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Layered niobium carbide enabling excellent kinetics and cycling stability of li-Mg-B-H hydrogen storage material Layered niobium carbide enabling excellent kinetics

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Rare Metals 2024年第3期43卷 1153-1166页

作者： li-wen Lu Hui Luo Guang-Xu li Yun li Xin-Hua Wang Cun-Ke Huang Zhi-QiangLan wen-Zheng Zhou Jin Guo Mohammad Ismail Hai-Zhen liu Guangxi Novel Battery Materials Research Center of Engineering Technology Guangxi Colleges and Universities Key Laboratory of Blue Energy and Systems IntegrationSchool of Physical Science and TechnologyGuangxi UniversityNanning530004China State Key Laboratory of Featured Metal Materials and life-Cycle Safety for Composite Structures Nanning530004China School of Mechanical and Electrical Engineering Quzhou College of TechnologyQuzhou324000China Department of Materials Science and Engineering Zhejiang UniversityHangzhou310027China Faculty of Ocean Engineering Technology and Informatics Universiti Malaysia Terengganu21030Kuala NerusTerengganuMalaysia Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin300071China

The li-Mg-B-H composite(2liBH_(4)+MgH_(2))has a high capacity of 11.4 wt%as a hydrogen storage ***,the slow kinetics and poor cycling stability severely restrict its practical *** this work,a layered Nb_(2)C MXene was first synthesized and then introduced to tailor the kinetics and cycling stability of the li-Mg-B-H *** milled 2liH+MgB_(2)composites were initially hydrogenated to obtain the 2liBH_(4)+MgH_(2)*** 2liBH_(4)+MgH_(2)+5wt%Nb_(2)C can release 9.0 wt%H_(2)in 30 min at 400℃,while it is only 2.7 wt%for the undoped 2liBH_(4)+MgH_(2).The dehydrogenation activation energies of MgH_(2)and liBH_(4)are 123 and 154 kJ·mol^(-1)respectively for the 5 wt%Nb_(2)C-doped composite,lower than the undoped composite(164 and 165 kJ·mol^(-1)).The 2liBH_(4)+MgH_(2)+5 wt%Nb_(2)C possesses excellent cycling stability,with the reversible capacity only slightly reduced from 9.4 wt%for the 1st cycle to 9.3 wt%for the 20th ***_(2)C keeps stable in the composite and acts as an efficient catalyst for the li-Mg-B-H *** is believed that both the layered structure and the active Nb element contribu te to the enhanced hydrogen storage performances of the li-Mg-B-H *** work confirms that the Nb_(2)C MXene with layered stru cture has a significant enhancing impact on the li-Mg-B-H hydrogen storage materials,which is different from the bulk NbC.

关键词： Hydrogen storage lithium borohydride Magnesium hydride Nb_(2)C MXene

入院时ISS评分、休克指数联合血清Syndecan-1、VWF对多发伤患者创伤性凝血病的预测价值研究

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现代生物医学进展 2024年第11期24卷 2079-2083,2144页

作者：钱龙杰苏文利朱文献陆景伟靖宇航王毅鑫上海中医药大学附属普陀医院急诊外科上海200333

目的:研究入院时损伤严重程度评分(ISS)、休克指数联合血清多配体蛋白聚糖-1(Syndecan-1)、血管性假血友病因子(VWF)对多发伤患者创伤性凝血病(TIC)的预测价值。方法:选取2019年1月至2022年12月在上海中医药大学附属普陀医院接受治疗的... 详细信息

目的:研究入院时损伤严重程度评分(ISS)、休克指数联合血清多配体蛋白聚糖-1(Syndecan-1)、血管性假血友病因子(VWF)对多发伤患者创伤性凝血病(TIC)的预测价值。方法:选取2019年1月至2022年12月在上海中医药大学附属普陀医院接受治疗的200例多发创伤患者。根据是否发生TIC分为TIC组(61例)以及非TIC(NTIC)组(139例)。对比两组入院时ISS评分、休克指数及血清Syndecan-1、VWF水平,单因素及多因素Logistic回归分析多发伤患者TIC发病的影响因素,受试者工作特征(ROC)曲线分析入院时ISS评分、休克指数及血清Syndecan-1、VWF对多发伤患者TIC发病的预测价值。结果:200例患者中,总计发生61例TIC患者,发生率是30.50%。TIC组的ISS评分、休克指数、Syndecan-1及VWF水平均较NTIC组更高(P<0.05)。多因素Logistic回归分析发现,低体温、酸中毒、格拉斯哥昏迷评分(GCS)<6分、并发重型颅脑损伤、入院时ISS评分升高、休克指数升高、血清Syndecan-1升高、VWF升高为多发伤患者TIC发病的危险因素。ROC曲线分析入院时ISS评分、休克指数及血清Syndecan-1、VWF等四指标联合应用对于TIC的预测价值最高,其中曲线下面积(AUC)为0.849、灵敏度为0.918、特异度为0.755,均较各项的单独预测效果更好。结论:多发伤患者入院时ISS评分升高、休克指数升高、血清Syndecan-1升高、VWF升高与TIC的发病有关。低体温、酸中毒、GCS<6分、并发重型颅脑损伤、入院时ISS评分升高、休克指数升高为多发伤患者TIC发病的危险因素。入院时ISS评分、休克指数联合血清Syndecan-1、VWF检测对多发伤患者TIC发病具有较高的预测价值。

关键词：损伤严重程度评分休克指数 Syndecan-1 VWF 多发伤创伤性凝血病预测价值

P-and SV-wave dispersion and attenuation in saturated microcracked porous rock with aligned penny-shaped fractures

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Petroleum Science 2024年第1期21卷 143-161页

作者： Sheng-Qing li wen-Hao Wang Yuan-Da su Jun-Xin Guo Xiao-Ming Tang School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina Laoshan National Laboratory Qingdao 266071ShangdongChina Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology Southern University of Science and TechnologyShenzhen 518055GuangdongChina Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055GuangdongChina

P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned ***,there are few existing models that incorporate the multiple wave attenuation mechanisms from the microscopic scale to the macroscopic ***,in this work,we developed a unified model to incorporate the wave attenuation mechanisms at different scales,which includes the microscopic squirt flow between the microcracks and pores,the mesoscopic wave-induced fluid flow between fractures and background(FB-WIFF),and the macroscopic Biot's global flow and elastic scattering(ES)from the *** Tang's modified Biot's theory and the mixed-boundary conditions,we derived the exact frequency-dependent solutions of the scattering problem for a single penny-shaped fracture with oblique incident P-and *** then developed theoretical models for a set of aligned fractures and randomly oriented fractures using the Foldy *** results indicated that microcrack squirt flow considerably influences the dispersion and attenuation of P-and SV-wave *** coupling effects of microcrack squirt flow with the FB-WIFF and ES of fractures cause much higher velocity dispersion and attenuation for P waves than for SV *** oriented fractures substantially reduce the attenuation caused by the FB-WIFF and ES,particularly for the ES attenuation of SV *** a comparison with existing models in the limiting cases and previous experimental measurements,we validated our model.

关键词： Aligned fractures P-and SV-wave Dispersion and attenuation Microcracked porous background FB-WIFF Elastic scattering Squirt flow

Serrated flow behavior of GH536 superalloy under different loading rates at room temperature

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Rare Metals 2024年第5期43卷 2317-2323页

作者： wen-Xiang Gao Dong Ma li-li Zhao Fan Ye ling Shao su-Jun Wu School of Materials Science and Technology Beihang UniversityBeijing100091China

Serrated flow phenomenon has been widely observed among different metals due to the potential influence on their *** tensile tests of nickel-based superalloy GH536 were carried out at loading rates of 0.06,0.60,3.60,and 36.00 mm·min^(-1)at room temperature,*** tensile stress-strain curves demonstrate repetitive and discontinuous yielding behavior,namely serrated *** is observed that the stress-strain curves were dominated by type B serration,and original annealing twin boundaries(TBs)were distorted to various degrees under comparatively different lower tensile *** contrast,the TBs almost disappear,and the type B serrations become smoother and regular under the higher loading *** phenomenon can be attributed to the interactions between TBs and dislocations during tensile *** effects of the mobile and immobile dislocations illustrate the unsteady amplitude of serrations observed in stress-strain *** electron microscope images of tested pieces reveal the interaction of dislocation and TB,with dislocation tangling around the TBs.

关键词： Nickel-based superalloy Serrations Twin boundaries Deformation mechanism

Pregnancy and fetal outcomes of chronic hepatitis C mothers with viremia in China

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World Journal of Gastroenterology 2022年第34期28卷 5023-5035页

作者： Calvin Q Pan Bao-Shen Zhu Jian-Ping Xu Jian-Xia li li-Juan sun Hong-Xia Tian Xi-Hong Zhang su-wen li Er-Hei Dai Center for liver Diseases Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Division of Gastroenterology and Hepatology Department of MedicineNYU Langone HealthNYU School of MedicineFlushingNY 11355United States Department of Obstetrics and Gynecology The Fifth Hospital of ShijiazhuangHebei Medical UniversityShijiazhuang 050021Hebei ProvinceChina School of Public Health North China University of Science and TechnologyTangshan 063210Hebei ProvinceChina Division of liver Disease Department of MedicineThe Fifth Hospital of ShijiazhuangHebei Medical UniversityShijiazhuang 050021Hebei ProvinceChina

BACKGROUND Data that assess maternal and infant outcomes in hepatitis C virus(HCV)-infected mothers are *** To investigate the frequency of complications and the associated risk *** We performed a cohort study to compare pregnancy and fetal outcomes of HCVviremic mothers with those of healthy *** factors were analyzed with logistic *** Among 112 consecutive HCV antibody-positive mothers screened,we enrolled 79 viremic *** randomly selected 115 healthy mothers from the birth registry as the *** to healthy mothers,HCV mothers had a significantly higher frequency of anemia[2.6%(3/115)vs 19.0%(15/79),Plikely to suffer anemia[adjusted odds ratio(OR):18.1,95%confidence interval(CI):4.3-76.6],require caesarian sections(adjusted OR:2.6,95%CI:1.4-4.9),and have nuchal cords(adjusted OR:5.6,95%CI:2.4-13.0).Their neonates were also more likely to have smaller head circumferences(adjusted OR:2.1,95%CI:1.1-4.3)and lower birth weights than the average(≤3250 gms)with an adjusted OR of 2.2(95%CI:1.2-4.0).The vertical transmission rate was 1%in HCV-infected *** Maternal HCV infections may associate with pregnancy and obstetric *** demonstrated a previously unreported association between maternal HCV viremia and a smaller neonatal head circumference,suggesting fetal growth restriction.

关键词： Hepatitis C virus viremia Mother-to-child transmission Pregnancy complications Maternal health Infant hepatitis C virus infection

Vibration-Based Fault Diagnosis for Railway Point Machines Using VMD and Multiscale Fluctuation-Based Dispersion Entropy

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Chinese Journal of Electronics 2024年第3期33卷 803-813页

作者： Yongkui suN Yuan CAO Peng li Guo XIE Tao wen Shuai su National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University School of Electronic and Information Engineering Beijing Jiaotong University Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi'an University of Technology Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University

As one of the most important railway signaling equipment,railway point machines undertake the major task of ensuring train operation *** fault diagnosis for railway point machines becomes a hot *** the advantage of the anti-interference characteristics of vibration signals,this paper proposes an novel intelligent fault diagnosis method for railway point machines based on vibration signals.A feature extraction method combining variational mode decomposition(VMD) and multiscale fluctuation-based dispersion entropy is developed,which is verified a more effective tool for feature ***,a two-stage feature selection method based on Fisher discrimination and ReliefF is proposed,which is validated more powerful than single feature selection ***,support vector machine is utilized for fault *** comparisons show that the proposed method performs *** diagnosis accuracies of normal-reverse and reverse-normal switching processes reach 100% and 96.57% ***,it is a try to use new means for fault diagnosis on railway point machines,which can also provide references for similar fields.

关键词： Fault diagnosis Vibrations support vector machines Diversity reception Switches Feature extraction Rail transportation

BL03HB: a Laue microdiffraction beamline for both protein crystallography and materials science at SSRF

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Nuclear Science and Techniques 2024年第7期35卷 68-78页

作者： Zhi-Jun Wang Si-Sheng Wang Zheng-Huang su li Yu Yu-Zhu Wang Bo sun wen wen Xing-Yu Gao Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China University of Chinese Academy of Science Beijing100049China

A Laue microdiffraction beamline (BL03HB) was constructed at the Shanghai SynchrotronRadiation Facility (SSRF). This beamline featu res two consecutive focusing points in twodifferent sectors within its end station, the first dedicated to protein crystallography and theother tailored to materials science applications. Based on a superbend dipole magnet with amagnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick- Baez mirrors to achieve a micro white beam as small as 4.2 um X4.3 pμm at the firstsector and 09 pum X 1.3 pum at the second sector in the standard beamline operation mode at *** X-ray microbeam in the two sectors can be easily switched between monochromatic andwhite beams by moving a four-bounce monochromator in or out of the light path, respectively. Inthe protein crystallography sector, white-beam Laue microdifraction was dermonstrated tosuccessully determine the structure of protein crystals from only a few images of diffraction data .collected by a Pilatus 2 M area detector. In the materials science sector, the white -beam Lauediffraction was collected in a reflection geometry using another Pilatus 2 M area detector, whichcould map the microstructural distribution on the sample surface by scanning the samples. Ingeneral, the BL03HB beamline promotes the application of Laue microdiffraction in both proteincrystallgraphy and materials science. This paper presents a comprehensive overview of theBL03HB beamline, end station, and the first commission results.

关键词： Crystallography White-beam Laue microdiffraction Beamline Synchrotron

A highly sensitive multiple-mode optical thermometer designed in Eu^(2+)/^(3+)and li^(+)co-doped polymorphism compound LaSc_(3)(BO_(3))_(4)

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Journal of Advanced Ceramics 2024年第6期13卷 821-833页

作者： Nan Yang Zhuo li Tingxia Zhou Ziwang Zhang wen Shi Yexiang Tong Jianxin Shi School of Chemistry IGCMESun Yat-sen UniversityGuangzhou 510006China MOE of the Key Laboratory of Bioinorganic and Synthetic Chemistry IGCMEThe Key Lab of Low-Carbon Chemistry&Energy Conservation of Guangdong ProvinceSun Yat-sen UniversityGuangzhou 510006China

Noncontact optical thermometers have attracted widespread attention,but existing problems such as single-mode and low-sensitivity thermometers still urgently need to be ***,a novel multiple-mode thermometer was designed for the polymorphism LaSc_(3)(BO_(3))_(4):Eu^(2+/3+),li^(+).X-ray diffraction(XRD)patterns revealed a slight transition betweenα-andβ-phases with the concentrations of the dopants,which is further proved by structure refinements and first-principles *** coexistence of Eu^(2+)and Eu^(3+)in the phosphors and their relative percentages were confirmed by X-ray absorption near-edge structure(XANES)*** from appropriate emissions from Eu^(2+)and Eu^(3+)without obvious energy transfer and their opposite changing trends with temperatures under 307 nm excitation,a triple-mode optical thermometer is obtained for this material within the temperature range of 150–450 *** highest sensitivities of 27.65,14.05,and 7.68%·K^(−1)are achieved based on two fluorescence intensity ratio(FIR)modes of Eu^(2+)and Eu^(3+)(5d–4f/^(5)D_(0)–^(7)F_(2,4))and the fluorescence lifetime(FL)mode of Eu^(2+),*** the best of our knowledge,the former is almost the highest in Eu^(2+)and Eu^(3+)co-doped *** results indicate that this material may be used as an excellent multiple-mode optical thermometer.

关键词： phase transition europium(Eu)ions multiple-mode optical thermometer thermal quenching properties fluorescence intensity ratio(FIR) fluorescence lifetime(FL)

A semi-analytical model for coupled flow in stress-sensitive multi-scale shale reservoirs with fractal characteristics

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Petroleum Science 2024年第1期21卷 327-342页

作者： Qian Zhang wen-Dong Wang Yu-liang su Wei Chen Zheng-Dong Lei Lei li Yong-Mao Hao Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Oil Development Branch Changqing Oilfield CompanyPetroChinaQingyang745708GansuChina PetroChina Research Institute of Petroleum Exploration&Development Beijing100083China

A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes due to stress sensitivity, which plays a crucial role in controlling pressure propagation and oil flow. This paper proposes a multi-scale coupled flow mathematical model of matrix nanopores, induced fractures, and hydraulic fractures. In this model, the micro-scale effects of shale oil flow in fractal nanopores, fractal induced fracture network, and stress sensitivity of multi-scale media are considered. We solved the model iteratively using Pedrosa transform, semi-analytic Segmented Bessel function, Laplace transform. The results of this model exhibit good agreement with the numerical solution and field production data, confirming the high accuracy of the model. As well, the influence of stress sensitivity on permeability, pressure and production is analyzed. It is shown that the permeability and production decrease significantly when induced fractures are weakly supported. Closed induced fractures can inhibit interporosity flow in the stimulated reservoir volume (SRV). It has been shown in sensitivity analysis that hydraulic fractures are beneficial to early production, and induced fractures in SRV are beneficial to middle production. The model can characterize multi-scale flow characteristics of shale oil, providing theoretical guidance for rapid productivity evaluation.

关键词： Multi-scale coupled flow Stress sensitivity Shale oil Micro-scale effect Fractal theory