检索结果-南通市图书馆

Mechanical performance of 22SiMn2TiB steel welded with lowtransformation- temperature filler wire and stainless steel filler wire

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第4期31卷 967-981页

作者： Zi-dong Lin kai-jie Song Zhen sun Zi-qian Zhu Xue-feng Zhao Constantinos Goulas Wei Ya Xing-hua Yu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China Department of Design Production and Management Faculty of Engineering Technology.University of TwenteEnschede 7500 AETheNetherlands Rotterdam Additive Manufacture Fieldlab(RAMLAB) Rotterdam 3089 JWTheNetherlands

TX-80 low-transformation-temperature(LTT)welding wire was used to replace the traditional ER 307Si welding wire to realize the connection of 22SiMn2TiB armor steel in manual overlay welding.The previously existing issues,such as welding cracks,large welding deformation,and severe welding residual stress,were solved to ensure good strength and ductility requirements.In particular,with the same welding conditions,TX-80 LTT wire eliminates welding cracks.It reduces the welding deformation no matter the base pretreatment of pre-setting angle or no pre-setting angle.By comparison,it was found that the microstructure at the TX-80 weld is mainly composed of martensite and a small amount of retained austenite.In contrast,the microstructure of the ER 307Si weld consists of a large amount of austenite and a small amount of skeleton-like ferrite.The variation trend of residual stress and microhardness from the weld to the base were investigated and compared with the mechanical properties of base materials.The TX-80 and the ER 307Si tensile samples elongation is 6.76%and 6.01%,while the ultimate tensile strengths are 877 and 667 MPa,respectively.The average impact toughness at room temperature of the ER 307Si weld is 143.9 J/cm^(2),much higher than that of the TX-80 weld,which is only 36.7 J/cm^(2).The relationship between impact and tensile properties with microstructure species and distribution was established.In addition,the fracture surface of the tensile and the impact samples was observed and analyzed.Deeper dimples,fewer pores,larger radiation zone,and shear lips of TX-80 samples indicate better tensile ductility and worse impact toughness than those of ER 307Si weld.

关键词： Low-transformation-temperature material 22SiMn2TiB steel Welding deformation Residual stress Martensitic transformation Mechanical property

Tumor-targeted self-assembled micelles reducing PD-L1 expression combined with ICIs to enhance chemo-immunotherapy of TNBC

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 305-310页

作者： Hongda Zhu kai Ma Rui Ruan Chaobo Yang Aqin Yan Jing Li Qi Yu Hongmei sun Mingxing Liu Hongmei Zheng Jing Gao Xiaofang Guan Zhu Dai Yao sun Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province) Key Laboratory of Fermentation Engineering (Ministry of Education)National “111” Center for Cellular Regulation and Molecular PharmaceuticsSchool of Food and Biological EngineeringHubei University of TechnologyWuhan 430068China Hubei Cancer Hospital Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430079China National Key Laboratory of Green Pesticide College of ChemistryCentral China Normal UniversityWuhan 430079China Key Laboratory of Medical Optics Suzhou Institute of Biomedical Engineering and TechnologyChinese Academy of SciencesSuzhou 215163China Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science Ministry of EducationQingdao University of Science and TechnologyQingdao 266000China

Immune checkpoint inhibitors(ICIs)therapy targeting programmed cell death ligand 1(PD-L1)and programmed death protein 1(PD-1)had exhibited significant clinical benefits for cancer treatment such as triple negative breast cancer(TNBC).However,the relatively low anti-tumor immune response rate and ICIs drug resistance highlight the necessity of developing ICIs combination therapy strategies to improve the anti-tumor effect of immunotherapy.Herein,the immunomodulator epigallocatechin gallate palmitate(PEGCG)and the immunoadjuvant metformin(MET)self-assembled into tumor-targeted micelles via hydrogen bond and electrostatic interaction,which encapsulated the therapeutic agents doxorubicin(DOX)-loaded PEGCG-MET micelles(PMD)and combined with ICIs(anti-PD-1 antibody)as therapeutic strategy to reduce the endogenous expression of PD-L1 and improve the tumor immunosuppressive microenvironment.The results presented that PMD integrated chemotherapy and immunotherapy to enhance antitumor efficacy in vitro and in vivo,compared with DOX or anti-PD-1 antibody for the therapy of TNBC.PMD micelles might be a potential candidate,which could remedy the shortcomings of antibody-based ICIs and provide synergistic effect to enhance the antitumor effects of ICIs in tumor therapy.

关键词： Immunotherapy Tumor-targeted Self-assembled micelles Metformin Reducing PD-L1 expression TNBC

MH-STRALP:A scoring system for prognostication in patients with upper gastrointestinal bleeding

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第3期16卷 790-806页

作者： Jun-Nan Hu Fei Xu Ya-Rong Hao Chun-Yan sun kai-Ming Wu Yong Lin Lan Zhong Xin Zeng Department of Gastroenterology Shanghai East HospitalTongji University School of MedicineShanghai 200120China Department of Gastroenterology Shanghai Changzheng HospitalNavy Military Medical UniversityShanghai 200003China

BACKGROUND Upper gastrointestinal bleeding(UGIB)is a common medical emergency and early assessment of its outcomes is vital for treatment decisions.AIM To develop a new scoring system to predict its prognosis.METHODS In this retrospective study,692 patients with UGIB were enrolled from two cen-ters and divided into a training(n=591)and a validation cohort(n=101).The clinical data were collected to develop new prognostic prediction models.The en-dpoint was compound outcome defined as(1)demand for emergency surgery or vascular intervention,(2)being transferred to the intensive care unit,or(3)death during hos-pitalization.The models’predictive ability was compared with previously esta-blished scores by receiver operating characteristic(ROC)curves.RESULTS Totally 22.2%(131/591)patients in the training cohort and 22.8%(23/101)in the validation cohort presented poor outcomes.Based on the stepwise-forward Lo-gistic regression analysis,eight predictors were integrated to determine a new post-endoscopic prognostic scoring system(MH-STRALP);a nomogram was de-termined to present the model.Compared with the previous scores(GBS,Rock-all,ABC,AIMS65,and PNED score),MH-STRALP showed the best prognostic prediction ability with area under the ROC curves(AUROCs)of 0.899 and 0.826 in the training and validation cohorts,respectively.According to the calibration cur-ve,decision curve analysis,and internal cross-validation,the nomogram showed good calibration ability and net clinical benefit in both cohorts.After removing the endoscopic indicators,the pre-endoscopic model(pre-MH-STRALP score)was conducted.Similarly,the pre-MHSTRALP score showed better predictive value(AUROCs of 0.868 and 0.767 in the training and validation cohorts,respectively)than the other pre-endoscopic scores.CONCLUSION The MH-STRALP score and pre-MH-STRALP score are simple,convenient,and accurate tools for prognosis prediction of UGIB,and may be applied for early decision on its management strategies.

关键词： Upper gastrointestinal bleeding Prognosis prediction Retrospective study Nomogram Post-endoscopic model Pre-endoscopic model

A sustainable process to 100%bio-based nylons integrated chemical and biological conversion of lignocellulose

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第2期9卷 390-402页

作者： Ruijia Hu Ming Li Tao Shen Xin Wang Zhuohua sun Xinning Bao Kequan Chen kai Guo Lei Ji Hanjie Ying Pingkai Ouyang Chenjie Zhu College of Biotechnology and Pharmaceutical Engineering Nanjing Tech UniversityNanjingChina National Engineering Research Center for Biotechnology Nanjing Tech UniversityNanjingChina Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijingChina

Considerable progress has been made in recent years to the development of sustainable polymers from bio-based feedstocks.In this study,100%bio-based nylons were prepared via an integrated chemical and biological process from lignocellulose.These novel nylons were obtained by the melt polymerization of 3-propyladipic acid derived from lignin and 1,5-pentenediamine/1,4-butanediamine derived from carbohydrate sugar.Central to the concept is a three-step noble metal free catalytic chemical funnelling sequence(Raney Ni mediated reductive catalytic fractionation-reductive funnelling-oxidative funnelling),which allowed for obtaining a single component 3-propyladipic acid from lignin with high efficiency.The structural and thermodynamic properties of the obtained nylons have been systematically investigated,and thus obtained transparent bio-based nylons exhibited higher Mw(>32,000)and excellent thermal stability(Td5%>265℃).Considering their moderate Tg and good melt strength,these transparent bio-based nylons could serve as promising functional additives or temperature-responsive materials.

关键词： Lignocellulose Lignin Reductive catalytic fractionation Bio-based nylon

A novel profile modification HPF-Co gel satisfied with fractured low permeability reservoirs in high temperature and high salinity

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 683-693页

作者： Ya-kai Li Ji-Rui Hou Wei-Peng Wu Ming Qu Tuo Liang Wei-Xin Zhong Yu-Chen Wen Hai-Tong sun Yi-Nuo Pan China University of Petroleum Beijing Beijing102249China PetroChina Tarim Oilfield Company Korla 841000XinjiangChina Key Laboratory of Improving Oil and Gas Recovery of Ministry of Education Northeast Petroleum University Daqing 163318HeilongjiangChina Xi'an Shiyou University Xi'an 710065ShaanxiChina Northwest Oilfield Company SINOPECUrumqi 830011XinjiangChina

Conformance control and water plugging are a widely used EOR method in mature oilfields.However,majority of conformance control and water plugging agents are unavoidable dehydrated situation in high-temperature and high-salinity low permeability reservoirs.Consequently,a novel conformance control system HPF-Co gel,based on high-temperature stabilizer(CoCl_(2)·H_(2)O,CCH)is developed.The HPF-Co bulk gel has better performances with high temperature(120℃)and high salinity(1×10^(5)mg/L).According to Sydansk coding system,the gel strength of HPF-Co with CCH is increased to code G.The dehydration rate of HPF-Co gel is 32.0%after aging for 150 d at 120℃,showing excellent thermal stability.The rheological properties of HPF gel and HPF-Co gel are also studied.The results show that the storage modulus(G′)of HPF-Co gel is always greater than that of HPF gel.The effect of CCH on the microstructure of the gel is studied.The results show that the HPF-Co gel with CCH has a denser gel network,and the diameter of the three-dimensional network skeleton is 1.5-3.5μm.After 90 d of aging,HPF-Co gel still has a good three-dimensional structure.Infrared spectroscopy results show that CCH forms coordination bonds with N and O atoms in the gel amide group,which can suppress the vibration of cross-linked sites and improve the stability at high temperature.Fractured core plugging test determines the optimized polymer gel injection strategy and injection velocity with HPF-Co bulk gel system,plugging rate exceeding 98%.Moreover,the results of subsequent waterflooding recovery can be improved by 17%.

关键词： Low permeability reservoir High-temperature resistant gel Complexation reaction Polymer gel injection strategy Plugging rate Enhanced oil recovery

Zwitterionic ring-opening polymerization of macrocyclic ethyleneoxy-substituted carbonate:Access to cyclic PEG-like polycarbonate

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第3期35卷 282-286页

作者： Jin Huang Jinwen Li Rui Yan Yuanyuan Qu Fengzhen Guo Lei Shen Can-liang Ma Jie sun Zhenjiang Li kai Guo State Key Laboratory of Materials-Oriented Chemical Engineering College of Biotechnology and Pharmaceutical EngineeringNanjing Tech UniversityNanjing 211816China Institute of Nanjing Advanced Biomaterials&Processing Equipment Lishui Economic Development ZoneNanjing 211299China

The innovation in polymer design to rival conventional polyethylene glycol(PEG)is an important approach to achieving a more sustainable society.Here,cyclic PEG-like polycarbonates having high molecular weight(4.4–49.5 kg/mol)were enabled through zwitterionic ring-opening polymerization(ZROP)of macrocyclic carbonates(MCs)mediated by N-heterocyclic carbene(NHC).The thermodynamic behavior of polymerization depends on the ring size of monomers.During this process,the ZROP of 11-membered MC was driven by the change of enthalpy(ΔH_(p))which differed from the ZROP of 14-membered MC driven by the entropic change(ΔS_(p)).Cyclic polycarbonates depicted improved thermostability(T_(d5%)≥204℃)and higher glass transition temperatures(T_(g)>–40℃)in comparison to their linear analogues(T_(d5%)≤185℃,T_(g)~–50℃).In addition,the mechanism of ZROP of MC was addressed through computational study.A distinct mechanism of polymerization distinguishable from the well-known NHC-mediated ZROP of cyclic esters was revealed,where the zwitterion from nucleophilic addition to MC,i.***.tetrahedral intermediate,cannot be ring-opened probably due to the delocalization of negative charge on the carbonate group,but serves as an active center for the polymerization.In comparison to PEG,the attained polymer demonstrated comparable hydrophilic and biocompatible properties,as revealed by the results of contact angle and in vitro cytotoxicity studies,suggesting that cyclic polycarbonate hold the promise as the alternative of PEG.

关键词： Zwitterionic ring-opening polymerization Cyclic polycarbonate Macrocycles Tetrahedral intermediate NHC carbene

Synthesis of medium-sized benzo[b]azocines and benzo[b]azonines by photoinduced 8-/9-endo sulfonyl-cyclization

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第8期66卷 2309-2316页

作者： kai sun Dongyang Zhao Quanxin Li Shaofei Ni Guangfan Zheng Qian Zhang College of Chemistry and Chemical Engineering Yantai UniversityYantai264005China College Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou515063China Department of Chemistry Northeast Normal UniversityChangchun130024China

An efficient photochemical radical sulfonyl cyclization of designed dienes to medium-sized benzo[b]azocines and benzo[b]azonines was developed.This chemoselective method provides new highly functionalized eight-and nine-membered N-heterocycles.Radical inhibition experiments,light on/off experiments,and apparent quantum efficiency calculations were used to clarify the radical mechanism.Density functional theory calculations enabled rationalization of the rate-determining step and observed chemoselectivity.Large-scale synthesis and derivatizations via epoxidation and convenient N-Ts deprotection showed the potential utility of this strategy.This photochemical method for synthesizing sulfonylbenzo[b]azocines and sulfonylbenzo[b]azonines with insertion of sulfur dioxide provides new sustainable routes for the synthesis of valuable medium-sized Nheterocycles.

关键词： photocatalysis medium-sized N-heterocycles radical cascade cyclization DFT study

Synthesis and applications of thiosulfonates and selenosulfonates as free-radical reagents

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第4期34卷 53-66页

作者： Xin Wang Jianping Meng Dongyang Zhao Shi Tang kai sun College of Chemistry and Chemical Engineering Yantai UniversityYantai 264005China College of Chemistry and Chemical Engineering Jishou UniversityJishou 416000China

Chalcogenative sulfones(thiosulfonates and selenosulfonates), as reactants for organic transformations,are widely used and interesting because of their potential to react with nucleophiles, electrophiles, and free radicals. As stable radical reagents, the synthesis and applications of chalcogenative sulfones have opened up a novel pathway to synthesize many kinds of compounds containing sulfur or selenium motifs. However, despite the numerous recent works on the synthesis and applications of thiosulfonates and selenosulfonates as radical reagents, no review has yet provided a summary of the literature. In this paper, we aim to review the synthesis and applications strategies of chalcogenative sulfones as radical reagents reported over the past several decades. Different types of catalysis are discussed in this review:(i) metal catalysis;(ii) visible-light catalysis;(iii) synergistic catalysis;and(iiii) other types. Concurrently,in visible-light catalysis and metallaphotoredox catalysis sections, we highlight that developing relatively environmentally friendly synthetic methods in this area is always a great challenge, but also a persistent pursuit. Finally, the scopes, limitations, mechanisms, and existing problems of some reactions are described briefly.

关键词： Chalcogenative sulfones Radical Synthesis Applications Mechanisms

Direct benzylation reactions from benzyl halides enabled by transition-metal-free photocatalysis

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第12期33卷 5074-5079页

作者： Panjie Xiang kai sun Shuang Wang Xiaolan Chen Lingbo Qu Bing Yu Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450001China Zhengzhou Tobacco Research Institute of CNTC Zhengzhou 450001China

An SN2-based photochemical strategy using dithiocarbamate anion as catalyst was developed for the activation of benzyl halides,which are extremely challenging to be applied as radical precursors in visible light photocatalysis.With this transition-metal-free and oxidant-free protocol,the benzylation(or cyanomethylation)of various heterocycles including quinoxalin-2(1H)-ones,coumarin,2-phenyl-2H-indazole,1-methyl-5-phenylpyrazin-2(1H)-one,1-(fluoromethyl)cinnolin-4(1H)-one,and 2,4-dibenzyl-1,2,4-triazine-3,5(2H,4H)-dione could be realized(46 examples,up to 98%yield).Importantly,some biologically relevant 3-benzylquinoxalin-2(1H)-ones were also be synthesized under mild conditions.

关键词： Benzylation Photocatalysis Transition-metal-free Radical reaction N-Heterocyclics