检索结果-南通市图书馆

New insights into hydraulic fracturing fluids used for hightemperature wells

Petroleum 2021年第1期7卷 70-79页

作者： Tariq Almubarak Leiming Li jun hong ng Hisham Nasr-El-Din Mohammed AlKhaldi Texas A&M University USA Aramco Services Company Saudi Arabia Saudi Aramco EXPEC ARC Saudi Arabia

Current interest in deep,low-permeability formations(<10 md)demands accelerated development of high-temperature hydraulic fracturing *** guar systems break down above 300°F and require higher polymer loadings to main... 详细信息

Current interest in deep,low-permeability formations(ng *** guar systems break down above 300°F and require higher polymer loadings to maintain thermal ***,higher polymer loadings generate more residue and damage to the proppant pack and the *** resolve these problems,a variety of high-temperature stabilizers are added to enhance the thermal stability of these fracturing fluids at temperatures above 300*** focus of this work is to:(1)identify those additives that best enhance temperature stability of fracturing fluids and(2)study the rheological influence of incorporating these additives on the fracturing fluid *** experimental fracturing-fluid solutions were prepared at a total polymer concentration of 30 and 40 lb/1000 *** such as synthetic polymer,oxygen scavengers,crosslinkers,crosslinker delay additives,and pH buffers were examined in this *** polymer solutions were crosslinked with a metallic crosslinker between 200 and 400°*** measurements were carried out in a highpressure/high-temperature(HP/HT)rheometer to evaluate rheology and thermal *** show that adding a synthetic polymer and a crosslinker with the slowest reaction rate improves the fracturing fluid thermal *** the three other additives tested,oxygen scavengers showed the greatest enhancement to thermal stability while pH buffers showed the *** the addition of high-temperature stabilizing additives,the fracturing fluid in this work was able to maintain a stable performance at temperatures up to 400°*** the thermal stability of fracturing fluids at a lower polymer loading remains a challenge in the *** work proposes techniques that can be used to enhance the thermal stability of fracturing *** knowledge about these different techniques will allow for better additive development and a

关键词： Oxygen scavenger Crosslinker Crosslinker delay Shear tolerance High temperature Synthetic polymer CMHPG Buffers

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evapotranspiration and its components partitioning based on an improved hydrological model: historical attributions and future projections

引用

Journal of Earth Science 2025年

作者： hong Du Sidong Zeng Yongyue Ji jun Xia College of Resources and Environmental Science， South-Central Minzu University Chongqing Institute of Green and Intelligent Technology， Chinese Academy of Sciences Chongqing School， University of Chinese Academy of Sciences State Key Laboratory of Water Resources and Hydropower Engineering Science， Wuhan University

Estimation and attribution of evapotranspiration （ET） and its components under changing environment is still a challenge but is essential for understanding the mechanisms of water and energy transfer subsequently regional water resources management. In this study， an improved hydrological model is developed to estimate evapotranspiration and its components i.e.， evaporation （E） and transpiration （T） by integrated the advantages of hydrological modeling constrained by water balance and the water-carbon close relationships. Results show that the improved hydrological model could captures ET and its components well in the study region. During the past years， annual ET and E increase obviously about 2.40mm/a and 1.42mm/a， particularly in spring and summer accounting for 90%. T shows less increasement and mainly increases in spring while it decreases in summer. Precipitation is the dominant factor and contributes 74.1% and 90.0% increases of annual ET and E， while the attribution of T changes is more complex by coupling of the positive effects of precipitation， rising temperature and interactive influences， the negative effects of solar diming and elevated CO2. In the future， ET and its components tend to increase under most of the Shared Socioeconomic Pathways （SSP） scenarios except for T decreases under the very high emissions scenario （SSP5-8.5） based on the projections. From seasonal perspective， the changes of ET and the components are mainly in spring and summer accounting for 75%， while more slightly changes are found in autumn and winter. This study highlights the effectiveness of estimating ET and its components by improving hydrological model within water-carbon coupling relationships， and more complex mechanisms of transpiration changes than evapotranspiration and evaporation changes under the interactive effects of climate variability and vegetation dynamics. Besides， decision makers should pay attention to the more increases in the undesirable E than desirab

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Thickness and sp3 bond modulation of（Ti/tetrahedral amorphous carbon）_n multilayer coatings

引用

Tungsten 2025年第1期7卷 152-160页

作者： Zhi-jun Xie Jia-Lin Li Ling Gong Xiang-Li Zhong hong-Jia Song Jin-Bin Wang National-Provincial Laboratory of Special Function Thin Film Materials School of Materials Science and Engineering Xiangtan University

The durability of wear-resistant tetrahedral amorphous carbon（ta-C） coatings is intimately linked to their thickness and the concentration of *** enhance the lifespan of the coatings,we have prepared a multilayer coating consisting of alternating layers of Ti and ta-C,denoted as（Ti/ta-C）_n,using arc ion plating.A multi-layer structure in conjunction with stage cooling is employed to enhance the thickness and promote *** results indicate that the ID/IGvalue,representing the ratio of the intensity of the D peak to that of the G peak in Raman spectroscopy,decreases from 0.85 when no stage cooling is applied to 0.35 when stage cooling is employed,suggesting an enhancement in the fraction of sp3bonds within the *** obtained（Ti/ta-C）_n multilayer coating without peeling off has a maximum thickness of 1.14 μm,which is almost double that of the ta-C coating single layer *** the same time,the coating has a low coefficient of friction,down to 0.069,and maintains excellent friction properties with a wear rate of 3.4×10-6mm3·N-1·*** results conclusively show that the preparation technology can enhance both thickness and sp3bonding in ta-C coatings,significantly expanding their utility across tools,molds,and precision engineering components.

关键词： Arc ion plating Multilayer structure sp3 bond Ta-C coating Wear resistance

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Stable copper boron–imidazolate cage as Cu-riched enzyme for highly efficient electrocatalytic CO2 reduction to ethylene

引用

Science China Chemistry 2025年

作者： jun-Qiang Chen Qiao-hong Li Qin-Long hong Ping Shao Hai-Xia Zhang Jian Zhang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Single-atom catalyst has garnered widespread attention to mimic mature enzymes due to its well-defined atomic structure and coordination environments. However, since the carbon–carbon（C–C） coupling reactions require synergistic catalysis of multiple sites, single-atom catalysts suffer from insufficient active sites and unclear reaction mechanisms. Controlling the reaction intermediates in a precisely targeted pocket through careful metal–organic cage design is therefore crucial. Here, we prepare a tetrahedral [Cu6L4]-type boron–imidazolate cage integrating highly active Cu sites and optimized cavity, which exhibits enzyme like specific catalytic performance in electrochemical CO2reduction reaction（CO2RR） to enhance the selectivity of *** analyses and computational calculations suggest that the single Cu site together with neighboring boron–imidazolate ligands provides suitably synergistic effects that enable the energetically favorable formation of an *COCHO intermediate, a key step determining selectivity. As a result, the [Cu6L4]-type cage of BIC-145 achieves a Faradaic efficiency of 28% for C2H4maintaining an average current density of -3.54 mA cm-2over a 5-hour electrolysis period. This work represents the first example for studying single-metal site catalysts with ultra-low coordination numbers through the rational design of metal–organic cages.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Discovery of a new family member of arsenic–vanadium polyoxometalates with high catalytic performance for one-pot coupling of CO2, epoxides and amines

引用

Tungsten 2025年第1期7卷 80-87页

作者： Fang-Qian Wang Yin Zhang Wei-Wei Wang Mei-Qian Fu hong-Bing Mo Wei-Dong Yu Chao Liu jun Yan College of Chemistry and Chemical Engineering Central South University junior Education Department Changsha Normal University School of Science Hunan University of Technology and Business

Arsenic-vanadium polyoxometalates（POMs） represent a family of tremendous potential catalysts owing to their peculiar physical and chemical *** in CO2conversion,using POMs to catalyze the conversion of CO2and epoxide into chemical intermediates is the research ***,A new family number of arsenic-vanadium POMs,[N（CH3）4]4[As8V12O38（H2O）]·2H2O({As8V12O38}),was reported and characterized by single-crystal X-ray diffraction,fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,*** from other allotropicity,{As8V12O38}shows a different structure pattern with an I-43d *** obtained {As8V12O38} was employed as a catalyst for the *** initial catalytic reaction confirmed that {As8V12O38} can catalyze the formation of epoxy carbonate by using 1.01 kPa CO2and epoxide at 70℃.Furtherly,when added amine in the catalytic system,oxazolidinone could be obtained by high yields,which provides an efficient way to convert CO2into profitable ***,a possible catalytic reaction mechanism was proposed by using different characterization analyses.{As8V12O38} first catalyzes the epoxide and CO2to form an epoxy carbonate and then catalyzes epoxy carbonate and benzylamine into oxazolidinone.

关键词： Arsenic CO2 conversion Oxazolidinone Polyoxometalates Vanadium

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

引用

Science China Chemistry 2025年第1期68卷 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-Cheng Tang Ding-Kang Chen Ming-Ming Cao Yao-Wen Chang hong-Yu Tang Chun-Mao Yuan jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词： metabolon Diels-Alder reaction semipinacol rearrangement biosynthesis notoamides spiro polycyclic alkaloids

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Enhanced Microwave Absorption Properties of Double-Layer Absorbers Based on Spherical NiO and Co_(0.2)Ni_(0.4)Zn_(0.4)Fe_2O_4 Ferrite Composites

引用

Acta Metallurgica Sinica(English Letters) 2018年第2期31卷 171-179页

作者： Pei-Jiang Liu Zheng-jun Yao Vincent Ming hong ng Jin-Tang Zhou Zhi-hong Yang Ling-Bing Kong College of Materials and Technology Nanjing University of Aeronautics and Astronautics Nanjing 211100 China Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing 211100 China School of Materials Science and Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore

Microwave absorption properties of spherical NiO particles and Co0.2Ni0.4Zn0.4Fe2O4（CNZF） ferrites with single-layer and double-layer absorbers were studied in the frequency range of 2–18 GHz. The spherical NiO particles were synthesized by using a hydrothermal process, while the CNZF powders were prepared by using a sol–gel autoignition method. The double-layer absorbers, composed of 30 wt% NiO as matching layer and 30 wt% CNZF as absorption layer,with a total thickness of 3.2 mm, exhibited a maximum reflection loss（RL） of –67.0 d B at 9.2 GHz and an effective absorbing bandwidth below –10 d B to be 3.9 GHz from 7.0 to 10.9 GHz. The excellent microwave absorption performance of the double-layer absorbers should be ascribed to the high impedance matching ratio, the great microwave attenuation capability, and well-coupled layer.

关键词： Hierarchical NiO particle Ferrite Impedance matching Microwave absorption property

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deciphering the molecular mechanisms of Simiaowan in the treatment of hyperuricemia: in vivo and in silico approaches

引用

Traditional Medicine Research 2025年第2期10卷 37-54页

作者： Yong-Chang Zeng jun-hong Wu Dan-Dan Xu Kang He Chang-Qing Liu Li-Fei Song Zheng-Zhi Wu Qian-Qian Jiang Shao-Yu Liang Department of Neurology The First Affiliated Hospital of Shenzhen UniversityShenzhen 518020China Pharmaceutical Department The Affiliated TCM Hospital of Guangzhou Medical UniversityGuangzhou 510000China School of Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China Guangzhou Zeli Medical Technology Co. Ltd.Guangzhou 510700China

Background:Simiaowan(SMW),a well-known traditional Chinese medicine,has been employed to treat hyperuricemia(HUA)and gout for ***,the bioactive components and underlying mechanisms have not been *** objective of this study was to identify the active components and potential mechanisms of SMW by integrating pharmacological experimentation,serum pharmacochemistry,network pharmacology and molecular ***:HUA rats modelling by high-fat/high-sugar diet and potassium oxonate/adenine oral administration were used to evaluate the pharmacodynamic effects of ***-Q-Exactive-MS/MS was employed to detect the bioactive components present in SMW-containing *** pharmacology and molecular docking were utilized to elucidate the potential targets and underlying ***:SMW effectively ameliorated HUA rats via the inhibition of uric acid(UA)production,promotion of UA excretion,improvement of lipid and glucose metabolic abnormalities,antioxidant,anti-inflammatory and anti-insulin resistance effects.A total of 73 compounds detected in SMW-containing serum were identified as potential active components,with alkaloids,flavonoids,organic acids,and terpenoids emerging as the primary active *** 203 corresponding targets were obtained as SMW anti-HUA/gout targets,which mainly participated in apoptosis,insulin resistance,TNF,PI3K-Akt,HIF-1,NF-κB,MAPK,IL-17 and TLR signaling *** docking indicated that active compounds(***,phellodendrine,quercetin,formononetin,ferulic acid)had superior binding abilities to the key targets(*** carrier family 22 member 12(URAT1),solute carrier family 22 member 6(OAT1),ATP-binding cassette sub-family G member 2(ABCG2),solute carrier family 2,facilitated glucose transporter member 9(GLUT9),xanthine dehydrogenase/oxidase(XDH),transcription factor p65(RELA),toll-like receptor 4(TLR4),prostaglandin G/H synthase 2(PTGS2),caspase-3(CASP3),insulin(INS)).Conclusion:S

关键词： hyperuricemia network pharmacology serum pharmacochemistry Simiaowan UPLC-Q-Exactive-MS/MS

来源：

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

Gut microbiota in cancer initiation,development and therapy

引用

Science China Life Sciences 2025年

作者： Ruyi Zhang Xiang Zhang Harry Cheuk Hay Lau jun Yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesCUHK Shenzhen Research InstituteThe Chinese University of Hong Kong

Cancer has long been associated with genetic and environmental factors,but recent studies reveal the important role of gut microbiota in its initiation and *** 13%of cancers are linked to infectious agents,highlighting the need to identify the specific microorganisms *** microbiota can either promote or inhibit cancer growth by influencing oncogenic signaling pathways and altering immune *** can lead to cancer,while certain probiotics and their metabolites may help reestablish microecological balance and improve anti-tumor immune *** into targeted approaches that enhance therapy with probiotics is ***,the effects of probiotics in humans are complex and not yet fully ***,methods to counteract harmful bacteria are still in *** clinical trials also indicate that modifying gut microbiota may help manage side effects of cancer *** research is crucial to understand better how gut microbiota can be used to improve cancer prevention and treatment outcomes.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Hydrogen generation from ammonia electrolysis on bifunctional platinum nanocubes electrocatalysts

引用

Journal of Energy Chemistry 2020年第8期29卷 234-240,I0009页

作者： Hui-Ying Sun Guang-Rui Xu Fu-Min Li Qi ng-Li ng hong Pu-jun Jin Pei Chen Yu Chen Key Laboratory of Macromolecular Science of Shaanxi Province Key Laboratory of Applied Surface and Colloid Chemistry(Ministry of Education)Shaanxi Key Laboratory for Advanced Energy DevicesSchool of Materials Science and EngineeringShaanxi Normal UniversityXi'an 710062ShaanxiChina School of Chemistry and Chemical Engineering Shaanxi Normal UniversityXi'an 710062ShaanxiChina

The ammonia electrolysis is a highly efficient and energy-saving method for ultra-pure hydrogen generation, which highly relies on electrocatalytic performance of electrocatalysts. In this work, high-quality platinum(Pt) nanocubes(Pt-NCs) with 4.5 nm size are achieved by facile hydrothermal synthesis. The physical morphology and structure of Pt-NCs are exhaustively characterized, revealing that Pt-NCs with special {100} facets have excellent uniformity, good dispersity and high crystallinity. Meanwhile, the electrocatalytic performance of Pt-NCs for ammonia electrolysis are carefully investigated in alkaline solutions, which display outstanding electroactivity and stability for both ammonia electrooxidation reaction(AEOR) and hydrogen evolution reaction(HER) in KOH solution. Furthermore, a symmetric Pt-NCs||Pt-NCs ammonia electrolyzer based on bifunctional Pt-NCs electrocatalyst is constructed, which only requires 0.68 V electrolysis voltage for hydrogen generation. Additionally, the symmetric Pt-NCs||Pt-NCs ammonia electrolyzer has excellent reversible switch capability for AEOR at anode and HER at cathode, showing outstanding alternating operation ability for ammonia electrolysis.

关键词： Ammonia electrolysis Water electrolysis Ammonia oxidation reaction Hydrogen evolution reaction Platinum nanocubes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：