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Zr/(Sc+Zr)微合金化对Al-Mg合金在热压缩变形中动态再结晶、位错密度和热加工性能的影响 被引量:4
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作者 邓英 朱鑫文 +4 位作者 赖毅 郭一帆 傅乐 徐国富 黄继武 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2023年第3期668-682,共15页
采用热压缩试验和电子显微分析方法研究Al-6.00Mg、Al-6.00Mg-0.10Zr和Al-6.00Mg-0.25Sc-0.10Zr (质量分数,%)合金的变形行为和显微组织特征。结果表明,在最大加工效率条件(673 K,0.01 s^(-1))下变形时,Al-6.00Mg、Al-6.00Mg-0.10Zr和Al... 采用热压缩试验和电子显微分析方法研究Al-6.00Mg、Al-6.00Mg-0.10Zr和Al-6.00Mg-0.25Sc-0.10Zr (质量分数,%)合金的变形行为和显微组织特征。结果表明,在最大加工效率条件(673 K,0.01 s^(-1))下变形时,Al-6.00Mg、Al-6.00Mg-0.10Zr和Al-6.00Mg-0.25Sc-0.10Zr合金的位错密度分别为2.68×10^(16)、8.93×10^(16)和6.1×10^(17)m^(-2);其动态再结晶分数分别为19.8%、15.0%和12.7%。中心点平均取向差(KAM)分析表明,通过添加Zr或Sc+Zr,Al-Mg合金晶界附近的位错密度增加。此外,基于动态材料模型(DMM)建立的热加工图表明,添加Zr或Sc+Zr能减小Al-Mg合金的低温不稳定域的范围,但会增大高温和高应变不稳定域的范围。实验结果进一步证明,在变形条件下,仅Al-6.00Mg-0.25Sc-0.10Zr合金在773 K和1 s^(-1)时开裂。 展开更多
关键词 AL-MG合金 SC ZR 热变形 位错密度 动态再结晶
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Al_(3)(Sc_(1-x)Zr_(x))纳米粒子对搅拌摩擦焊Al-Mg-Mn合金显微组织和力学性能的影响
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作者 朱鑫文 邓英 +5 位作者 赖毅 郭一帆 杨子昂 傅乐 徐国富 黄继武 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2023年第1期25-35,共11页
通过拉伸测试和显微分析方法研究搅拌摩擦焊Al-5.50Mg-0.45Mn和Al-5.50Mg-0.45Mn-0.25Sc-0.10Zr(质量分数,%)合金的显微组织和力学性能。结果表明,Al-Mg-Mn接头的屈服强度、抗拉强度和伸长率分别为(191±3)MPa、(315±1)MPa和(4... 通过拉伸测试和显微分析方法研究搅拌摩擦焊Al-5.50Mg-0.45Mn和Al-5.50Mg-0.45Mn-0.25Sc-0.10Zr(质量分数,%)合金的显微组织和力学性能。结果表明,Al-Mg-Mn接头的屈服强度、抗拉强度和伸长率分别为(191±3)MPa、(315±1)MPa和(4.8±1.9)%,Al-Mg-Mn-Sc-Zr接头的分别为(288±5)MPa、(391±2)MPa和(3.4±1.0)%。相比Al-Mg-Mn接头,Al-Mg-Mn-Sc-Zr接头晶粒更细小、平均取向差角更低、小角度晶界百分数更高。两种接头的断裂位置均位于焊核区(WNZ),在该“最薄弱微区”内,Al_(3)(Sc_(1-x)Zr_(x))纳米粒子的平均尺寸为(9.92±2.69)nm,可提供有效奥罗万和晶界强化,使Al-Mg-Mn接头的屈服强度提高97 MPa。 展开更多
关键词 铝合金 强度 搅拌摩擦焊 纳米粒子 显微组织
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常压酸溶-电感耦合等离子体质谱法测定地球化学勘查样品中的铌钽 被引量:13
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作者 邓长生 李盛富 +3 位作者 张建梅 王明力 勒孚河 牛芳红 《岩矿测试》 CAS CSCD 北大核心 2018年第4期364-370,共7页
常压酸溶法因溶矿效率高、成本低、检出限低,在地质实验室被广泛应用,但采用常用的氢氟酸-硝酸-盐酸-高氯酸四酸法处理样品,铌钽溶出率低,铌钽在容器壁发生水解和聚合反应导致其部分吸附或沉降,从而使测试结果偏低。因此,应用常压酸溶-... 常压酸溶法因溶矿效率高、成本低、检出限低,在地质实验室被广泛应用,但采用常用的氢氟酸-硝酸-盐酸-高氯酸四酸法处理样品,铌钽溶出率低,铌钽在容器壁发生水解和聚合反应导致其部分吸附或沉降,从而使测试结果偏低。因此,应用常压酸溶-电感耦合等离子体质谱(ICP-MS)分析地球化学勘查样品中的铌钽,需要解决的两个关键问题是铌钽的溶出率和试液中铌钽的水解。针对溶出率的不足,本方法在酸体系中引入硫酸,即氢氟酸-硝酸-盐酸-高氯酸-硫酸可以完全将铌钽溶出;针对水解,采用5%氢氟酸-5%硫酸-5%过氧化氢为提取剂,并采取与样品前处理相同分析流程的标准物质制作曲线,这两个方法相结合能有效抑制样品溶液中铌钽的水解,同时标准物质制作曲线法降低了ICP-MS分析中的样品溶液与标准溶液基体不一致引起的误差。本方法经国家标准物质验证,相对误差小于±7%,相对标准偏差在3.11%~6.27%之间(n=11),铌钽的检出限分别为0.04μg/g和0.03μg/g,相比于碱熔法检出限0.33μg/g具有明显优势,可以准确测定地球化学勘查样品中的铌钽。 展开更多
关键词 地球化学勘查样品 电感耦合等离子体质谱法 常压酸溶 标准曲线法
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基于稳健性设计原理的接触件插拔力质量一致性优化方法 被引量:13
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作者 凌三强 徐乐 +1 位作者 付饶 翟国富 《机械工程学报》 EI CAS CSCD 北大核心 2017年第4期190-197,共8页
基于简支梁结构理论提出斜线簧接触件插拔力计算模型,通过试验与仿真对比分析,验证了该模型的正确性。利用稳健性设计原理,对斜线簧接触件的关键参数进行参数设计和容差设计,确定设计参数中心值的最优组合和容差最佳分配方案。基于蒙特... 基于简支梁结构理论提出斜线簧接触件插拔力计算模型,通过试验与仿真对比分析,验证了该模型的正确性。利用稳健性设计原理,对斜线簧接触件的关键参数进行参数设计和容差设计,确定设计参数中心值的最优组合和容差最佳分配方案。基于蒙特卡洛思想,通过虚拟装配斜线簧接触件,获得优化前后的斜线簧接触件插拔力的质量特性分布,并选取按优化前后的尺寸要求装配的斜线簧接触件测试插拔力,统计分析得出插拔力合格率,对比优化前后的斜线簧接触件插拔力的质量特性分布,分析表明优化后的插拔力合格率得到很大提升。 展开更多
关键词 斜线簧接触件 插拔力 稳健性设计原理 质量一致性
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肠道菌群与子宫内膜癌关系研究进展 被引量:8
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作者 谢玉培 勒孚银 谭布珍(指导) 《中国免疫学杂志》 CAS CSCD 北大核心 2020年第22期2815-2816,F0003,I0002,共4页
子宫内膜癌是女性常见的恶性肿瘤之一,其发病率介于宫颈癌与卵巢癌之间,病因尚不明确,发病危险因素多样,与多种良性疾病如胰岛素抵抗、肥胖等相关。肠道微生物是人体数量最大的“共生菌”,其数量多达人体细胞总数的10倍。近年来,肠道微... 子宫内膜癌是女性常见的恶性肿瘤之一,其发病率介于宫颈癌与卵巢癌之间,病因尚不明确,发病危险因素多样,与多种良性疾病如胰岛素抵抗、肥胖等相关。肠道微生物是人体数量最大的“共生菌”,其数量多达人体细胞总数的10倍。近年来,肠道微生物的研究取得了巨大进展,不仅全面揭示了肠道微生物的生理学功能,还进一步阐明了其与良性疾病和恶性肿瘤的关系。本文就肠道微生物对子宫内膜癌发生、治疗、预后的影响进行讨论与总结,并初步探讨肠道微生物在子宫内膜癌预防、治疗、预后中的应用。 展开更多
关键词 肠道微生物 子宫内膜癌 胰岛素抵抗 肥胖
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基于指纹图谱与多指标成分定量结合化学模式识别分析的小儿热速清颗粒质量评价研究 被引量:3
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作者 周爱鲜 廖正根 +3 位作者 勒孚仕 刘慧星 赵国巍 梁新丽 《药物分析杂志》 CAS CSCD 北大核心 2024年第6期1062-1073,共12页
目的:采用指纹图谱、多指标成分含量测定与化学模式识别分析技术相结合的方法研究不同批次小儿热速清颗粒,为其质量评价提供依据。方法:采用SuperLu C18色谱柱(250 mm×4.6 mm, 5μm),流动相为甲醇(A)-0.1%磷酸水(B),梯度洗脱,体积... 目的:采用指纹图谱、多指标成分含量测定与化学模式识别分析技术相结合的方法研究不同批次小儿热速清颗粒,为其质量评价提供依据。方法:采用SuperLu C18色谱柱(250 mm×4.6 mm, 5μm),流动相为甲醇(A)-0.1%磷酸水(B),梯度洗脱,体积流量1.0 mL·min^(-1),柱温30℃,检测波长280 nm,对15批小儿热速清颗粒指纹图谱进行相似度评价,指认出11个特征成分,并对葛根素、连翘酯苷A、连翘苷、黄芩苷、汉黄芩苷、黄芩素、汉黄芩素7个有效成分进行含量测定,采用聚类分析(HCA)及主成分分析(PCA)对15批样品进行分类并进行正交最小偏二乘法-判别分析(OPLS-DA),筛选出样品批次间差异成分。结果:建立了小儿热速清颗粒HPLC指纹图谱及7个成分的含量测定方法,且这2种方法学验证的结果均符合要求,确定了28个共有峰,并指认了11个色谱峰,15个批次相似度范围为0.995~0.999;HCA和PCA结果显示15个批次成分聚为2类,OPLS-DA分析筛选出13个造成样品批次间差异的标志物;多指标成分含量测定表明不同批次间小儿热速清颗粒中化学成分含量差异性较小。结论:建立的小儿热速清颗粒HPLC指纹图谱及7个成分含量测定方法的专属性强,准确、可靠,结合化学模式识别可有效的用于小儿热速清颗粒的质量控制。 展开更多
关键词 小儿热速清颗粒 高效液相色谱法 指纹图谱 相似度评价 化学模式识别 主成分分析 多成分含量测定 质量评价 相关性分析
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酸菜中乳酸菌的分离筛选及富硒性能研究 被引量:5
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作者 舒梅 钟婵 +2 位作者 吴国平 郭道初 林丽萍 《江西农业大学学报》 CAS CSCD 北大核心 2019年第5期986-992,共7页
以丰城市富硒地区的农家酸菜为原料,分离筛选出2株产酸和富硒能力较强的乳酸菌,经生理生化测定和16s rDNA基因序列同源性分析,这2株细菌分别为植物乳杆菌和类植物乳杆菌,命名为LCFC001、LCFC002。在MRS培养基37℃培养,2株乳酸菌的延滞期... 以丰城市富硒地区的农家酸菜为原料,分离筛选出2株产酸和富硒能力较强的乳酸菌,经生理生化测定和16s rDNA基因序列同源性分析,这2株细菌分别为植物乳杆菌和类植物乳杆菌,命名为LCFC001、LCFC002。在MRS培养基37℃培养,2株乳酸菌的延滞期约4 h,培养18 h左右到达稳定期,浓度达2.5×10^10 CFU/mL,培养基pH值则从起始的6.3降至3.0。在MRS液体培养时,2株乳酸菌可耐终浓度320μg/mL亚硒酸钠;当培养液含亚硒酸钠浓度为20μg/mL时,菌株对硒的转化率可达74.5%。研究表明,分离的2株乳酸菌具有优良的无机硒耐受和转化性能。 展开更多
关键词 乳酸菌 酸菜 富硒性能
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从《重楼玉钥》初探郑梅涧针灸治疗喉疾的思路 被引量:4
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作者 张立志 许能贵 +1 位作者 常乐 付丹丹 《辽宁中医杂志》 CAS 北大核心 2017年第1期74-75,共2页
《重楼玉钥》为清代新安医家郑梅涧所著,主张针药并用,尤其推崇针灸,首创"郑氏三针"说,即"开风路针""破皮针"与"气针",对针灸治疗喉疾颇有研究。学术价值较高,可读性较强。文章就郑梅涧《重楼... 《重楼玉钥》为清代新安医家郑梅涧所著,主张针药并用,尤其推崇针灸,首创"郑氏三针"说,即"开风路针""破皮针"与"气针",对针灸治疗喉疾颇有研究。学术价值较高,可读性较强。文章就郑梅涧《重楼玉钥》对有关喉科针灸治疗的学术思想进行了初步探讨,通过归纳和分析"郑氏三针"的特色,并从其首从"风"治、宛陈则除之、调气为先三个方面阐述治喉疾理论,笔者认为该理论充分、透彻,实用性强,对于临床喉科类疾病的防治具有重要指导意义,应进行进一步的临床研究和推广应用。 展开更多
关键词 针灸 郑梅涧 《重楼玉钥》 思路
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内蒙古绒山羊骨骼肌蛋白差异表达谱分析 被引量:2
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作者 赵珺 张文广 +5 位作者 苏蕊 刘志红 张燕军 王乐 付绍印 李金泉 《西北农林科技大学学报(自然科学版)》 CSCD 北大核心 2016年第8期1-6,共6页
【目的】研究内蒙古绒山羊背最长肌、臂三头肌和臀肌的蛋白差异表达谱。【方法】以3只在相同背景下饲养的绒山羊成年母羊为研究对象,屠宰后取背最长肌、臂三头肌和臀肌3个部位骨骼肌,采用差异双向电泳方法建立蛋白质谱,找出17个差异表... 【目的】研究内蒙古绒山羊背最长肌、臂三头肌和臀肌的蛋白差异表达谱。【方法】以3只在相同背景下饲养的绒山羊成年母羊为研究对象,屠宰后取背最长肌、臂三头肌和臀肌3个部位骨骼肌,采用差异双向电泳方法建立蛋白质谱,找出17个差异表达蛋白点,并进行质谱分析。【结果】成功鉴定并匹配到15个差异表达蛋白,其中9个与山羊肌肉发育相关。背最长肌中发现的位于FGF2反义链的蛋白的功能主要是独立控制FGF2的表达,同时具有激素调节和抗增殖的作用;背最长肌和臂三头肌中发现的轻链肌球蛋白(MyLC)家族成员,其类型在2种肌肉组织中不同,功能是控制肌肉收缩。背最长肌和臂三头肌中的MyLC蛋白分子质量存在差异。【结论】建立了绒山羊骨骼肌差异蛋白谱,挖掘到了与肉质相关的蛋白,其主要为控制肌肉收缩的结构蛋白。 展开更多
关键词 绒山羊 骨骼肌 差异蛋白 质谱分析
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常态及故障条件下的多传感器任务管控调度研究
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作者 罗旋 陈冰 +1 位作者 勒孚龙 鲁志波 《数学的实践与认识》 北大核心 2017年第10期112-121,共10页
针对多传感器控制中的常态和故障情况问题,建立了描述常态和故障条件下的多传感器控制的多目标规划模型,通过偏离度指数,应用遗传算法求得常态控制问题最优解.其次将传感器故障转化成伪执行器故障运用改进的遗传算法,实现了多传感器故... 针对多传感器控制中的常态和故障情况问题,建立了描述常态和故障条件下的多传感器控制的多目标规划模型,通过偏离度指数,应用遗传算法求得常态控制问题最优解.其次将传感器故障转化成伪执行器故障运用改进的遗传算法,实现了多传感器故障情形下最优控制求解.仿真结果表明了最优控制方案的有效性. 展开更多
关键词 多传感器故障 遗传算法 多目标规划 最优控制
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Antibacterial sorbicillin and diketopiperazines from the endogenous fungus Penicillium sp. GD6 associated Chinese mangrove Bruguiera gymnorrhiza 被引量:5
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作者 JIANG Cheng-Shi ZHOU Zhen-Fang +4 位作者 YANG Xiao-Hong LAN le-fu GU Yu-Cheng YE Bo-Ping GUO Yue-Wei 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2018年第5期358-365,共8页
One new sorbicillin derivative, 2-deoxy-sohirnone C(1), one new diketopiperazine alkaloid, 5 S-hydroxynorvalineS-Ile(2), and two naturally occurring diketopiperazines, 3 S-hydroxylcyclo(S-Pro-S-Phe)(3) and cyclo(S-Phe... One new sorbicillin derivative, 2-deoxy-sohirnone C(1), one new diketopiperazine alkaloid, 5 S-hydroxynorvalineS-Ile(2), and two naturally occurring diketopiperazines, 3 S-hydroxylcyclo(S-Pro-S-Phe)(3) and cyclo(S-Phe-S-Gln)(4), together with three known compounds were isolated from the Chinese mangrove endophytic fungus Penicillium sp. GD6. Their structures were determined on the basis of extensive spectroscopic analyses and by comparison with literature data. The absolute configuration of 3-hydroxyl moiety in 3 was determined by Mosher's method, while the absolute stereochemistry of 2 and 4 was established by comparison with the CD spectra of natural and synthesized diketopiperazines. Compound 1 showed moderate antibacterial activity against Methicillin-resistant Staphylococcus aureus with a MIC value of 80 μg·m L^(-1). 展开更多
关键词 MANGROVE PENICILLIUM sp. Sorbicillin derivative DIKETOPIPERAZINE ALKALOIDS
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Facile and effective synthesis strategy for terbium-doped hydroxyapatite toward photoelectric devices and flexible functional fibers
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作者 Xiao-Dong Zhang Kun Nie +10 位作者 Zi-Yao Hu Ran-Ran Zhou Xiu-Qiang Duan Wu-Bin Dai Song-Song Nie Song-Jun Yao Luo-Xin Wang le-fu Mei Hua Wang Yi-Yi Yao Xiao-Xue Ma 《Rare Metals》 SCIE EI CAS CSCD 2024年第4期1713-1723,共11页
As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biol... As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biological probes,drug delivery,optoelectronic materials,fluorescence anti-counterfeiting,and other aspects.In this paper,we put forward the preparation of HAP doped with terbium(Ⅲ)ions(Tb^(3+))by hydrothermal co-precipitation.By controlling the Tb^(3+)doping content in reaction and the reaction time,the changes in HAP's structure,morphology,and luminescence properties under different conditions were studied.When the doping amount of Tb^(3+)reached an optimal value,the dipole-quadrupole would occur and the concentration would be quenched.The control experiment showed that the optimal Tb3+content was 7.5×10^(-5)mol,which showed the best fluorescence performance.HAP,a non-luminous material,was rarely used in the field of fluorescent anti-counterfeiting and photoelectric devices.We proposed to prepare a luminescent aramid/polyphenylene sulfide(ACFs/PPS)fiber paper and a new light-emitting diode(LED)using the Tb-doped HAP phosphor.The composite sample exhibited an excellent stability and fluorescence performance,which also demonstrated a possibility of HAP applications in anticounterfeiting and photoelectric.The introduction of Tb3+dopant HAP was done to give HAP optical properties and broaden the application range of HAP. 展开更多
关键词 HYDROXYAPATITE Rare earth luminescence Photoelectric device ARAMID Polyphenylene sulfide fiber paper Luminescent fiber
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Design,synthesis and biological evaluation of LpxC inhibitors with novel hydrophilic terminus 被引量:2
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作者 Shi Ding Wen-Ke Wang +4 位作者 Qiao Cao Wen-Jing Chu le-fu Lan Wen-Hao Hu Yu-She Yang 《Chinese Chemical Letters》 SCIE CAS CSCD 2015年第6期763-767,共5页
In order to develop novel LpxC inhibitors with good activities and metabolic stability, two series of compounds with hydrophilic terminus have been synthesized and their in vitro antibacterial activities against Esche... In order to develop novel LpxC inhibitors with good activities and metabolic stability, two series of compounds with hydrophilic terminus have been synthesized and their in vitro antibacterial activities against Escherichial coil and Pseudomonas aemginosa were evaluated. Especially, compounds 22b and c exhibited comparable antibacterial activities to CHIR-090 and better metabolic stability than CHIR-090 and LPC-011 in liver microsomes (rat and mouse), which indicated the terminal methylsulfone may be a preferred structure in the design of LpxC inhibitors and worthy of further investigations. 展开更多
关键词 LpxC CHIR-090 Kojic acid derivatives Methylsulfone derivatives Metabolic stability
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Determining the major Bt refuge crops for cotton bollworm in North China 被引量:1
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作者 le-fu Ye Xue fu +2 位作者 Fang Ouyang Bao-Yu Xie Feng Ge 《Insect Science》 SCIE CAS CSCD 2015年第6期829-839,共11页
Evaluation of the effectiveness of refuge strategies involved in cotton boll- worm Bt resistance management would be aided by technologies that allow monitoring and quantification of key factors that affect the proces... Evaluation of the effectiveness of refuge strategies involved in cotton boll- worm Bt resistance management would be aided by technologies that allow monitoring and quantification of key factors that affect the process under field conditions. We hy- pothesized that characterization of stable carbon and nitrogen isotopes in adult bollworm, Helicoverpa armigera (Htibner) (Lepidoptera: Noctuidae) moths may aid in determining the larval host that they developed upon. We found moths reared from larvae fed on peanut, soybean or cotton, respectively, could be differentiated using isotopic analyses that also corresponded to their respective larval host origins. These techniques were then used to classify feral second-generation bollworm moths caught in Bt cotton (Gossypium hirsu- rum) fields into different populations based on their isotopic signatures. In 2006-2007 feral moths captured in Bt cotton fields predominantly correlated with the peanut (Arachis hypogea) having served as their larval host, indicating this is the most important refuge crop for Bt-susceptible bollworm individuals (providing 58%-64% individuals) during independent moth peaks for the second generation in North China. The remaining feral moths correlated with soybean (Glycine max) (0-10%); other C3 plant (20%-22%) and non-C3 plant (12%-14%) host types also provided some Bt-sensitive moths. Field obser- vations showed that peanut constitutes the primary refuge crop contributing to sustaining Bt-susceptible moths dispersing into cotton in North China. These results suggest that peanut may be a more effective refuge to sustain Bt-susceptible bollworm individuals and reduce the risk of development of a Bt-resistant biotype. 展开更多
关键词 cluster analysis cotton bollworm host plant stable isotope transgenic Bt-cotton
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Corrosion Behavior of Ferritic/Martensitic Steels CNS-Ⅰ and Modified CNS-Ⅱ in Supercritical Water 被引量:1
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作者 YANG Ying YAN Qing-zhi +2 位作者 YANG Ya-feng ZHANG le-fu GE Chang-chun 《Journal of Iron and Steel Research International》 SCIE CAS CSCD 2012年第5期69-73,36,共6页
The corrosion behaviors of CNS-I and modified CNS-II were evaluated by exposing to superciritical water (SCW) at 550℃ and 25 MPa with a dissolved oxygen concentration of 200× 10 ^-9 for up to 1 000 h. Detailed... The corrosion behaviors of CNS-I and modified CNS-II were evaluated by exposing to superciritical water (SCW) at 550℃ and 25 MPa with a dissolved oxygen concentration of 200× 10 ^-9 for up to 1 000 h. Detailed corrosion results of these two alloys were provided, including the growth rate of the oxide scales, microstructure of the oxide scales, distribution of phases and alloying elements. The mass gains of CNS-I and modified CNS-II were 609.73 mg/dm2 and 459.42 mg/dm2 , respectively, after exposing to SCW for 1 000 h. A duplex oxide scale with an outer porous magnetite layer and an inner relatively dense magnetite/spinel-mixed layer was identified on CNS-I and modified CNS-II after the test. The oxide scales were rather porous at the beginning of the test but the porosity decreased with increase of the exposure duration. It was found that Fe was enriched in the outer oxide layer, Cr was enriched in the inner oxide layer and O existed at a very high concnetration in the whole oxide scale. Other alloying elements such as Mo, W, Mn were depleted from the outer oxide layer and showed slightly enrichment in the inner oxide layer. The distributution of Ni was different from other elements, it was enriched in the interface bewteen the base metal and the oxide scale and depleted in the outer and inner oxide layers. 展开更多
关键词 ferritic/martensitic steel supercritical water corrosion kinetics oxide scale morphology and structure
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Genetic Differentiation Analyses Based on mtDNA COⅡ Gene Sequences Among Different Geographic Populations of Aphis glycines(Hemiptera: Aphididae) in Northeast China 被引量:1
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作者 Li Ran Han Lan-lan +4 位作者 Ye le-fu Zhang Hong-yu Sun Wen-peng Tong Xin Zhao Kui-jun 《Journal of Northeast Agricultural University(English Edition)》 CAS 2015年第3期23-31,共9页
Aphis glycines (Hemiptera: Aphididae) is considered as a cosmopolitan pest of cultivated soybean, major difficulties in its control measures may be due to its higher genetic diversity; however, the knowledge about ... Aphis glycines (Hemiptera: Aphididae) is considered as a cosmopolitan pest of cultivated soybean, major difficulties in its control measures may be due to its higher genetic diversity; however, the knowledge about population genetic diversity of this species is limited. This study aimed to represent the genetic differentiation among different geographic populations of soybean aphid in Northeast China. In order to investigate and assess the genetic diversity, genetic differentiation, molecular variance, population structure, ecological importance and evolutionary history of A. glycines, we sequenced a fragment of one protein-coding gene, the cytochrome c oxidase I/of mitochondrial DNA gene. The results showed that four haplotypes were defined among CO 11 gene of 180 sequences of soybean aphid in Northeast China including H1 shared by all the populations. Lower haplotype diversity (Hd=0.3590± 0.0420) and nucleotide diversity (Pi=0.0012±0.0002) were observed and high gene flow was detected in every two populations, while most of the variation (80.81%) arose from variability within A. glycines from individuals. Low genetic differentiation and high gene flow (Nm=2.106) indicated a high migration rate between the populations, which might reveal that gene flow in different geographic populations did not affect by geographical distance. The phylogenetic tree and the haplotype network ofA. glycines were obtained based on sequences of CO Ⅱ gene, there were no significant genealogical branches or clusters recognized in NJ tree, and no clear distribution, delineation of haplotypes were demonstrated in the haplotype network according to geographical location. This study rejected the vicariance hypothesis: geographic isolation could be a barrier and it restricted A. glycines gene flow among 10 populations. 展开更多
关键词 Aphis glycines mtDNA CO geographic population gene flow genetic differentiation
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Studies on Occurrence Ecological Factors and Management Strategies of Ambrostoma quadriimpressum in Harbin City
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作者 Ma Xiao-chi Wei Wei +5 位作者 Ye le-fu Zhao Jia-nan Zhao Kui-jun Wang Zi-jian Liu Xiao-jie fu Xue 《Journal of Northeast Agricultural University(English Edition)》 CAS 2016年第1期9-15,共7页
This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle (different effects of minimum and maximum values, relations between each two variables were also explored) and dis... This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle (different effects of minimum and maximum values, relations between each two variables were also explored) and discussed current management measures. The results showed that among these factors, interval between elm trees significantly affected damage level by this leaf beetle species, and perimeter of elm trunk could change this effect. On the other side, while middle values for each index were deleted, effects comparison between minimum and maximum parts showed that good root soil as overwintering was related with more damage; more severe damages on elm tree would result in more control measures used; on elm tree with bigger mink, more damages were observed; and if other elm tree was closer, more damages would occur. Secondly, good root soil was related with more measures used; good root soil was correlated with smaller perimeter; good root soil was associated with bigger interval. Thirdly, more measures were correlated with bigger perimeter; more measures were also correlated with good root soil. Fourthly, bigger perimeter was correlated with worse root soil. Current dominant control measures included chemical pesticide application preventing adult insects from descending or climbing up along trunk before and after overwintering. These results suggested that we should focus on elm leaf beetle management on all the elm trees instead of only on bigger elm trees at proper period simultaneously because occurrence on these elm trees were related intensively although this adult elm leaf beetle species could not fly and had limited movement ability. 展开更多
关键词 elm leaf beetle monophagous Ulmus pumila ecological factor
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Computational analysis of apatite-type compounds for band gap engineering: DFT calculations and structure prediction using tetrahedral substitution
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作者 Hai-Kun Liu Li-Bing Liao +7 位作者 Yuan-Yuan Zhang Sergey MAksenov Ning Liu Qing-Feng Guo Dina V.Deyneko Tian-Yi Wang le-fu Mei Cheng-Hua Sun 《Rare Metals》 SCIE EI CAS CSCD 2021年第12期3694-3700,共7页
Mineral apatite compounds have attracted significant interest due to their chemical stability and adjustable hexagonal structure,which makes them suitable as new photovoltaic functional materials.The band gap of natur... Mineral apatite compounds have attracted significant interest due to their chemical stability and adjustable hexagonal structure,which makes them suitable as new photovoltaic functional materials.The band gap of natural apatite is ~5.45 eV,and such a large value limits their applications in the field of catalysis and energy devices.In this research,we designed a method to narrow the band gap via the tetrahedral substitution effect in apatite-based compounds.The density functional theory(DFT) and experimental investigation of the electronic and optical properties revealed that the continuous incorporation of [MO_(4)]^(4-) tetrahedrons(M=Si,Ge,Sn,and Mn) into the crystal lattice can significantly reduce the band gap.In particular,this phenomenon was observed when the[MnO_(4)]^(4-) tetrahedron replaces the [PO_(4)]^(4-) tetrahedron because of the formation of a Mn 3 d-derived conduction band minimum(CBM) and interacts with other elements,leading to band broadening and obvious reduction of the band gap.This approach allowed us to propose a novel scheme in the band gap engineering of apatite-based compounds toward an entire spectral range modification. 展开更多
关键词 APATITE Density functional theory(DFT) Band gap engineering Structure prediction Tetrahedral substitution
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Degradation of Cry1Ab Protein Within Transgenic Bt Maize Tissue by Composite Microbial System of MC1
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作者 Meng Yao Gu Wan-rong +3 位作者 Ye le-fu Chen Dong-sheng Li Jing Wei Shi 《Journal of Northeast Agricultural University(English Edition)》 CAS 2014年第4期10-17,共8页
Environmental safety issues involved in transgenic plants have become the concern of researchers, practitioners and policy makers in recent years. Potential differences between Bt maize(ND1324 and ND2353 expressing t... Environmental safety issues involved in transgenic plants have become the concern of researchers, practitioners and policy makers in recent years. Potential differences between Bt maize(ND1324 and ND2353 expressing the insecticidal Cry1Ab protein) and near-isogenic non-Bt varieties(ND1392 and ND223) in their influence on the composite microbial system of MC1 during the fermentation process were studied during 2011-2012. Cry1Ab protein in Bt maize residues didn't affect characteristics of lignocellulose degradation by MC1, pH of fermentation broth decreasing at initial stage and increasing at later stage of degradation. The quality of various volatile products in fermentation broth showed that no signifi cant difference of residues fermentation existed between Bt maize and non-Bt maize. During the fermentation MC1 efficiently degraded maize residues by 83%-88%, and cellulose, hemicelluloses and lignin content decreased by 70%-72%, 72%-75% and 30%-37%, respectively. Besides that, no consistent difference was found between Bt and non-Bt maize residues lignocellulose degradation by MC1 during the fermentation process. MC1 degraded 88%-89% Cry1Ab protein in Bt maize residues, and in the fermentation broth of MC1 and bacteria of MC1 Cry1Ab protein was not detected. DGGE profi le analyses revealed that the microbial community drastically changed during 1-3 days and became stable until the 9th day. Though the dominant strains at different fermentation stages had signifi cantly changed, no difference on the dominant strains was observed between Bt and non-Bt maize at different stages. Our study indicated that Cry1Ab protein did not infl uence the growth characteristic of MC1. 展开更多
关键词 Bt maize degradation of Cry1AB protein composite microbial system of MC1
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