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Nitrogen removal characteristics of heterotrophic nitrification-aerobic denitrification by Alcaligenes faecalis c16

chinese Journal of chemical Engineering 2015年第5期23卷 827-834页

作者： Yuxiang Liu Yao wang Yi Li Hua An Yongkang Lv college of Environmental Science and Engineering Taiyuan University of Technology National Major Science and Technology Program Management Office for Water Pollution control and Treatment Shanxi Key Lab of coal Science and Technology Taiyuan University of Technology

Alcaligenes faecalis c16 was found to have the ability to heterotrophically nitrify and aerobically denitrify. In order to further understand its nitrogen removal ability and mechanism, the growth and ammonium removal response were investigated at different c/N ratios and ammonium concentrations in the medium with citrate and acetate as carbon source separately. Furthermore, experiments of nitrogen sources, production of nitrogen gas and enzyme assay were conducted. Results show that the bacterium converts NH+4-N and produces NH2 OH during the growing phase and nitrite accumulation is its distinct metabolic feature. A. faecalis c16 is able to tolerate not only high ammonium concentration but also high c/N ratio, and the ammonium tolerance is associated with carbon source and c/N ratio. The nitrogen balance under different conditions shows that approximately28%–45% of the initial ammonium is assimilated into the cells, 44%–60% is denitrified and several percent is converted to nitrification products. A. faecalis c16 cannot utilize hydroxylamine, nitrite or nitrate as the sole nitrogen source for growth. However, nitrate can be used when ammonium is simultaneously present in the medium. A possible pathway for nitrogen removal by c16 is suggested. The preliminary enzyme assay provides more evidence for this nitrogen removal pathway.

关键词： Heterotrophic nitrification-aerobic denitrification Alcaligenes faecalis Hydroxylamine oxidase Nitrate reductase Nitrite reductase

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Synergistic Effects of Aluminum Hypophosphite on Intumescent Flame Retardant Polypropylene System

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chinese Journal of Polymer Science 2015年第2期33卷 318-328页

作者： Miao-jun xu Jing wang Yue-hang Ding 李斌 Heilongjiang Key Laboratory of Molecular Design and Preparation of Flame Retarded Materials College of ScienceNortheast Forestry University

The effects of aluminum hypophosphite（AHP） as a synergistic agent on the flame retardancy and thermal degradation behavior of intumescent flame retardant polypropylene composites（PP/IFR） containing ammonium polyphosphate（APP） and triazine charring-foaming agent（cFA） were investigated by limiting oxygen index（LOI）, UL-94 measurement, thermogravimetric analysis（TGA）, cone calorimeter test（cONE）, scanning electron microscopy（SEM） and x-ray photoelectron spectroscopy（xPS）. It was found that the combination of IFR with AHP exhibited an evident synergistic effect and enhanced the flame retardant efficiency for PP matrix. The specimens with the thickness of 0.8 mm can pass UL-94 V-0 rating and the LOI value reaches 33.5% based on the total loading of flame retardant of 24 wt%, and the optimum mass fraction of AHP/IFR is 1：6. The TGA data revealed that AHP could change the degradation behavior of IFR and PP/IFR system, enhance the thermal stability of the IFR and PP/IFR systems at high temperatures and promote the char residue formation. The cONE results revealed that IFR/AHP blends can efficiently reduce the combustion parameters of PP, such as heat release rate（HRR）, total heat release（THR）, smoke production rate（SPR） and so on. The morphological structures of char residue demonstrated that AHP is of benefit to the formation of a more compact and homogeneous char layer on the materials surface during burning. The analysis of xPS indicates that AHP may promote the formation of sufficient char on the materials surface and improve the flame retardant properties.

关键词： Synergistic effect Intumescent flame retardant Aluminum hypophosphite Thermal degradation Polypropylene

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Targeting“undruggable”c-Myc protein by synthetic lethality

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Frontiers of Medicine 2021年第4期15卷 541-550页

作者： chen wang Hui Fang Jiawei Zhang Ying Gu Division of Genome Medicine and cancer Institute(Key Laboratory of cancer Prevention and Intervention China National Ministry of Education)the Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Institute of Genetics Zhejiang University and Department of GeneticsZhejiang University School of MedicineHangzhou 310058China Zhejiang Laboratory for Systems&Precision Medicine Zhejiang University Medical CenterHangzhou 311121China

Synthetic lethal screening,which exploits the combination of mutations that result in cell death,is a promising method for identifying novel drug *** method provides a new avenue for targeting Uundruggable,9 proteins,such as ***,we revisit current methods used to target c-Myc and discuss the important functional nodes related to c-Myc in non-oncogene addicted network,whose inhibition may cause a catastrophe for tumor cell destiny but not for normal *** further discuss strategies to identify these functional nodes in the context of synthetic *** review the progress and shortcomings of this research field and look forward to opportunities offered by synthetic lethal screening to treat tumors potently.

关键词： synthetic lethality undruggable transcription factor c-Myc

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Distribution and phenogenetic diversity of Synechococcus in the Bohai Sea, china

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Journal of Oceanology and Limnology 2022年第2期40卷 592-604页

作者： Ting wang xi cHEN Jialin LI Song QIN college of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China Key Lab of coastal Biology and Biological Resource Utilization Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China college of Marine Life Science Ocean University of ChinaQingdao 266005China center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Synechococcus is one of the most abundant picocyanobacteria in marine ecosystem,and the absence of Prochlorococcus would make it indispensable as a primary producer in the Bohai Sea,North ***,the abundance distribution and genetic diversity of Synechococcus in this region have rarely been *** this study,the distribution pattern of Synechococcus abundance was investigated during four cruises in April,June,August,and November from 2018 to 2019,moreover,its phenogenetic diversity was studied based on high-throughput sequencing of the cpe BA *** results demonstrate that phycoerythrin-containing Synechococcus was most abundant in August when temperature was high and oxygen saturation was *** this period,Synechococcus pigment type(PT)2 was abundant in the Bohai Bay and Laizhou Bay under conditions of high nutrient concentration,temperature,and *** comparison,PT3,especially those clusters characterized with high or variable ratio of phycourobilin and phycoerythrobilin,was predominant in the Bohai Strait and Liaodong Bay under conditions of high salinity,pH,and oxygen ***,co-occurrence correlations using network analysis revealed that Synechococcus PTs were related to 15.37%-43.48%of the prokaryotic *** PT3c/PT3d and PT2 were the most important PTs in the *** hierarchical clustering revealed that taxa co-occurred with Synechococcus PTs diff ered among *** could be attributed to the substance exchange and the environmental impact,which calls for more studies in the future.

关键词： Synechococcus phenogenetic diversity co-occurrence network coastal ecosystem Bohai Sea

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Development of Biomimetic Synthesis of Propindilactone G

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chinese Journal of chemistry 2020年第11期38卷 1339-1352页

作者： Yu wang Bo chen xubiao He Jinghan Gui cAS Key Laboratory of Synthetic chemistry of Natural Substances Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China

of main observation and conclusion The natural product propindilactone G is a complex Schisandra nortriterpenoid with a unique 5/5/7/6/5 pentacyclic *** full paper describes the development of concise biomimetic synthesis of propindilactone G from a known steroid *** key c19-OH intermediate was synthesized via Breslow and Suarez radical remote c—H ***-Meerwein rearrangement was subsequently utilized for the expansion of the B *** invert the configuration of the c1O tertiary alcohol,an intramolecular peroxide cyclization catalyzed by BF3-Et2O was *** 5/5 fused lactone system was then assembled in a biomimetic transesterification/oxa-Michael addition *** work should provide experimental support for the proposed biosynthetic pathway and facilitate investigation of the biological activities of pro pindilactone G.

关键词： lactone utilized rearrangement

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Synthesis of Tin Oxide Through Thermal Decomposition of Sn_2(NH_4)_2(c_2O_4)_3 and Its Gas Sensing Property

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chemical Research in chinese Universities 2005年第6期21卷 641-645页

作者： SHI Juan WU Shi-hua wang Shu-rong School of Materials Science and chemical Engineering Tianjin Polytechnic University Tianjin 300160 P. R. China Department of chemistry Nankai University Tianjin 300071 P. R. China

Nanocrystalline tin oxide samples were prepared by using Sn2 （NH4 ）2 （c2O4）3 as the precursor. The thermal decompositions were respectively conducted at 250,450 and 650 ℃. TG-DTA, xRD, TEM, FTIR were used to characterize the samples. The indirect heating sensors by using these materials as sensitive bodies were fabricated on an alumina tube with Au electrodes and platinum wires. Sensing properties of these sensors were investigated. It was found that the tin oxide sample obtained by thermal decomposition at 450 ℃ has a higher sensitivity to c2H5OH and a higher selectivity to hexane and ammonia than those obtained via the conventional precipitate method and the working temperatures needed were greatly decreased.

关键词： Tin dioxide Thermal decomposition Gas sensing property Selectivity

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On the energy conservation and critical velocities for the propagation of a "steady-shock" wave in a bar made of cellular material

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Acta Mechanica Sinica 2013年第3期29卷 420-428页

作者： Li-Li wang Li-Ming Yang Yuan-Yuan Ding Mechanics and Material Science Research center Ningbo University

The propagation of shock waves in a cellular bar is systematically studied in the framework of continuum solids by adopting two idealized material models, viz. the dynamic rigid, perfectly plastic, locking （D-R-PP-L） model and the dynamic rigid, linear hardening plastic, locking （D-R-LHP-L） model, both considering the effects of strain-rate on the material properties. The shock wave speed relevant to these two models is derived. consider the case of a bar made of one of such material with initial length L 0 and initial velocity v i impinging onto a rigid target. The variations of the stress, strain, particle velocity, specific internal energy across the shock wave and the cease distance of shock wave are all determined analytically. In particular the ＂energy conservation condition＂ and the ＂kinematic existence condition＂ as proposed by Tan et al. （2005） is re-examined, showing that the ＂energy conservation condition＂ and the consequent ＂critical velocity＂, i.e. the shock can only be generated and sustained in R-PP-L bars when the impact velocity is above this critical velocity, is incorrect. Instead, with elastic deformation, strain-hardening and strain-rate sensitivity of the cellular materials being considered, it is appropriate to redefine a first and a second critical impact velocity for the existence and propagation of shock waves in cellular solids. Starting from the basic relations for shock wave propagating in D-R-LHP-L cellular materials, a new method for inversely determining the dynamic stress-strain curve for cellular materials is proposed. By using e.g. a combination of Taylor bar and Hopkinson pressure bar impact experimental technique, the dynamic stress-strain curve of aluminum foam could bedetermined. Finally, it is demonstrated that this new formulation of shock theory in this one-dimensional stress state can be generalized to shocks in a one-dimensional strain state, i.e. for the case of plate impact on cellular materials, by simply making proper

关键词： cellular solids 1D shock theory D-R-PP-L model D-R-SHP-L model Energy conservation across shock critical velocities

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Effects of Surface State and Applied Stress on Stress corrosion cracking of Alloy 690TT in Lead-containing caustic Solution

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Journal of Materials Science & Technology 2012年第9期28卷 785-792页

作者： Zhiming Zhang Jianqiu wang En-Hou Han Wei Ke State Key Laboratory for corrosion and Protection Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The effects of surface state and applied stress on the stress corrosion cracking （Scc） behaviors of thermally treated （TT） Alloy 690 in 10 wt% NaOH solution with 100 mg/L litharge at 330 ℃ were investigated using c-ring samples with four kinds of surface states and two different stress levels. Sample outer surfaces of the first three kinds were ground to 400 grit （ground）, shot-peened （SP） and electro-polished （EP） and the last one was used as the as-received state. Two samples of every kind were stressed to 100% and 200% yield stress of Alloy 690TT, respectively. The results showed that the oxide film consisted of three layers whereas continuous layer rich in cr was not found. The poor adhesive ability indicated that the oxide film could not protect the matrix from further corrosion. Lead was found in the oxide film and the oxides at the crack paths and accelerated the dissolution of thermodynamically unstable cr in these locations and also in the matrix. The crack initiation and propagation on Alloy 690TT were effectively retarded by SP and EP treatments but were enhanced by grinding treatment, compared with the cracks on the as-received surface. The cracking severity was also enhanced by increasing the externally applied stress. The accelerated dissolution of cr and the local tensile stress concentration in the near-surface layer caused by cold-working and higher applied stress reduced the Scc-resistance of Alloy 690TT in the studied solution.

关键词： Alloy 690TT Surface state Applied stress Stress corrosion cracking

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Efficient stochastic analysis of unsaturated slopes subjected to various rainfall intensities and patterns

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Geoscience Frontiers 2023年第1期14卷 346-359页

作者： xin Gu Lin wang Qiang Ou Wengang Zhang School of civil Engineering Chongqing UniversityChongqing 400045China

Rainfall infiltration poses a disastrous threat to the slope stability in many regions around the *** paper proposes an extreme gradient boosting(xGBoost)-based stochastic analysis framework to estimate the rainfall-induced slope failure *** unsaturated slope under rainfall infiltration in spatially varying soils is selected in this study to investigate the influences of the spatial variability of soil properties(including effective cohesion c',effective friction angleφ'and saturated hydraulic conductivity k_(s)),as well as rainfall intensity and rainfall pattern on the slope failure *** show that the proposed framework in this study is capable of computing the failure probability with accuracy and high *** spatial variability of k_(s)cannot be overlooked in the reliability ***,the rainfall-induced slope failure probability will be *** is found that the rain-fall intensity and rainfall pattern have significant effect on the probability of ***,the failure probabilities under various rainfall intensities and patterns can be easily obtained with the aid of the proposed framework,which can provide timely guidance for the landslide emergency management departments.

关键词： Slope stability Rainfall infiltration Stochastic analysis Sspatial variability

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The effect of different coatings on bone response and degradation behavior of porous magnesium-strontium devices in segmental defect regeneration

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Bioactive Materials 2021年第6期6卷 1765-1776页

作者： Nan Zhang Weidan wang xiuzhi Zhang Krishna.c.Nune Ying Zhao Na Liu R.D.K.Misra Ke Yang Lili Tan Jinglong Yan Department of Orthopedic Surgery The 2nd Affiliated Hospital of Qiqihar Medical UniversityQiqihar161000China Department of Orthopaedics Affiliated Zhongshan Hospital of Dalian UniversityDalian116001China Institute of Metal Research Chinese Academy of SciencesShenyang110016China Department of Orthopedic Surgery The 2nd Affiliated Hospital of Harbin Medical UniversityHarbin150081China Department of Metallurgical Material and Biomedical EngineeringThe University of Texas at EI PasoTX79968USA Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen518055China

Regeneration of long-bone segmental defects remains a challenge for orthopedic *** treatment options often require several revision procedures to maintain acceptable alignment and achieve osseous healing.A novel hollow tubular system utilizing magnesium-strontium(Mg-Sr)alloy with autogenous morselized bone filled inside to repair segmental defects was *** improve the corrosion and biocompatible properties,two coatings,ca-P and Sr-P coatings,were prepared on surface of the *** of applying these coated implants was systematically evaluated in vitro and in vivo,and simultaneously to have a better understanding on the relationship of degradation and bone regeneration on the healing *** to the in vitro corrosion study by electrochemical measurements,greater corrosion resistance was obtained for ca-P coated sample,and attributed to the double-layer protective *** cytotoxicity and alkaline phosphatase(ALP)assays demonstrated enhanced bioactivity for Sr-P coated group because of the long-lasting release of beneficial Sr^(2+).At 12 weeks post-implantation with Mg-Sr alloy porous device,the segmental defects were effectively repaired with respect to both integrity and *** addition,compared with the ca-P coated implant,the Sr-P coated implant was more proficient at promoting bone formation and *** summary,the Sr-P coated implants have bioactive properties and exceptional durability,and promote bone healing that is close to the natural rate,implying their potential application for the regeneration of segmental defects.

关键词： Magnesium-strontium alloy Segmental defect Degradation behavior Bone regeneration

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