检索结果-南通市图书馆

mLife 2024年第1期3卷 87-100页

作者： Yakun Li Yuyun Wei Xiao guo Xiaohui Li Lining Lu Lihua Hu zheng-guo he State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources Guangxi Research Center for Microbial and Enzyme Engineering TechnologyCollege of Life Scienceand TechnologyGuangxi UniversityNanningChina

Insertion sequences(ISs)exist widely in bacterial genomes,but their roles in the evolution of bacterial antiphage defense remain to be ***,we report that,under the pressure of phage infection,the IS1o96 transposition of Mycobacterium smegmatis into the Isr2 gene can occur at high frequencies,which endows the mutant mycobacterium with a broad-spectrum antiphage ***2 functions as a negative regulator and directly silences expression of a gene island composed of 11 lipid metabolism-related *** complete or partial loss of the gene island leads to a significant decrease of bacteriophage adsorption to the mycobacterium,thus defending against phage ***,a phage that has evolved mutations in two tail-filament genes can re-escape from the Isr2 inactivation-triggered host *** study uncovered a new signaling pathway for activating antimycobacteriophage immunity by Is transposition and provided insight into the natural evolution of bacterial antiphage defense.

关键词： antiphage defense bacteriophage gene island insertion sequence mycobacteria

Adverse effect of niobium and boron on hot deformation behavior of sulfur-containing steel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第1期31卷 252-263页

作者： guo-ning he Shi-qi Wan Bo Jiang Chao-lei Zhang Ya-zheng Liu Chun-jing Wu School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China

The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were *** compression and tenssion tests were carried out by Gleeble3800 at the austenite region from 850 to 1150℃and the adverse effects of Nb and B were analyzed by the fracture,microstructure and precipitate *** compression tests showed that the proportions of instable area in hot processing maps of 0.021%Nb and Nb-B steels were higher and the deformability of Nb free steel was *** tensile deformation experiments showed that the reduction areas of Nb free,0.021%Nb and Nb-B steels were 92%-99%,84%-98%and 67%-97%,*** addition of Nb or Nb and B inhibited the dynamic recrystallization during hot deformation,and consequently,more deformed grains were then formed in 0.021%Nb and Nb-B steels thus to obtain the microstructure with worse uniformity and then deteriorate the *** addition,the interaction between inclusions and microalloyed elements was also *** particles of 0.021%Nb and Nb-B steels dynamically precipitated during deformation and precipitated together with MnS thus to worsen the deformability,resulting in the decrease of reduction area.

关键词： Hot deformation Gear steel Processing map Dynamic recrystallization Microalloying

Double-confined nanoheterostructure Sb/Sb_(2)S_(3)@Ti_(3)C_(2)T_(x)@C toward ultra-stable Li-/Na-ion batteries

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5期43卷 2067-2079页

作者： Dan Wang Qun Ma Huan he Zhi-Yuan Wang Run-guo zheng Hong-Yu Sun Yan-guo Liu Chun-Li Liu School of Materials Science and Engineering Northeastern UniversityShenyang110819China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China Key Laboratory of Dielectric and Electrolyte Functional Material hebei Province Qinhuangdao 066004China Department of Physics and Oxide Research Center Hankuk University of Foreign StudiesYongin 17035Korea

Antimony-based materials with high capacities and moderate potentials are promising anodes for lithium-/-sodium-ion ***,their tremendous volume expansion and inferior conductivity lead to poor structural stability and sluggish reaction ***,a doubleconfined nanoheterostructure Sb/Sb_(2)S_(3)@Ti_(3)C_(2)T_(x)@C has been fabricated through a solvothermal method followed by low-temperature heat *** dual protection of“MXene”and“carbon”can better accommodate the volume expansion of Sb/Sb_(2)S_(3).The strong covalent bond(Ti-S,Ti-O-Sb,C-O-Sb)can firmly integrate Sb-based material with Ti_(3)C_(2)T_(x)and carbon,which significantly improves the structure *** addition,the carbon layer can restrain the oxidation of MXenes,and the nano-Sb/Sb_(2)S_(3)can facilitate electron/ion transport and suppress the restacking of *** heterogeneous interface between Sb and Sb_(2)S_(3)can further promote interfacial charge *** MXene-Sb/Sb_(2)S_(3)@C-1 with the optimal Sb content shows high specific capacities,comparable rate properties and ultra-stable cycling performances(250 m Ah·g^(-1)after 2500 cycles at 1 A·g^(-1)for sodium-ion batteries).Ex situ X-ray diffractometer(XRD)test reveals the storage mechanism including the conversion and alloying process of MXene-Sb/Sb_(2)S_(3)@*** voltammetry(CV)test results demonstrate that the pseudocapacitance behavior is dominant in MXene-Sb/Sb_(2)S_(3)@C-1,especially at large *** design paves the way for exploring high-performance alloy-based/conversion-type anode for energy storage devices.

关键词： Sb/Sb_(2)S_(3) MXene Carbon Anode Lithium-ion batteries Sodium-ion batteries

Potential transformation of organic matter by microbes in cryoconite,Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第6期67卷 1978-1989页

作者： Bixi guo Yongqin LIU Kevin Xu ZHONG Quan SHI Chen he Qiang zheng Ruanhong CAI State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Center for the Pan-Third Pole Environment Lanzhou UniversityLanzhou 730000China Department of Earth Oceanand Atmospheric SciencesUniversity of British ColumbiaVancouverBC V6T 1Z4Canada State Key Laboratory of heavy Oil Processing Petroleum Molecules Engineering Center(PMEC)China University of PetroleumBeijing 102249China State Key Laboratory for Marine Environmental Science Collage of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Fujian Key Laboratory of Marine Carbon Sequestration Xiamen UniversityXiamen 361005China

Microorganisms play an essential role in the glacier carbon cycle;how they transform organic matter in mountain glacial cryoconite remains to be ***,we applied ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)and deep sequencing of 16S rRNA gene,to investigate the temporal microbial transformation of dissolved organic matter(DOM)of the Tibetan Plateau *** the 60-day incubation,we found that DOM in cryoconite underwent a three-stage transformation,with decreasing bioavailability over *** microbial community did not change much in the first week while degrading DOM molecules that were associated with higher H/C_(wa)and lower O/C_(wa).During days 15-30,DOM composition remained stable while microbial diversity *** day 60,the DOM was microbially converted into a higher state of recalcitrance,with higher values of aromatic index,O/C_(wa),and lower H/C_(wa),which contained molecules containing more *** among various microbial taxa,like Cyanobacteria,Bacteroidota,Gammaproteobacteria,Firmicutes,and Actinobacteriota,drove the DOM transformation in *** study sheds light on the in-situ transformation of DOM composition meditated by microbial populations in cryoconite at a temporal scale,providing new insights into understanding the microbial roles in the glacier organic carbon transformation.

关键词： Cryoconite Dissolved organic matter Biodegradation Microbial community Temporal variation

同方期刊数据库

Differentially private SGD with random features

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 1-23页

作者： WANG Yi-guang guo zheng-chu Polytechnic Institute of Zhejiang University Zhejiang UniversityHangzhou 310015China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China

In the realm of large-scale machine learning,it is crucial to explore methods for reducing computational complexity and memory demands while maintaining generalization ***,since the collected data may contain some sensitive information,it is also of great significance to study privacy-preserving machine learning *** paper focuses on the performance of the differentially private stochastic gradient descent(SGD)algorithm based on random *** begin,the algorithm maps the original data into a lowdimensional space,thereby avoiding the traditional kernel method for large-scale data storage ***,the algorithm iteratively optimizes parameters using the stochastic gradient descent ***,the output perturbation mechanism is employed to introduce random noise,ensuring algorithmic *** prove that the proposed algorithm satisfies the differential privacy while achieving fast convergence rates under some mild conditions.

关键词： learning theory differential privacy stochastic gradient descent random features reproducing kernel Hilbert spaces

Body size induced changes in metabolic carbon of soil nematodes under N deposition and precipitation regime change in a temperate grassland

在线全文

学校读者我要写书评

暂无评论

Ecological Processes 2024年第1期13卷 120-131页

作者： Shuyan Cui Xiaomei Mo guo zheng College of Life Science Shenyang Normal University

Background Global climate change has resulted in precipitation regimes exhibiting an increasing trend in rainfall intensity but a reduction in its frequency. Nitrogen(N) deposition is a crucial component of the global N cycling. Nematode body size is a trait that responds to climate change and is used as a standard trait-based indicator in soil community analysis. Variations in body size influence metabolic carbon(C). We examined the ways by which body size and metabolic C of nematodes respond to changing precipitation regimes and how N deposition regulates these responses by an 8-year manipulative *** Nematode body size was indicated by the community-weighted mean(CWM) mass. We quantified C metabolism components of soil nematodes including production C, respiration C, and corresponding C use efficiency(CUE) under different precipitation intensities and N addition in a semi-arid steppe on the Mongolian Plateau. The Mantel test was used to determine the correlations between CWM, CUE and environmental factors. The partial least squares path modeling(PLS-PM) was conducted to quantify direct or indirect contributions among latent *** We found that heavy precipitation intensity increased the CWM mass of total nematodes and omnivorespredators without N addition. N addition decreased CWM mass of bacterivores across all the precipitation intensity treatments. Stronger precipitation intensities might be favorable for nematode production and respiration C. Variations in the nematode CWM mass drove the CUE to change with N *** Our findings provide new insights into the mechanisms underlying nematode body size and C metabolism, and highlight that explorative studies, such as manipulative experiments, are needed to identify traits underlying size-related effects and to investigate how they affect CUE of nematodes. These efforts may increase our understanding of how changes in precipitation regimes and N deposition may alter soil nema

关键词： Community-weighted mean Metabolic footprint Nitrogen addition Precipitation intensity

Multi-timescale optimization scheduling of interconnected data centers based on model predictive control

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2024年第1期18卷 28-41页

作者： Xiao guo Yanbo Che Zhihao zheng Jiulong SUN Energy Power Electrical Automation and Information EngineeringTianjin UniversityTianjin 300072China

With the promotion of“dual carbon”strategy,data center(DC)access to high-penetration renewable energy sources(RESs)has become a trend in the ***,the uncertainty of RES poses challenges to the safe and stable operation of DCs and power *** this paper,a multi-timescale optimal scheduling model is established for interconnected data centers(IDCs)based on model predictive control(MPC),including day-ahead optimization,intraday rolling optimization,and intraday real-time *** day-ahead optimization stage aims at the lowest operating cost,the rolling optimization stage aims at the lowest intraday economic cost,and the real-time correction aims at the lowest power fluctuation,eliminating the impact of prediction errors through coordinated multi-timescale *** simulation results show that the economic loss is reduced by 19.6%,and the power fluctuation is decreased by 15.23%.

关键词： model predictive control interconnected data center multi-timescale optimized scheduling distributed power supply/landscape uncertainty

Characterization of a novel regulatory pathway for mannitol metabolism and its coordination with biofilm formation in Mycobacterium smegmatis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2018年第9期45卷 477-488页

作者： Jialing Hu Hua Zhang Si Zhou Weihui Li zheng-guo he National Key Laboratory of Agricultural Microbiology College of Life Science and TechnologyHuazhong Agricultural University

Biofilm formation has been implicated to be tightly regulated in bacteria. Mycobacterial species possess a unique cell-wall structure; however, the underlying regulation mechanism for their biofilm formation remains largely unclear. In this study, we characterized a hypothetical mannitol metabolism and transportation gene cluster（Ms5571-Ms5576）, designated as mmt operon, whose expression significantly contributes to the biofilm formation in Mycobacterium smegmatis. We showed that in the operon the Ms5575 gene encodes a GntR-like transcriptional repressor and the Ms5576 gene encodes a mannitol2-dehydrogenase which can produce D-mannitol from D-mannose. Strikingly, the D-mannitol molecule can derepress the negative regulation of Ms5575 on the mmt operon to stimulate the operon＇s expression. Consistently, addition of D-mannitol into the medium can obviously induce mycobacterial biofilm formation. Furthermore, we found that Ms0179 positively regulates the mmt operon through its downstream regulator Ms0180. Ms0180 directly binds the mmt operon to positively regulate its expression. Both Ms0179 and Ms0180 significantly affect the mycobacterial biofilm formation. Taken together, we explored a regulatory pathway for the mannitol metabolism and its coordination with the biofilm formation in M. smegmatis. This finding provides novel insights into the unique mechanism of biofilm formation regulation in mycobacteria.

关键词： Transcription regulation Biofilm formation Mannitol Mycobacteria

MpbR,an essential transcriptional factor for Mycobacterium tuberculosis survival in the host,modulates PIM biosynthesis and reduces innate immune responses

在线全文

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2019年第12期46卷 575-589页

作者： Yugang Li Weihui Li Zhiwei Xie Hui Xu zheng-guo he National Key Laboratory of Agricultural Microbiology College of Life Science and TechnologyHuazhong Agricultural UniversityWuhan430070China State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources College of Life Science and TechnologyGuangxi UniversityNanning530004China

Mycobacterium tuberculosis possesses unique cellular envelope components that contribute to bacterial escape from host immune *** mannosides(PIMs)and their higher derivatives are important molecules implicated in host-pathogen interactions in the course of ***,the biosynthetic regulation of these specific lipids and its effect on the bacterial fate in the infected host remain ***,we show that a hypothetical *** transcriptional factor designated as MpbR negatively regulates two transporter genes and affects mycobacterial PIM biosynthesis and biofilm *** inhibits the accumulation of acylated PIM lipids and triggers the mycobacterium to reduce the production of reactive oxygen species and NO during infection,which enhances the survival of *** in *** deletion reduces *** lung burdens and inflammation of infected *** findings provide new insights into the regulation of mycobacterial lipid metabolism and its correlation with pathogenesis of ***.

关键词： Mycobacterium tuberculosis Transcriptional factor Lipid metabolism

Warming intensified the effects of nitrogen addition on N_(2)O emissions from alpine meadow in the northern Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第1期15卷 101-112页

作者： Ming-Jie LI Yi-Qing GE Hasbagan GANJURJAV guo-zheng HU Hong-Bao WU Jun YAN Shi-Cheng he Qing-Zhu GAO Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China National Agricultural Experimental Station for Agricultural Environment Nagqu 852100China Ecology and Nature Conservation Institute Chinese Academy of ForestryBeijing 100091China College of Resource and Environment Anhui Science and Technology UniversityFengyang 233100China Nagqu Agriculture Animal Husbandryand Prataculture Science and Technology Research and Extension CenterNagqu 852100China Tongliao Experimental Middle School Tongliao 028000China

Warming and nitrogen(N)addition may impact soil nitrous oxide(N_(2)O)emissions,but the relationship between plant community composition and soil microbial activities remains *** a two-year field study in the Qinghai-Tibet Plateau,open-top chambers were used to quantify the effects of warming,N-addition,and their interactions on N_(2)O *** found that the N-addition greatly increased N_(2)O emissions by 77.4%in 2018 when compared to the control *** contrast,warming showed little effect on N_(2)0 emissions but did increase the activity of enzymes associated with soil nitrification and denitrification.A combined effect of warming and N-addition of resulted in 208.6%(2018)and 90.8%(2019)increase in N_(2)0 emissions,respectively,compared to the individual treatments of warming or *** warming in alpine meadows is causally linked to increased legume biomass which is further intensified with the *** legume biomass(phed microbial carbon/nitrogen(MBC/MBN)(phe addition of warming further intensifies this *** increased dominance of legumes and microbial N content contributes to this *** outcomes suggest that warming and atmospheric N deposition can stimulate N_(2)O emissions of alpine meadows inthefuture.

关键词： Alpine meadow Community composition Nitrogen addition Nitrous oxide flux Qinghai-Tibet Plateau Warming