检索结果-内蒙古大学图书馆

A general method for instantaneous undeformed chip thickness calculation in five-axis milling based on Boolean operations

引用

INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2021年第7-8期116卷 2325-2334页

作者： li, Guochao liu, Yunlong Zhao, Donghao Dai, Lei Zhou, Honggen Jing, xuwen Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang 212003 Jiangsu Peoples R China Jiangsu Univ Sci & Technol Jiangsu Prov Key Lab Adv Mfg Marine Mech Equipmen Zhenjiang 212003 Jiangsu Peoples R China

Instantaneous undeformed chip thickness (IUCT) plays a critical role in optimizing and monitoring of five-axis milling processes, as it determines machining precision and tool life by affecting cutting forces. Analytical and numerical methods have been widely used for IUCT calculation. However, these methods have some deficiencies, such as solving the unsolvable transcendental equations, modeling the complex cutting edge trajectory, and poor adaptability for five-axis milling. Therefore, a Boolean method which consists of subtraction and intersection operations is developed. First, the blank for the current cutting edge is obtained by the Boolean subtraction operation between the workpiece and the swept volume that produced by the front cutting edges. Second, the Boolean intersection operation is executed between the blank and the auxiliary edge entity (AEE) that corresponding to the tool edge. Then, the IUCT of each cutting edge or each cutting point can be deduced based on the Boolean result with the known blank geometry, tool geometry, tool path, and machining parameters. The method is verified by milling force experiments. It is an efficient, accurate, and general method because it does not need to establish complex mathematical or numerical models. The calculated IUCT will promote the optimizing and monitoring of five-axis milling processes.

关键词： Chip thickness Boolean operation Five-axis milling Milling force

来源：评论

学校读者我要写书评

暂无评论

Combined Separated Oscillatory Fields Technique

Combined Separated Oscillatory Fields Technique

引用

European Frequency and Time Forum (EFTF)

作者： Fuyu Sun Chao li xuwen Hu Shougang Zhang National Time Service Center Chinese Academy of Sciences Xi'an China Key Laboratory of Time Reference and Applications Chinese Academy of Sciences Xi'an China

ISBN: (数字)9798350354270

ISBN: (纸本)9798350354287

Ramsey's method of separated oscillatory fields (SOFs) has been originally used in beam magnetic resonance apparatuses, which leads to the establishment of atomic definition of time interval and frequency. Since then, various versions of the SOFs technique have been widely used for precise measurement of different physical quantities. Here, we present an alternative method to generate atomic beam magnetic resonance signals by combining two Ramsey cavities with phase differences of 0 and 1t. It is found that the strength of the resonance signals generated using this combined SOFs technique is approximately twice that of the resonance signals produced by the conventional SOFs techniques. In addition to generating stronger resonance, the combined Ramsey method eliminates the Rabi background superimposed on the Ramsey interference pattern without increasing the Ramsey signal linewidth. Thus, this technique serves a promising tool for high-precision measurements.

关键词： Atomic measurements Time-frequency analysis Magnetic field measurement Atomic beams Magnetic resonance Europe Interference

来源：评论

学校读者我要写书评

暂无评论

Pilot-scale catalytic ozonation pretreatment for improving the biodegradability of fixed-bed coal gasification wastewater

引用

PROCESS SAFETY AND ENVIRONMENTAL PROTECTION 2021年 148卷 13-19页

作者： Chen, Xiaoya Wang, Chunrong Jiang, Longxin li, Haiyan Wang, Jianbing He, xuwen China Univ Min & Technol Beijing Sch Chem & Environm Engn Beijing 100083 Peoples R China

Achieving zero liquid dischargeis a requirement for the development of the coal chemical industry;high pollutant concentration, strong biotoxicity, and poor biodegradability (BOD5/COD=0.1-0.2) make fixed-bed coal gasification wastewater difficult to treat. This study synthesized a Fe-Mn/lava catalyst (FMLC) and performed a pilot-scale test on catalytic ozonation for the pretreatment of fixed-bed coal gasification wastewater. The effects of ozone and catalyst dosages were investigated, and the changes in the organics, biotoxicity, and biodegradability of wastewater were analyzed using three-dimensional fluorescence spectroscopy, BOD5/COD, and specific oxygen uptake rate (SOUR). Energy consumption was also calculated. The removal efficiencies (at a flow rate of 1.0 m(3)/h, ozone dosage of 179 g/h, and catalyst dosage of 40 kg/m(3)) of COD and BOD5 were 61.77% and 16.98%, respectively, after 30 days of continuous operation. Toxic refractory macromolecular organic pollutants were transformed into small, biodegradable substances. BOD5/COD increased from 0.16 to 0.35, and SOUR decreased from 2.8460 to 2.3180 mgO(2)/(gMLSS.h). The operating cost was 1.24 kWh/kg COD. Catalytic ozonation as a pretreatment technology markedly improved biodegradability, reduced biotoxicity, and looks to be promising for treating fixed-bed coal gasification wastewater. (C) 2020 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.

关键词： Fixed-bed coal gasification wastewater Pilot-scale Catalytic ozonation Fe-Mn/lava catalyst Pretreatment Biodegradability

来源：评论

学校读者我要写书评

暂无评论

诉讼威慑与公司治理优化——基于康美药业集体诉讼的事件研究证据

引用

北京工商大学学报（社会科学版） 2024年第4期39卷 129-142页

作者：李春涛闫续文宋敏河南大学国际商学院河南开封475001 中南财经政法大学金融学院湖北武汉430073 武汉大学经济与管理学院湖北武汉430072

股东的权利,从享有公司收益、参与重大决策,到提起诉讼要求损害赔偿,被广泛认为是一个经济体中有效配置资本的重要影响因素。康美药业案作为中国第一起实质性集体诉讼,其判决结果深刻影响了资本市场主体的行为。采用事件研究法,以2018—... 详细信息

股东的权利,从享有公司收益、参与重大决策,到提起诉讼要求损害赔偿,被广泛认为是一个经济体中有效配置资本的重要影响因素。康美药业案作为中国第一起实质性集体诉讼,其判决结果深刻影响了资本市场主体的行为。采用事件研究法,以2018—2022年中国A股上市公司为样本,检验了2021年11月12日康美药业证券虚假陈述集体诉讼案一审判决所带来的强化股东保护的公司治理效应。结果发现,盈余管理程度高、被交易所问询多以及存在关联交易的企业,在康美药业案一审判决前后的市场反应更差。此外,相较于其他重要事件日,一审判决对潜在违规企业的威慑更为明显,且威慑效应具有持续性,公司更倾向于守法经营,带来公司治理的优化。为保障中小股东的合法权益,建议政府进一步降低集体诉讼门槛和维权成本,为投资者提供便捷有效的诉讼维权渠道;上市公司增强财务信息质量和透明度,守法经营,依法披露,提升内部治理水平。

关键词：康美药业盈余管理问询函关联交易事件研究集体诉讼

来源：评论

学校读者我要写书评

暂无评论

广州从化南平村风水林植物群落学特征及规划建议

引用

南方林业科学 2019年第1期47卷 49-54页

作者：李磊李许文倪建中代色平乳源瑶族自治县林业局广东乳源512700 广州市林业和园林科学研究院广东广州510405 广州市景观建筑重点实验室广东广州510405

采用现场全面踏查和样地调查相结合的方法,研究了广东省广州市从化区南平村风水林植物群落特征。在3个面积为400 m2的调查样方中,共记录植物134种(包括种下单位),隶属于77科114属。植物种类丰富,以大戟科、桑科、壳斗科和紫金牛科植物... 详细信息

采用现场全面踏查和样地调查相结合的方法,研究了广东省广州市从化区南平村风水林植物群落特征。在3个面积为400 m2的调查样方中,共记录植物134种(包括种下单位),隶属于77科114属。植物种类丰富,以大戟科、桑科、壳斗科和紫金牛科植物占优势。该群落具有南亚热带常绿阔叶林的典型群落结构,垂直结构分层明显,层次清晰。400 m2样地面积内,乔灌木群落的Shannon-Winner指数都在2.7以上,Simpson多样性指数在0.8以上,群落均匀度在2.0以上。该样地生物多样性的各项指标远远大于本地的一些风水林。研究成果对广州从化乡村绿化美化建设、风水林的保护、生态公益林造林、园林开发应用具有参考价值。

关键词：风水林树种组成群落结构物种丰富度规划建议广州

来源：评论

学校读者我要写书评

暂无评论

Analysis and Design of Adversarial Virtual Simulation Training System 21

Analysis and Design of Adversarial Virtual Simulation Traini...

引用

13th International Conference on Computer Modeling and Simulation, ICCMS 2021

作者： Sun, xuwen li, Shixiong Xing, Yu Dalian Naval Academy China China Coast Guard Academy China

ISBN: (纸本)9781450389792

In order to improve the high degree of close to training reality for college teaching and training, an antagonistic virtual simulation training system is constructed by analyzing and designing. First, the basic process of antagonistic training is analyzed for preparation, training implantation, and training evaluation, then the process is modeled, and modeled. And then, functional requirements of adversarial virtual simulation training is analyzed and studied, after which, the technical architecture is designed, and core technique is discussed. The study lays a foundation for the design and implementation of the antagonistic virtual simulation training system in future. © 2021 ACM.

关键词： E-learning

来源：评论

学校读者我要写书评

暂无评论

Two New Baccharane Glycosides from Seeds of Impatientis balsamina L. with in vitro Growth Inhibitory Activity in Human Cancer A375 Cells

引用

Chemical Research in Chinese Universities 2017年第5期33卷 753-757页

作者： WU Oian JIN Yongri YAO Hua liU Ying li Peng li xuwen College of Chemistry Jilin University Changchun 130021 P R. China Scientific Research Center China-Japan Union Hospital of Jilin University Changchun 130021 P. R. China

Two new baccharane-type glycosides（1 and 2）, together with seven known baccharane-type glycosides （3u9） hosenkoside A, hosenkoside B, hosenkoside C, hosenkoside F, hosenkoside M, hosenkoside K and hosenko- side G were isolated from the dried seeds of Impatientis balsamina L. The new baccharane-type glycosides were identified as honsenkol A-3-O-β-D-glucopyranosyl-26-O-p-D-glucopyranosyl-28-O-β-D-glucopyranosyl-O-β-D- glucopyranosyl（1） and （3S,4R,17R,20S）17-hydrroxy-3-O-β-D-xylopyranose（12）-β-D-glucopyranosyl-26-O-β-D- glucopyranosyl-28-O-β-D-glucopyranosyl-21,24-epoxybaccharane（2）, respectively, by spectroscopic methods, in- cluding NMR（1D and 2D）, IR and HR-ESI-MS. Compounds 1 and 2 were evaluated for in vitro inhibitory activity against the cell lines. Compound 2 with a new baccharane skeleton had anti-hepatic fibrosis activity against A375 cells in bioassay results, which means the new compounds have potential value in antitumor applications.

关键词： Impatientis balsamina L. Seed Baccharane-type glycoside Cytotoxic activity

来源：评论

学校读者我要写书评

暂无评论

Use of Triangular Silver Nanoplates as Low Potential Redox Mediators for Electrochemical Sensing

引用

ANALYTICAL CHEMISTRY 2021年第6期93卷 3295-3300页

作者： Gao, xuwen Dong, Shuangtian Fu, li Zhang, Bin Hsu, Hsien-Yi Zou, Guizheng Shandong Univ Sch Chem & Chem Engn Jinan 250100 Peoples R China City Univ Hong Kong Sch Energy Hong Kong 999077 Peoples R China City Univ Hong Kong Dept Mat Sci & Engn Hong Kong 999077 Peoples R China

Redox mediators can facilitate the electrochemical communication between targets and electrodes for material characterization and investigation. To provide an alternative to the chemical-based redox mediators, herein, we present a nanoparticle-based redox mediator, i.e., the trisodium citrates (TSC)-capped triangular silver nanoplates (Tri-Ag-NPTSC), which demonstrates an efficient oxidative process at around 0.13 V (vs Ag/AgCl) with acceptable redox reversibility by exploiting the interaction between the carbonyl group of TSC and the Ag element of Tri-Ag-NPTSC. The TSC of Tri-Ag-NPs can be selectively replaced by thiols and enable the obtained Tri-Ag-NPTSC-thol with changed electrochemical redox response, which could be utilized to determine various thiols at 0.13 V, a much lowered oxidative potential than traditional redox mediators, with a similar linear response range, response slope, and limit of detection (LOD). This work proposes a surface-engineering approach to design and develop electrochemical redox probes using Ag nanoparticles with particular morphology, indicating that the interaction between the carbonyl group and Ag nanoparticles might be extended to sensing application beyond the surface-enhanced Raman scattering.

关键词： Silver nanoparticle Thiol

来源：评论

学校读者我要写书评

暂无评论

Dual-potential encoded electrochemiluminescence for multiplexed gene assay with one luminophore as tag

引用

BIOSENSORS & BIOELECTRONICS 2023年第1期236卷 115418页

作者： Gao, xuwen Ren, Xiaoxuan Ai, Yaojia li, Mengwei Zhang, Bin Zou, Guizheng Shandong Univ Sch Chem & Chem Engn Jinan 250100 Peoples R China

Multiplexed gene assay for simultaneously detecting the multi-targets of nucleic acids is strongly anticipated for the accurate diseases diagnosis and prediction, and all commercial available gene assays for IVD are a kind of single-target assay. Herein, a dual-potential encoded and coreactant-free electrochemiluminescence (ECL) strategy is proposed for the multiplexed gene assay, which can be conveniently carried out by directly oxidizing the same luminescent tag of dual-stabilizers-capped CdTe nanocrystals (NCs). The CdTe NCs linked with sulfhydryl-RNA via Cd-S bond merely exhibits one ECL process around 0.32 V with a narrow triggeringpotential-window of 0.35 V, while CdTe NCs linked with amino-RNA via amide linkage solely gives off one ECL process around 0.82 V with a narrow triggering-potential-window of 0.30 V. Multiplexing ECL of both sulfhydryl-RNA-functionalized CdTe NCs and amino-RNA-functionalized CdTe NCs can be utilized to simultaneously detect the open reading frame 1ab (ORF1ab) and the nucleoprotein (N) genes without crosstalk, in which ECL of sulfhydryl-RNA-functionalized CdTe NCs can dynamically determine ORF1ab from 200 aM to 10 fM with a limit of detection (LOD) of 100 aM, while ECL of amino-RNA-functionalized CdTe NCs can linearly detect N gene from 5 fM to 1 pM with a LOD of 2 fM. Post-engineering CdTe NCs with RNA in a labeling-bond engineering way would provide a potential-selective and encoded ECL strategy for multiplexed gene assay with one luminophore.

关键词： Electrochemiluminescence Bond -involved Coreactant-free Potential -resolved Multiplexing gene assay Dual -potential encoded

来源：评论

学校读者我要写书评

暂无评论

Hermetic Packaging Based on Cu-Sn and Au-Au Dual Bonding for High-Temperature Graphene Pressure Sensor

引用

MICROMACHINES 2022年第8期13卷 1191-1191页

作者： Wang, Junqiang Zhang, Haikun Chen, xuwen li, Mengwei North Univ China Acad Adv Interdisciplinary Res Taiyuan 030051 Peoples R China North Univ China Not Key Lab Instrumentat Sci & Dynam Measurement Taiyuan 030051 Peoples R China

A chip-level hermetic package for a high-temperature graphene pressure sensor was investigated. The silicon cap, chip and substrate were stacked by Cu-Sn and Au-Au bonding to enable wide-range measurements while guaranteeing a high hermetic package. Prior to bonding, the sample was treated with Ar (5% H-2) plasma. The Cu-Sn bonding was firstly performed at 260 degrees C for 15 min with a pressure of 9.9 MPa, and the corresponding process conditions for Au-Au bonding has increased to 300 degrees C, 20 min and 19.8 MPa respectively. The average shearing strength was 14.3 MPa, and an excellent leak rate of 1.72 x 10(-4) Pa center dot cm(3)/s was also achieved. After high-temperature storage (HTS) at 350 degrees C for 10 h, the resistance of graphene decreased slightly because the dual bonding provided oxygen-free environment for graphene. The leakage rate of the device slightly increased to 2.1 x 10(-4) Pa center dot cm(3)/s, and the average shear strength just decreased to 13.5 MPa. Finally, under the pressure range of 0-100 MPa, the graphene pressure sensor exhibited a high average sensitivity of 3.11 omega/MPa. In conclusion, the dual bonding that combined Cu-Sn and Au-Au is extremely suitable for hermetic packaging in high-temperature graphene pressure sensors.

关键词： Cu-Sn bonding Au-Au bonding graphene high-temperature pressure sensor

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：