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Morphology and orientation relationship of VC precipitates in HSLA steel

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Journal of University of Science and Technology Beijing 2006年第5期13卷 420-423页

作者： Shijian Yan Xiaoping liu Wenhuai tian Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China

The morphology and distribution of VC precipitates in HSLA steel as well as the orientation relationship between VC precipitate and α-Fe were studied by transmission electron microscopy （TEM）. The chemical composition of the VC precipitate was analyzed qualitatively by using analytical electron microscopy （AEM） equipped with an energy dispersive spectrum （EDS） system. The VC precipitate is needle-like in shape with a size of about 10 nm in length and is homogeneously dispersed in the α-Fe matrix. The smaller lattice misfit along the 〈100〉 lattice direction of α-Fe matrix leads to VC precipitate forming with its long axes nearly parallel to the 〈100〉 lattice direction of α-Fe matrix. It is confirmed that the orientation relationship between VC precipitate and α- Fe is the ＂N-W＂ orientation relation by selected area electron diffraction （SAED） patterns.

关键词： vanadium micro-alloyed steels VC precipitation orientation relationship

A Note on Closeness between NP-Hard Sets and C=P

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Journal of Computer Science & Technology 2000年第2期15卷 194-195页

作者：刘田 Department of Computer Science and Technology Peking University Beijing P.R. China

Two sets are close if their symmetric difference is a sparse set. It is shown that NP-hard sets are not C=P-close unless NP C=C=P. This improves the previous result and has implication in quantum compulation.

关键词： NP-hard exact counting closeness quantum computation

Reactive adsorption of thiophene on Ni/ZnO adsorbent:Effect of ZnO textural structure on the desulfurization activity

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Journal of Natural Gas Chemistry 2010年第3期19卷 327-332页

作者： Jingcheng Zhang Yunqi liu Shuang tian Yongming Chai Chenguang liu State Key Laboratory of Heavy Oil Processing Key Laboratory of Catalysis CNPC China University of Petroleum Qingdao 266555 Shandong China

To better understand the nature of reactive adsorption of thiophene on Ni/ZnO adsorbent,the effect of ZnO textural structure on the desulfurization activity was *** materials were synthesized by low-temperature solid-state reaction and the corresponding Ni/ZnO adsorbents were prepared by incipient impregnation *** analysis results showed that the crystalline sizes of ZnO as-synthesized as well as the BET surface areas varied obviously with the calcination *** activity evaluations indicated that the Ni/ZnO adsorbents prepared with ZnO possessed a favorable textural structure as active component exhibited good activity of removing *** evolutions of the main crystalline phases of Ni/ZnO adsorbents before and after reaction confirmed that ZnO played a crucial role in taking up S element and converting it into ZnS in the reactive adsorption *** was concluded that ZnO with larger surface area and smaller crystal particles resulted in better desulfurization activity,which may be the main reason for the different activities of the Ni/ZnO adsorbents prepared with ZnO calcined at different temperatures.

关键词： Ni/ZnO reactive adsorption textural structure low-temperature solid-state reaction thiophene

Decode protein-metabolite regulatory network: one MIDAS at a time

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Signal Transduction and Targeted Therapy 2023年第9期8卷 3896-3898页

作者： tian liu Chen Gao Department of Pharmacology and Systems Physiology University of CincinnatiCincinnatiOHUSA

In a recent study published in Science,Hicks et *** Mass spectrometry integrated with equilibrium dialysis for the discovery of allostery systematically(MIDAS)to explore protein-metabolite interactome and have revealed previously unknown regulation for lactate dehydrogenase.1 This report brings an exciting new approach to address a long-standing challenge in *** functions are orchestrated by an interactive network of molecular constituents,the physical interactions between proteins and other molecular entities,such as DNA,RNA,and *** basic vocabulary for the book of life,these interactions are the fundamental mechanisms for complex physiology and diseases.

关键词： network such she

Cloning, expression and biocharacterization of OfCht5, the chitinase from the insect Ostrinia furnacalis

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Insect Science 2013年第2期20卷 147-157页

作者： Qingyue Wu tian liu Qing Yang Department of Bioscience and Biotechnology Dalian University of Technology Dafian China

Chitinase catalyzes β,4-glycosidic linkages in chitin and has attracted re- search interest due to it being a potential pesticide target and an enzymatic tool for preparation of N-acetyl-β D-glucosamine. An individual insect contains multiple genes encoding chitinases, which vary in domain architectures, expression patterns, physiological roles and biochemical properties. Herein, Of ChtS, the glycoside hydrolase family 18 chiti- nase from the widespread lepidopteran pest Ostrinia furnacalis, was cloned, expressed in the yeast Pichia pastoris and biochemically characterized in an attempt to facilitate both pest control and biomaterial preparation. Complementary DNA sequence analysis indicated that Of CHT5 consisted of an open reading frame of 1 665-bp nucleotides. Phy- logenic analysis suggested Of Cht5 belongs to the Group I insect chitinases. Expression of Of Cht5 in Pichia pastoris resulted in highest specific activity after 120 h of induction with methanol. Through two steps of purification, consisting of ammonium sulfate pre- cipitation and metal chelating chromatography, about 7 mg of the recombinant Of Cht5 was purified to homogeneity from 1 L culture supernatant. Of Cht5 effectively converted colloidal chitin into chitobiose, but had relatively low activity toward a-chitin. When chi- tooligosaccharides [（GlcNAc）n, n = 3-6] were used as substrates, Of Cht5 was observed to possess the highest catalytic efficiency parameter toward （GlcNAc）4 and predominan- tely hydrolyzed the second glycosidic bond from the non-reducing end. Together with fl-N-acetyl-D-hexosaminidase OfHexl, Of Cht5 achieved its highest efficiency in chitin degradation that yielded N-acetyl-β D-glucosamine, a valuable pharmacological reagent and food supplement, within a molar concentration ratio of Of Cht5 versus Of Hexl in the range of 9 ： 1-15 ： 1. This work provides an alternative to existing preparation of chitinase for pesticides and other applications.

关键词： chitin chitinase glycoside hydrolase N-acetyl-β-D-glucosamine Ostriniafurnacalis pest control

Position-Aware and Subgraph Enhanced Dynamic Graph Contrastive Learning on Discrete-Time Dynamic Graph

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Computers, Materials & Continua 2024年第11期81卷 2895-2909页

作者： Jian Feng tian liu Cailing Du College of Computer Science&Technology Xi’an University of Science and TechnologyXi’an710054China

Unsupervised learning methods such as graph contrastive learning have been used for dynamic graph represen-tation learning to eliminate the dependence of ***,existing studies neglect positional information when learning discrete snapshots,resulting in insufficient network topology *** the same time,due to the lack of appropriate data augmentation methods,it is difficult to capture the evolving patterns of the network *** address the above problems,a position-aware and subgraph enhanced dynamic graph contrastive learning method is proposed for discrete-time dynamic ***,the global snapshot is built based on the historical snapshots to express the stable pattern of the dynamic graph,and the random walk is used to obtain the position representation by learning the positional information of the ***,a new data augmentation method is carried out from the perspectives of short-term changes and long-term stable structures of dynamic ***,subgraph sampling based on snapshots and global snapshots is used to obtain two structural augmentation views,and node structures and evolving patterns are learned by combining graph neural network,gated recurrent unit,and attention ***,the quality of node representation is improved by combining the contrastive learning between different structural augmentation views and between the two representations of structure and *** results on four real datasets show that the performance of the proposed method is better than the existing unsupervised methods,and it is more competitive than the supervised learning method under a semi-supervised setting.

关键词： Dynamic graph representation learning graph contrastive learning structure representation position representation evolving pattern

POLY(MALEIC ANHYDRIDE-CO-ACRYLIC ACID)/POLY(ETHYLENE GLYCOL)HYDROGELS WITH pH- AND IONIC-STRENGTH-RESPONSES

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Chinese Journal of Polymer Science 2010年第6期28卷 951-959页

作者： Meng Yang Bo-tian liu Ge Gao Xiao-li liu Feng-qi liu College of Chemistry and Macdiarmid Laboratory Jilin University Changchun 130012 China

Poly（maleic anhydride-coacrylic acid）,P（MA-AA）,was synthesized by the free-radical copolymerization of maleic anhydride with acrylic acid,and fast responsive pH-sensitive poly（maleic anhydride-co-acrylic acid）/polyethylene glycol,P（MA-AA）/PEG,hydrogels were prepared using PEG as macromolecular cross-linking ***-IR and ~1H-NMR spectrometry were applied to characterize the structure of P（MA-AA）.The influences of pH and ionic strength on the swelling behavior of P（MA-AA）/PEG hydrogels and the swelling-deswelling changes along with the repeated changes between acid and alkali conditions were *** results showed that there was a hundredfold difference in the swelling ratios between the conditions of acid and alkali,and the swelling capability could not be weakened after multiple swelling-deswelling *** results of swelling kinetics demonstrated that the response rate of P（MA-AA）/PEG hydrogels was very fast,because the swelling transition points always occurred at 10 *** pH-responsive hydrogels reported here might be a smart material for potentially applications in many areas,including biosensors,drug-delivery devices and tissue engineering.

关键词： pH-response P(MA-AA) Macromolecular cross-linking agent External cross-linking

Some Structural Properties of SAT

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Journal of Computer Science & Technology 2000年第5期15卷 439-444页

作者：刘田 Department of Computer Science and Technology Peking University Beijing P.R. China

The following four conjectures about structural properties of SAT are studied in this paper. (1) SAT ∈ PSPARSEnNP; (2) SAT ∈ SRTDtt; (3) SAT ∈ PttbAPP; (4) FPttSAT = FPlogSAT. It is proved that some pairs of these conjectures imply P = NP, for example, if SAT E pSPARsEnNP and SAT 6 PttbAPP, or if SAT E SRTDtt and SAT E PttbAPP, then P = NP. This improves previous results in literature.

关键词： structural complexity SAT sparse set approximable set truthtable reduction non-adaptive search reducible to decision.

Surveys of harvest technology of winter bamboo shoots

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Journal of Forestry Research 2011年第3期22卷 487-490页

作者： liu tian-hu College of Engineering South China Agricultural University 483 Wushan street Guangzhou 510643 China.

Winter bamboo shoots are widely used in Asian cuisine. We surveyed growth depth （tail depth and root depth）, harvest speed, and harvest processes to provide information for developing new harvest technology. The tail depth of most winter bamboo shoots was 100 350 mm below the soil surface, and the root depth was 200 500 mm below the soil surface. Most winter bamboo shoots were difficult to locate with only the naked eye. The digging depth was 200 500 mm to cut winter bamboo shoots from the root. The highest harvest rate was 7.75 times faster than the slowest one and the average harvest speed ratio of men： women was about 1.71：1. The harvest process of winter bamboo shoots was divisible into three steps： searching, digging a hole （around the shoot） and cutting the root. The ratio of searching time to the sum of digging and cutting time was about 8：1, showing that searching required more time than digging and cutting together.

关键词： winter shoots Phyllostachys pubescens harvest survey