检索结果-南通市图书馆

Impact of Local Climate Zones on the Urban Heat and Dry Islands in Beijing:Spatial Heterogeneity and Relative Contributions

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

Journal of meteorological Research 2024年第1期38卷 126-137页

作者： Zuofang ZHENG Fu LUO Nana LI Hua gao Yuanjian YANG Institute of Urban meteorology China Meteorological AdministrationBeijing 100089 School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Key Laboratory of Urban meteorology China Meteorological AdministrationBeijing 100089

Based on the building height and density data on a 100-m resolution,hourly 2-m temperature and humidity data at83 automatic weather stations,and gridded local climate zone(LCZ)data on a 120-m resolution in urban Beijing in2020,this study first employs the semivariogram combined with building parameters to calculate spatial correlations and has identified an LCZ grid resolution of 500 m suitable for best usage of the available observation ***,how the spatially heterogeneous LCZs affect and contribute to the canopy urban heat island intensity(UHII)and urban dry island intensity(UDII)are quantitatively *** is found that UHII is high in winter and low in summer with a unimodal diurnal variation while UDI is low in winter but high in summer with a bimodal diurnal *** LCZ with compact mid-rise(open high-rise)buildings exhibits the highest UHII(UDII),followed by the compact high-rise(compact low-rise),while the LCZ of scattered trees presents both the lowest UHII and the lowest *** most significant difference in the UHII(UDII)among the nine LCZ types in the urban area of Beijing is2.62℃(1.1 g kg^(-1)).Area-weighted averaging analysis reveals that the open mid-rise LCZ is the most significant contributor to the UHII(UDII),immediately followed by compact mid-rise(open low-rise),with the least contribution from bare rock or paved(scattered trees).The results also indicate that beyond the intrinsic physical properties of the LCZs of a city,their area proportions cannot be overlooked in evaluating their impact on the UHI and *** quantitatively findings could help urban planners to create a livable urban climate and environment by adjusting the relevant land use.

关键词： local climate zone(LCZ) urban heat island(UHI) urban dry island(UDI) distribution pattern contribution rate Beijing

Polyvinyl alcohol fiber cement-stabilized macadam:A review and performance evaluation

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 406-423页

作者： Chaohui Wang Jikang Liu Shaochang Chen Feng Chen Zhiwei gao School of Highway Chang'an UniversityXi'an 710064China Shaanxi Transportation Technology Consulting Co. Ltd.Xi'an 710068China School of Information Engineering Xizang Minzu UniversityXianyang 712082China

This review evaluated research results on polyvinyl alcohol fiber cement-stabilized macadam(PVA-FCSm)to further improve the long-term durability of road structures and promote its in-depth study and high-quality *** suitable PVA fiber technical indexes for ordinary cement-stabilized macadam(CSm)were *** difference in the mechanical properties between CSm and PVA-FCSm was *** extent to which PVA fibers enhance the durability of CSm were ***,the mechanism of enhancement of CSm by PVA fibers was ***,the performance of each type of fiber cement-stabilized macadam(FCSm)was compared and *** results indicated that the suggested PVA fiber length and content for CSm were 12-30 mm and 0.6-1.2 kg/m^(3),*** different ages,the mean degree of improvement in the unconfined compressive strength was 14%,20%,and 14%,that in the compressive resilience modulus was 8%,11%,and 6%,and that in the splitting strength was 29%,15%,and 22%,*** different ages,the mean degree of decreased in the dry shrinkage coefficient was 21%,16%,and 15%and that in the temperature shrinkage coefficient(20℃-30℃)was 23%,23%,and 18%,*** coefficients increased with extended curing ***,at the same stress level,PVA-FCSm has a higher fatigue life compared to *** bridging effect,high strength,and high modulus of PVA fiber enhance the strength and anti-cracking of *** recommended fiber type for CSm is PVA fiber.

关键词： Highway and railway engineering PVA fiber cement-stabilized macadam mechanical performance Durability Enhancement mechanism Performance valuation

Tribological and Corrosion Properties of the CoCrAlYTaSiC-xCNTs Coatings Deposited by Laser Cladding

在线全文

学校读者我要写书评

暂无评论

Acta metallurgica Sinica(English Letters) 2024年第4期37卷 726-738页

作者： Hai Zhao Yi Ding Wei gao Bo Yu Jinghui Li mingya Zhang School of material Science and Engineering Anhui University of TechnologyMaanshan243002China maanshan Iron&Steel Co. LtdMaanshan243000China Applied Technology Research Institute Jiujiang Vocational UniversityJiujiang332000China School of metallurgical Engineering Anhui University of TechnologyMaanshan243002China

The mCrAlY coating has been potential candidate for the parts applied in friction and corrosion conditions, and CNTs (carbon nanotubes) are expected to improve the service performance of coatings owing to high lubrication and low chemical reactivity. In this work, a systematic investigation on the tribological and corrosion properties of CoCrAlYTaSiC-xCNTs coatings deposited by laser melting was analyzed. Results showed that the coatings had good-quality without typical metallurgical defects. The CNTs addition homogenized and refined the microstructure of coating, and also improved the tribological and corrosion properties. As the CNTs content changed from 0 to 4 wt%, the wear rate of coating decreased from 16.23 × 10^(-3) to 7.58 × 10^(-3) mg m^(−1), the jcorr of coating decreased from 4.13 × 10^(-4) to 1.23 × 10^(-4) A cm^(−2), and the Rct values increased from 12.69 to 25.07 Ω cm2.

关键词： mCrAlY coating Laser melting deposition Friction Electrochemical corrosion

Hypoxia-mediated programmed cell death is involved in the formation of wooden breast in broilers

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

Journal of Animal Science and Biotechnology 2024年第5期15卷 1918-1931页

作者： xinrui Zhang Tong xing Lin Zhang Liang Zhao Feng gao College of Animal Science and Technology Key Laboratory of Animal Origin Food Production and Safety Guarantee of Jiangsu ProvinceJiangsu Collaborative Innovation Center of Meat Production and ProcessingQuality and Safety ControlNanjing Agricultural UniversityNo.1 WeigangNanjingJiangsu 210095P.R.China

Background Wooden breast(WB)myopathy is a common myopathy found in commercial broiler chickens *** examination has revealed that WB myopathy is accompanied by damage to the pectoralis major(Pm)***,the underlying mechanisms responsible for the formation of WB in broilers have not been fully *** study aimed to investigate the potential role of hypoxia-mediated programmed cell death(PCD)in the formation of WB *** Histological examination and biochemical analysis were performed on the Pm muscle of the control(CON)and WB groups.A significantly increased thickness of the breast muscle in the top,middle,and bottom portions(Pmage of myofibers in the WB *** number of capillaries per fiber in Pm muscle,and the levels of p O_(2) and s O_(2) in the blood,were significantly decreased(Pxic conditions in the Pm muscle of the WB *** further evaluated the PCD-related pathways including autophagy,apoptosis,and necroptosis to understand the consequence response to enhanced hypoxic conditions in the Pm muscle of birds with *** ratio of LC3 II to LC3 I,and the autophagy-related factors HIF-1α,BNIP3,Beclin1,AmPKα,and ULK1 at the m RNA and protein levels,were all significantly upregulated(Pm muscle of the WB *** apoptotic index,as well as the expressions of Bax,Cytc,caspase 9,and caspase 3,were significantly increased(Pm muscle,indicating the occurrence of apoptosis mediated by the mitochondrial ***,the expressions of necroptosis-related factors RIP1,RIP3,and mLKL,as well as NF-κB and the pro-inflammatory cytokines TNF-α,IL-1β,and IL-6,were all significantly enhanced(Pm *** T

关键词： Apoptosis Autophagy Broiler chicken Hypoxia Necroptosis Wooden breast

LLm4CP:Adapting Large Language models for Channel Prediction

在线全文

学校读者我要写书评

暂无评论

Journal of Communications and Information Networks 2024年第2期9卷 113-125页

作者： Boxun Liu xuanyu Liu Shijian gao xiang Cheng Liuqing Yang State Key Laboratory of Advanced Optical Communication Systems and Networks School of ElectronicsPeking UniversityBeijing 100871China Internet of Things Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China Internet of Things Thrust and Intelligent Transportation Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China Department of Electronic and Computer Engineering and Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina

Channel prediction is an effective approach for reducing the feedback or estimation overhead in massive multi-input multi-output (m-mImO) systems. However, existing channel prediction methods lack precision due to model mismatch errors or network generalization issues. Large language models (LLms) have demonstrated powerful modeling and generalization abilities, and have been successfully applied to cross-modal tasks, including the time series analysis. Leveraging the expressive power of LLms, we propose a pre-trained LLm-empowered channel prediction(LLm4CP)method to predict the future downlink channel state information (CSI) sequence based on the historical uplink CSI sequence. We fine-tune the network while freezing most of the parameters of the pre-trained LLm for better cross-modality knowledge transfer. To bridge the gap between the channel data and the feature space of the LLm,preprocessor, embedding, and output modules are specifically tailored by taking into account unique channel characteristics. Simulations validate that the proposed method achieves state-of-the-art (SOTA) prediction performance on full-sample, few-shot, and generalization tests with low training and inference costs.

关键词： channel prediction massive multi-input multi-output(m-mImO) large language models(LLms) fine-tuning time-series

A nonlinear wake model of a wind turbine considering the yaw wake steering

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

Journal of Oceanology and Limnology 2024年第3期42卷 715-727页

作者： Yunzhou LI Zhiteng gao Shoutu LI Suiping QI xiaoyu TANG College of meteorology and Oceanography National University of Defense TechnologyChangsha 410073China multi-function Towing Tank School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou 730050China Institute of Oceanographic Instrumentation Qilu University of Technology(Shandong Academy of Sciences)Qingdao 266061China State Key Laboratory of Industrial Control Technology College of Control Science and EngineeringZhejiang UniversityHangzhou 310027China Laoshan Laboratory Qingdao 266237China

Duo to fluctuations in atmospheric turbulence and yaw control strategies,wind turbines are often in a yaw *** predict the far wake velocity field of wind turbines quickly and accurately,a wake velocity model was derived based on the method of momentum conservation considering the wake steering of the wind turbine under yaw *** consider the shear effect of the vertical incoming wind direction,a two-dimensional Gaussian distribution function was introduced to model the velocity loss at different axial positions in the far wake region based on the assumption of nonlinear wake *** work also developed a“prediction-correction”method to solve the wake velocity field,and the accuracy of the model results was verified in wake experiments on the Garrad Hassan wind ***,a 33-kW two-blade horizontal axis wind turbine was simulated using this method,and the results were compared with the classical wake model under the same parameters and the computational fluid dynamics(CFD)simulation *** results show that the nonlinear wake model well reflected the influence of incoming flow shear and yaw wake steering in the wake velocity ***,computation of the wake flow for the Horns Rev offshore wind farm with 80 wind turbines showed an error within 8%compared to the experimental *** established wake model is less computationally intensive than other methods,has a faster calculation speed,and can be used for engineering calculations of the wake velocity in the far wakefield of wind turbines.

关键词： far wake wake model wake steering wind shear wind farm

Cellular atlases of ovarian microenvironment alterations by diet and genetically-induced obesity

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第1期67卷 51-66页

作者： Yonghui Jiang xueying gao Yue Liu xueqi Yan Huangcong Shi Rusong Zhao Zi-Jiang Chen Fei gao Han Zhao Shigang Zhao Center for Reproductive medicine Shandong UniversityJinan 250012China Research Unit of Gametogenesis and Health of ART-Offspring Chinese Academy of Medical Sciences(No.2021RU001)Jinan 250012China Key Laboratory of Reproductive Endocrinology of ministry of Education Shandong UniversityJinan 250012China Shandong Key Laboratory of Reproductive medicine Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250012China Shandong Provincial Clinical Research Center for Reproductive Health Jinan 250012China National Research Center of Assisted Reproductive Technology and Reproductive Genetics Shandong UniversityJinan 250012China The Affiliated Suzhou Hospital of Nanjing medical University Suzhou Municipal HospitalGusu SchoolNanjing Medical UniversitySuzhou 215000China Center for reproductive medicine Ren Ji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200127China Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics Shanghai 200127China State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of ScienceBeijing 100101China

Obesity,which can arise from genetic or environmental factors,has been shown to cause serious damages to the reproductive *** ovary,as one of the primary regulators of female fertility,is a complex organ comprised of heterogeneous cell types that work together to maintain a normal ovarian microenvironment(OmE).Despite its importance,the effect of obesity on the entire ovary remains poorly *** this study,we performed ovary single-cell and nanoscale spatial RNA sequencing to investigate how the OmE changed under different kinds of obesity,including high-fat diet(HFD)induced obesity and Leptin ablation induced obesity(OB).Our results demonstrate that OB,but not HFD,dramatically altered the proportion of ovarian granulosa cells,theca-interstitial cells,luteal cells,and endothelial ***,based on the spatial dynamics of follicular development,we defined four subpopulations of granulosa cell and found that obesity drastically disrupted the differentiation of mural granulosa cells from small to large antral ***,HFD enhanced follicle-stimulating hormone(FSH)sensitivity and hormone conversion,while OB caused decreased sensitivity,inadequate steroid hormone conversion,and impaired follicular *** differences can be explained by the differential expression pattern of the transcription factor ***,our study provides a powerful and high-resolution resource for profiling obesity-induced OmE and offers insights into the diverse effects of obesity on female reproductive disorders.

关键词： obesity ovarian microenvironment snRNA-seq Stereo-seq Foxo1

Evaluating the performance and influencing factors of three portable black carbon monitors for field measurement

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第5期139卷 320-333页

作者： Liqing Wu Yicheng Shen Fei Che Yuzhe Zhang Jian gao Chong Wang State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Jinan Ecological Environmental Protection Grid-Based Supervision Center Jinan 250013China

Black carbon(BC)is associated with adverse human health and climate *** BC spatial distribution imperatively requires low-cost and portable *** portable BC monitors are commercially available,but their accuracy and reliability are not always satisfactory during continuous field *** study evaluated three models of portable black carbon monitors,C12,mA350 and DST,and investigates the factors that affect their *** monitors were tested in urban Beijing,where portable devices running for one month alongside a regular-size reference aethalometer *** study considers several factors that could influence the monitors'performance,including ambient weather,aerosol composition,loading artifacts,and built-in *** results show that mA350and DST present considerable discrepancies to the reference instrument,mainly occurring at lower concentrations(0-500 ng/m^(3))and higher concentrations(2500-8000 ng/m^(3)),*** discrepancies were likely caused by the anomalous noise of mA350 and the loading artifacts of *** study also suggests that the ambient environment has limited influence on the monitors'performance,but loading artifacts and accompanying compensation algorithms can result in unrealistic *** on the evaluation,the study suggests that C12 is the best choice for unsupervised field measurement,DST should be used in scenarios where frequent maintenance is available,and mA350 is suitable for research purposes with post-processing *** study highlights the importance of assigning portable BC monitors to appropriate applications and the need for optimized real-time compensation algorithms.

关键词： Black carbon Aethalometer Loading artifact Performance evaluation Portable device

Large reversible magnetocaloric effect in antiferromagnetic Er_(3)Si_(2)C_(2) compound

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第8期42卷 1555-1559,I0005页

作者： Hao Sun Lu Tian xinqiang gao Zhaojun mo Jun Shen Baogen Shen School of Rare Earths University of Science and Technology of ChinaHefei230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341000China Department of Energy and Power Engineering School of Mechanical EngineeringBeijing Institute of TechnologyBeijing100081China

The magnetic properties,magnetic phase transition and magnetocaloric effects(mCE) of Er_(3)Si_(2)C_(2) compound were investigated based on theoretical calculations and experimental *** on the first principles calculations,the antiferromagnetic(AFm) ground state type in Er_(3)Si_(2)C_(2) compound was predicted and its electronic structure was *** experimental results show that Ei_(3)Si_(2)C_(2) compound is an AFm compound with the Neel temperature(T_(N) of 7 K and undergoes a field-induced firstorder magnetic phase transition from AFm to ferromagnetic(Fm) under magnetic fields exceeding 0.6 T at 2 *** magnetic transition process of Er_(3)Si_(2)C_(2) compound was investigated and *** values of the maximum magnetic entropy change(-ΔS_(m)^(max)) and the refrigeration capacity(RC) are 17 J/(kg·K)and 193 J/kg under changing magnetic fields of 0-5 T,*** a potential cryogenic magnetic refrigerant,the Er_(3)Si_(2)C_(2) compound also provides an interesting research medium to study the magnetic phase transition process.

关键词： magnetic materials magnetocaloric metamagnetic transitions magnetic phase transition Rare earths