wing Unmanned Aerial Vehicles(UAVs)in dense obstacle environments remains computationally intractable.This paper proposes a Safe Flight Corridor constrained Sequent... Generating dynamically feasible trajectory for fixed-wing Unmanned Aerial Vehicles(UAVs)in dense obstacle environments remains computationally intractable.This paper proposes a Safe Flight Corridor constrained Sequential Convex Programming(SFC-SCP)to improve the computation efficiency and reliability of trajectory generation.SFC-SCP combines the front-end convex polyhedron SFC construction and back-end SCP-based trajectory optimization.A Sparse A^(*)Search(SAS)driven SFC construction method is designed to efficiently generate polyhedron SFC according to the geometric relation among obstacles and collision-free waypoints.Via transforming the nonconvex obstacle-avoidance constraints to linear inequality constraints,SFC can mitigate infeasibility of trajectory planning and reduce computation complexity.Then,SCP casts the nonlinear trajectory optimization subject to SFC into convex programming subproblems to decrease the problem complexity.In addition,a convex optimizer based on interior point method is customized,where the search direction is calculated via successive elimination to further improve efficiency.Simulation experiments on dense obstacle scenarios show that SFC-SCP can generate dynamically feasible safe trajectory rapidly.Comparative studies with state-of-the-art SCP-based methods demonstrate the efficiency and reliability merits of SFC-SCP.Besides,the customized convex optimizer outperforms off-the-shelf optimizers in terms of computation time. 展开更多
关键词 Fixed-wing unmanned aerial vehicle Efficient trajectory planning Safe flight corridor Sequential convex programming Customized convex optimizer
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Methodology,progress and challenges of geoscience knowledge graph in International Big Science Program of Deep-Time Digital Earth 被引量:1
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作者 ZHU Yunqiang WANG Qiang +9 位作者 WANG Shu SUN Kai WANG Xinbing LV Hairong HU Xiumian ZHANG Jie WANG Bin QIU Qinjun YANG Jie ZHOU Chenghu 《Journal of Geographical Sciences》 2025年第5期1132-1156,共25页
Deep-time Earth research plays a pivotal role in deciphering the rates,patterns,and mechanisms of Earth's evolutionary processes throughout geological history,providing essential scientific foundations for climate... Deep-time Earth research plays a pivotal role in deciphering the rates,patterns,and mechanisms of Earth's evolutionary processes throughout geological history,providing essential scientific foundations for climate prediction,natural resource exploration,and sustainable planetary stewardship.To advance Deep-time Earth research in the era of big data and artificial intelligence,the International Union of Geological Sciences initiated the“Deeptime Digital Earth International Big Science Program”(DDE)in 2019.At the core of this ambitious program lies the development of geoscience knowledge graphs,serving as a transformative knowledge infrastructure that enables the integration,sharing,mining,and analysis of heterogeneous geoscience big data.The DDE knowledge graph initiative has made significant strides in three critical dimensions:(1)establishing a unified knowledge structure across geoscience disciplines that ensures consistent representation of geological entities and their interrelationships through standardized ontologies and semantic frameworks;(2)developing a robust and scalable software infrastructure capable of supporting both expert-driven and machine-assisted knowledge engineering for large-scale graph construction and management;(3)implementing a comprehensive three-tiered architecture encompassing basic,discipline-specific,and application-oriented knowledge graphs,spanning approximately 20 geoscience disciplines.Through its open knowledge framework and international collaborative network,this initiative has fostered multinational research collaborations,establishing a robust foundation for next-generation geoscience research while propelling the discipline toward FAIR(Findable,Accessible,Interoperable,Reusable)data practices in deep-time Earth systems research. 展开更多
关键词 deep-time Earth geoscience knowledge graph Deep-time Digital Earth International Big Science program
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预应变速率对QP1180钢微观组织和力学性能的影响
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作者 徐飞越 李兵 +3 位作者 张鹏 陈文轩 张红霞 邢俊峰 《精密成形工程》 北大核心 2025年第8期107-114,共8页
目的研究不同预应变速率对QP1180钢的影响,探究适宜的预应变速率,分析不同预应变速率下的微观组织演变与力学响应,从而优化QP1180高强钢的综合性能。方法首先通过QP1180钢进行不同速率的预应变处理,随后采用光学显微镜、扫描电镜、XRD... 目的研究不同预应变速率对QP1180钢的影响,探究适宜的预应变速率,分析不同预应变速率下的微观组织演变与力学响应,从而优化QP1180高强钢的综合性能。方法首先通过QP1180钢进行不同速率的预应变处理,随后采用光学显微镜、扫描电镜、XRD测试和拉伸试验及硬度测试等方法系统研究QP1180钢的变化规律和力学性能。结果不同预应变速率下的微观组织类型没有明显变化,随着预应变速率的增加,残余奥氏体含量下降,马氏体含量增加。当预应变速率为10^(−1) s^(−1)时,试样硬度值达到最高为398.7HV。随着预应变速率由10^(−4) s^(−1)增加至10^(−1) s^(−1),QP1180钢的屈服强度逐渐增加,由1157.2 MPa增大至1297.6 MPa,伸长率由15.8%下降到13.2%,而抗拉强度并没有明显差异,用强塑积的大小来反映材料综合性能的好坏,在低预应变速率10^(−4) s^(−1)下,强塑积最高为21.3 GPa·%,综合性能最优。试样的拉伸断口断裂方式均属于韧性断裂,且都存有明显的韧窝状花样。结论系统分析了不同预应变速率下QP1180钢的组织演变规律和力学性能,得出材料在预应变量为4%、速率为10^(−4) s^(−1)条件下,综合性能最好,研究结果对QP1180钢的安全服役具有一定的指导意义。 展开更多
关键词 qp1180钢 预应变速率 微观组织 力学性能 残余奥氏体
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预处理条件对QP980钢组织及塑性失稳行为的影响
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作者 张鹏 李兵 +2 位作者 徐飞越 汪锐杰 王敏 《材料导报》 北大核心 2025年第8期220-225,共6页
吕德斯应变的存在会显著影响先进高强钢的冲压成形性能。本工作通过合理设计预处理条件对QP980钢的微观组织及塑性失稳行为进行分析研究。结果表明:经过预应变(4%)和热处理(300℃/10 min)后,能显著提升QP980钢的强度性能。在综合延伸率... 吕德斯应变的存在会显著影响先进高强钢的冲压成形性能。本工作通过合理设计预处理条件对QP980钢的微观组织及塑性失稳行为进行分析研究。结果表明:经过预应变(4%)和热处理(300℃/10 min)后,能显著提升QP980钢的强度性能。在综合延伸率仅降低2.9%的前提下,抗拉强度值提升150 MPa,屈服强度值增加466 MPa。这得益于回火过程中过渡碳化物的弥散强化以及相变诱导塑性效应。此外,经预应变和回火热处理后的QP980钢呈现出了明显的吕德斯应变特征。通过分离预处理条件进行对比研究发现:残余奥氏体的稳定性是影响QP980钢是否发生吕德斯应变的主要因素,预应变和回火过程皆会消耗掉部分不稳定残余奥氏体。在残余奥氏体稳定性过高时,这意味着较小应变条件下相变诱导塑性效应不易发生,此时塑性失稳现象容易出现,拉伸变形过程中会产生吕德斯带。 展开更多
关键词 qp980 相变诱导塑性效应 预应变 吕德斯应变 残余奥氏体稳定性
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AQP5调控细胞程序性死亡在干燥综合征中的研究现状
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作者 王友霞 李翠娟 +4 位作者 巩振东 呼睿 胡勇 张惜燕 王其鎏 《重庆医科大学学报》 北大核心 2025年第10期1385-1391,共7页
水通道蛋白5(aquaporin 5,AQP5)是一种能明显提升细胞膜水通透性,参与水的分泌、吸收过程,以及维持细胞内外水分子的平衡状态,跨膜转运水的特异性蛋白。细胞程序性死亡(programmed cell death,PCD)与干燥综合征(sj?gren’s syndrome,SS... 水通道蛋白5(aquaporin 5,AQP5)是一种能明显提升细胞膜水通透性,参与水的分泌、吸收过程,以及维持细胞内外水分子的平衡状态,跨膜转运水的特异性蛋白。细胞程序性死亡(programmed cell death,PCD)与干燥综合征(sj?gren’s syndrome,SS)的发生发展过程有着密切的联系。AQP5可能通过调节PCD机制,进而影响SS的发生与发展。本文综述了近年来关于AQP5在PCD相关的细胞凋亡、焦亡、自噬及铁死亡等过程调控中的分子机制,同时深入探讨了其对SS可能产生的潜在影响,旨在为SS的临床预防与治疗提供理论依据。 展开更多
关键词 水通道蛋白5 干燥综合征 细胞程序性死亡
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Irreversible electroporation combined with anti-programmed cell death protein 1 therapy promotes tumor antigen-specific CD8+T cell response 被引量:1
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作者 Yang-Yang Ma Xiao-Hua Wang +2 位作者 Jian-Ying Zeng Ji-Bing Chen Li-Zhi Niu 《World Journal of Gastrointestinal Oncology》 2025年第3期237-245,共9页
BACKGROUND Irreversible electroporation(IRE)is a novel local tumor ablation approach with the potential to activate the host’s immune system.However,this approach is insufficient to prevent cancer progression,and com... BACKGROUND Irreversible electroporation(IRE)is a novel local tumor ablation approach with the potential to activate the host’s immune system.However,this approach is insufficient to prevent cancer progression,and complementary approaches are required for effective immunotherapy.AIM To assess the immunomodulatory effects and mechanism of IRE combined antiprogrammed cell death protein 1(PD-1)treatment in subcutaneous pancreatic cancer models.METHODS C57BL-6 tumor-bearing mice were randomly divided into four groups:Control group;IRE group;anti-PD-1 group;and IRE+anti-PD-1 group.Tumor-infiltrating T,B,and natural killer cell levels and plasma concentrations of T helper type 1 cytokines(interleukin-2,interferon-γ,and tumor necrosis factor-α)were evaluated.Real-time PCR was used to determine the expression of CD8(marker of CD8+T cells)in tumor tissues of the mice of all groups at different points of time.The growth curves of tumors were drawn.RESULTS The results demonstrated that the IRE+anti-PD-1 group exhibited significantly higher percentages of T lymphocyte infiltration,including CD4+and CD8+T cells compared with the control group.Additionally,the IRE+anti-PD-1 group showed increased infiltration of natural killer and B cells,elevated cytokine levels,and higher CD8 mRNA expression.Tumor volume was significantly reduced in the IRE+anti-PD-1 group,indicating a more pronounced therapeutic effect.CONCLUSION The combination of IRE and anti-PD-1 therapy promotes CD8+T cell immunity responses,leading to a more effective reduction in tumor volume and improved therapeutic outcomes,which provides a new direction for ablation and immunotherapy of pancreatic cancer. 展开更多
关键词 Irreversible electroporation Pancreatic cancer programmed cell death protein 1 blockade CD8+T cell Anticancer immunity
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Programmed cell death 1 inhibitor sintilimab plus S-1 and gemcitabine for liver metastatic pancreatic ductal adenocarcinoma
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作者 Shi-Qiong Zhou Peng Wan +3 位作者 Seng Zhang Yuan Ren Hong-Tao Li Qing-Hua Ke 《World Journal of Clinical Oncology》 2025年第2期29-35,共7页
BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a highly aggressive cancer with poor prognosis.When it metastasizes to the liver,treatment options become particularly limited and challenging.Current treatment opti... BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a highly aggressive cancer with poor prognosis.When it metastasizes to the liver,treatment options become particularly limited and challenging.Current treatment options for liver metastatic PDAC are limited,and chemotherapy alone often proves insufficient.Immunotherapy,particularly programmed cell death 1(PD-1)inhibitors like sintilimab,shows potential efficacy for various cancers but has limited reports on PDAC.This study compares the efficacy and safety of sintilimab plus S-1 and gemcitabine vs S-1 and gemcitabine alone in liver metastatic PDAC.AIM To explore the feasibility and effectiveness of combined PD-1 inhibitor sintilimab and S-1 and gemcitabine(combination group)vs S-1 and gemcitabine used alone(chemotherapy group)for treating liver metastatic pancreatic adenocarcinoma.METHODS Eligible patients were those with only liver metastatic PDAC,an Eastern Cooperative Oncology Group performance status of 0-1,adequate organ and marrow functions,and no prior anticancer therapy.Participants in the combination group received intravenous sintilimab 200 mg every 3 weeks,oral S-140 mg/m²twice daily on days 1-14 of a 21-day cycle,and intravenous gemcitabine 1000 mg/m²on days 1 and 8 of the same cycle for up to eight cycles or until disease progression,death,or unacceptable toxicity.Participants in the chemotherapy group received oral S-140 mg/m²twice daily on days 1-14 of a 21-day cycle and intravenous gemcitabine 1000 mg/m²on days 1 and 8 of the same cycle for up to eight cycles.Between June 2020 and December 2021,66 participants were enrolled,with 32 receiving the combination treatment and 34 receiving chemotherapy alone.RESULTS The group receiving the combined therapy exhibited a markedly prolonged median overall survival(18.8 months compared to 10.3 months,P<0.05)and progression-free survival(9.6 months vs 5.4 months,P<0.05).compared to the chemotherapy group.The incidence of severe adverse events did not differ significantly between the two groups(P>0.05).CONCLUSION The combination of PD-1 inhibitor sintilimab with S-1 and gemcitabine demonstrated effectiveness and safety for treating liver metastatic PDAC,meriting further investigation. 展开更多
关键词 IMMUNOTHERAPY programmed cell death 1 inhibitor Sintilimab Chemotherapy METASTATIC Pancreatic ductal adenocarcinoma
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Evaluation of Integer Programming Solvers to Improve the Efficiency of Individual Work Planning
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作者 Keiichi Takahashi 《Open Journal of Modelling and Simulation》 2025年第1期51-64,共14页
This study proposes a novel approach to optimizing individual work schedules for book digitization using mixed-integer programming (MIP). By leveraging the power of MIP solvers, we aimed to minimize the overall digiti... This study proposes a novel approach to optimizing individual work schedules for book digitization using mixed-integer programming (MIP). By leveraging the power of MIP solvers, we aimed to minimize the overall digitization time while considering various constraints and process dependencies. The book digitization process involves three key steps: cutting, scanning, and binding. Each step has specific requirements and limitations such as the number of pages that can be processed simultaneously and potential bottlenecks. To address these complexities, we formulate the problem as a one-machine job shop scheduling problem with additional constraints to capture the unique characteristics of book digitization. We conducted a series of experiments to evaluate the performance of our proposed approach. By comparing the optimized schedules with the baseline approach, we demonstrated significant reductions in the overall processing time. In addition, we analyzed the impact of different weighting schemes on the optimization results, highlighting the importance of identifying and prioritizing critical processes. Our findings suggest that MIP-based optimization can be a valuable tool for improving the efficiency of individual work schedules, even in seemingly simple tasks, such as book digitization. By carefully considering specific constraints and objectives, we can save time and leverage resources by carefully considering specific constraints and objectives. 展开更多
关键词 Mixed Integer programming Scheduling Optimization Work Planning Book Scanning Gantt Chart
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A Fault Location Method for Student Homework Program
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作者 Li Zhang Zheyu Yang +2 位作者 Hao Li Jing Jiang Zian Sun 《计算机教育》 2025年第3期111-121,共11页
In order to solve the code debugging difficulties faced by students and relieve the pressure of manual personalized tutoring,this paper proposes a method for locating faults in student code,called SCFL(student code fa... In order to solve the code debugging difficulties faced by students and relieve the pressure of manual personalized tutoring,this paper proposes a method for locating faults in student code,called SCFL(student code fault location).This method utilizes a historical correct code repository composed of correct codes submitted by previous students in the same assignments.It standardizes the erroneous code and historical correct code variables simultaneously and calculates the abstract syntax change tree.Then,by establishing the mapping between the abstract syntax change tree and the student assignment code,the fault location results of the student assignment are calculated.The evaluation experiments show that the SCFL method has a result of 9.25 in the cumulative inspection statement count and 15.9%in the fault localization cost indicator.Both indicators are better than the three currently commonly used spectrum-based baseline methods. 展开更多
关键词 programming education Fault localization Personalized tutoring programming practice
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