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基于光腔衰荡光谱技术NO_(3)和N_(2)O_(5)在线测量系统的表征与应用
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作者 张田甜 左澎 +3 位作者 马璟钰 叶春翔 林伟立 朱彤 《北京大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第3期563-574,共12页
报道自主研发的基于光腔衰荡光谱技术的大气NO_(3)/N_(2)O_(5)在线测量系统及其参数表征结果。在时间分辨率为1min的情况下,NO_(3)和N_(2)O_(5)最低检测限分别为1.7×10^(-12)和2.9×10^(-12)。在采样流量6L/min和使用1天滤膜... 报道自主研发的基于光腔衰荡光谱技术的大气NO_(3)/N_(2)O_(5)在线测量系统及其参数表征结果。在时间分辨率为1min的情况下,NO_(3)和N_(2)O_(5)最低检测限分别为1.7×10^(-12)和2.9×10^(-12)。在采样流量6L/min和使用1天滤膜的情况下,利用标准源实验确定NO_(3)和N_(2)O_(5)的采样损耗分别为17.0%和18.0%。Allan方差分析结果表明,在60~100s积分条件下可获得较好的系统稳定性。在北京城区开展大气NO_(3)和N_(2)O_(5)观测,结果表明测量系统可以满足大气环境中NO_(3)及N_(2)O_(5)的高灵敏度测量。 展开更多
关键词 no_(3) N_(2)O_(5) 光腔衰荡光谱技术 参数表征
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纳米MoS_(2)固体薄膜制备及在钢领上的应用研究
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作者 张一鸣 张天羿 +2 位作者 何瑶 陈志军 曹根阳 《纺织器材》 2024年第3期1-6,共6页
为了减小纺织机械及器材专件的摩擦磨损,对比分析普通MoS_(2)油和脂与纳米MoS_(2)固体薄膜的润滑机理和特性,提出一种在钢领上采用真空化学气相沉积法合成纳米MoS_(2)固体薄膜的制备工艺;通过X射线衍射谱图和原子力显微镜,分析纳米MoS_... 为了减小纺织机械及器材专件的摩擦磨损,对比分析普通MoS_(2)油和脂与纳米MoS_(2)固体薄膜的润滑机理和特性,提出一种在钢领上采用真空化学气相沉积法合成纳米MoS_(2)固体薄膜的制备工艺;通过X射线衍射谱图和原子力显微镜,分析纳米MoS_(2)固体薄膜的组织结构及表面形貌,并对纳米MoS_(2)钢领进行镀铬镀氟渗杂复合膜处理。通过对比纳米MoS_(2)固体薄膜钢领与普通钢领纺纱质量,指出:纳米MoS_(2)固体薄膜具有优异的润滑性能,可以代替普通润滑油,达到纺织设备及器材专件少用油、不用油及无油自润滑的目的;纳米MoS_(2)的制备方法是制约其应用和发展的瓶颈;镀铬镀氟渗杂复合膜纳米MoS_(2)钢领在潮湿环境中不易生锈,较普通钢领的成纱质量好,值车工劳动强度小,钢领使用寿命延长。 展开更多
关键词 化学气相沉积法 纳米MoS_(2) 固体薄膜 流体润滑 钢领 摩擦 磨损 渗杂
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高含CO_(2)凝析气藏成藏过程中的流体相行为及油环体积预测
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作者 陈浩 左名圣 +5 位作者 王红平 王朝锋 徐程浩 杨柳 刘希良 袁志文 《吉林大学学报(地球科学版)》 CAS CSCD 北大核心 2024年第5期1506-1518,共13页
成藏后期的CO_(2)充注导致里贝拉区块高含CO_(2)次生凝析气藏的流体相行为十分复杂,油环体积预测难度很大。本文通过流体相平衡模拟、组分梯度分布计算及CO_(2)充注可视化实验,刻画了CO_(2)充注过程中的油气相行为,揭示了油环体积的动... 成藏后期的CO_(2)充注导致里贝拉区块高含CO_(2)次生凝析气藏的流体相行为十分复杂,油环体积预测难度很大。本文通过流体相平衡模拟、组分梯度分布计算及CO_(2)充注可视化实验,刻画了CO_(2)充注过程中的油气相行为,揭示了油环体积的动态变化规律,建立了基于气顶气组分拟合的高含CO_(2)次生凝析气藏油环体积预测新方法。研究结果表明:1)CO_(2)充注下的油环体积变化分为4个阶段:充注初期,油环以溶胀为主;充注前期,CO_(2)不断置换并萃取油相中的轻质组分,油环体积迅速降低;充注中期,CO_(2)持续萃取油相的轻、中质组分,油环体积缓慢减小;充注后期,CO_(2)-原油组分传质作用明显减弱,压缩效应导致油环体积进一步减小。2)轻质组分的强流动性使气顶气组成均一,重力分异作用使纵向上油环组分呈梯度变化。3)油环体积与气顶气组成和气油比密切相关。4)基于气顶气拟合新方法和不同井深现场勘探预测的油环体积占比分别为19.21%和22.30%,与CO_(2)充注可视化实验获得的油环体积占比(20.60%)较为吻合。 展开更多
关键词 气藏 CO_(2)-原油组分传质 流体相行为 油环体积预测 组分梯度分布 可视化实验
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Coupling between the Cenozoic west Pacific subduction initiation and decreases of atmospheric carbon dioxides 被引量:2
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作者 Guozhi Xie Fanfan Tian +3 位作者 Kun Wang Yuanyuan Xiao Tianyu Chen Weidong Sun 《Acta Geochimica》 EI CAS CSCD 2023年第3期387-392,共6页
At the beginning of the Cenozoic,the atmospheric CO_(2)concentration increased rapidly from~2000 ppmv at 60 Ma to~4600 ppmv at 51 Ma,which is 5–10 times higher than the present value,and then continuous declined from... At the beginning of the Cenozoic,the atmospheric CO_(2)concentration increased rapidly from~2000 ppmv at 60 Ma to~4600 ppmv at 51 Ma,which is 5–10 times higher than the present value,and then continuous declined from~51 to 34 Ma.The cause of this phenomenon is still not well understood.In this study,we demonstrate that the initiation of Cenozoic west Pacific plate subduction,triggered by the hard collision in the Tibetan Plateau,occurred at approximately 51 Ma,coinciding with the tipping point.The water depths of the Pacific subduction zones are mostly below the carbonate compensation depths,while those of the Neo-Tethys were much shallower before the collision and caused far more carbonate subducting.Additionally,more volcanic ashes erupted from the west Pacific subduction zones,which consume CO_(2).The average annual west Pacific volvano eruption is 1.11 km~3,which is higher than previous estimations.The amount of annual CO_(2)absorbed by chemical weathering of additional west Pacific volcanic ashes could be comparable to the silicate weathering by the global river.We propose that the initiation of the western Pacific subduction controlled the long-term reduction of atmospheric CO_(2)concentration. 展开更多
关键词 Subduction initiation in the west Pacific Collision of the Neo-Tethys Volcano eruption rates Cenozoic CO_(2)declining Carbonate compensation depths Chemical weathering
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Reconstruction of summer temperature variation from maximum density of alpine pine during 1917-2002 for west Sichuan Plateau, China 被引量:17
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作者 WU Pu WANG Lily SHAO Xuemei 《Journal of Geographical Sciences》 SCIE CSCD 2008年第2期201-210,共10页
Having analyzed the tree ring width and maximum latewood density of Pinus densata from west Sichuan, we obtained different climate information from tree-ring width and maximum latewood density chronology. The growth o... Having analyzed the tree ring width and maximum latewood density of Pinus densata from west Sichuan, we obtained different climate information from tree-ring width and maximum latewood density chronology. The growth of tree ring width was responded princi- pally to the precipitation in current May, which might be influenced by the activity of southwest monsoon, whereas the maximum latewood density reflected summer temperature (June-September). According to the correlation relationship, a transfer function had been used to reconstruct summer temperature for the study area. The explained variance of reconstruction is 51% (F=52.099, p〈0.0001). In the reconstruction series: before the 1930s, the climate was relatively cold, and relatively warm from 1930 to 1960, this trend was in accordance with the cold-warm period of the last 100 years, west Sichuan. Compared with Chengdu, the warming break point in west Sichuan is 3 years ahead of time, indicating that the Tibetan Plateau was more sensitive to temperature change. There was an evident summer warming signal after 1983. Although the last 100-year running average of summer temperature in the 1990s was the maximum, the running average of the early 1990s was below the average line and it was cold summer, but summer drought occurred in the late 1990s. 展开更多
关键词 west Sichuan (province) plateau tree ring summer temperature
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泛素连接酶MuRF2通过抑制线粒体自噬减轻心肌细胞缺氧损伤
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作者 孙美琪 张瑜 +4 位作者 徐方晶 方克宝 王一帆 朱力 何军 《宁夏医科大学学报》 2024年第4期338-344,359,共8页
目的探讨泛素连接酶肌肉环指状蛋白2(muscle ring finger protein 2,MuRF2)对缺氧心肌细胞活力和自噬的调控作用。方法构建大鼠源MuRF2基因过表达和敲减慢病毒载体,分别感染大鼠心肌细胞H9C2。将H9C2细胞分为阴性对照组(NC)、阳性对照组... 目的探讨泛素连接酶肌肉环指状蛋白2(muscle ring finger protein 2,MuRF2)对缺氧心肌细胞活力和自噬的调控作用。方法构建大鼠源MuRF2基因过表达和敲减慢病毒载体,分别感染大鼠心肌细胞H9C2。将H9C2细胞分为阴性对照组(NC)、阳性对照组[MuRF2过表达空载体组(LV-Vector)、MuRF2敲减空载体组(LV-RNAi-Vector)]、Mu RF2过表达组(LV-MuRF2)和MuRF2敲减组(LV-RNAi-MuRF2),缺氧培养(5%CO_(2)、1%O_(2)、94%N_(2))后,采用CCK-8法和ELISA法检测心肌细胞损伤水平,利用透射电子显微镜检测心肌细胞超微结构和自噬水平变化,采用Western blot测定自噬相关蛋白LC3-Ⅱ和P62的表达水平。结果与对照组相比,缺氧组心肌细胞间隙增大、细胞皱缩、多见漂浮的死亡细胞和细胞碎片,心肌细胞活力下降、肌钙蛋白Ⅰ(cTnⅠ)含量增加(P均<0.05);电子显微镜下可观察到部分线粒体发生肿胀,并存在嵴断裂、嵴溶解现象,自噬小体散在胞质内;缺氧组LC3-Ⅱ蛋白表达水平升高,P62蛋白表达水平降低(P均<0.05)。缺氧培养后,与NC组和LV-Vector组相比,LV-MuRF2组细胞活力增加,偶见自噬小体,LC3-Ⅱ蛋白表达水平降低、P62蛋白表达水平增高(P均<0.05);与NC组和LV-RNAi-Vector组相比,LV-RNAi-MuRF2组细胞活力降低,可见大量自噬小体,LC3-Ⅱ蛋白表达水平升高、P62蛋白表达水平降低(P均<0.05)。结论泛素连接酶MuRF2可减轻缺氧所致的心肌细胞损伤,其机制可能与抑制心肌细胞线粒体自噬有关。 展开更多
关键词 泛素连接酶 肌肉环指状蛋白2 心肌细胞 缺氧 线粒体自噬
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^(12)C^(16)O_(2)分子位于1.57μm的饱和吸收光谱
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作者 江山 谈艳 +2 位作者 刘安雯 周晓国 胡水明 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第1期13-18,I0117,共7页
本文展示了基于光梳锁频-光腔衰荡光谱装置测量的^(12)C^(16)O_(2)分子位于1.57μm附近的30012←00001振动带中转动量子数最高为68的共计37根振转跃迁的饱和吸收光谱,其频率确定至kHz水平;文献和CDSD2019数据库中的多普勒光谱确定的3001... 本文展示了基于光梳锁频-光腔衰荡光谱装置测量的^(12)C^(16)O_(2)分子位于1.57μm附近的30012←00001振动带中转动量子数最高为68的共计37根振转跃迁的饱和吸收光谱,其频率确定至kHz水平;文献和CDSD2019数据库中的多普勒光谱确定的30012振动态的振转能级与本工作确定的数值存在超过1 MHz的偏差. 展开更多
关键词 饱和吸收光谱 光腔衰荡光谱 ^(12)C^(16)O_(2) 高精密
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Overexpression of the M2 isoform of pyruvate kinase is an adverse prognostic factor for signet ring cell gastric cancer 被引量:19
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作者 Jae Yun Lim Sun Och Yoon +4 位作者 So Young Seol Soon Won Hong Jong Won Kim Seung Ho Choi Jae Yong Cho 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第30期4037-4043,共7页
AIM:To investigate M2 isoform of pyruvate kinase(PKM2) expression in gastric cancers and evaluate its potential as a prognostic biomarker and an anticancer target.METHODS:All tissue samples were derived from gastric c... AIM:To investigate M2 isoform of pyruvate kinase(PKM2) expression in gastric cancers and evaluate its potential as a prognostic biomarker and an anticancer target.METHODS:All tissue samples were derived from gastric cancer patients underwent curative gastrectomy as a primary treatment.Clinical and pathological information were obtained from the medical records.Gene expression microarray data from 60 cancer and 19 noncancer gastric tissues were analyzed to evaluate the expression level of PKM2 mRNA.Tissue microarrays were constructed from 368 gastric cancer patients.Immunohistochemistry was used to measure PKM2 expression and PKM2 positivity of cancer was determined by proportion of PKM2-positive tumor cells and staining intensity.Association between PKM2 expression and the clinicopathological factors was evaluated and the correlation between PKM2 and cancer prognosis was evaluated.RESULTS:PKM2 mRNA levels were increased more than 2-fold in primary gastric cancers compared to adjacent normal tissues from the same patients(log transformed expression level:7.6 ± 0.65 vs 6.3 ± 0.51,P < 0.001).Moreover,differentiated type cancers had significantly higher PKM2 mRNA compared to undifferentiated type cancers(log transformed expression level:7.8 ± 0.70 vs 6.7 ± 0.71,P < 0.001).PKM2 protein was mainly localized in the cytoplasm of primary cancer cells and detected in 144 of 368(39.1%) human gastric cancer cases.PKM2 expression was not related with stage(P = 0.811),but strongly correlated with gastric cancer differentiation(P < 0.001).Differentiated type cancers expressed more PKM2 protein than did the undifferentiated ones.Well differentiated adenocarcinoma showed 63.6% PKM2-positive cells;in contrast,signet-ring cell cancers showed only 17.7% PKM2-positive cells.Importantly,PKM2 expression was correlated with shorter overall survival(P < 0.05) independent of stage only in signet-ring cell cancers.CONCLUSION:PKM2 expression might be an adverse prognostic factor for signet-ring cell carcinomas.Its function and potential as a prognostic marker should be further verified in gastric cancer. 展开更多
关键词 Gastric cancer M2 isoform of pyruvate kinase Biomarker Signet ring cell carcinoma Prognosis
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Tree-Ring Carbon Isotopic Constraints on Carbon-Water Exchanges between Atmosphere and Biosphere in Drought Regions in Northwestern China 被引量:1
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作者 WANG Shilu WAN Guojiang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第2期301-305,共5页
The comparison between the carbon isotope and the index of ring width of a pine disc from the Tuomuer Peak region in Xinjiang shows that the effects of climate changes on the tree-ring growth and carbon isotopic fract... The comparison between the carbon isotope and the index of ring width of a pine disc from the Tuomuer Peak region in Xinjiang shows that the effects of climate changes on the tree-ring growth and carbon isotopic fractionation varies with time. The reason is probably relative to the characters of climate changes and adaptability of the tree-ring growth to climate changes. The relationships between the atmospheric CO2 level and the revised δ13Cair by the tree-ring carbon isotope indicate that the carbon cycle is not in a steady state, but under a stage-change condition in this area. It also can be concluded that the ratio of CO2 from the terrestrial eco-system has increased, and the flux of CO2 exchange between the atmosphere and the biosphere was gradually increasing over the past century. In addition, the results also confirm the validity and superiority of the carbon isotope to the research of the water-use efficiency. 展开更多
关键词 tree ring carbon isotope CO_(2) exchange water-use efficiency
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Octa-membered Water Ring Chain Based on Sulfonic Group in Ni(II) Complex with 2-[(E)-(2-Oxidophenyl)methyleneamino] Ethanesulfonato and 2,2′-Bipyridinyl 被引量:2
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作者 张淑华 李光照 +1 位作者 钟凡 冯小珍 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第12期1491-1494,共4页
The title compound, [Ni(tssb)(2,2-bipy)2].5(H2O) 1 (tssbH2 =2-[(E)-(2-oxido- phenyl)methyleneamino]ethanesulfonato, 2,2-bipy = 2,2'-bipyridinyl), belongs to orthorhombic, space group Pbcn with a = 20.3983... The title compound, [Ni(tssb)(2,2-bipy)2].5(H2O) 1 (tssbH2 =2-[(E)-(2-oxido- phenyl)methyleneamino]ethanesulfonato, 2,2-bipy = 2,2'-bipyridinyl), belongs to orthorhombic, space group Pbcn with a = 20.3983(18), b = 17.6929(15), c = 17.0897(15) nm, V= 6167.8(9) nm^3, Mr= 688.38, Z = 8, De = 1.481 g.cm^-3, F(000) = 2880,μ = 0.758 mm-1 and S =1.099. Each NiIr atom is six-coordinated by one N and one O atoms from one tssb^2- anion and four N atoms from two 2,2-bipy ligands to give a distorted octahedral geometry. Noticeably, there exists a rare octa-mem- bered water ring which presents a 1D chain by sulfonic group. 展开更多
关键词 II Octa-membered Water ring Chain Based on Sulfonic Group in Ni Bipyridinyl Complex with 2 Ethanesulfonato and 2 2 Oxidophenyl)methyleneamino
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专一选择性反应策略合成2′-O-甲基腺嘌呤核苷
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作者 薛莲 杜杨 +1 位作者 张宇 罗军 《合成化学》 CAS 2024年第5期424-436,443,共14页
2′-O-烷基核糖核苷由于其在赋予寡核苷酸高度的目标特异性、代谢稳定性以及优良的药代动力学和药效动力学特征上所展现的重要作用,成为了反义药物研究领域的热点,尤其是2′-O-甲基腺嘌呤核苷,作为第二代反义寡核苷酸的关键原料药,其的... 2′-O-烷基核糖核苷由于其在赋予寡核苷酸高度的目标特异性、代谢稳定性以及优良的药代动力学和药效动力学特征上所展现的重要作用,成为了反义药物研究领域的热点,尤其是2′-O-甲基腺嘌呤核苷,作为第二代反义寡核苷酸的关键原料药,其的高效合成研究具有重要意义。现有合成方法存在的成本高和选择性不足等问题,本文基于专一选择性反应思路设计了一条新的合成路线,即以腺嘌呤核苷为起始物,经过缩醛化实现2′-和3′-位羟基选择性地保护、环状缩醛保护基可控区域选择性还原开环、2′-位羟基选择性甲基化及氢化脱苄反应,成功实现了2′-O-甲基腺嘌呤核苷的高效合成,单程总产率为36.7%。此策略不仅每一步反应表现出高选择性以及温和的反应条件,而且使用的试剂更加廉价易得,合成步骤也相对简短,为核苷类化合物核糖骨架上羟基的区域选择性功能化提供了新的思路。 展开更多
关键词 反义寡核苷酸 腺嘌呤核苷 2′-O-甲基腺嘌呤核苷 缩醛化 还原开环 烷基化 氢化脱苄
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Genome-wide identification and expression analysis of Gossypium RING-H2 finger E3 ligase genes revealed their roles in fiber development,and phytohormone and abiotic stress responses 被引量:6
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作者 QANMBER Ghulam YU Daoqian +5 位作者 LI Jie WANG Lingling MA Shuya LU Lili YANG Zuoren LI Fuguang 《Journal of Cotton Research》 2018年第1期3-19,共17页
Background: RING H2 finger E3 ligase (RH2FE3) genes encode cysteine rich proteins that mediate E3 ubiquitin ligase activity and degrade target substrates. The roles of these genes in plant responses to phytohormone... Background: RING H2 finger E3 ligase (RH2FE3) genes encode cysteine rich proteins that mediate E3 ubiquitin ligase activity and degrade target substrates. The roles of these genes in plant responses to phytohormones and abiotic stresses are well documented in various species, but their roles in cotton fiber development are poorly understood. To date, genome wide identification and expression analyses of Gossypium hirsutum RH2FE3 genes have not been reported. Methods: We performed computational identification, structural and phylogenetic analyses, chromosomal distribution analysis and estimated KJKs values of G hirsutum RH2FE3 genes. Orthologous and paralogous gene pairs were identified by all versus all BLASTP searches. We predicted cis regulatory elements and analyzed microarray data sets to generate heatmaps at different development stages. Tissue specific expression in cotton fiber, and hormonal and abiotic stress responses were determined by quantitative real time polymerase chain reaction (qRT PCR) analysis. Results: We investigated 140 G hirsutum, 80 G. orboreum, and evolutionary mechanisms and compared them with orthologs 89 G. roimondii putative RH2FB genes and their in Arobidopsis and rice. A domain based analysis of the G hirsutum RH2FE3 genes predicted conserved signature motifs and gene structures. Chromosomal localization showed the genes were distributed across all G hirsutum chromosomes, and 60 duplication events (4 tandem and 56 segmental duplications) and 98 orthologs were detected, cis elements were detected in the promoter regions of G hirsutum RH2FE3 genes. Microarray data and qRT PCR analyses showed that G hirsutum RH2FE3 genes were strongly correlated with cotton fiber development. Additionally, almost all the (brassinolide, gibberellic acid (GA), indole 3-acetic acid drought, and salt). dentified genes were up regulated in response to phytohormones (IAA), and salicylic acid (SA)) and abiotic stresses (cold, heat, Conclusions: The genome wide identification, comprehensive analysis, and characterization of conserved domains and gene structures, as well as phylogenetic analysis, cis element prediction, and expression profile analysis of G hirsutum RH2FE3 genes and their roles in cotton fiber development and responses to plant hormones and abiotic stresses are reported here for the first time. Our findings will contribute to the genome wide analysis of putative RH2FE3 genes in other species and lay a foundation for future physiological and functional research on G hirsutum RH2FE3 genes. 展开更多
关键词 Gossypium hirsutum Upland cotton ring H2 finger E3 ligase Phylogenetic analysis cis elements Gene duplication Expression profile analysis
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食管癌组织中FOXM1和RNF2表达与临床病理参数及预后的相关性分析
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作者 贾亚松 彭小乐 +1 位作者 姚文杰 葛广林 《标记免疫分析与临床》 CAS 2024年第6期1068-1073,1124,共7页
目的探讨食管癌组织中叉头盒蛋白M1(FOXM1)和环指蛋白2(RNF2)表达与临床病理参数及预后的相关性。方法选取我院2018年1月至2019年12月期间收治的120例食管癌患者作为研究对象,收集术中切除的食管癌组织标本及癌旁组织标本。另选取45例... 目的探讨食管癌组织中叉头盒蛋白M1(FOXM1)和环指蛋白2(RNF2)表达与临床病理参数及预后的相关性。方法选取我院2018年1月至2019年12月期间收治的120例食管癌患者作为研究对象,收集术中切除的食管癌组织标本及癌旁组织标本。另选取45例食管癌患者并收集术中切除的食管癌组织标本作为验证组。检测食管癌组织及癌旁组织中FOXM1和RNF2的表达水平,分析二者相关性及其与患者预后状态的关系,并探讨影响食管癌患者预后状态的影响因素。结果食管癌组织中FOXM1和RNF2表达水平均高于癌旁组织(P<0.05);食管癌组织FOXM1和RNF2表达水平呈正相关(r=0.625,P<0.05);FOXM1高表达组及RNF2高表达组TNM分期为Ⅲ+Ⅳ期、发生淋巴结转移、浸润深度为深层的食管癌患者所占比例高于FOXM1低表达组及RNF2低表达组(P<0.05);癌组织中呈现出FOXM1低表达及RNF2低表达的食管癌患者其3年生存率(47.45%、48.33%)明显高于FOXM1高表达和RNF2高表达者(27.87%、26.67%)( χ^(2)=4.302、6.009,P=0.038、0.014);TNM分期、淋巴结转移、浸润深度、FOXM1及RNF2是食管癌患者死亡的危险因素(P<0.05);验证组中,FOXM1高表达组和RNF2高表达组发生淋巴结转移、TNM分期为Ⅲ+Ⅳ期、浸润深度为深层的患者所占比例分别高于FOXM1低表达组和RNF2低表达组(P<0.05),而3年生存率则分别低于FOXM1低表达组和RNF2低表达组(P<0.05)。结论FOXM1和RNF2在食管癌患者癌组织中的表达水平与其临床病理特征及3年生存率有关。 展开更多
关键词 食管癌 叉头盒蛋白M1 环指蛋白2 临床病理特征 预后
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A New Complex [Ni(L)_2]·2H_2O Containing an Interesting Six-membered Water Ring (HL=2-Iminomethyl-6-methoxy-phenol)
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作者 张淑华 曾明华 梁宏 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第7期785-788,共4页
A new complex, [Ni(L)2]·2(H2O) I (HL = 2-iminomethyl-6-methoxyphenol), has been synthesized and structurally determined. The crystal belongs to the trigonal system, space group R3- with a = 1.9341 (3), b ... A new complex, [Ni(L)2]·2(H2O) I (HL = 2-iminomethyl-6-methoxyphenol), has been synthesized and structurally determined. The crystal belongs to the trigonal system, space group R3- with a = 1.9341 (3), b = 1.9341 (3), C = 1.2048(2) nm, V = 3.9029(11) nm^3, Mr = 395.05, Z = 9, Dc = 1.513 g·cm^-3, F(000) = 1854,μ= 1.153 mm^-1 and S = 1.014. Each Ni^Ⅱ atom is four-coordinated by two N and two O atoms from two different L anions to give a slightly distorted square-plane geometry. The complex forms a 3-D network structure through N-H...O and O-H...O hydrogen bonds containing an interesting six-membered water ring. 展开更多
关键词 six-membered water ring 2-iminomethyl-6-methoxy-phenol structure
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RING-OPENING POLYMERIZATION OF l,4-DIOXAN-2-ONE INITIATED BY LANTHANUM TRIS(2,6-DI-TERT-BUTYL-4-METHYLPHENOLATE) 被引量:1
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作者 沈之荃 郑豪 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2007年第4期427-430,共4页
The ring-opening polymerization of 1,4-dioxan-2-one (PDO) was carried out by lanthanum tris(2,6-di-tert-butyl-4- methylphenolate) (La(OAr)3) as novel single component initiaLor. The influences of polymerizatio... The ring-opening polymerization of 1,4-dioxan-2-one (PDO) was carried out by lanthanum tris(2,6-di-tert-butyl-4- methylphenolate) (La(OAr)3) as novel single component initiaLor. The influences of polymerization reaction temperature and the molar ratio of monomer to initiator on the monomer conversion and molecular weight of poly(1,4-dioxan-2-one) (PPDO) were explored. PPDO with high viscosity average molecular weight of 1.95×10^5 can be prepared at 40℃ when [PDO]/ [La(OAr)3] molar ratio was 800. Mechanism investigation shows that the polymerization proceeds through a "coordination- insertion" mechanism with selective rupture of acyl-oxygen be,nd of PDO. 展开更多
关键词 Lanthanum tris(2 6-di-tert-butyl-4-methylphenolate) 1 4-dioxan-2-one ring-opening polymerization.
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CO_(2)压缩机活塞环变形与制冷剂泄漏模拟
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作者 王洪利 董博 《化学工程》 CAS CSCD 北大核心 2024年第2期61-65,88,共6页
为研究活塞环在压缩机工作过程中运动及变形对制冷剂泄漏的影响,利用Solidworks软件建立活塞环三维模型,通过ANSYS软件对活塞环进行流固耦合数值模拟,进而研究活塞环在最大温度与压力载荷下的变形情况;建立制冷剂泄漏通道模型,并编写pro... 为研究活塞环在压缩机工作过程中运动及变形对制冷剂泄漏的影响,利用Solidworks软件建立活塞环三维模型,通过ANSYS软件对活塞环进行流固耦合数值模拟,进而研究活塞环在最大温度与压力载荷下的变形情况;建立制冷剂泄漏通道模型,并编写profile程序,获得活塞环位置改变及入口压力变化下通道内制冷剂泄漏速度的变化规律。结果表明:在压缩行程结束之际制冷剂泄漏量达到最大值,活塞环在膨胀行程及压缩行程下存在纵向位移,2个行程下,最下方的活塞环3速度最大,中间的活塞环2速度最小;与膨胀行程相比,压缩行程下3道活塞环的整体速度更大,其位移所需要的时间更短。研究结果对活塞环受力分析及制冷剂泄漏提供了理论依据。 展开更多
关键词 CO_(2)活塞压缩机 活塞环 泄漏量 流固耦合 数值模拟
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活塞环表面MoS_(2)薄膜在干摩擦和贫油润滑条件下的摩擦学性能研究
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作者 李楠 车银辉 王铭昌 《材料保护》 CAS CSCD 2024年第3期80-87,共8页
大功率、长冲程和高爆发压柴油机是交通运输、工程机械、国防装备和核电应急发电机领域的重要动力设备。柴油机关键运动副活塞环-缸套在冷/热启动时,缸套的上下止点位置处于干摩擦或贫油润滑状态,易发生局部异常磨损导致动力性能丧失。... 大功率、长冲程和高爆发压柴油机是交通运输、工程机械、国防装备和核电应急发电机领域的重要动力设备。柴油机关键运动副活塞环-缸套在冷/热启动时,缸套的上下止点位置处于干摩擦或贫油润滑状态,易发生局部异常磨损导致动力性能丧失。为抑制活塞环-缸套运动副的异常磨损,采用磁控溅射技术在活塞环表面制备了MoS_(2)薄膜;利用SRV-IV微动摩擦磨损试验机模拟柴油机频繁冷/热启动工况,评价了表面附加MoS_(2)薄膜的活塞环与缸套摩擦副的摩擦学性能;利用扫描电镜(SEM)表征了MoS_(2)薄膜微观结构和摩擦前后摩擦副的表面形貌。结果表明:相比于原始CKS活塞环-缸套,MoS_(2)薄膜活塞环-缸套在干摩擦条件下的摩擦系数从1.07大幅降低至0.11,缸套磨损率从8.61×10^(-6) mm^(3)/(N·m)降低至3.71×10^(-8) mm^(3)/(N·m);在常温贫油条件下摩擦系数从0.18降低至0.11,磨损率从1.43×10^(-7) mm^(3)/(N·m)降低至3.22×10^(-8) mm^(3)/(N·m);在高温贫油条件下摩擦系数从0.12降低至0.08,磨损率从7.08×10^(-8) mm^(3)/(N·m)降低至1.12×10^(-8 )mm^(3)/(N·m);摩擦过程中活塞环表面MoS_(2)薄膜的转移是摩擦副摩擦学性能提升的主要原因。 展开更多
关键词 活塞环-缸套 MoS_(2)薄膜 磁控溅射 摩擦磨损性能
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Preparation of 2 (5H)-Furanones by Ring Expansion of 4-Hydroxy-2-cyclobutenones
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《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第S1期338-338,共1页
关键词 Furanones by ring Expansion of 4-Hydroxy-2-cyclobutenones
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The Ring-Opening Reaction of 7,7’-Dimethyl-2, 5-bis(trimethylsilyl)-dithieno[2,3-b:3’,2’-d]silole in the Presence of NXS (X = Cl, Br, I)
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作者 Caiyun Zhao Li Xu +3 位作者 Jianwu Shi Chunli Li Zhihua Wang Hua Wang 《International Journal of Organic Chemistry》 2011年第4期162-166,共5页
In this paper, the synthetic method for making 7,7’-dimethyl-2,5-bis(trimethylsilyl)-dithieno[2,3-b:3’,2’-d] silole (1) was developed by using 2,2’-dibromo-5,5’-bis-trimethyl-silanyl[3,3’]bithiophenyl as startin... In this paper, the synthetic method for making 7,7’-dimethyl-2,5-bis(trimethylsilyl)-dithieno[2,3-b:3’,2’-d] silole (1) was developed by using 2,2’-dibromo-5,5’-bis-trimethyl-silanyl[3,3’]bithiophenyl as starting material in one pot reaction. In the presence of NXS (X = Cl, Br, I), a novel ring-opening reation was occurred on the silole ring of 1 in DMF or THF. By using such kind of reaction, two types of ring opened products, (2’-halo-5,5’-bis(trimethylsilanyl)[3,3’]bithiophenyl-2-yl)-dimethylsilanols and 2,2’-dihalo-5,5’-bis(trimethylsi- lanyl)[3,3’]bithiophenyls were obtained efficiently. 展开更多
关键词 Dithieno[2 3-b:3’ 2’-d]silole HALOGENATION ring-OPENING SILAnoL
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Primary signet ring cell carcinoma of prostate (report of 2 cases)
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作者 戚晓平 《外科研究与新技术》 2003年第2期121-121,共1页
Objective To study the clinical features of primary signet ring cell carcinoma of prostate. Methods 2 cases of primary signet ring cell carcinoma of the prostate were studied and reviewed. Results The age of the 2 pat... Objective To study the clinical features of primary signet ring cell carcinoma of prostate. Methods 2 cases of primary signet ring cell carcinoma of the prostate were studied and reviewed. Results The age of the 2 patients was 64 and 73. The clinical symptoms were dysuria, vesical irritability and perineum discomfort. Histologically, signet ring cell carcinoma was composed of round cells with abundant clear cytoplasm and crescent-shaped nuclei on one side. Mitosis were frequently observed. Immunohistochemical testing showed the cancer cell was positive for prostate specific antigen (PSA.), prostate acid phosphatase ( PAP ), AR, cytokeratin and negative for caicinoernbryonic antigen (CEA), alcian blue/ periodic arid-schiff (AB/PAS). One case (stage D) died 6 months after bilateral orchiectomy and flutamide therapy because of wide-spead metastasis; the other (stage B2) has been surviving 25 months after radical prostatectomy, bilateral orchiectomy, endocrine therapy and local irradiation ministration. 展开更多
关键词 of Primary signet ring cell carcinoma of prostate report of 2 cases
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