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A post-modification approach to independent compo-nent analysis for resolution of overlapping GC/MS signals: from independent components to chemical components

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Science China Chemistry 2007年第4期50卷 530-537页

作者： WANG Wei CAI WenSheng SHAO XueGuang Department of Chemistry University of Science and Technology of ChinaHefei 230026China Department of Chemistry Nankai UniversityTianjin 300071China

Independent component analysis (ICA) has demonstrated its power to extract mass spectra from over-lapping GC/MS signal. However, there is still a problem that mass spectra with negative peaks at some m/z will be obtained in the resolved results when there are overlapping peaks in the mass spectra of a mixture. Based on a detail theoretical analysis of the preconditions for ICA and the non-negative property of GC/MS signals, a post-modification based on chemical knowledge (PMBK) strategy is pro-posed to solve this problem. By both simulated and experimental GC/MS signals, it was proved that the PMBK strategy can improve the resolution effectively.

关键词： independent component analysis (ICA) post modification immune algorithm (IA) GC/MS

Microstructure and mechanical properties of friction stir welding joint during post weld heat treatment with different zigzag lines

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Rare Metals 2019年第11期38卷 1070-1077页

作者： Zhi-Li Hu Qiu Pang Ming-Liang Dai Hubei Key Laboratory of Advanced Technology of Automobile Components Wuhan University of TechnologyWuhan 430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of TechnologyWuhan 430070China School of Mechanical and Electrical Engineering Wuhan Donghu UniversityWuhan 430212China

Zigzag line is a common defect in friction stir welding(FSW) *** formation mechanism of the zigzag line in Al-Cu alloy FSW joint and its influence on the microstructure and mechanical properties during post weld heat treatment(PWHT) were studied by scanning electron microscopy(SEM),microhardness and tensile *** is found that the occurrence of zigzag line for PWHT joint is determined by PWHT process which in nature depends on residual stress and thermal stress of FSW *** optimization of PWHT process to reduce the residual and thermal stress can trigger for the deterioration of mechanical properties of PWHT joints with zigzag *** obvious decrease of tensile properties is observed for T6-450 and T6-495 joints although zigzag line appears in the *** determines the sizes of zigzag line cracks and consequently determines the fracture location and characteristics of FSW joint.

关键词： Friction stir welding post weld heat treatment Zigzag line Mechanical properties

Insight into removal of dissolved organic matter in post pharmaceutical wastewater by coagulation-UV/H_2O_2

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Journal of Environmental Sciences 2019年第2期31卷 329-338页

作者： Feng Qian Mengchang He Jieyun Wu Huibing Yu Liang Duan State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal University State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences

The removal of four dissolved organic matter(DOM) fractions, non-acid hydrophobics,hydrophobic acids, hydrophilics and transphilics, was achieved by coagulation-UV/H_2O_2 oxidation in post-pharmaceutical wastewater(PhW W). Coagulation with Polyferric chloride(PFC), Polymeric ferric sulfate(PFS) and Polymeric aluminum ferric chloride(PAFC) was studied separately to evaluate the effects of the initial pH and coagulant dosage. The coagulation-UV/H_2O_2 oxidation method resulted in much higher reduction rates for dissolved organic carbon(DOC)(by 75%) and UV_(254)(by 92%) than coagulation or UV/H_2O_2 oxidation alone. The proportion of non-acid hydrophobics, hydrophobic acids, transphilics and hydrophilics removed by coagulation was 54%, 49%, 27% and 12 %, while the combined treatment removed 92%, 87%,70% and 39%, respectively. Parallel factor analysis(PARAFAC) of fluorescence measurements revealed that the humic-like fluorescent component C4 showed the highest removal(by 44%)during the coagulation stage. After coagulation-UV/H_2O_2 treatment, the humic-like fluorescent component C3 had the highest removal(by 72%), whereas xenobiotic organic fluorescent components C1 and C4 remained recalcitrant to decomposition. Significant correlations(R2> 0.8)between C1 and the hydrophobic acids and non-acid hydrophobics suggested the possibility of using fluorescence spectroscopy as an effective tool to assess variations in DOM fraction treatment efficacy in coagulation-UV/H_2O_2 systems. After the combined treatment, toxic inhibition of cellular activity by post PhW W decreased from 88% to 47% and biodegradability increased from 0.1 to 0.52.

关键词： post PhWW Coagulation UV/H2O2 PARAFAC DOM fractionation Toxicity

Microstructure and Wear Resistance Evolution of HVOFSprayed WC-(W,Cr)_2C-Ni Coating with post Heat Treatment In Air Atmosphere

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稀有金属材料与工程 2012年第S1期41卷 388-393页

作者： Hou Guoliang1,2,Zhou Huidi1,An Yulong1,2,Liu Guang1,2,Chen Jianmin1,Chen Jie1,2 1 State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China 2 Graduate University,Chinese Academy of Sciences,Beijing 100049,China Chinese Acad Sci Lanzhou Inst Chem Phys State Key Lab Solid Lubricat Lanzhou 730000 Peoples R China Chinese Acad Sci Grad Univ Beijing 100049 Peoples R China

WC-(W,Cr)2C-Ni coating was prepared on 1Cr18Ni9Ti stainless steel and C-276 Ni-base Hastelloy by high velocity oxy-fuel(HVOF)*** effect of post heat treatment in air atmosphere on the microstructure,phase composition,microhardness,fracture toughness,and wear resistance of HVOF-sprayed WC-(W,Cr)2C-Ni coating was *** microstructure and phase composition of the coatings were analyzed by means of field emission scanning electron microscopy(FESEM)and X-ray diffraction(XRD).The microhardness and fracture toughness of the coatings were measured using a microhardness tester and a Vickers hardness ***,dry friction and wear behavior of the coatings sliding against Si3N4 ball was investigated using an oscillating friction and wear tester;and the worn surfaces of the coatings were analyzed by means of scanning electron microscopy(SEM).It was found that heat treatment within 500-800°C resulted in crystallization of amorphous phase in as-sprayed coating,generating nanoscale new phases such as NiWO4,CrWO4 and ***,heat treatment led to increase of the microhardness of as-sprayed coating,and the highest microhardness was obtained after heat treatment at 800°*** fracture toughness and wear resistance of the as-sprayed coating increased with increasing heat treatment temperature up to 700°C but tended to decrease with further elevating *** other words,the mechanical properties and wear resistance of the as-sprayed coatings were worsened owing to excessive growth of oxidation grains and depletion of ductile Ni binder after heat treatment above 700°*** it was suggested that as-sprayed ceramic composite coating should be post heat treated in air at a moderate temperature of 700°C so as to achieve the optimized mechanical properties and wear resistance.

关键词： HVOF WC-(W,Cr)2C-Ni coating post heat treatment microstructure wear resistance

An in Vitro Investigation of Acid Etching Treatment Prior to post and Core Cementation and Teeth Fracture Resistance

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Journal of Wuhan University of Technology(Materials Science) 2019年第5期34卷 1233-1237页

作者： MA Xiaoni GAO Xu XU Xin School of Stomatology Shandong UniversityJinan 250012China Handong Provincial Key Laboratory of Oral Tissue Regeneration Jinan 250012China School of Material Science and Engineering Shandong UniversityJinan 250012China Yantai Stomatological Hospital Yantai 264000China

In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with cast post and core with two kinds of surface treatment technology and acid etching preparation on the dentinal surface. Sixty-four recently extracted human single-rooted first premolars were endodontically treated and sectioned approximately 1.5 mm above the cementoenamel junction to remove the coronal portion. Each specimen received a cast post, core build-up and a metal alloy crown restoration. All teeth were randomly divided into the smooth surface post, core repair group, the sand blasting surface post, and core repair group, each group was divided into 10 s, 30 s, 60 s acid corrosion treatment group and control group. In acid test groups, an acid etching solution was applied for 10, 30 and 60 seconds, respectively, to the root canal wall surface. Each specimen was embedded in acrylic resin block and tested in an electronic universal testing machine. Fracture loads results showed that canal acid etching could increase teeth fracture resistance strength both in smooth groups and sandblasting group, and achieved the best effect when acid etching for 30 s. Sand spray treatment on the surface of the cast metal post can improve the flexural strength of the teeth after postcrown restoration. Acid etching on the root canal wall surfaces and sand spray treatment on the surface of the cast metal post can improve the flexural strength of the root after post-crown restoration. Therefore, these two methods could be used to strengthen the tooth fracture resistance, and maintain the long-term therapeutic effect of cast post and core restoration.

关键词： acid etching cast post and core resistance strength surface treatment

Methanol extract of Desmodium gangeticum DC root mimetic post-conditioning effect in isolated perfused rat heart by stimulating muscarinic receptors

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Asian Pacific Journal of Tropical Medicine 2012年第6期5卷 448-454页

作者： Gino A Kurian Jose Paddikkala Medical Biochemistry School of Chemical and BiotechnologySASTRA UniversityThirumalaisamudramThanjavurTamil NaduIndiaPin:613402 Department of Plant Biotechnology Amala Cancer Research CenterAmalanagarTrichurKeralaIndia

Objective:To evaluate pharmacological mimetic action of herbal extract Desmodium gangeticum (DC) roots on ischemia reperfusion ***:With the help of Langendroff perfusion technique,ischemic post condition(POC) mimetic action of DG methanol root extract was evaluated and compared by using standard drugs that acts as muscarinic receptor agonist and antagonist,namely acetylcholine(Ach) and atropine(Atr) respectively in an isolated rat heart. Results:The physiological parameters like left ventricular developed pressure,end diastolic pressure and working index of isolated rat heart showed significant recovery in DG root extract administrated rat heart,similar to the recovery by *** results showed muscarinic receptor agonist like action for DG methanol root extract,confirmed in rat heart by muscarnic receptor agonist(acetylcholine) and anatoginst(atropine).Administration of DC root extract prior to reperfusion showed better antioxidant status in myocardial tissue homogenate and mitochondrial,complemented by the levels of cardiac specific marker proteins in myocardial tissue and *** though DG methanol root extract mimics its action similar to that of Ach,the myocardial protection mediated by the extract was superior to Ach,due to the presence of antioxidants in the crude ***:DG methanol root extract provides myocardial protection towards IRI by stimulating muscarinic receptors.

关键词： Myocardial ischemia reperfusion Ischemic precondition Ischemic post conditioning Acetyl choline Desmodium gangeticum Muscarinic receptor

Study on CO_2 Absorption by Aqueous Benzylamine and Its Formulations with Monoethanolamine as a Component for post-Combustion Capture Process

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China Petroleum Processing & Petrochemical Technology 2016年第3期18卷 7-14页

作者： Gao Jie Yin Jun Zhu Feifei Chen Xin Tong Ming Kang Wanzhong Zhou Yanbo Lu Jun Key Laboratory of Coal Gasification and Energy Chemical Engineering of Ministry of Education East China University of Science & Technology SINOPEC Ningbo Engineering Co. Ltd.

Benzylamine(BZA) has been identified as a promising candidate for CO_2 capture process; however the evaluation of BZA in the packed column was very few. Thus, in this work, the absorption and regeneration performance of unblended BZA solvent as well as a series of amine concentrations and ratios in the formulations were studied using a semibatch bubbling reactor. And due to the formation of ivory-white precipitates in solvents containing higher BZA ratios, a 4:1 molar ratio of MEA/BZA mixed solvent was used to study its performance in a pilot-scale test bed. The results showed that a higher BZA ratio in the MEA/BZA mixed solvent resulted in a faster absorption rate, a higher mass transfer and heat transfer rate and a better cyclic performance, but the mass transfer rate of BZA decreased more quickly than MEA with the increase of CO_2 loading of the solvents. In addition, at high CO_2 loading in the MEA/ BZA mixed solvent with a molar ratio of 4:1, the ivory-white precipitates were generated which could cause blockage of the packing in the absorber, the stripper and the liquid pipelines.

关键词： benzylamine (BZA) monoethanolamine (MEA) post combustion CO2 capture pilot plant mass transfer

A Genetically Encoded Toolkit for Probing the post Translational Modifications of Lysine in Mammalian Cells

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生物物理学报 2009年第S1期25卷 166-167页

作者： Dan Groff Peter G.Schultz The Scripps Research Institute 10550 N.Torrey Pines RdLa JollaCA92037USA

post translational modifications (PTMs) of lysine play a crucial role on modulating the activity and stability of essential proteins in eukaryotic cells including the tumor

关键词： post translational modifications photocaged Lysine Unnatural amino acid Mammalian cells.

Evi-1 and MDS1-Evi-1 genes in pathogenesis of myelodysplastic syndromes and post-MDS acute myeloid leukemia

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Chinese Medical Journal 1999年第12期 56-62页

作者：徐开林王立郝玉书邵宗鸿孟庆祥李克晁恒军唐克晶王玲

Objective To investigate expression of Evi 1 and MDS1 Evi 1 genes in myelodysplastic syndromes (MDS) and post MDS acute myeloid leukemia (post MDS AML), and its role in pathogenesis or progression of MDS and post MDS AML Methods Expression of Evi 1 and MDS1 Evi 1 genes was examined in 31 MDS, 11 post MDS AML, and 34 de novo AML patients by a semi quantitative reverse transcription polymerase chain reaction (RT PCR) Results Evi 1 expression was not detected in bone marrow samples of 8 normal controls, but low MDS1 Evi 1 expression levels (MDS1 Evi 1/GAPDH0 1) were markedly higher than those in the controls Evi 1 expression was gradually increased in 4 of 5 RAEB T patients with transformation from MDS to AML The percentages of Evi 1 and MDS1 Evi 1 expression in post MDS AML patients were significantly (Ppost MDS AML

关键词： myelodysplastic syndromes · post MDS acute myeloid leukemia · gene expression · Evi 1 MDS1 Evi 1