检索结果-南通市图书馆

Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids

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 551-566页

作者： Li-Li Yang Ze-yu Liu Shi-bo Wang Xian-bo he Guan-Cheng Jiang Jie Zhang MOE Key Laboratory of Petroleum Engineering State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum(Beijing)Changping DistrictBeijing102249China MOE Key CNPC Drilling Research Institute Changping DistrictBeijing102206China

With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to reservoir damage and wellbore *** this paper,micronized barite(MB)was modified(mMB)by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite *** suspension stability of water-based drilling fluids(WBDFs)weighted with API barite:mMB=2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs,exhibiting the static sag factor within 0.54 and the whole stability index of *** viscosity and yield point reached the minimum,with a reduction of more than 40%compared with API barite only at the same *** multi-stage filling and dense accumulation of weighting materials and clays,filtration loss was decreased,mud cake quality was improved,and simultaneously it had great reservoir protection performance,and the permeability recovery rate reached 87%.In addition,it also effectively improved the lubricity of *** sticking coefficient of mud cake was reduced by 53.4%,and the friction coefficient was ***,mMB can serve as a versatile additive to control the density,rheology,filtration,and stability of WBDFs weighted with API barite,thus regulating comprehensive performance and achieving reservoir protection *** work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs.

关键词： Drilling fluids Weighting materials Filtration control Reservoir protection Stability property

Sequence-Controlled Synthesis of Alternating Poly(ester amide)s using Water as Control Agent in One-Pot

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8期42卷 1015-1020页

作者： Tao Liu Fang-Fang Niu Kan Cheng yu-Min Xia bo-Mou Ma Xue-Li Wang Jian-Yong yu and Yong he State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Innovation Center for Textile Science and Technology Donghua UniversityShanghai 201620China

Poly(ester amide)s(PEAs)attract much attention as a new kind of biodegradable ***,the synthesis of PEAs with sequence-regulated chain structures is still complicated due to the multistep polymerization,high monomer purity,as well as the usage of organic solvents,which greatly inhibits its development and ***,a one-pot strategy without solvent was developed to synthesize the alternating PEA fromα,ω-amino alcohol and dicarboxylic acid by sequential polycondensation,where water was used as the controlling agent for amidation and ***,the amidation and esterification were controlled to proceed in turn by adding or removing water,realizing the one-pot preparation of alternating *** resultant PEA is characterized by^1H-and^(13)C-NMR,and its chain structure is confirmed to be highly quasi-alternating similar to alternating PEAs prepared by classical methods The evaluations from DSC and DMA demonstrate that the properties of quasi-alternating PEA(T_(m)=102℃,ΔH_(m)=30J·g^(-1))are far superior to those of random PEA(T_(m)=72℃,ΔH_(m)<1 J·g^(-1)).

关键词： Biodegradable macromolecules Polymer architectures Sequence-controlled synthesis One-pot polymerization

Insight into structural degradation of NCMs under extreme fast charging process

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

Rare Metals 2024年第1期43卷 41-50页

作者： yu Tang Xing-yu Wang Jin-Can Ren bo-Wen Chen Zhi-Yong Huang Wei Wang Ya-Lan Huang Bing-Hao Zhang Si Lan Zhang-Long he Qi Liu Hao he Department of Physics City University of Hong KongHong Kong 999077China Shenzhen Research Institute City University of Hong KongShenzhen 518057China College of Materials Science and Engineering Changsha University of Science&TechnologyChangsha 410114China

Lithium-ion batteries(LIBs)with extreme fast charging(XFC)capability are considered an effective way to alleviate range anxiety for electric vehicle(EV)*** to the high ionic and electronic conductivity of LiNi_(x)Co_(y)Mn_zO_(2)(x+y+z=1,NCM)cathodes,the inevitable Li plating of graphite in NCM|graphite cell is usually identified as a key bottleneck for XFC ***,the capacity decay mechanism of cathode materials under XFC has not been fully *** this work,three typical NCM cathode materials with different Ni fractions were chosen and their electrochemical performances under XFC associated with structural evolution were investigated.A faster capacity decay of NCMs under XFC conditions is observed,especially for Ni-rich ***-situ X-ray diffraction(XRD)reveals that the multiple caxis parameters appear at the high-voltage regions in Nirich NCMs,which is probably triggered by the larger obstruction of Li(de)***,NCMs with moderate Ni fraction also present a similar trend under XFC *** phenomenon is more detrimental to the structural and morphological stability,resulting in a faster capacity decay than that under low current *** work provides new insight into the degradation mechanism of NCMs under XFC conditions,which can promote the development of NCM cathode materials with XFC capability.

关键词： Lithium-ion batteries Ni fraction Extreme fast charging Structural evolution

Black hole evaporation and its remnants with the generalized uncertainty principle including a linear term

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第2期76卷 125-136页

作者： bo yu Zheng-wen Long College of Physics Guizhou UniversityGuiyang550025China

In recent years,researchers have investigated the evaporation of Schwarzschild black holes using various forms of the generalized uncertainty principle(GUP),metric quantum correction,and noncommutative geometry,***,there are differences between the GUP correction and the other two methods in terms of describing the later stages of black hole ***,some studies argue that the GUP with a negative parameter cannot effectively correct black hole evaporation,while others contend that the positivity or negativity of the GUP parameters should not affect the correction *** the above into consideration,we reconsider black hole evaporation with the generalized uncertainty principle including a linear term(LGUP),and examine the case of negative *** results indicate that the evaporation behavior of both Schwarzschild black holes and Reissner–Nordstr?m black holes,under LGUP correction,is consistent with the results of metric quantum correction and non-commutative ***,the negative parameter LGUP can also effectively correct for black hole evaporation.

关键词： black hole evaporation generalized uncertainty principle negative parameter

Demonstration of high-dimensional controlled quantum teleportation for the first time

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 163-164页

作者： yu-bo Sheng Lan Zhou College of Electronic and Optical Engineering and College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China

Controlled quantum teleportation(CQT) [1] is the tripartite version of quantum teleportation and it allows the teleportation of an unknown quantum state under the control of a third party. Compared with low-dimensional counterparts,high-dimensional CQT can exhibit larger information transmission capacity and a higher control power [2,3].

关键词： quantum dimensional high

Corrugated Graphene Paper Reinforced Silicone Resin Composite for Efficient Interface Thermal Management

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7期42卷 1002-1014,I0010页

作者： bo-Wen Wang heng Zhang Qing-Xia he Hui-Tao yu Meng-Meng Qin Wei Feng Tianjin Key Laboratory of Composite and Functional Materials School of Materials Science and EngineeringTianjin UniversityTianjin300350China International Engineering Institute Tianjin UniversityTianjin300350China

With the rapid development of high-power-density electronic devices,interface thermal resistance has become a critical barrier for effective heat management in high-performance electronic ***,there is an urgent demand for advanced thermal interface materials(TIMs)with high cross-plane thermal conductivity and excellent compressibility to withstand increasingly complex operating *** achieve this aim,a promising strategy involves vertically arranging highly thermoconductive graphene on ***,with the currently available methods,achieving a balance between low interfacial thermal resistance,bidirectional high thermal conductivity,and large-scale production is ***,we prepared a graphene framework with continuous filler structures in in-plane and cross-plane directions by bonding corrugated graphene to planar graphene *** interface interaction between the graphene paper framework and polymer matrix was enhanced via surface functionalization to reduce the interface thermal *** resulting three-dimensional thermal framework endows the polymer composite material with a cross-plane thermal conductivity of 14.4 W·m^(-1)·K^(-1)and in-plane thermal conductivity of 130W·m^(-1)·K^(-1)when the thermal filler loading is 10.1 wt%,with a thermal conductivity enhancement per 1 wt%filler loading of 831%,outperforming various graphene structures as *** its high thermal conductivity,low contact thermal resistance,and low compressive modulus,the developed highly thermoconductive composite material demonstrates superior performance in TIM testing compared with TFLEX-700,an advanced commercial TIM,effectively solving the interfacial heat transfer issues in electronic *** novel filler structure framework also provides a solution for achieving a balance between efficient thermal management and ease of processing.

关键词： Graphene paper Vertically aligned structure Cross-plane thermal conductivity Low compressive modulus Thermal interface material

Microstructural evolution,mechanical properties and degradation mechanism of PS-PVD quasi-columnar thermal barrier coatings exposed to glassy CMAS deposits

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 3329-3340页

作者： Zi-yue yu Liang-Liang Wei Xing-Ye Guo Bao-Peng Zhang Qing he Hong-bo Guo School of Materials Science and Engineering Beihang University Key Laboratory of High-Temperature Structure Materials and Protective Coatings (Ministry of Industry and Information Technology) Beihang University Surface Engineering Research Institute Chinese Academy of Agricultural Mechanization Sciences

Thermal barrier coatings（TBCs） applied in aeroengines tend to be attacked by molten calcia-magnesiaalumino-silicate（CMAS） at high operating ***-stabilized zirconia（YSZ） coatings with quasicolumnar microstructure were fabricated by plasma spray physical vapor deposition（PS-PVD） *** chemic al changes,micros tructural transform ation,mechanical properties and degradation mechanisms of the CM AS-interacted TBCs in the thermal cycling tests were *** YSZ grains were dissolved in the CMAS melts,and then the ZrO2grains were reprecipitated with spherical shape,accompanying with phase transformation from tetragonal（t） to monoclinic（m）.The thermal cycling tests reveal that the YSZ coating fails at the early stage due to the attack of *** fractures in intracolumns lead to partial spallation of the *** failure of the coating occurs at the interfaces between thermally grown oxides（TGO） layer and YSZ topcoat;especially,the hardness and Young's modulus of the YSZ coatings increase intensively,as the coatings were infiltrated by the CMAS for a long time.

关键词： CMAS Thermal barrier coatings Young’s modulus Thermal cycling behavior PS-PVD

Risk factors for lymph node metastasis in superficial esophageal squamous cell carcinoma

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第13期30卷 1810-1814页

作者： Yan-bo yu Department of Gastroenterology Laboratory of Translational GastroenterologyQilu HospitalShandong UniversityJinan 250012Shandong ProvinceChina

In this editorial,we comment on the article by Wang et al published in the recent issue of the World Journal of Gastroenterology in *** focused on identifying risk factors for lymph node metastasis(LNM)in superficial esophageal squamous cell carcinoma(SESCC)patients and how to construct a simple and reliable clinical prediction model to assess the risk of LNM in SESCC patients,thereby helping to guide the selection of an appropriate treatment *** current standard treatment for SESCC is radical esophagectomy with lymph node ***,esophagectomy is associated with considerable morbidity and *** resection(ER)offers a safer and less invasive alternative to surgical resection and can enable the patient's quality of life to be maintained while providing a satisfactory ***,since ER is a localized treatment that does not allow for lymph node dissection,the risk of LNM in SESCC limits the effectiveness of *** LNM status can aid in determining whether patients with SESCC can be cured by ER without the need for additional *** studies have shown that tumor size,macroscopic type of tumor,degree of differentiation,depth of tumor invasion,and lymphovascular invasion are factors associated with LNM in patients with *** addition,tumor budding is commonly associated with LNM,recurrence,and distant metastasis,but this topic has been less covered in previous *** comprehensively evaluating the above risk factors for LNM,useful evidence can be obtained for doctors to select appropriate treatments for SESCC patients.

关键词： Superficial esophageal squamous cell carcinoma Endoscopic resection Lymph node metastasis Risk factors Tumor budding Predictive model

Mean field game of optimal relative investment with jump risk

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

Science China Mathematics 2024年第5期67卷 1159-1188页

作者： Lijun bo Shihua Wang Xiang yu School of Mathematics and Statistics Xidian UniversityXi'an 710126China School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong KongChina

In this paper,we study the n-player game and the mean field game under the constant relative risk aversion relative performance on terminal wealth,in which the interaction occurs by peer *** the model with n agents,the price dynamics of underlying risky assets depend on a common noise and contagious jump risk modeled by a multi-dimensional nonlinear Hawkes *** a continuum of agents,we formulate the mean field game problem and characterize a deterministic mean field equilibrium in an analytical form under some conditions,allowing us to investigate some impacts of model parameters in the limiting model and discuss some financial ***,based on the mean field equilibrium,we construct an approximate Nash equilibrium for the n-player game when n is sufficiently *** explicit order of the approximation error is also derived.

关键词： relative performance contagious jump risk mean field game with jumps mean field equilibrium approximate Nash equilibrium

同方期刊数据库