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Failure mechanism and safety control technology of a composite strata roadway in deep and soft rock masses:a case study

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Journal of Mountain Science 2024年第7期21卷 2427-2444页

作者： ZHAO Chengwei ZHOU Hui SUN Xiaoming ZHANG Yong MIAO Chengyu wang Jian State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory for GeoMechanics and Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China

The construction of coal mines often encounters deep composite soft rock roadways,which is characterized by significant deformation and poor *** deeply study the failure mechanism and large deformation challenges of a composite strata roadway in deep and soft rock masses,a numerical model of 3DEC tetrahedral blocks was established based on the method of rock quality designation(RQD).The results showed that original support cannot prevent asymmetric failure and large deformation due to the adverse geological environment and unsuitable support *** to the failure characteristics,a coupling support of“NPR bolt/cable+mesh+shotcrete+steel pipe”was proposed to control the stability of the surrounding *** excellent mechanical properties of large deformation(approximately 400 mm)and high constant resistance force(bolt with 180 k N;cable with 350 k N)were evaluated by the tensile *** numerical results showed that the maximum deformation was minimized to 243 mm,and the bearing capacity of the surrounding rock of the roadway was *** field test results showed that the maximum deformation of the surrounding rock was 210 mm,and the forces of the NPR bolt and cable were stable at approximately 180 k N and 350 k N,*** demonstrated the effectiveness of the coupling support with the NPR bolt and cable,which could be a guiding significance for the safety control of large deformation and failure in deep composite soft rock roadways.

关键词： 3DEC Composite strata roadway Soft rock NPR bolt and cable Asymmetric large deformation

Adsorption limitation investigation on olefins for Cu–BTC

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Friction 2024年第4期12卷 606-617页

作者： Xiao YANG Yunbo wang Weihua CAO Ruizheng JIANG Guoxin XIE Yuying CAO Xiaowen QI School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Key Laboratory of Self-Lubricating Spherical Plain Bearing Technology of Hebei Province Yanshan UniversityQinhuangdao 066004China State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China Aviation Key Laboratory of Science and Technology on Generic Technology of Self-Lubricating Spherical Plain Bearing Yanshan UniversityQinhuangdao 066004China

To utilize Cu-benzene-1,3,5-tricarboxylate(Cu-BTC)adsorbed lubricant oils in the self-lubricating field,the adsorption properties of Cu-BTC on different 1-olefins must be *** this work,1-hexene,1-octene,1-nonene,1-decene,1-undecene,and 1-dodecene were studied by the Monte Carlo method and *** adsorption limit of Cu-BTC for n-olefins was determined as 1-undecene by the adsorption *** suggested a limit for even straight-chain molecules to the adsorption of *** maximum ratio of the olefin length of the largest pore diameter(L/D)of Cu-BTC was approximately ***,theoretical calculations(radial distribution function(RDF))and experiments(infrared(IR)spectra)confirmed the interaction of n-olefin adsorbates and the Cu-BTC framework occurred between the-CH=of olefins and the Cu and O atoms of the Cu-BTC *** work adds to the understanding and investigation of the adsorption of liquid lubricants using Cu-BTC as a metal-organic framework(MOF).

关键词： metal-organic framework(MOF) Cu-benzene-1,3,5-tricarboxylate(Cu-BTC) Monte Carlo method adsorption properties 1-olefins

Performance analysis of the tight combination of GPS, BDS, GALILEO, and QzsS mixed frequencies signals

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Geodesy and Geodynamics 2024年第4期15卷 366-378页

作者： Yu Han Fangjun Qin Xugang Lian Shengliang wang Leiyuan Qian Wenhua Huang College of Electrical Engineering Naval University of EngineeringWuhan 430033China College of Mining Engineering Taiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Satellite Navigation System and Equipment Technology Shijiazhuang 050081China State Key Laboratoryof Geodesy and Earth'sDynamics Innovation AcademyforPrecision Measurement Scienceand Technology Chinese Academy of SciencesWuhan 430077China China Energy Engineering Group Shanxi Electric Power Engineering CO.LTD. Taiyuan 030001China

With the gradual development and modernization of satellite navigation systems,using observation information from multi-GNss has become one of the hot-spot issues in recent ***-system loose combinations form double-difference observation equations within their respective systems,and the positioning effect is ***,the interchangeability and compatible interoperability between global navigation satellite systems(GNSS)cannot be truly *** the same time,when the number of visible satellites decreases abruptly,the positioning performance deteriorates *** paper focuses on the GNsS multi-system tight combination relative positioning technique,gives a mathe-matical model of multi-system tight combination relative positioning considering differential inter-system bias(DISB),and analyzes the time-varying characteristics of DISB at overlapping and non-overlapping frequencies among GPS/Galileo,GPS/BDS,and GPS/QZSS in terms of receiver brand,tem-perature,and receiver *** GNsS tight combination relative positioning performance is verified by static data from Curtin University and dynamic data measured at Taiyuan University of *** results show that compared with loose combination,the ambiguity-fixed rate increases from 62.18%to 97.60%for static data and from 74.97%to 99.53%for dynamic data when the elevation mask angle is 50°,resulting in a significant improvement in positioning performance.

关键词： GNSS Mix frequencies Redundancy Tightcombination Differential inter-system bias

Estimating shear strength of high-level pillars supported with cemented backfilling using the HoekeBrown strength criterion

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 454-469页

作者： Kaizong Xia Congxin Chen Xiumin Liu Yue wang Xuanting Liu Jiahao Yuan State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Deep metal mines are often mined using the high-level pillars with subsequent cementation backfilling(HLSCB)mining *** the design stage,it is therefore important to have a reasonable method for determining the shear strength of the high-level pillars(*** and internal friction angle)when they are supported by cemented *** this study,a formula was derived for the upper limit of the confining pressure σ3max on a high-level pillar supported by cemented backfilling in a deep metal mine.A new method of estimating the shear strength of such pillars was then proposed based on the Hoek eBrown failure *** analysis indicates that the horizontal stress σhh acting on the cemented backfill pillar can be simplified by expressing it as a constant value.A reasonable and effective value for σ3max can then be *** value of s3max predicted using the proposed method is generally less than 3 *** this range,the shear strength of the high-level pillar is accurately calculated using the equivalent MohreCoulomb *** proposed method can effectively avoid the calculation of inaccurate shear strength values for the high-level pillars when the original HoekeBrown criterion is used in the presence of large confining pressures,*** situation in which the cohesion value is too large and the friction angle is too small can effectively be *** proposed method is applied to a deep metal mine in China that is being excavated using the HLSCB *** shear strength parameters of the high-level pillars obtained using the proposed method were input in the numerical *** numerical results show that the recommended level heights and sizes of the high-level pillars and rooms in the mine are rational.

关键词： Deep metal mines High-level pillars HoekeBrown strength criterion Cemented backfilling Confining pressure Shear strength

Beyond 1,4-addition of in-situ generated(aza-)quinone methides and indole imine methides

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Chinese Chemical Letters 2024年第7期35卷 35-53页

作者： Yan-Li Li Zhi-Ming Li Kai-Kai wang Xiao-Long He Medical College Xinxiang UniversityXinxiang 453000China School of Pharmacy Xinxiang UniversityXinxiang 453000China School of Food and Bioengineering Xihua UniversityChengdu 610039China

The conjugate addition of in-situ generated(aza-)quinone methides(QMs)and indole imine methides(IIMs)emerged as a powerful protocol to access densely functionalized benzenes and *** alcohols,aminobenzhydryl alcohols,and varied indolylmethanols served as most effective precursors for the in-situ generation of such reactive species under acid *** relevant propargylic alcohol has proven to be an elegant precursor to generate the propargylic-QMs and-IIMs via the acid promoted dehydration process,thus enabling diverse challenging remote activation to proceed conjugate1,6-and 1,***,the heteroarene has proven to be workable to transfer the LUMO of the p-QMs and 2-IIMs,thus inducing the remote nucleophilic dearomative *** conjugate additions of(aza-)p-QMs and varied IIMs has made significant contribution in the field of remote activation chemistry in past *** review summarizes the latest advances of the remote conjugate additions of the in-situ generated QMs and IIMs.

关键词： Conjugate addition QMs IIMs LUMO Remote activation Dearomative addition

Knockout of a rice K5.2 gene increases Ca accumulation in the grain

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Journal of Integrative Plant Biology 2024年第2期66卷 252-264页

作者： Peitong wang Naoki Yamaji Namiki Mitani-Ueno Jun Ge Jian Feng Ma National Key Laboratory of Crop Genetics&Germplasm Enhancement and Utilization College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjing 210095China Institute of Plant Science and Resources Okayama UniversityKurashiki 710-0046Japan

Rice is a staple food for half of the world’s population,but it is a poor dietary source of calcium(Ca)due to the low *** is an important issue to boost Ca concentration in this grain to improve Ca deficiency risk,but the mechanisms underlying Ca accumulation are poorly ***,we obtained a rice(Oryza sativa)mutant with high shoot Ca *** mutant exhibited 26%-53% higher Ca in shoots than did wild-type rice(WT)at different Ca *** concentration in the xylem sap was 36% higher in the mutant than in the *** was no difference in agronomic traits between the WT and mutant,but the mutant showed 25% higher Ca in the polished grain compared with the ***-based cloning combined with a complementation test revealed that the mutant phenotype was caused by an 18-bp deletion of a gene,OsK5.2,belonging to the Shaker-like K+channel ***5.2 was highly expressed in the mature region of the roots and its expression in the roots was not affected by Ca levels,but upregulated by low *** showed that OsK5.2 was mainly expressed in the pericycle of the *** together,our results revealed a novel role for OsK5.2 in Ca translocation in rice,and will be a good target for Ca biofortification in rice.

关键词： accumulation biofortification calcium OsK5.2 pericycle rice translocation

Exposure to ephedrine attenuates Th1/Th2 imbalance underlying OVA-induced asthma through airway epithelial cell-derived exo-somal lnc-TRPM2-AS

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Chinese Journal of Natural Medicines 2024年第6期22卷 530-540页

作者： HU Yan wang Mengqing XIE Jing JIAO Luojia DING Yi LUO Yinhe Department of Pediatrics The First Hospital of Hunan University of Chinese MedicineChangsha 410007China Hunan University of Chinese Medicine Changsha 410208China Department of Rehabilitation Medical CollegeChangsha Civil Affairs Vocational and Technical CollegeChangsha 410004Hunan ProvinceChina Teaching and Research Office of Chinese and Western Combination Hunan University of Chinese MedicineChangsha 410208China

Although various anti-inflammatory medications,such as ephedrine,are employed to manage cough-variant asthma,their underlying mechanisms are yet to be fully *** studies suggest that exosomes derived from airway epithelial cells(AECs)contain components like messenger RNAs(mRNAs),micro-RNAs(miRNAs),and long noncoding RNA(lncRNA),which play roles in the occurrence and progression of airway *** study investigates the influence of AEC-derived exosomes on the efficacy of ephedrine in treating cough-variant *** established a mouse model of asthma and measured airway resist-ance and serum inflammatory cell ***-time polymerase chain reaction(RT-qPCR),Western blotting,and enzyme-linked im-munosorbent assay(ELISA)analyses were used to assess gene and protein expression *** were isolated and *** immunoprecipitation(RIP)and RNA pull-down assays were conducted to examine the interaction between hnRNPA2B1 and *** the ovalbumin(OVA)-challenged mouse model,ephedrine treatment reduced inflammatory responses,air-way resistance,and Th1/Th2 cell *** from OVA-treated AECs showed elevated levels of lnc-TRPM2-AS1,which were diminished following ephedrine *** exosomal lnc-TRPM2-AS1 mediated the Th1/Th2 imbalance in CD4^(+)T cells,with its packaging into exosomes being facilitated by *** study unveils a novel mechanism by which ephedrine ameli-orates OVA-induced CD4^(+)T cell imbalance by suppressing AEC-derived exosomal *** findings could provide a theoretical framework for using ephedrine in asthma treatment.

关键词： Asthma Ephedrine Exosomal lnc-TRPM2-AS1 Th1/Th2 imbalance HnRNPA2B1 Airway epithelial cells

Task-Oriented Semantic Communication with Foundation Models

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China Communications 2024年第7期21卷 65-77页

作者： Chen Mingkai Liu Minghao Zhang Zhe Xu Zhiping wang Lei Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China School of Ocean Information Engineering Jimei UniversityXiamen 361021China Key Laboratory of Underwater Acoustic Communication and Marine Information Technology(Xiamen University) Ministry EducationXiamen 361005China

In the future development direction of the sixth generation(6G)mobile communication,several communication models are proposed to face the growing challenges of the *** rapid development of artificial intelligence(AI)foundation models provides significant support for efficient and intelligent communication *** this paper,we propose an innovative semantic communication paradigm called task-oriented semantic communication system with foundation ***,we segment the image by using task prompts based on the segment anything model(SAM)and contrastive language-image pretraining(CLIP).Meanwhile,we adopt Bezier curve to enhance the mask to improve the segmentation ***,we have differentiated semantic compression and transmission approaches for segmented ***,we fuse different semantic information based on the conditional diffusion model to generate high-quality images that satisfy the users'specific task ***,the experimental results show that the proposed system compresses the semantic information effectively and improves the robustness of semantic communication.

关键词： diffusion model foundation model joint source-channel coding task-oriented semantic communication

On implications of somatostatin in diabetic retinopathy

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Neural Regeneration Research 2024年第9期19卷 1984-1990页

作者： Yanhong Fang Qionghua wang Youjian Li Li Zeng Jian Liu Kepeng Ou Department of Ophthalmology Chongqing University Jiangjin HospitalChongqingChina College of Pharmacy National&Local Joint Engineering Research Center of Targeted and Innovative TherapeuticsIATTIChongqing University of Arts and SciencesChongqingChina Shandong Provincial Hospital Shandong Laboratory Animal CenterScience and Technology Innovation CenterShandong First Medical University&Shandong Academy of Medical SciencesJinanShandong ProvinceChina Academic Unit of Ophthalmology Bristol Medical SchoolUniversity of BristolBristolUK

Somatostatin,a naturally produced neuroprotective peptide,depresses excitatory neurotransmission and exerts anti-proliferative and anti-inflammatory effects on the *** this review,we summarize the progress of somatostatin treatment of diabetic retinopathy through analysis of relevant studies published from February 2019 to February 2023 extracted from the PubMed and Google Scholar *** neuroprotection,which occurs as a consequence of declined expression or dysregulation of retinal somatostatin in the very early stages of diabetic retinopathy,triggers retinal neurovascular unit impairment and microvascular *** replacement is a promising treatment for retinal neurodegeneration in diabetic *** pre-clinical and clinical trials of somatostatin analog treatment for early diabetic retinopathy have been *** one such trial(EUROCONDOR),topical administration of somatostatin was found to exert neuroprotective effects in patients with pre-existing retinal neurodysfunction,but had no impact on the onset of diabetic ***,we concluded that somatostatin restoration may be especially beneficial for the growing population of patients with early-stage *** order to achieve early prevention of diabetic retinopathy initiation,and thereby salvage visual function before the appearance of moderate non-proliferative diabetic retinopathy,several issues need to be *** include the needs to:a)update and standardize the retinal screening scheme to incorporate the detection of early neurodegeneration,b)identify patient subgroups who would benefit from somatostatin analog supplementation,c)elucidate the interactions of somatostatin,particularly exogenously-delivered somatostatin analogs,with other retinal peptides in the context of hyperglycemia,and d)design safe,feasible,low cost,and effective administration routes.

关键词： diabetes retinopathy excitotoxicity growth hormone insulin like growth factor irisin neurodegeneration neuroinflammation neuroprotection neurovascular unit octreotide oxidative stress somatostatin