检索结果-南通市图书馆

水压-氯盐侵蚀耦合作用下膏体充填材料力学性能实验研究

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2024年第5期31卷 1574-1591页

作者：李宗蓄尹大伟柳慧敏谭毅李学龙 State Key Laboratory of Mine Disaster Prevention and Control Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China Henan Key Laboratory for Green and Efficient Mining&Comprehensive Utilization of Mineral Resources Henan Polytechnic UniversityJiaozuo 454000China

在膏体充填开采中,煤矸石-粉煤灰胶结充填材料(CGFB)可有效控制地表沉降。CGFB在被注入采空区后会受到水压影响和氯离子侵蚀。因此,研究水压和氯离子侵蚀对CGFB性能的影响对于实现有效的绿色开采至关重要。将CGFB试样在0、0.5、1.5或3.0... 详细信息

在膏体充填开采中,煤矸石-粉煤灰胶结充填材料(CGFB)可有效控制地表沉降。CGFB在被注入采空区后会受到水压影响和氯离子侵蚀。因此,研究水压和氯离子侵蚀对CGFB性能的影响对于实现有效的绿色开采至关重要。将CGFB试样在0、0.5、1.5或3.0 MPa的氯化钠溶液中浸泡15天,通过单轴压缩试验、声发射信号监测、数字散斑应变测量、扫描电子显微镜和X射线衍射研究了试样的力学性能和劣化机理。结果表明,随着浸泡压力的增加,试样单轴抗压强度先增大后减小。当浸泡压力从0 MPa增加到1.5 MPa时,平均单轴抗压强度增加了43.5%。当浸泡压力从1.5 MPa增加到3.0 MPa时,平均单轴抗压强度下降18.9%。此外,水压会促进氯离子进入CGFB内部并产生弗里德尔盐。较高的水压-氯盐耦合作用增加了CGFB的孔隙率,与0 MPa样品相比,3.0 MPa样品的孔隙率增加8.2%。高水压作用下,膏体充填体内部孔隙裂纹发育贯通,力学性能劣化,其密实度与抗压强度下降。

关键词：水压氯盐侵蚀煤矸石-粉煤灰充填变形局部化带声发射信号细观形貌

AE waveform characteristics of rock mass under uniaxial loading based on Hilbert-Huang transform

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2021年第6期28卷 1843-1856页

作者： li xue-long CHEN Shao-jie liU Shu-min li Zhong-hui Mine Disaster Prevention and Control-Ministry of State Key Laboratory Breeding Base Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Coal Mine Disaster Dynamics and Control College of Resource and Safety EngineeringChongqing UniversityChongqing 400030China

Acoustic Emission(AE)waveforms contain information on microscopic structural features that can be related with damage of coal rock *** this paper,the Hilbert-Huang transform(HHT)method is used to obtain detailed structural characteristics of coal rock masses associated with damage,at different loading stages,from the analyses of the characteristics of AE *** results show that the HHT method can be used to decompose the target waveform into multiple intrinsic mode function(IMF)components,with the energy mainly concentrated in the c1−c4 IMF components,where the c1 component has the highest frequency and the largest amount of *** the loading continues,the proportion of energy occupied by the low-frequency IMF component shows an increasing *** the initial compaction stage,the Hilbert marginal spectrum is mainly concentrated in the low frequency range of 0−40 *** plastic deformation stage is associated to energy accumulation in the frequency range of 0−25 kHz and 200−350 kHz,while the instability damage stage is mainly concentrated in the frequency range of 0−25 *** 20 kHz,the instability damage reaches its maximum *** is a relatively clear instantaneous energy peak at each stage,albeit being more distinct at the beginning and at the end of the compaction *** the effective duration of the waveform is short,its resulting energy is small,and so there is a relatively high value from the instantaneous energy *** waveform lasts a relatively long time after the peak that coincides with failure,which is the period where the waveform reaches its maximum energy *** Hilbert three-dimensional energy spectrum is generally zero in the region where the real energy is *** addition,its energy spectrum is intermittent rather than *** is therefore consistent with the characteristics of the several dynamic ranges mentioned above,and it indicates more clearly the low-frequency energy concentration in the critical sta

关键词： acoustic emission waveform Hilbert-Huang transform coal rock

lignin-reinforced PVDF electrolyte for dendrite-free quasi-solid-state li metal battery

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1006-1016页

作者： Xin-Yang Chen xue-Jie Gao Han-Yan Wu Yu-long liu Xiao-Fei Yang Run-Cang Sun Center for lignocellulosic Chemistry and Biomaterials College of Light Industry and Chemical EngineeringDalian Polytechnic UniversityDalian116034China Division of Energy Storage Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China School of Chemistry Northeast Normal UniversityChangchun130024China

Quasi-solid-state lithium metal batteries(QSSLMBs)assembled with polyvinylidene fluoride(PVDF)are a promising class of next-generation rechargeable batteries due to their safety,high energy density,and superior interfacial ***,PVDF has a series of inherent drawbacks such as low ionic conductivity,ease of crystallization,and hydrophobic character that leading to poor cell *** tackle these issues,a lignin-reinforced PVDF electrolyte is proposed in this work to solve these drawbacks of PVDF and enhance the comprehensive performance of *** lithophilic polar groups of lignin can promote uniform deposition of li on the *** with the improved mechanical properties can efficiently prevent li dendrites penetration through the *** addition,more active sites provided by lignin can also enhance li^(+)transport and lead to a faster electrochemical reaction *** from the ingenious design,li symmetric cells with 5%lignin-PVDF quasi-solid-state electrolyte can operate for 900 h at a high current density/capacity of 5 mA·cm^(-2)/5 mAh·cm^(-2),while shortcircuiting occurs after 56 h for the counterpart(pure PVDF).Moreover,a full cell of li/5%lignin-PVDF/LFP cell demonstrates a high capacity of 96.2 mAh·g^(-1)after 2000 cycles at 10 *** work is expected to open up promising opportunities to develop other high-energy/power-density QSSLMBs.

关键词： Quasi-solid-state electrolyte lignin PVDF Dendrite-free li metal battery

Ni-Catalyzed Enantioselective Difunctionalization of Alkynes to Azepine Derivatives Bearing a Quaternary Center and an Unprotected Imine

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第8期42卷 873-878页

作者： Jian long Zhiwu Lu Xiao-lin li Peng xue Wen-Bo liu Engineering Research Center of Organosilicon Compounds&Materials(Ministry of Education)and College of Chemistry and Molecular Sciences Wuhan UniversityWuhanHubei430072 China

Comprehensive Summary,The azepine ring is a prominent structural scaffold in biologically significant molecules. In this study, we present a Ni(II)-catalyzed asymmetric difunctionalization of alkynes, involving intermolecular regioselective arylation and intramolecular nitrile addition, enabling the synthesis of enantioenriched azepine derivatives. This reaction simultaneously installs an all-carbon quaternary stereocenter and introduces an unprotected imine functionality, showing great promise for subsequent transformations. The reaction exhibits good tolerance toward various functional groups, resulting in high yields and enantioselectivities. The synthetic utility of this methodology is further demonstrated through gram-scale synthesis and product derivatization. This research offers an efficient approach to the synthesis of seven-membered nitrogen heterocycles.

关键词： Nickel Asymmetric catalysis N-Heterocycles Alkyne functionalization Quaternary centers

Cross-linked Electrospun Gel Polymer Electrolytes for lithium-Ion Batteries

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 Polymer Science 2024年第8期42卷 1021-1028页

作者： xue Gong Qin Xiao Qing-Yin li Wen-Cui liang Feng Chen long-Yu li Shi-Jie Ren College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

lithium-ion batteries(liBs)benefit from an effective electrolyte system design in both terms of their safety and energy storage ***,a series of precursor membranes with high porosity were produced using electrospinning technology by mixing PVDF and triblock copolymer(PS-PEO-PS),resulting in a porous structure with good interconnections,which facilitates the absorbency of a large amount of electrolyte and further increases the ionic conductivity of gel polymer electrolytes(GPEs).It has been demonstrated that post-cross-linking of the precursor membranes increa ses the rigidity of the nanofibers,which allows the polymer film to be dimensionally sta ble up to 260℃while maintaining superior electrochemical *** obtained cross-linked GPEs(CGPEs)showed high ionic conductivity up to 4.53×10^(-3)S·cm^(-1).With the CGPE-25,the assembled li/liFeP04 half cells exhibited good rate capability and maintained a capacity of 99.4%and a coulombic efficiency of99.3%at 0.1 *** results suggest that the combination of electrospinning technique and post-cross-linking is an effective method to construct polymer electrolytes with high thermal stability and steadily decent electrochemical performance,particularly useful for lithium-ion battery applications that require high-temperature usage.

关键词： Electrospinning Cross-linked Gel polymer electrolytes lithium-ion batteries

Congener-derived template to construct lithiophilic organic-inorganic layer/interphase for high volumetric capacity dendrite-free li metal batteries

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 453-460页

作者： Kang Yang long li Yuanbin Xiao Qiaoli Zhang Chenpeng Xi Borong li Yan Yu Chengkai Yang Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China

The development of lithium-metal batteries(LMBs)is seriously restricted by the out-of-control dendrites growth and infinite volume ***,a pervasive organic-inorganic layer construction strategy is reported for the composite lithium metal anode with congener-derived organic-inorganic solid electrolyte interphase(SEI).In this strategy,the organic-inorganic Ag@polydopamine(Ag@PDA)layer is coated on the arbitrary substrates by a simple two-step *** thin and stable congener-derived SEI is insitu formed with fewer inorganic components and more organic components during charging/*** polydopamine with sufficient adhesion groups and lithiophilic Ag layer realize near-zero nucleation overpotential during lithium *** low interface resistance and stable lithium deposition are ***,the practical areal and volumetric capacities of the composite anode with three-dimensional copper(3DCu)as the substrate are 10 mAh/cm^(2)and 1538 mAh/cm^3(*** mass of anode).The symmetrical cell shows very low polarization voltage(10 mV)and more than 2500 h cycles life at 1 mA/cm^(2)(1 mAh/cm^(2)).The liNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)-based full cells show improved capacity retention(82%)after 100 cycles at 0.5 *** modified lithiophilic anode with congener-derived interphase provides a promising strategy to realize the next-generation dendrite-free LMBs.

关键词： lithium metal anode Congener-derived lithiophilicity Volumetric capacity Organic-inorganic interphase

Integration of urchin-like MnCo_(2)O_(4)@C core–shell nanowire arrays within porous copper current collector for superior performance li-ion battery anodes

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第2期43卷 599-611页

作者： xue-Ru Zhang Qiong Wu Yong Zhang Xi-Fei li Ting Xie Yu-Cheng Wu Instrumental Analysis Center Hefei University of TechnologyHefei230009China Key Laboratory of Advanced Functional Materials and Devices of Anhui Province Hefei230009China School of Materials Science and Engineering Hefei University of TechnologyHefei230009China Institute of Advanced Electrochemical Energy Xi’an University of TechnologyXi’an710048China

Spinel MnCo_(2)O_(4) is a promising energy storage candidate as anode materials in lithium-ion batteries owing to synergistic effects of two intrinsic solid-state redox ***,low conductivity,poor rate capacity and rapid capacity fading have seriously impaired its practical *** overcome the inferiorities,urchin-like MnCo_(2)O_(4)@C core–shell nanowire arrays have been fabricated directly within a porous copper current collector via a facile hydrothermal method followed by a chemical vapor deposition carbonization *** a typical nanowire,the core is composed of interconnected MnCo_(2)O_(4)nanoparticles and the shell shows as a thin amorphous carbon *** integrated MnCo_(2)O_(4)@C/Cu structure could act as working anodes without using additives or polymer *** MnCo_(2)O_(4)@C/Cu possesses slightly longer li-ion insertion/desertion pathway than that of MnCo_(2)O_(4)/Cu,the carbon shell could effectively prevent the pulverization of MnCo_(2)O_(4) and lower down charge transfer resistance and actively participate in li-ion *** rearrangement of carbon atoms during lithiation/delithiation cycling could inhibit the formation of passive solid electrolyte interphase *** a result,the MnCo_(2)O_(4)@C/Cu electrode presents superior rate capacity(600 mAh·g^(−1) at 1 A·g^(−1)) and better stability(797 mAh·g^(−1) after 200 cycles at 100 mA·g^(−1)).The excellent reversible li ion storage capacity,cycling stability and rate capacity endow MnCo_(2)O_(4)@C/Cu great potential as stable and high output integrated anode materials in li-ion batteries.

关键词： MnCo_(2)O_(4)@C Urchin-like nanowire arrays Core-shell Integrated anode materials lithium-ion batteries

Two sandwich-type uranyl-containing polytungstates catalyze aerobic synthesis of benzimidazoles

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1316-1322页

作者： Yu-Feng liu Qi-long Hu xue-Jiao Chen Ke li Pei Luo Guo-Ping Yang School of Chemistry and Material Science Jiangxi Province Key Laboratory of Synthetic ChemistryJiangxi Key Laboratory for Mass Spectrometry and InstrumentationEast China University of TechnologyNanchang330013China School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen518055China

Diversified synthetic strategies are extremely important for the structural diversity of uranium-containing polyoxometalates(U-POMs)and their functional ***,two sandwich-type U-POMs were reported,which are Na_(5.6)K_(6.4)[(UO_(2))(H_(2)O)(TeW_(9)O_(33))]_(2)·21H_(2)O(UTeW_(9))and Na_(8.9)K_(2.7)H_(1.19)[K_(0.79)(UO_(2))_(2.21)(PW_(9)O_(34))_(2)]·12H_(2)O(UPW_9)using in-situ strategy and lacunary precursor strategy,***_9 shows a typical Keggin-typeopen or half-sandwich configuration.

关键词： configuration expansion sandwich

The effects of in ovo feeding of selenized glucose on liver selenium concentration and antioxidant capacity in neonatal broilers

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第6期35卷 312-315页

作者： Jiahui li Qiao Shi Ying xue Mingde Zheng long liu Tuoyu Geng Daoqing Gong Minmeng Zhao Jiangsu Key Laboratory of Animal genetic Breeding and Molecular Design College of Animal Science and TechnologyYangzhou UniversityYangzhou 225009China Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China Yangzhou UniversityYangzhou 225009China

Selenium is an essential trace element for humans and *** the active center of selenoproteins,the addition of selenium is beneficial to enhance the antioxidant ***,the high cost limits the application of organic Se in agriculture animal *** glucose(SeGlu)is a newly invented organoselenium material with good stability,low toxicity and low *** assay found that SeGlu was able to increase selenium deposition in liver of newborn broilers,and enhance the antioxidant capacity of liver by elevating the activities of antioxidant enzymes such as total superoxide dismutase and glutathione *** paper as the first example clarifying the mechanism of SeGlu to enhance the antioxidant ability of chicks,shows that SeGlu can be used as an organic selenium enrichment additive for early nutrition of *** a cross-discipline study involving chemistry,biology and agriculture animal science,the work may be beneficial for studies in related fields and prompt the development of the selenium science.

关键词： Selenized glucose In ovo feeding Antioxidant capacity Selenium Broiler