检索结果-南通市图书馆

Experimental Study of Local Scour Around Four Piles Under Different Attack Angles and Gap Ratios

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 612-624页

作者： LIU ming-ming TANG Guo-qiang JIN xin GENG Shao-yang School of Architecture and Engineering Liaocheng UniversityLiaocheng 252000China Water-Sediment Regulation and Sand Effective Utilization Special Laboratory of Shandong Provincial Education Department Liaocheng UniversityLiaocheng 252000China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China College of Energy Chengdu University of TechnologyChengdu 610059China

In an effort to investigate and quantify the patterns of local scour,researchers embarked on an in-depth study using a systematic experimental *** research focused on the effects of local scour around a set of four piles,each subjected to different hydromechanical *** particular,this study aimed to determine how different attack angles—the angles at which the water flow impinges on the piles,and gap ratios—the ratios of the spacing between the piles to their diameters,influence the extent and nature of scour.A comprehensive series of 35 carefully designed experiments were orchestrated,each designed to dissect the nuances in how the gap ratio and attack angle might contribute to changes in the local scour observed at the base of pile *** these experimental trials,a wealth of local scour data were collected to support the *** data included precise topographic profiles of the sediment bed around the pile groups,as well as detailed scour time histories showing the evolution of scour at strategic feature points throughout the test *** analysis of the experimental data provided interesting *** study revealed that the interplay between the gap ratio and the attack angle had a pronounced influence on the scouring dynamics of the pile *** of the key observations was that the initial phases of scour,particularly within the first hour of water flow exposure,were characterized by a sharp increase in the scour depth occurring immediately in front of the *** this initial rapid development,the scour depth transitioned to a more gradual change *** contrast,the scour topography around the piles continuously *** suggests that sediment displacement and the associated sculpting of the seabed around pile foundations are sustained and progressive processes,altering the underwater landscape over *** results of this empirical investigation have significant implications for the design and constructio

关键词： local scour piles gap ratio attack angle

Reaction behavior of MgO refractory with high-Mn and high-Al steel

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6期31卷 1389-1398页

作者： Ling-zhong Kong Lin Zu Jie yang Xi-min Zang xin yang ming Kang School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

To understand the mechanism of the interfacial reaction between high-Mn and high-Al steel and MgO refractory,a series of laboratory experiments as well as thermodynamic calculations were *** effects of Mn and Al contents in the steel and the reaction time on the interfacial reaction were *** was observed that the erosion of the MgO refractory is caused by the reaction of Al and Mn in the steel with MgO in the refractory,which would lead to the formation of(Mn,Mg)O·Al_(2)O_(3) spinel and(Mn,Mg)O solid *** formation mechanism of the spinel and solid solution is as *** Al in the steel firstly reacts with MgO in the refractory to generate MgO·Al_(2)O_(3) spinel,and then,the spinel reacts with Mn in the steel to form(Mn,Mg)O·Al_(2)O_(3) ***,the MnO in the spinel reacts with the MgO in the inner refractory to form(Mn,Mg)O solid *** addition,only(Mn,Mg)O·Al_(2)O_(3) spinel is present in the interfacial reaction layer of the refractory when the Al content in the steel is sufficient.

关键词： High-Mn high-Al steel MgO refractory Reaction behavior Spinel

Visible Light-Induced[3+2]Annulation Reaction of Alkenes with Vinyl Azides:Direct Synthesis of Functionalized Pyrroles

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 Journal of Chemistry 2024年第2期42卷 151-156页

作者： ming yang xin-Yu Wang Jie Wang Yu-Long Zhao Jilin Province Key Laboratory of Organic Functional Molecular Design&Synthesis Faculty of ChemistryNortheast Normal UniversityChangchunJilin 130024China

A photocatalytic[3+2]annulation of alkenes with vinyl azides was developed under irradiation by visible light in the presence of organic dye *** substrate scope and high functional group tolerance were demonstrated by more than 50 *** reaction provides a novel and efficient method for the synthesis of polyfunctionalized pyrroles under very mild metal-free conditions without other additives.

关键词： Photocatalysis Vinyl azides Alkenes Pyrroles Annulation Radical reactions

Synchronous occurrence of extramedullary plasmacytoma and squamous cell carcinoma in situ in the larynx: a case report

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 Journal of Cancer 2010年第12期29卷 1029-1034页

作者： Xiao-Li Zhang Dai-Qiang Li Jing-Jia Li Shi-Sheng Li xin-ming yang Department of Otolaryngology-Head and Neck Surgery the Second Xiangya Hospital Central South University Changsha Hunan 410011 P. R. China Department of Pathology the Second Xiangya Hospital Central South University Changsha Hunan 410011 P. R. China

Extramedullary plasmacytoma of the larynx is rare, especially when coexisted with squamous cell carcinoma in situ. We report a 56-year-old woman with hoarseness for 6 months and dysphonia for a week. Fiberoptic laryngoscopic examination showed a red, smooth-surface swelling in the submucous region of the left ventricle and ventricular band of the larynx. The patient underwent vertical laryngectomy and modified left neck dissection. Postoperative pathologic examination revealed coexisting plasmacytoma and carcinoma in situ. Bone marrow biopsy and systemic radiogram showed no positive findings. The hepatic and renal functions were normal. Monoclonal immunoglobulin light chain of type kappa was detected in urine. Hence, a laryngeal extramedullary plasmacytoma with carcinoma in situ was diagnosed. No recurrence or progression was observed during a 2-year follow-up. Here, we discussed the risk factors, diagnosis, and therapy for this rare disease.

关键词：鳞状细胞癌原位病例报告浆细胞同步病理检查免疫球蛋白危险因素

Neural Network-Based State Estimation for Nonlinear Systems With Denial-of-Service Attack Under Try-Once-Discard Protocol

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2182-2184页

作者： Xueli Wang Shangwei Zhao ming yang xin Wang Xiaoming Wu the Key Laboratory of Computing Power Network and Information Security Ministry of EducationShandong Computer Science CenterQilu University of Technology(Shandong Academy of Sciences)Jinan 250014 Shandong Provincial Key Laboratory of Computer Networks Shandong Fundamental Research Center for Computer ScienceJinan 250014China Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China

Dear Editor,This letter deals with state estimation issues of discrete-time nonlinear systems subject to denial-of-service(DoS)attacks under the try-once-discard(TOD)*** specifically,to reduce the communication burden,a TOD protocol with novel update rules on protocol weights is designed for scheduling measurement *** addition,unknown nonlinear functions vulnerable to DoS attacks are considered due to the openness and vulnerability of the network.

关键词： Service DoS service

Facile Synthesis of Polyisothioureas via Alternating Copolymerization of Aziridines and Isothiocayanates

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第3期42卷 292-298,I0005页

作者： Hao-Tian Zhang ming-xin Niu Qi Zhang Chen-yang Hu Xuan Pang Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Materials Science and Engineering Jilin UniversityChangchun 130025China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Isothiourea is an important class of sulfur-containing molecules showing unique catalytic and biological activities. As such,polyisothiourea is envisioned to be an interesting type of polymer that potentially exhibits a number of interesting properties. However, there is no access to synthesizing well-defined polyisothiourea, and currently isothiourea-containing polymers are mainly prepared by immobilizing onto other polymer's side chain. Herein, we report the first facile synthesis of polyisothioureas via alternating copolymerization of aziridines and isothiocayanates. Mediated by the catalytic system of phosphazene superbases/alcohol, a broad scope of aziridines and isothiocayanates could be transformed into polyisothioureas with adjustable substitutions(11 examples). The structures of obtained polyisothioureas were fully characterized with ^(1)H-NMR, ^(13)C-NMR, and ^(1)H-^(13)C HMBC NMR. Moreover, the polyisothioureas show tunable thermal properties depending on substitutions on the isothiourea linkages. The novel structure of these polyisothioureas will enable a powerful platform for the discovery of nextgeneration functional plastics.

关键词： Polyisothioureas Alternative copolymer Aziridines Isothiocayanates

Preparation of Chemically Recyclable Poly(ether-alt-ester) by the Ring Opening Polymerization of Cyclic Monomers Synthesized by Coupling Glycolide and Epoxides

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 168-175,I0006页

作者： Feng Ren Zhuang-Zhuang Liang ming-xin Niu Chen-yang Hu Xuan Pang Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China

Polyester and polyether are two key oxygenated polymers, and completely alternative sequence of poly(ester-alt-ether) could efficiently combine the advantages(including flexibility, degradability, etc.) of both segments. Currently, despite their copolymers could be synthesized from one-pot mixture of cyclic esters and epoxides, perfectly alternative microstructure is very challenging to realize and typically restricted to certain monomer pairs. Moving forward, synthesizing poly(ester-alt-ether) from commercially available and largescale monomers would be a significant advance. For example, successfully commercialized poly(glycolic acid)(PGA), which is not easily soluble in polymers due to its high crystallinity and is brittle and difficult to control the degradation cycle, would encounter a new paradigm if engineered into poly(ester-altether). In this work, starting from the design of monomer with hybrid structures, we successfully synthesized a series of 1,4-dioxan-2-one containing different substituents based on glycolide(GA) and epoxides using commercially available Salen-Cr(III) and PPNCl catalytic *** new monomers underwent ring-opening polymerization(ROP) to form a series of poly(ester-alt-ether) with perfectly alternating glycolic acid and propylene glycol repeat units under catalytic system of thiourea/base. The poly(ester-alt-ether) have significantly lower glass-transition temperature than PGA. Additionally, the poly(ester-alt-ether) can be chemically recovered to monomer using Sn(Oct)2 or 1,8-diazabicyclo[5.4.0]undecane-7-ene(DBU) as a catalyst in solution, thus establishing a closed-loop life cycle. From monomers derived from GA and epoxides, this work furnishes a novel strategy for the synthesis of poly(ester-alt-ether) with chemical recyclability.

关键词： Polyester Polyether Alternative copolymer Ring-opening polymerization

Polyoxometalates-derived ternary metal oxides electrocatalyst for N_(2) reduction under ambient conditions

在线全文

学校读者我要写书评

暂无评论

Tungsten 2024年第2期6卷 428-437页

作者： Meng-Le yang Zhong-xin Jin Xi-Xian Cao xin-ming Wang Hui-Yuan Ma Hai-Jun Pang Gui-xin yang The School of Material Science and Chemical Engineering Harbin University of Science and TechnologyHarbin 150040China

Accelerating the breaking of the nitrogen nonpolar bond(N≡N)is an important factor to improve the effi ciency of the electro-catalytic nitrogen reduction reaction(e-NRR).In this work,polyoxometalates-derived FeMo-based ternary oxide materials MoO_(2)-Mo_(4)O_(11)-FeMoO_(4)@X(abbreviated as MoFeO@X,X represents the synthesis temperature of 650,750 and 850℃)were designed and synthesized for e-NRR under ambient *** scanning electron microscopy images of MoFeO@750 show an ellipsoidal-like structure(0.86×0.6μm).The relatively large specifi c surface area,formation of multiple interfaces,together with the synergistic eff ect of iron and molybdenum bimetals,would make MoFeO@X catalyst more easily absorb and activate N_(2)in the ***,the synthesized MoFeO@750 shows an optimal NH_(3)production rate of 16.57μg·h^(−1)·mg cat.^(−1)and Faradaic effi ciency of 12.33%at−0.3 V versus reversible hydrogen electrode(ν***),with outstanding electrochemical and structural stability.

关键词： Polyoxometalates Electrocatalytic nitrogen reduction reaction Ternary oxide Electrocatalyst

Combinatorial reasoning-based abnormal sensor recognition method for subsea production control system

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2758-2768页

作者： Rui Zhang Bao-Ping Cai Chao yang Yu-ming Zhou Yong-Hong Liu xin-yang Qi College of Mechanical and Electronic Engineering China University of Petroleum BGP Inc. China National Petroleum Corporation

The subsea production system is a vital equipment for offshore oil and gas production. The control system is one of the most important parts of it. Collecting and processing the signals of subsea sensors is the only way to judge whether the subsea production control system is normal. However, subsea sensors degrade rapidly due to harsh working environments and long service time. This leads to frequent false alarm incidents. A combinatorial reasoning-based abnormal sensor recognition method for subsea production control system is proposed. A combinatorial algorithm is proposed to group sensors. The long short-term memory network(LSTM) is used to establish a single inference model. A counting-based judging method is proposed to identify abnormal sensors. Field data from an offshore platform in the South China Sea is used to demonstrate the effect of the proposed method. The results show that the proposed method can identify the abnormal sensors effectively.

关键词： Abnormal sensor Combinatorial algorithm Fault identification Subsea production control system