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Fabrication of 4-Inch Nano Patterned Wafer with High Uniformity by Laser Interference Lithography 被引量:3
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作者 Gen Yue Yu Lei +2 位作者 Jun-Hui Die Hai-Qiang Jia Hong Chen 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第5期56-59,共4页
We report the fabrication of 4-inch nano patterned wafer by two-beam laser interference lithography and analyze the uniformity in detail. The profile of the dots array with a period of 800 nm divided into five regions... We report the fabrication of 4-inch nano patterned wafer by two-beam laser interference lithography and analyze the uniformity in detail. The profile of the dots array with a period of 800 nm divided into five regions is characterized by a scanning electron microscope. The average size in each region ranges from 270 nm to 320 nm,and the deviation is almost 4%, which is approaching the applicable value of 3% in the industrial process. We simulate the two-beam laser interference lithography system with MATLAB software and then calculate the distribution of light intensity around the 4 inch area. The experimental data fit very well with the calculated results. Analysis of the experimental data and calculated data indicates that laser beam quality and space filter play important roles in achieving a periodical nanoscale pattern with high uniformity and large area. There is the potential to obtain more practical applications. 展开更多
关键词 exp Fabrication of 4-Inch Nano patterned Wafer with high Uniformity by Laser Interference Lithography
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Microorganisms in Small Patterned Ground Features and Adjacent Vegetated Soils along Topographic and Climatic Gradients in the High Arctic, Canada 被引量:1
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作者 Grizelle González Francisco J. Rivera-Figueroa +2 位作者 William A. Gould Sharon A. Cantrell José R. Pérez-Jiménez 《Open Journal of Soil Science》 2014年第1期47-55,共9页
In this study, we determine differences in total biomass of soil microorganisms and community structure (using the most probable number of bacteria (MPN) and the number of fungal genera) in patterned ground features (... In this study, we determine differences in total biomass of soil microorganisms and community structure (using the most probable number of bacteria (MPN) and the number of fungal genera) in patterned ground features (PGF) and adjacent vegetated soils (AVS) in mesic sites from three High Arctic islands in order to characterize microbial dynamics as affected by cryoturbation, and a broad bioclimatic gradient. We also characterize total biomass of soil microorganisms and the most probable number of bacteria along a topographic gradient within each bioclimatic subzone to evaluate whether differences in topography lead to differences in microbial dynamics at a smaller scale. We found total microbial biomass C, the most probable number of heterotrophic bacteria, and fungal genera vary along this bioclimatic gradient. Microbial biomass C decreased with increasing latitude. Overall, microbial biomass C, MPN and the number of fungal isolates were higher in AVS than in PGFs. The effects which topographic position had on microbial biomass C varied across the bioclimatic gradient as there was no effect of topographic position in Isachsen (subzone A) and Mould Bay (subzone B), when compared to Green Cabin (subzone C, warmer site).There was no effect of topographic position on MPN counts at Mould Bay and Green Cabin. However, in Isachsen, MPN counts were highest in the wet topographic position as compared to the mesic and dry. In conclusion, PGFs seem to decouple the effect climate that might have on the total biomass of soil microorganisms along the bioclimatic gradient;and influence gets ameliorated as latitude increases. Similarly, the effect of topography on the total microbial biomass is significant at the warmest bioclimatic zone of the gradient. Thus, climate and topographic effects on total microbial biomass increase with warmer climate. 展开更多
关键词 Soil MICROORGANISMS high Artic CANADA patterned FEATURES MICROBIAL Biomass
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Precursory atmospheric teleconnection patterns for strong Siberian High events
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作者 Jian Song Ning Shi Qilei Huang 《Atmospheric and Oceanic Science Letters》 CSCD 2023年第5期17-21,共5页
本文利用日本55年逐日再分析资料,发现在SH异常增强前,有三种不同的大气遥相关型前兆信号,即斯堪的纳维亚(SCA)型,西太平洋(WP)型,极地-欧亚(POL)型据此,本文将异常增强的SH分为对应的三类事件.合成结果表明,三类事件在典型环流特征和... 本文利用日本55年逐日再分析资料,发现在SH异常增强前,有三种不同的大气遥相关型前兆信号,即斯堪的纳维亚(SCA)型,西太平洋(WP)型,极地-欧亚(POL)型据此,本文将异常增强的SH分为对应的三类事件.合成结果表明,三类事件在典型环流特征和对东亚气温的影响上存在着明显的不同.具体而言,SCA类事件主要表现为在欧亚中高纬度上自西向东的波列异常,WP类事件表现为环流异常自下游太平洋/俄罗斯远东地区向西发展的特征,POL型事件的显著信号则来源于自极区向南移动的反气旋式环流异常.在对东亚地表气温的影响上,SCA类与POL类事件类似,它们均可造成大范围的低温异常.而WP类仅在我国北方和东部地区造成强度较弱的地表气温异常,但该异常的持续性特征较明显。 展开更多
关键词 西伯利亚高压 大气遥相关 气温异常
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Analysis of Dual-Core Type City and Its Hinterland Contact Pattern under the Background of High-Speed Rail Networking—Urban Agglomeration in Zhejiang Province as an Example
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作者 Xiaohong Ren 《Journal of Transportation Technologies》 2016年第4期207-217,共12页
Under the background of high-speed rail networking, this paper uses the passenger trains, the type and direction of the railway via Hang Yong and its extension road line, to construct adsorption and dependency index a... Under the background of high-speed rail networking, this paper uses the passenger trains, the type and direction of the railway via Hang Yong and its extension road line, to construct adsorption and dependency index among cities, depict the contact pattern between the Hang Yong dual-core and its hinterland, measure the “net effect” that two center cities (Hangzhou, Ningbo) have on their hinterland, and estimate population agglomeration potential and future possible population flows of Zhejiang Province and the main sample cities. The result shows that, compared with Ningbo, Hangzhou has stronger radiation force to the vast majority of sample cities, and the sample cities affected more by Ningbo mainly concentrates in Ningbo-Taizhou-Wenzhou along;in addition, the sample cities such as Hangzhou, Ningbo and so on show better population agglomeration, then the population “scramble” phenomenon between cities has begun to appear. 展开更多
关键词 high-Speed Rail Networking Contact pattern Measurement
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时速600 km高速磁浮车站分布间距及列车停站方式研究
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作者 黄树明 《铁道运输与经济》 北大核心 2026年第2期99-107,共9页
当前高速磁浮已成为国家综合交通重要发展战略,但由于其超高速特性,且涉及与既有高速铁路合理分工问题,其车站分布及列车停站方式无法照搬既有高速铁路经验,为适应未来高速磁浮发展需求,亟需对其车站分布及列车停站方式进行研究。分析... 当前高速磁浮已成为国家综合交通重要发展战略,但由于其超高速特性,且涉及与既有高速铁路合理分工问题,其车站分布及列车停站方式无法照搬既有高速铁路经验,为适应未来高速磁浮发展需求,亟需对其车站分布及列车停站方式进行研究。分析高速磁浮车站分布对列车运行效率、客流及运行时间的影响,提出综合交通立体成网条件下,时速600 km高速磁浮应尽量选择大型城市设站、兼顾中型城市,车站分布间距宜在100~150 km,设站密度约为通道内既有高速铁路的1/3~1/2。针对高速磁浮列车不同停站方式对通过能力、运行时间、服务水平的影响,提出时速600 km高速磁浮平均设站间距在150 km以上时,宜采用站站停模式;平均设站间距在100 km以下时,可采用差异化停站模式;平均站间距在100~150 km之间时,可结合通道内高速铁路运营情况、客流情况、工程经济、财务效益等综合因素合理确定列车停站模式。 展开更多
关键词 时速600 km 高速磁浮 车站分布间距 列车停站方式 京沪高速磁浮 京广高速磁浮
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农畜产品供应链视域下农牧业高质量发展机理及对策
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作者 张建军 《供应链管理》 2026年第1期45-52,共8页
农畜产品供应链是农牧业发展的重要载体,其高质量发展是农牧业高质量发展的重要抓手。文章重点阐述供应链视域下农牧业高质量发展机理即通过供应链视域战略的实施,有效解决农畜产品供应链在产地、产品、参与主体、流通环节以及信息化等... 农畜产品供应链是农牧业发展的重要载体,其高质量发展是农牧业高质量发展的重要抓手。文章重点阐述供应链视域下农牧业高质量发展机理即通过供应链视域战略的实施,有效解决农畜产品供应链在产地、产品、参与主体、流通环节以及信息化等方面的核心痛点,进而间接实现农牧业高质量发展的目标,包括通过全链条协同与培育新质生产力实现产出高效、通过全链条资源整合与精细化管理实现资源节约、通过全链条节能减排与资源循环利用实现环境友好、通过全链条质量检测与风险管控实现产品安全、通过全链条信息共享与精准预测实现调控有效。在上述分析基础上,围绕农畜产品供应链生产方式、市场主体、市场主体间关系、生产要素以及健全产业链等方面提出农牧业高质量发展的对策。 展开更多
关键词 农畜产品供应链 农牧业 高质量发展 新发展格局
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稳步扩大制度型开放的理论逻辑、现实挑战与实践方略
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作者 林峰 《财贸研究》 北大核心 2026年第1期1-10,共10页
党的二十届四中全会鲜明提出“稳步扩大制度型开放”,为新时代推进高水平对外开放指明了战略方向。文章系统阐释了稳步扩大制度型开放的理论逻辑、现实挑战与实践方略。研究认为,制度型开放的理论基础在于通过对规则、规制、治理和标准... 党的二十届四中全会鲜明提出“稳步扩大制度型开放”,为新时代推进高水平对外开放指明了战略方向。文章系统阐释了稳步扩大制度型开放的理论逻辑、现实挑战与实践方略。研究认为,制度型开放的理论基础在于通过对规则、规制、治理和标准等制度要素的系统性重塑,降低制度性交易成本,提升开放型经济运行的稳定性与可预期性,从而为高水平对外开放和“双循环”新发展格局提供制度支撑。然而,在稳步扩大制度型开放的过程中,仍面临外部不确定性上升、制度供给相对不足、区域开放进程不均衡以及市场主体响应有限等多重制约。因此,应围绕高标准规则对接、规制体系改革、治理能力现代化和标准国际化等关键环节施策发力,增强制度型开放的系统性、协同性与可持续性。 展开更多
关键词 制度型开放 高水平对外开放 “双循环”新发展格局
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基于高效液相色谱指纹图谱结合多成分含量测定的通脉降糖胶囊质量控制的研究
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作者 李叶 杨长花 +9 位作者 罗晨曦 杨青 王苗 赵扬 谭未未 周佳琳 彭修娟 黄壮壮 刘峰 陈衍斌 《西北药学杂志》 2026年第1期35-41,共7页
目的建立通脉降糖胶囊的高效液相色谱(high-performance liquid chromatography,HPLC)指纹图谱,同步建立其6种特征成分的含量测定方法,以期完善该制剂的质量控制体系。方法采用Diamonsil Plus C_(18)色谱柱(250 mm×4.6 mm,5μm);... 目的建立通脉降糖胶囊的高效液相色谱(high-performance liquid chromatography,HPLC)指纹图谱,同步建立其6种特征成分的含量测定方法,以期完善该制剂的质量控制体系。方法采用Diamonsil Plus C_(18)色谱柱(250 mm×4.6 mm,5μm);以乙腈-体积分数0.1%磷酸水溶液为流动相,指纹图谱采用梯度洗脱程序1,含量测定采用梯度洗脱程序2;检测波长为250 nm;流速为1.0 mL·min^(-1);柱温为35℃;进样量为10μL。借助中药色谱指纹图谱相似度评价系统(2012版),构建11批通脉降糖胶囊的HPLC指纹图谱并进行相似度评价。结果指纹图谱共标识24个共有峰,其中10种成分得到指认;方法学考察结果显示,该方法精密度、重复性、稳定性均良好,11批通脉降糖胶囊指纹图谱的相似度均>0.99,化学成分一致性良好。6种成分含量测定结果显示,标准曲线线性关系良好(R^(2)≥0.999),平均加样回收率为91.93%~106.13%,回收率相对标准偏差(relative standard deviation,RSD)≤2.65%。结论所建立的HPLC指纹图谱和多成分含量测定方法准确、灵敏、重复性良好,为通脉降糖胶囊的质量控制提供了科学依据。 展开更多
关键词 通脉降糖胶囊 多成分含量测定 高效液相色谱 指纹图谱 质量控制
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高含水油藏密井网与化学驱提高采收率机理及实践
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作者 吴德君 于春磊 +5 位作者 刘西雷 鲁轩 陶德硕 李晓宁 汪歆迪 张先敏 《石油与天然气化工》 北大核心 2026年第1期84-90,共7页
目的针对高含水油藏常规开发方式剩余油动用难度大、采收率提高受限的难题,探索密井网与化学驱的协同增效机制,以指导现场高效开发。方法综合运用物理模拟(二维平板填砂模型)和数值模拟技术,揭示了密井网与化学驱的扩大波及范围与高效... 目的针对高含水油藏常规开发方式剩余油动用难度大、采收率提高受限的难题,探索密井网与化学驱的协同增效机制,以指导现场高效开发。方法综合运用物理模拟(二维平板填砂模型)和数值模拟技术,揭示了密井网与化学驱的扩大波及范围与高效驱油机理,分析了储层非均质性、井网类型及注采参数对开发效果的影响,并在G油田Q区块开展了实例验证。结果井网加密通过增强井间连通性和流线重置,强制动用相对低渗区剩余油;化学驱则通过调驱和洗油作用,提高驱油效率。二者协同实现了“宏观波及与微观驱替”的双重强化,且储层非均质性越强,协同增效潜力越大。现场实践表明,采用优化的150 m×75 m正对排状井网,可使区块采收率最大提高13.3%。结论密井网与化学驱协同开发模式能够显著提高高含水油藏的采收率,为同类油藏的深度开发提供了有效的技术路径。 展开更多
关键词 高含水油藏 化学驱 密井网 协同机理 提高采收率
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高职院校高效能治理的影响因素与组态模式研究
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作者 杨宜 王凤宏 夏飞 《教育与职业》 北大核心 2026年第2期73-79,共7页
本文选取80所高职院校作为研究案例,采用模糊集定性比较分析方法(fsQCA),以“制度体系完善、生态体系构建、智慧体系应用、改革创新能力、师资建设能力、专业建设能力”为条件变量,系统探究高职院校高效能治理的影响因素与组态模式。结... 本文选取80所高职院校作为研究案例,采用模糊集定性比较分析方法(fsQCA),以“制度体系完善、生态体系构建、智慧体系应用、改革创新能力、师资建设能力、专业建设能力”为条件变量,系统探究高职院校高效能治理的影响因素与组态模式。结果显示,共有四种组态模式可以实现高职院校高效能治理,概括为制度改革引领模式、产教融合导向模式、智慧赋能驱动模式和综合治理推进模式。据此,建议政府层面优化政策支持与资源协同,院校层面提升治理效能与持续改进,行业企业层面深化协同共治与能力反哺。 展开更多
关键词 高职院校 高效能治理 模糊集定性比较分析 组态模式
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高过成熟页岩储层孔隙水实验技术与赋存规律研究进展及启示
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作者 申宝剑 王鹏威 +3 位作者 魏祥峰 万成祥 李楚雄 李倩文 《石油实验地质》 北大核心 2026年第1期50-60,共11页
孔隙水分布与赋存特征对页岩气赋存和富集具有重要影响,但现有研究对孔隙水的认识仍不充分,制约了页岩气富集机理研究和勘探开发部署。系统论述了当前页岩储层孔隙水实验测试技术及赋存规律研究进展,并结合勘探实践提出了未来重点攻关... 孔隙水分布与赋存特征对页岩气赋存和富集具有重要影响,但现有研究对孔隙水的认识仍不充分,制约了页岩气富集机理研究和勘探开发部署。系统论述了当前页岩储层孔隙水实验测试技术及赋存规律研究进展,并结合勘探实践提出了未来重点攻关方向。研究表明:(1)页岩储层含水饱和度评价主要依靠测井计算法和实验测试法,孔隙水微观赋存状态与可动性表征多采用核磁共振实验与分子模拟技术;(2)页岩储层孔隙水赋存状态可分为结构水、层间水、束缚水(水膜束缚水与毛管束缚水)及自由水;(3)页岩储层孔隙水优先分布在亲水孔隙内,其在有机/无机孔中的分布受介质界面润湿性、岩石矿物组分及孔隙结构等因素共同控制。(4)高过成熟页岩通常具有超低含水饱和度特征,但受有机质石墨化及后期构造调整作用的影响,亦可形成高含水页岩。未来需深化原位条件下页岩含水饱和度评价方法,提升改进自动化实验技术与装备,提高分析效率并推动实验流程标准化。同时应加强原位条件下页岩孔隙水赋存状态与多尺度分布特征研究,深化高过成熟页岩高含水成因机制认识,重建孔隙水赋存差异演化路径,构建考虑受孔隙水影响的页岩气地质评价参数体系,为深层—超深层页岩气勘探部署和开发决策提供理论依据。 展开更多
关键词 高过成熟页岩 孔隙水 实验技术 赋存规律 四川盆地
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基于双波长指纹图谱结合化学模式识别的平纳蜜膏质量标准研究
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作者 张明惠 杨青青 +2 位作者 尹梦晴 张晓莉 马璇 《药学前沿》 2026年第2期211-218,共8页
目的建立10批平纳蜜膏双波长指纹图谱,并结合化学模式识别方法,为其质量控制及标准制定提供依据。方法采用HPLC法,色谱柱为Shim Nex CS C_(18)柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.4%磷酸水溶液,梯度洗脱,柱温为30℃,流速为1.0 ... 目的建立10批平纳蜜膏双波长指纹图谱,并结合化学模式识别方法,为其质量控制及标准制定提供依据。方法采用HPLC法,色谱柱为Shim Nex CS C_(18)柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.4%磷酸水溶液,梯度洗脱,柱温为30℃,流速为1.0 mL/min,检测波长为330 nm和245 nm,进样量为10μL。采用中药色谱指纹图谱相似度评价系统(2012版)对10批平纳蜜膏的HPLC色谱图进行分析,建立双波长指纹图谱。然后针对330 nm波长下的指纹图谱,进一步进行了聚类分析、主成分分析以及正交偏最小二乘法-判别分析。结果建立10批平纳蜜膏的HPLC双波长(330 nm与245 nm)指纹图谱,分别在两波长下标定13个与7个共有峰。通过与对照品对比,指认出咖啡酸、蒙花苷、木犀草素、芹菜素、一枝蒿酮酸共5种成分,所有样品相似度均大于0.9。化学模式识别分析结果表明,10批样品可划分为3类,并筛选出峰2(咖啡酸)、峰10、峰1、峰3、峰6(蒙花苷)共5个差异性成分。结论本研究建立的双波长指纹图谱以及化学模式识别方法准确可靠,可为平纳蜜膏的质量标准研究提供重要的数据支持。 展开更多
关键词 平纳蜜膏 双波长 指纹图谱 高效液相色谱 化学模式识别 质量标准 质量控制
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Authentication and distinction of Shenmai injection with HPLC fingerprint analysis assisted by pattern recognition techniques 被引量:5
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作者 Xue-Feng Lu Kai-Shun Bi +1 位作者 Xu Zhao Xiao-Hui Chen 《Journal of Pharmaceutical Analysis》 CAS 2012年第5期327-333,共7页
In this paper, the feasibility and advantages of employing high performance liquid chromatographic (HPLC) fingerprints combined with pattern recognition techniques for quality control of Shenmai injection were inves... In this paper, the feasibility and advantages of employing high performance liquid chromatographic (HPLC) fingerprints combined with pattern recognition techniques for quality control of Shenmai injection were investigated and demonstrated. The Similarity Evaluation System was employed to evaluate the similarities of samples of Shenmai injection, and the HPLC generated chromatographic data were analyzed using hierarchical clustering analysis (HCA) and soft independent modeling of class analogy (SIMCA). Consistent results were obtained to show that the authentic samples and the blended samples were successfully classified by SIMCA, which could be applied to accurate discrimination and quality control of Shenmai injection. Furthermore, samples could also be grouped in accordance with manufacturers. Our results revealed that the developed method has potential perspective for the original discrimination and quality control of Shenmai injection. 展开更多
关键词 Shenmai injection high performance liquidchromatography FINGERPRINT pattern recognition
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CAD/CAM新技术及ABS新材料在高锰钢辙叉木模中的应用
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作者 高彦吉 李明刚 《山西建筑》 2026年第1期156-159,188,共5页
介绍了CAD/CAM新技术及ABS新材料在高锰钢辙叉铸造用木模中的应用。通过分析传统木模制作过程存在的加工周期长、成品精度低、使用耐久性差等问题,探讨了采用CAD/CAM新技术及ABS新材料制作高锰钢辙叉铸造木模的具体应用。研究表明,CAD/... 介绍了CAD/CAM新技术及ABS新材料在高锰钢辙叉铸造用木模中的应用。通过分析传统木模制作过程存在的加工周期长、成品精度低、使用耐久性差等问题,探讨了采用CAD/CAM新技术及ABS新材料制作高锰钢辙叉铸造木模的具体应用。研究表明,CAD/CAM技术显著提高了木模的设计精度和生产效率,减少了人工误差,缩短了生产周期。文中还通过实际案例分析,验证了CAD/CAM新技术及ABS新材料在提升产品质量和生产效率方面的显著效果。 展开更多
关键词 CAD/CAM技术 ABS材料 高锰钢辙叉 铸造木模 数控加工
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Structural patterns of fault damage zones in carbonate rocks and their influences on petroleum accumulation in Tazhong Paleo-uplift, Tarim Basin, NW China 被引量:8
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作者 NENG Yuan YANG Haijun DENG Xingliang 《Petroleum Exploration and Development》 2018年第1期43-54,共12页
Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal t... Based on the outcrop survey,3D seismic data interpretation,drilling data analysis,the structural patterns and distribution of fault damage zones in carbonate strata of Tazhong Paleo-uplift were established to reveal the oil and gas enrichment law in the fault damage zones.The following findings were reached:(1)Through the filed survey,the fault damage zone system consists of fault core,damage zone with branch fault and fracture network.Affected by the active nature of the major faults,the fault damage zones differ in planar pattern and scale along the major faults.(2)3D seismic profiles reveal that there are three types of fault damage zones in carbonate strata in Tazhong paleo-uplift,strike-slip fault damage zones,thrust fault damage zones and superimposed fault damage zones.Featuring3 flowers and 3 root belts in vertical,the strike-slip fault damage zone can be subdivided into linear type,oblique type,feather type and horsetail type in plane.Thrust fault damage zones can be further divided into fault anticline type,anticline type and slope type.As the superimposition result of the above two kinds of fault damage zones,superimposed fault damage zones appear in three patterns,intersect type,encompassment type and penetrating type.(3)Cores from wells and geochemical data show oil and gas may migrate along the major fault and laterally.The feather type in strike-slip fault system,fault anticline type in thrust fault damage zone and intersect type in superimposed fault damage zone are possible sites for high production and efficiency wells. 展开更多
关键词 TAZHONG PALEO-UPLIFT CARBONATE STRATA fault damage zone structural pattern high production well area
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高比例新能源电力系统暂态电压失稳形态及机理
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作者 徐式蕴 彭龙 +2 位作者 孙华东 赵兵 张剑云 《中国电机工程学报》 北大核心 2026年第1期1-16,I0001,共17页
随着电力系统中新能源等电力电子设备大规模接入,其快速控制特性加快了系统电压动态过渡过程,电压稳定问题已由单一“荷侧”逐渐向“源荷侧”共同发展,电压失稳形态及演化过程发生了显著变化。该文归纳了高比例新能源电力系统电压失稳... 随着电力系统中新能源等电力电子设备大规模接入,其快速控制特性加快了系统电压动态过渡过程,电压稳定问题已由单一“荷侧”逐渐向“源荷侧”共同发展,电压失稳形态及演化过程发生了显著变化。该文归纳了高比例新能源电力系统电压失稳典型场景,梳理了新能源接入点3类新型电压失稳形式:有功功率切换引起的电压振荡、功率下降导致的持续低电压,以及无功功率切换引发的电压振荡问题。同时,阐述了在忽略系统戴维南等值电阻条件下,负荷与新能源接入点静态电压失稳机理的一致性,并进一步分析了等值电阻对送端与受端系统静态电压稳定性的差异化影响。在此基础上,总结新能源接入点可能引发的新型暂态电压失稳机理,并提出暂态电压失稳风险工程实用量化评估方法。该文研究成果可为新型电力系统电压稳定特性认知及工程应用提供一定理论支撑。 展开更多
关键词 高比例新能源 电压失稳形态 静态电压稳定 暂态电压稳定 反复穿越失稳 临界短路比
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Control of Asymmetric Flow Fields of Slender Bodies at High Angle of Attack 被引量:4
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作者 明晓 顾蕴松 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2006年第2期168-174,共7页
The wind tunnel experiments is conducted to get inspiration for understanding the mechanism of the asymmetric flow pattern and developing an innovative flow control technique for a slender body at high angle of attack... The wind tunnel experiments is conducted to get inspiration for understanding the mechanism of the asymmetric flow pattern and developing an innovative flow control technique for a slender body at high angle of attack. The bi-stable situation of the side forces is observed, which could be easily switched by a tiny disturbances either from coming flow or from artificial disturbances at nose tip (including manufacturing defect). In turbulent flows the side forces switched randomly between positive and negative. There exists a hysteresis loop of side force with the rolling angle. A rod in front of the slender body is used to change the vortex pattern, which could be kept even the rod is moved out from the stream. A miniature strake attached to the nose tip of the model can be moved to different circumferential position. When the strake is stationary, the hysteresis loop disappears and the side force does not change with the turbulent fluctuation of coming flow. The results from dynamic measurements of section side force indicates that when the strake swung at lower frequency the side force can follow the cadence of the swinging strake. With increasing frequency, the magnitude of the side force decreases. At still high frequency, the side force diminishes to zero. If the strake is swinging, while the middle position can be changed to different circumferential angle Фs on either left or right side, the side forces can be changed proportionally with the angle Фs. On the basis of the experimental results, the mechanism of the asymmetry is discussed. 展开更多
关键词 high angle of attack asymmetric vortex pattern flow control
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Simple Metrics for Representing East Asian Winter Monsoon Variability:Urals Blocking and Western Pacific Teleconnection Patterns 被引量:1
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作者 Hoffman H.N.CHEUNG Wen ZHOU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第6期695-705,共11页
Instead of conventional East Asian winter monsoon indices (EAWMIs), we simply use two large-scale teleconnection patterns to represent long-term variations in the EAWM. First, the Urals blocking pattern index (UBI... Instead of conventional East Asian winter monsoon indices (EAWMIs), we simply use two large-scale teleconnection patterns to represent long-term variations in the EAWM. First, the Urals blocking pattern index (UBI) is closely related to cold air advection from the high latitudes towards western Siberia, such that it shows an implicit linkage with the Siberian high intensity and the surface air temperature (SAT) variations north of 40°N in the EAWM region. Second, the well-known western Pacific teleconnection index (WPI) is connected with the meridional displacement of the East Asian jet stream and the East Asian trough. This is strongly related to the SAT variations in the coastal area south of 40°N in the EAWM region. The temperature variation in the EAWM region is also represented by the two dominant temperature modes, which are called the northern temperature mode (NTM) and the southern temperature mode (STM). Compared to 19 existing EAWMIs and other well-known teleconnection patterns, the UBI shows the strongest correlation with the NTM, while the WPI shows an equally strong correlation with the STM as four EAWMIs. The UBI-NTM and WPI-STM relationships are robust when the correlation analysis is repeated by (1) the 31-year running correlation and (2) the 8-year high-pass and low-pass filter. Hence, these results are useful for analyzing the large-scale teleconnections of the EAWM and for evaluating this issue in climate models. Int particular, more studies should focus on the teleconnection patterns over extratropical Eurasia. 展开更多
关键词 East Asian winter monsoon Urals blocking high western Pacific teleconnection pattern TELECONNECTION
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新质生产力对OFDI高质量发展的影响及空间异质性
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作者 王智新 蒲维 《国际商务研究》 北大核心 2026年第1期46-58,共13页
本文在省份层面构建新质生产力与OFDI高质量发展的统计指标体系并开展统计监测,深入探究新质生产力对OFDI高质量发展的影响及空间异质性。研究发现,新质生产力对中国OFDI高质量发展具有显著的正向影响,这一结论经过内生性问题处理和稳... 本文在省份层面构建新质生产力与OFDI高质量发展的统计指标体系并开展统计监测,深入探究新质生产力对OFDI高质量发展的影响及空间异质性。研究发现,新质生产力对中国OFDI高质量发展具有显著的正向影响,这一结论经过内生性问题处理和稳健性检验后依然成立。这种正向促进效应对临海、创新能力强、政策环境好、“一带一路”沿线的省份更加显著;新质生产力通过技术创新、人力资本促进中国OFDI高质量发展;地区对外开放增强新质生产力对OFDI高质量发展的促进效应。进一步研究发现,新质生产力对OFDI高质量发展的影响存在空间异质效应。研究结论对中国因地制宜培育和发展新质生产力、加快OFDI高质量发展、提升国际循环质量和水平、塑造国际合作和竞争新优势等具有重要的理论价值和现实意义。 展开更多
关键词 新质生产力 OFDI高质量发展 国际循环 新发展格局 科技创新
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Fast algorithm on string cross pattern matching
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作者 LiuGongshen LiJianhua LiShenghong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第1期179-186,共8页
Given a set U which is consisted of strings defined on alphabet Σ, string cross pattern matching is to find all the matches between every two strings in U. It is utilized in text processing like removing the duplicat... Given a set U which is consisted of strings defined on alphabet Σ, string cross pattern matching is to find all the matches between every two strings in U. It is utilized in text processing like removing the duplication of strings. This paper presents a fast string cross pattern matching algorithm based on extracting high frequency strings. Compared with existing algorithms including single-pattern algorithms and multi-pattern matching algorithms, this algorithm is featured by both low time complexity and low space complexity. Because Chinese alphabet is large and the average length of Chinese words is much short, this algorithm is more suitable to process the text written by Chinese, especially when the size of Σ is large and the number of strings is far more than the maximum length of strings of set U. 展开更多
关键词 pattern matching high frequency string string cross pattern matching.
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