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Discovery of the choristodere Hyphalosaurus baitaigouensis from the Lower Cretaceous jiufotang Formation of western Liaoning,China and its paleobiogeographic significance

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Journal of Palaeogeography 2024年第3期13卷 547-562页

作者： Li-Jun zhang shu-An ji Hai-Chun zhang South China Sea Culture Museum Hainan Tropical Ocean UniversitySanya 572022Hainan ProvinceChina Key Laboratory of Stratigraphy and Paleontology Ministry of Natural ResourcesInstitute of GeologyChinese Academy of Geological SciencesBeijing 100037China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008Jiangsu ProvinceChina

The water-living reptile genus Hyphalosaurus was previously discovered in the Lower Cretaceous Yixian Formation bearing the middle Jehol Biota in western Liaoning,*** complete skeletons of Hyphalosaurus are reported for the first time from the jiufotang Formation bearing the late Jehol Biota at two sites in western *** show the typical characteristics of Hyphalosaurus baitaigouensis in terms of the contact between some cranial bones and the number of cervical and dorsal vertebrae,and therefore are assigned to *** discovery extends the stratigraphic range of this species from the Yixian Formation to the overlying jiufotang *** paper further briefly compares the main characteristics of the two skeletons,summarizes the temporal and spatial distribution of Hyphalosaurus,and discusses the palaeogeographic evolution of western Liaoning at the middle and late Jehol Biota stages based on the aquatic habits of Hyphalosaurus and the geological background of western *** analytical results show that the volcanic downwarped lakes,with distinct geographical divisions in western Liaoning during the deposition of the Yixian Formation,had not completely disappeared till the deposition of the jiufotang *** palaeo-lake in the Fuxin-Yixian Basin underwent the process of generation,expansion and shrinkage during the depositional period of the Yixian Formation and finally merged into a large *** palaeo-Dalinghe River,which connected the main basins in western Liaoning during the depositional period of the jiufotang Formation,was formed simultaneously.

关键词： Western liaoning Jehol biota jiufotang formation Hyphalosaurus baitaigouensis Palaeobiogeography

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Ag-Cd合金贝氏体相变内耗

物理学报 1986年第3期 379-383页

作者：张骥华陈树川徐祖耀上海交通大学

使用低频倒扭摆测量了Ag-42.3at％Cd合金在室温至250℃范围内等温过程中内耗随时间的变化和不同升温速率下内耗与温度的关系。试验表明, Ag-Cd合金发生贝氏体相变时内耗升高是由于贝氏体相变形核过程中母相基体点阵的不稳定,内耗的升高... 详细信息

使用低频倒扭摆测量了Ag-42.3at％Cd合金在室温至250℃范围内等温过程中内耗随时间的变化和不同升温速率下内耗与温度的关系。试验表明, Ag-Cd合金发生贝氏体相变时内耗升高是由于贝氏体相变形核过程中母相基体点阵的不稳定,内耗的升高决定于贝氏体形核率J*与点阵局部软化区单位体积内耗值Qs-1的乘积。

关键词：贝氏体相变形核过程 Ag-Cd 内耗值

集成深度强化学习在股票指数投资组合优化中的应用分析

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计算机科学与探索 2025年第01期19卷 237-244页

作者：冀中张文嘉天津大学电气自动化与信息工程学院天津大学佐治亚理工深圳学院

基于集成深度强化学习的投资组合选择是当前量化金融领域的关键技术之一。然而，目前采用上一窗口阶段最优指标决定下一阶段代理的集成滚动窗口方法存在一定的滞后性。为了有效应对这一不足，提出了双层嵌套集成深度强化学习方法。该方... 详细信息

基于集成深度强化学习的投资组合选择是当前量化金融领域的关键技术之一。然而，目前采用上一窗口阶段最优指标决定下一阶段代理的集成滚动窗口方法存在一定的滞后性。为了有效应对这一不足，提出了双层嵌套集成深度强化学习方法。该方法对三种代理（优势演员-评论员、深度确定性策略梯度和近端策略优化）进行两层嵌套模式，第一层集成通过最优化夏普比率进行阶段模型选择，第二层通过加权投票的方法集成三种深度强化学习算法，从单次训练中收集多个模型快照，在训练期间利用这些模型进行集成预测。分别对上证50投资指数和道琼斯指数及其包含的股票进行了投资组合研究，将持有指数被动策略和均值方差投资组合策略作为基线策略。实验采用了投资组合价值、年化回报率、年化波动率、最大回撤和夏普比率等指标作为对比指标。结果表明，所提出的集成方法在实用性和有效性上表现出较好的性能。

关键词：股票投资组合交易策略深度强化学习双层嵌套集成深度强化学习方法集成学习

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新鲜鸭蛋与咸蛋特征介电参数的提取

西北农林科技大学学报（自然科学版） 2013年第9期41卷 145-150页

作者：曹旭东刘亚龙唐燕杜光源景晨娟张继澍西北农林科技大学理学院陕西杨凌712100 西北农林科技大学生命科学学院陕西杨凌712100

【目的】用非破坏性手段提取新鲜鸭蛋与咸蛋的特征介电参数，为实现咸蛋腌制进度的动态、无损检测提供参考。【方法】以新鲜鸭蛋和市售咸蛋为材料，用电子天平、游标卡尺测定对比二者在质量、蛋形指数、蛋黄指数等方面的差异；用日置智... 详细信息

【目的】用非破坏性手段提取新鲜鸭蛋与咸蛋的特征介电参数，为实现咸蛋腌制进度的动态、无损检测提供参考。【方法】以新鲜鸭蛋和市售咸蛋为材料，用电子天平、游标卡尺测定对比二者在质量、蛋形指数、蛋黄指数等方面的差异；用日置智能3532—50型LCR数字测试仪在测试频段（500～5000000Hz）内以对数形式取41个频率点，测定并绘制新鲜鸭蛋和咸蛋的介电参数与测试频率的关系曲线，通过介电参数与频率的相关分析，筛选可以区分二者的特征介电参数。【结果】新鲜鸭蛋和市售咸蛋的介电参数均与测试频率显著相关（P〈O．05），新鲜鸭蛋和市售咸蛋的相对介电常数e’，在500～5000000Hz测试频段内有极显著差异（P〈O．01）；二者的损耗因子D的相对误差较大，复阻抗Z无显著差异。【结论】相对介电常数e’，可以作为区分新鲜鸭蛋和市售咸蛋的特征介电参数，其最适测试频率为200000～2000000Hz。

关键词：咸蛋介电特性特征介电参数无损检测

具阻尼的Gross-Pitaevskii(GP)方程的整体解(英文)

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四川师范大学学报（自然科学版） 2003年第5期26卷 441-444页

作者：张健舒级刘妍丽四川师范大学数学与软件科学学院四川成都610066

考虑临界的具阻尼的Gross Pitaevskii(GP)方程iφt=-Δφ+｜x｜2φ+g｜φ｜4/Dφ+iaφ,t≥0,x∈RD,g<0,a<0,这里D是空间维数.这个方程很好地描述了吸引的玻色爱因斯坦凝聚(BEC).通过偏微分方程的严格理论和变分方法,获得了整体解的一... 详细信息

考虑临界的具阻尼的Gross Pitaevskii(GP)方程iφt=-Δφ+｜x｜2φ+g｜φ｜4/Dφ+iaφ,t≥0,x∈RD,g<0,a<0,这里D是空间维数.这个方程很好地描述了吸引的玻色爱因斯坦凝聚(BEC).通过偏微分方程的严格理论和变分方法,获得了整体解的一个充分条件,而这个条件利用了非线性数量场方程-Δu+2bu-｜u｜4/Du=0的唯一正解.

关键词：整体解阻尼 Gross-Pitaevskii(GP)方程玻色-爱因斯坦凝聚 BEC 变分方法

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间接电氧化法制备对苯二甲酸

青岛科技大学学报（自然科学版） 2006年第2期27卷 104-107页

作者：张学超田立朋谢永超张积树青岛科技大学化学与分子工程学院山东青岛266042

研究了槽外式间接电氧化对二甲苯生成对苯二甲酸的反应,得出最佳条件:投料比n(Cr(Ⅳ))∶n(对二甲苯)=4.5∶1,硫酸浓度5.0 mol.L-1,六价铬离子浓度0.45mol.L-1,反应温度110℃。在此条件下,对苯二甲酸的收率可达78.5%。同时,对铬酸氧化对... 详细信息

研究了槽外式间接电氧化对二甲苯生成对苯二甲酸的反应,得出最佳条件:投料比n(Cr(Ⅳ))∶n(对二甲苯)=4.5∶1,硫酸浓度5.0 mol.L-1,六价铬离子浓度0.45mol.L-1,反应温度110℃。在此条件下,对苯二甲酸的收率可达78.5%。同时,对铬酸氧化对二甲苯残液循环利用进行了研究,电解液循环利用10次以上,铬离子的转化率和电流效率保持稳定。

关键词：间接电氧化对二甲苯对苯二甲酸

Sauropod Teeth from the Lower Cretaceous Luohandong Formation of Ordos Basin,Inner Mongolia

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Acta Geologica Sinica(English Edition) 2017年第3期91卷 791-796页

作者： HOU Yandong zhang Lifu jiANG Shan ji shu-an Institute of Geology Chinese Academy of Geological Sciences Administration of the National Natural Protection Region on the Otog Dinosaur Tracks Natural History Museum of Guangxi

The Early Cretaceous Zhidan Group in the northern Ordos Basin, Inner Mongolia, yielded a large number of tetrapods, including turtles, choristoderes, crocodyliforms, psittacosaurs, stegosaurs, theropods and birds. Well-preserved sauropod teeth have been found in the Luohandong Formation, a middle-upper unit of the Zhidan Group. The large V-shaped wear facet, low slenderness index value, labial grooves, lingual ridge and concavity on the tooth crown suggest that these teeth are from titanosauriforms. Moreover, the presence of the prominent bosses on the lingual side of the tooth crown indicates these teeth should be identified as Euhelopus teeth further. The existence of Euhelopus in Ordos Basin （Inner Mongolia）, Shandong Province and western Liaoning Province shows some connections about vertebrate faunas during Early Cretaceous in these areas. Other tetrapod groups such as turtles （Sinemys, Ordosemys）, choristoderes （Ikechosaurus）, psittacosaurs （Psittacosaurus） and birds （Cathayornis） provide more evidences for this viewpoint.

关键词： Lower Cretaceous Luohandong Formation Ordos Basin Sauropoda Euhelopus

Low-energy electronic properties of a Weyl semimetal quantum dot

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Science China(Physics,Mechanics & Astronomy) 2018年第11期61卷 84-98页

作者： shu-Feng zhang Chang-Wen zhang Pei-ji Wang Qing-Feng Sun School of Physics and Technology University of Jinan Jinan 250022 China International Center for Quantum Materials School of Physics Peking University Beijing 100871 China Collaborative Innovation Center of Quantum Matter Beijing 100871 China

We investigate the low-energy electronic structure ofa Weyl semimetal quantum dot （QD） with a simple model Hamiltonian with only two Weyl points. Distinguished from the semiconductor and topological insulator QDs, there exist both surface and bulk states near the Fermi level in Weyl semimetal QDs. The surface state, distributed near the side surface of the QD, contributes a circular persistent current, an orbital magnetic moment, and a chiral spin polarization with spin-current locking. There are always surface states even for a strong magnetic field, even though a given surface state gradually evolves into a Landau level with increasing magnetic field. It indicates that these unique properties can be tuned via the QD size. In addition, we show the correspondence to the electronic structures of a three-dimensional Weyl semimetal, such as Wey[ point and Fermi arc. Because a QD has the largest surface-to-volume ratio, it provides a new platform to verify Weyl semimetal by separating and detecting the signals of surface states. Besides, the study of Weyl QDs is also necessary for potential applications in nanoelectronics.

关键词： quantum dot Weyl semimetal Landau quantization

Large-Sized Ankylosaur(Dinosauria) from the Lower Cretaceous jiufotang Formation of Western Liaoning,China

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Acta Geologica Sinica(English Edition) 2014年第4期88卷 1060-1065页

作者： ji shu-an zhang Lijun zhang shudong zhang Lijun 1 jiANG Shan Institute of Geology Chinese Academy of Geological Sciences Key Laboratory of Stratigraphy andPaleontology Ministry of Land and Resources Beijing 100037 China Administration Bureau of Fossil Resource Protection of Liaoning Province Shenyang 110032 Liaoning China Administration Branch of Fossil Protection Bureau of Land and Resources of Kazuo County Kazuo122300 Liaoning China Shenyang Center of the China Geological Survey Shenyang 110034 Liaoning China

Two incomplete bones referred to ankylosaur scapulocoracoid and humerus are described, which were discovered from the Early Cretaceous jiufotang Formation of Dachengzi Town, Kazuo County, Liaoning Province. Ankylosaur dinosaurs have ever been found in the Lower Cretaceous Yixian, Fuxin and Sunjiawan Formations of western Liaoning. The occurrence of ankylosaurs within jiufotang Formation improves our knowledge on the ankylosaur stratigraphic distribution. Based on the length of scapulocoracoid, the new dinosaur is estimated to exceed 6.0 meters long, representing the largest ankylosaur in western Liaoning.

关键词： Kazuo County Liaoning Province Lower Cretaceous jiufotang Formation Ankylosauria