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Synthesis of a New Ligand Containing 1, 7-Diaza-12-crown-4 and the Application in Asymmetric Cyclopropanation Reaction

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Chinese Chemical Letters 2003年第6期14卷 579-580页

作者： Cheng Yun WANG zhi cai SHANG Jiang Hua MEI qing Sen YU Department of Chemistry Zhejiang UniversityHangzhou 310027

A new chiral multidenate ligand (S, S)-1,7-bis(4-benzyloxazolin-2-yl-methyl)-1, 7-diaza- 12-crown-4 1 has been synthesized and used as ligand in the copper catalyzed asymmetric cyclopropanation of 1, 1-diphenylethylene.

关键词： S, S)-1, 7-Bis (4-benzyloxazolin-2-yl-methyl)-1,7-diaza-12-crown-4 asymmetric cy-clopropanation

Effect of high-temperature reduction pretreatment on internal quality of 42CrMo casting billet

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Journal of Iron and Steel Research International 2021年第6期28卷 693-702页

作者： Hong-qiang Liu zhi-cheng Cheng Wei Yu Zhao-yuan Zhou Lei Cheng qing-wu cai Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China

Comparative analysis was conducted to illustrate the effect of high-temperature reduction pretreatment on the internal quality of 42CrMo casting *** of macrostructure clarifies that reduction pretreatment could reduce the size of central cavities and equiaxed crystals and improve the segregation degree and porosity on *** bainite matrix and granular structure on segregation bands mainly dominate the microstructure of original billet,while pro-eutectoid ferrite and its accompanying troostite are added due to the application of reduction ***,C,Mn,and Mo are suggested to be enriched in segregation bands where pores and inclusions tend to be *** clarifying the microstructure evolution during cooling process,physical compression and multiplication of prior austenite grain boundaries caused by recrystallization are regarded as the main reasons in improving the internal quality of 42CrMo billet.

关键词： 42CrMo billet Reduction pretreatment Continuous casting Recrystallization

Automatic pattern acquisition from game records in GO

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 100-105页

作者： LIU zhi-qing DOU qing School of Software Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Computer programs of GO are typically constructed using a knowledge-based approach with heuristics and pattern matching because of enormous complexities of the game. In this approach, quantity, quality, and consistency of patterns used in computer programs of GO to a large extent determine the strengths of the programs. This study presents an effective method to acquire automatically comprehensive GO patterns from large collections of game records. Statistical usages of the patterns ensure consistency and quality of the patterns, which in turn can help improve the strengths of computer GO programs. Additionally, statistical usages of patterns from different sources of game records clearly show subtle and significant discrepancies among various types of GO players, and clarify certain myths in the playing of GO.

关键词： computer games automatic knowledge acquisition,spatial patterns recognition

光谱辐射照度国际关键比对装置、方法与结果分析

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光谱学与光谱分析 2025年第1期45卷 1-7页

作者：代彩红王彦飞李玲吴志峰谢一航中国计量科学研究院光学与激光计量科学研究所北京100029

基于高温黑体辐射源和双光栅光谱辐射比较测量系统,中国计量科学研究院自主研制了新一代光谱辐射照度国家基准装置,波长范围覆盖230~2550 nm,以一组稳定的卤钨灯作为副基准灯组,保存和传递光谱辐射照度量值。黑体的温度溯源至铂-碳Pt-C... 详细信息

基于高温黑体辐射源和双光栅光谱辐射比较测量系统,中国计量科学研究院自主研制了新一代光谱辐射照度国家基准装置,波长范围覆盖230~2550 nm,以一组稳定的卤钨灯作为副基准灯组,保存和传递光谱辐射照度量值。黑体的温度溯源至铂-碳Pt-C和铼-碳Re-C共晶点黑体,在3021 K采用钨碳-碳WC-C共晶点黑体进行验证。采用新基准装置,2017年-2019年NIM参加国际计量局组织的光谱辐射照度国际关键比对CCPR-K1.a,比对由全俄光学物理学测量研究院(VNIIOFI)主导,共有12个实验室参加。比对结果表明:除少数实验室外,在250~290、300~1300、1500~2500 nm波长范围,各参比实验室之间的一致性分别为±2.0%、±1.0%和±2.0%。在紫外、可见和近红外波段,NIM与国际比对参考值的平均相对偏差分别为0.13%、0.28%和0.15%。在250~2500 nm全波段,NIM与国际比对参考值的平均相对偏差为0.17%,与2004年平均相对偏差0.9%相比,测量能力提升显著。

关键词：光谱辐射照度国际比对高温黑体测量不确定度国家基准

Systematic diesel molecular performance evaluation based on quantitative structure-property relationship model

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Petroleum Science 2022年第2期19卷 809-818页

作者： Guang-qing cai Lin-Zhou Zhang State Key Laboratory of Heavy Oil Processing Petroleum Molecular Engineering Center(PMEC)China University of PetroleumBeijing 102249China

The production and separation of optimal molecules in diesel fuels require a systematic property evaluation for the containing *** paper evaluates the diesel molecules based on four key quality indicators:low-temperature fluidity,cleanliness,ignition,and power *** established the corresponding quantitative structure-property relationship models for corresponding properties,which are freezing point,yield sooting index,cetane number,and combustion *** models were applied for the screening of the high-performance molecules that is suitable for *** molecular performance distribution of the conventional diesel and biodiesel were also ***,we analyzed the effect of different transformation paths on molecular properties,giving guidance on the conversion process design.

关键词： Diesel Optimal molecules QSPR Molecular screening

Identification of in vitro and in vivo metabolites of 12β-hydroxylveratroylzygadenine associated with neurotoxicity by using HPLC–MS/MS

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Chinese Chemical Letters 2014年第8期25卷 1107-1111页

作者： Yue Cong Jing-Gong Guo zhi Tang qing-Chun Zhang Zong-Wei cai Institute of Pharmacy Pharmaceutical College Henan University State Key Laboratory of Environmental and Biological Analysis Department of Chemistry Hong Kong Baptist University The Key Laboratory of Plant Stress Biology Henan University

Metabolism study was carried out on 12b-hydroxylveratroylzygadenine（VOG） that is a cevine-type alkaloid existing in Veratrum nigrum L. and a neurotoxic component. In order to better understand the potential mechanism of neurotoxicity of VOG, this study measured VOG-induced DNA damage in the cerebellum and cerebral cortex of mice after 7 days repetitive oral dose by using single-cell gel electrophoresis（Comet assay）. High performance liquid chromatography-tandem mass spectrometry（LC–MS/MS） was developed and applied to separate and identify in vitro and in vivo metabolites of VOG for investing the possible relationship of metabolism and neurotoxicity. In vitro experiment was carried out using rat liver microsomes, while the in vivo study was conducted on rats. The obtained results indicated that VOG might cause DNA damage in cerebellum and cerebral cortex of mice in a dosedependent manner. Hydrolysis of ester bond and O-demethylation were proposed to be the main in vivo metabolic pathways of VOG, while the major in vitro metabolic pathways were proposed as methyl oxidation to aldehyde, dehydrogenation, hydrolysis of ester bond, hydrolysis of ester bond together with acetylation, and methoxylation. O-Demethylation reaction was likely to be associated with reactive oxygen species production, leading to the DNA damage.

关键词： 12β-Hydroxylveratroylzygadenine Metabolites O-Demethylation LC-MS

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主路式水肥一体机施肥系统的设计与试验

农机化研究 2025年第2期47卷 68-74页

作者：李擎李家春熊贤沙蔡家斌贵州大学机械工程学院贵阳550025

针对现阶段水肥一体化设备存在施肥不均、自动化程度不高及滞后性严重的问题,根据现代化农业节水省肥和减少环境污染的灌溉要求,设计了一款可实现自动混肥、施肥、节水灌溉的主路式水肥一体化施肥机。根据液肥的EC和pH值调节过程的特点... 详细信息

针对现阶段水肥一体化设备存在施肥不均、自动化程度不高及滞后性严重的问题,根据现代化农业节水省肥和减少环境污染的灌溉要求,设计了一款可实现自动混肥、施肥、节水灌溉的主路式水肥一体化施肥机。根据液肥的EC和pH值调节过程的特点,开发了以SIEMENS S7-1200为核心的液肥控制系统硬件,并结合MatLab设计了以模糊PID为控制器的液肥EC和pH值控制系统。为验证施肥机在实际应用中的精确性和鲁棒性,设计了施肥系统动态调节性能试验,结果表明:在施肥阶段,模糊PID控制系统具有较短的稳态时间和较小的超调量,相比于PID控制系统,对EC和pH值进行调节的稳态时间分别减少了37.7%和52.1%,稳态超调量分别降低了1.2%和2.2%,可实现对混肥溶液进行迅速有效的调节,满足现代农业实际生产需要。

关键词：水肥一体化施肥机模糊PID 过程控制

Suppressing Effects of Ag Wetting Layer on Surface Conduction of Er Silicide/Si(001) Nanocontacts

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Chinese Physics Letters 2018年第8期35卷 74-78页

作者： qing Han Qun cai State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 Collaborative Innovation Center of Advanced Microstructures Nanjing 210093

Current-voltage electrical characteristics of Er silicide/Si（001） nanocontacts are measured in situ in a scanning tunneling microscopy system. Introduced as a new technique to suppress surface leakage conduction on Si（001）,a silver wetting layer is evaporated onto the substrate surface kept at room temperature with Er Si2 nanoislands already existing. The effects of the silver layer on the current-voltage characteristics of nanocontacts are *** experimental results reveal that the silver layer at coverage of 0.4–0.7 monolayer can suppress effectively the current contribution from the surface conduction path. After the surface leakage path of nanocontacts is obstructed, the ideality factor and the Schottky barrier height are determined using the thermionic emission theory, about 2 and 0.5 eV, respectively. The approach adopted here could shed light on the intrinsic transport properties of metal-semiconductor nanocontacts.

关键词： Ag Suppressing Effects of Ag Wetting Layer on Surface Conduction of Er Silicide/Si Nanocontacts

A Generalization of Implicit Ore-condition for Hamiltonicity of k-connected Graphs

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Acta Mathematicae Applicatae Sinica 2020年第3期36卷 620-626页

作者： Jun-qing cai Lin WANG School of Management Qufu Normal UniversityRizhao 276826China

In 2005,Flandrin et *** that if G is a k-connected graph of order n and V(G)=X1∪X2∪···∪Xk such that d(x)+d(y)≥n for each pair of nonadjacent vertices x,y∈Xi and each i with i=1,2,···,k,then G is *** order to get more sufficient conditions for hamiltonicity of graphs,Zhu,Li and Deng proposed the definitions of two kinds of implicit degree of a vertex v,denoted by id1(v)and id2(v),*** this paper,we are going to prove that if G is a k-connected graph of order n and V(G)=X1∪X2∪···∪Xk such that id2(x)+id2(y)≥n for each pair of nonadjacent vertices x,y∈Xi and each i with i=1,2,···,k,then G is hamiltonian.

关键词： implicit degree Hamiltonian cycle cyclability