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Understanding the Relationship Between Shrinking Cities and Land Prices:Spatial Pattern,Effectiveness,and Policy Implications

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Chinese Geographical Science 2024年第1期34卷 1-18页

作者： WANG Xiaohui PENG Li HUANG Kexin DENG Wei College of Geography and Resources Sichuan Normal UniversityChengdu610101China Key Laboratory of Land Resources Evaluation and Monitoring in southwest Ministry of EducationSichuan Normal UniversityChengdu610101China

Urban shrinkage has emerged as a widespread phenomenon globally and has a significant impact on land,particularly in terms of land use and *** study focuses on 2851 county-level cities in China in 2005–2018(excluding Hong Kong,Macao,Taiwan,and‘no data’areas in Qinhai-Tibet Plateau)as the fundamental units of *** employing nighttime light(NTL)data to identify shrinking cities,the propensity score matching(PSM)model was used to quantitatively examine the impact of shrinking cities on land prices,and evaluate the magnitude of this *** findings demonstrate the following:1)there were 613 shrinking cities in China,with moderate shrinkage being the most prevalent and severe shrinkage being the least.2)Regional disparities are evident in the spatial distribution of shrinking cities,especially in areas with diverse terrain.3)The spatial pattern of land price exhibits a significant correlated to the economic and administrative levels.4)Shrinking cities significantly negatively impact on the overall land price(ATT=–0.1241,P<0.05).However,the extent of the effect varies significantly among different spatial *** study contributes novel insights into the investigation of land prices and shrinking cities,ultimately serving as a foundation for government efforts to promote the sustainable development of urban areas.

关键词： shrinking cities land price propensity score matching(PSM) relative effectiveness China

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Doppler-resilient waveform design in integrated MIMO radar-communication systems

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Science China(Information Sciences) 2024年第1期67卷 187-202页

作者： Zhengchun ZHOU Bing LIU Bingsheng SHEN Avik Ranjan ADHIKARY Pingzhi FAN Institute of Mobile Communications Southwest Jiaotong University Department of Mathematics Southwest Jiaotong University

In recent years,the increased high-rate wireless services(5G and 6G) and reliable sensing capabilities(automotive radar,air traffic control,geophysical monitoring),have led to more serious spectrum ***,radars and communication systems are often seen to be “competing” for the same *** this scenario,an integrated platform for radar and communication systems seems to be an optimal solution to address the *** this paper,we propose a preamble waveform design based on zero-correlation zone(ZCZ) and zero odd-correlation zone(ZOCZ) sequence sets,which are Doppler resilient in multiple-input,multiple-output(MIMO) *** preamble waveforms can be simultaneously used for channel estimation and radar sensing in RadCom *** ambiguity function of the proposed waveforms displays low/zero sidelobes within a time-delay correlation ***,we give some numerical results to show the efficiency of the proposed waveforms in radar sensing and channel estimation.

关键词： ambiguity function correlation channel estimation integrated radar and communication (RadCom) systems MIMO radar zero correlation zone (ZCZ) sequence set zero odd-correlation zone (ZOCZ) sequence set

Ambient electrocatalytic synthesis of urea by co-reduction of NO_(3)^(-) and CO_(2) over graphene-supported In_(2)O_(3)

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Chinese Chemical Letters 2024年第3期35卷 538-543页

作者： Yini Mao Yong Jiang Hao Liu Yimin Jiang Ming Li Wei Su Rongxing He Key Laboratory of Luminescence Analysis and Molecular Sensing(southwest university) Ministry of EducationCollege of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China Key Laboratory of Beibu Gulf Environment Change and Resources Utilization(Nanning normal university) Ministry of EducationCollege of Chemistry and Life ScienceNanning Normal UniversityNanning 530000China

Urea plays a vital role in the sustainable development of mankind as it is one of the most important nitrogen *** synthesis of urea is accompanied by a high level of energy consumption while electrocatalytic methods suffer from low yields and poor *** work achieves efficient synthesis of urea by designing the graphene-In_(2)O_(3)electrocatalysts for the co-activated reduction of nitrate and carbon dioxide,where the formation rate of urea,Faraday efficiency(FE)and carbon selectivity at-0.35 V *** can reach 357.47μg mg^(-1)h^(-1),10.46%and~100%,***,the key intermediates in the C–N coupling reaction are demonstrated to be*NH_(2)and*CO_(2),which is of novelty compared to previous *** work may provide inspiration for subsequent studies on the reaction mechanism of the electrochemical synthesis of urea,as well as theoretical guidance for the sustainable synthesis of some other important chemical substances.

关键词： Graphene-supported In_(2)O_(3) Dispersion effect Efficient C-N coupling Key intermediate Urea

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Nest complexity correlates with larger brain size but smaller body mass across bird species

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Integrative Zoology 2024年第3期19卷 496-504页

作者： Shaobin LI Yuxin LIU Xiaolong DU Guopan LI Wenbo LIAO College of Life Science Yangtze UniversityJingzhouChina Key Laboratory of southwest China Wildlife Resources Conservation(Ministry of Education) China West Normal UniversityNanchongChina

Amniotes differ substantially in absolute and relative brain size after controlling for allometry,and numerous hypotheses have been proposed to explain brain size *** size is thought to correlate with processing capacity and the brain’s ability to support complex manipulation such as nest-building *** increased complexity of nest structure is supposed to be a measure of an ability to manipulate nesting material into the required *** degree of nest-structure complexity is also supposed to be associated with body mass,partly because small species lose heat faster and delicate and insulated nests are more crucial for temperature control of eggs during incubation by small ***,we conducted comparative analyses to test these hypotheses by investigating whether the complexity of species-typical nest structure can be explained by brain size and body mass(a covariate also to control for allometric effects on brain size)across 1353 bird species from 147 *** with these hypotheses,our results revealed that avian brain size increases as the complexity of the nest structure increases after controlling for a significant effect of body size,and also that a negative relationship exists between nest complexity and body mass.

关键词： body size brain size comparative analysis nest building nest type reproductive investment

Eco-physiological characteristics of Tetracentron sinense *** in response to different light intensities

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Journal of Forestry Research 2024年第3期35卷 29-44页

作者： Rong Wang Xueheng Lu Hongyan Han Xuemei Zhang Yonghong Ma Qinsong Liu Xiaohong Gan Key Laboratoryof southwest Wildlife Resources Conservation Ministry of EducationChina West Normal UniversityNanchong 637009People's Republic of China Institute of Plant Adaptation and Utilization in southwest Mountain China West Normal UniversityNanchong 637009People's Republic of China Office of the People's Government of Yuexi County Yuexi County 616650Liangshan Yi Autonomous PrefecturePeople's Republic of China

The regeneration of Tetracentron sinense *** poor in the understory and in open areas due to the charac-teristics of natural regeneration of the species on forest edges and in *** is unclear whether different light intensities in various habitats affect eco-physiological characteristics of saplings and their natural *** this study,the light intensity in *** habitats was simulated by artificial shading(L1:100%NS(natural sunlight)in the open;L2:50%NS in a forest gap or edge;L3:10%NS in understory)to investigate differences in morphology,leaf structure,physiology,and photosynthesis of 2-year-old sap-lings,and to analyze the mechanism of light intensity on sapling *** differences were observed in morphology(including leaf area,and specific leaf area)under different light *** to L1 and L3,chloroplast structure in L2 was *** increasing time,superoxide dismutase(SOD)and catalase(CAT)activities in L2 became gradually higher than under the other light intensities,while malondialdehyde(MDA)content was *** decreased osmoregulation substance contents of leaves but increased *** results suggest that light intensities significantly affect the eco-physiological characteristics of *** saplings and they would respond most favorably at intermediate levels of light by optimizing eco-physiological ***,50%natural sunlight should be created to promote saplings establishment and population recovery of *** during in situ conservation,including sowing mature seeds in forest edges or gaps and providing appropriate shade protection for seedlings and saplings in the open.

关键词： Chloroplast ultrastructure Eco-physiological characteristics Light intensities Sapling establishment Tetracentron sinense Oliv

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Impact of non-ideal UE hardware on cell-free massive MIMO network with centralized operation

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Science China(Information Sciences) 2024年第4期67卷 255-271页

作者： Ning LI Pingzhi FAN Institute of Mobile Communications southwest Jiaotong university

This paper investigates the impact of non-ideal user equipment(UE) hardware on a cell-free(CF) massive MIMO(mMIMO) network with centralized operation under spatially correlated channels. The minimum mean-squared error(MMSE) estimator can be derived with the help of the generic non-ideal UE hardware model. It is demonstrated that even if the effective signal-to-noise ratio approaches infinity, pilot contamination and imperfect hardware can cause a non-zero estimation error floor. After that, a lower bound is determined for the ergodic uplink capacity of the centralized CF mMIMO network under non-ideal UE hardware. Moreover, the optimal receive combining vector is obtained to maximize the uplink spectral efficiency(SE). The maximum ratio(MR) and regularized zero-forcing(RZF) combining schemes are offered as alternatives in light of the computational complexity of the MMSE receiver. Comparing the RZF to the MMSE scheme under different levels of hardware impairments, our findings indicate that the RZF receiver suffers a negligible loss in total SE. For MR combining, a novel closed-form uplink achievable SE expression is obtained based on the MMSE estimator and the use-and-then-forget bounding technique. This expression gives vital insights into the achievable uplink performance with UE hardware impairments. Besides, for various hardware impairment factors, the impact of pilot sequence length on average sum SE is disclosed for different receive combining schemes. To increase the overall SE of the max-min fairness scheme, a heuristic fractional power control scheme with UE hardware impairments is developed, which can essentially avoid sacrificing the SE of other UEs while maximizing the SE of the unluckiest UE in the whole network. Finally,our theoretical performance analysis and power control algorithm are validated by simulation results, and fundamental design guidelines are provided for selecting hardware satisfying the practical UE requirements.

关键词： cell-free massive MIMO centralized operation spatially correlated channels hardware impairments channel estimation uplink spectral efficiency optimal receive combining pilot length design fractional power control

Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 855-871页

作者： Peng Chen Wenhao Chen Jiaxin Chen Zhiyu Chen Yang Tang Ge Liu Bensheng Huang Zhiqing Zhang School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China Sichuan Provincial Engineering Research Center of Advanced Materials Manufacturing Technology for Shale Gas High-Efficient Exploitation Southwest Petroleum UniversityChengdu 610500China College of Materials Science and Engineering Chongqing UniversityChongqing 400045China School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China School of Robot Engineering Yangtze Normal UniversityChongqing 408100China

The investigation concentrates on friction stir welded(FSW)Al-Cu-Li alloy concerning its local microstructural evolution and mechanical *** grain features were characterized by electron back scattered diffraction(EBSD)technology,while precipitate characterization was conducted by using transmission electron microscopy(TEM)aligned along[011]Al and[001]Al zone *** mechanical properties are evaluated through micro-hardness and tensile *** can be found that nugget zones exhibit finely equiaxed grains evolved through complete dynamic recrystallization(DRX),primarily occurring in continuous dynamic recrystallization(CDRX)and discontinuous dynamic recrystallization(DDRX).In the thermal-mechanically affected zone(TMAZ),numerous sub-structured grains,exhibiting an elongated morphology,were created due to partial DRX,signifying the dominance of CDRX,DDRX,and geometric dynamic recrystallization(GDRX)in this region.T_(1)completely dissolves in the nugget zone(NZ)leading to the formation of Guinier-Preston zones and increase ofδ′,β′and S′.Conversely,T_(1)partially solubilizes in TMAZ,the lowest hardness zone(LHZ)and heat affected zone(HAZ),and the residual T_(1)undergoes marked coarsening,revealing various T_(1)*** solubilization and coarsening of T_(1)are primary contributors to the degradation of hardness and strength.θ′primarily dissolves and coarsens in NZ and TMAZ,whilst this precipitate largely coarsens in HAZ and LHZ.σ,TB,grain boundary phases(GBPs)and precipitate-free zone(PFZ)are newly generated during FSW.σexists in the TMAZ,LHZ and HAZ,whereas TB nucleates in *** and PFZ mostly develop in LHZ and HAZ,which can cause strain localization during tensile deformation,potentially leading to LHZ joint fracture.

关键词： Al-Cu-Li alloy Friction stir welding Microstructure evolution Mechanical properties

Body color plasticity of Diaphorina citri reflects a response to environmental stress

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Insect Science 2024年第3期31卷 937-952页

作者： Jiayao Fan Feng Shang Huimin Pan Chenyang Yuan Tianyuan Liu Long Yi Jinjun Wang Wei Dou Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionSouthwest UniversityChongqingChina Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River(Ministry of Education) Southwest UniversityChongqingChina Academy of Agricultural Sciences Southwest UniversityChongqingChina National Navel Orange Engineering Research Center Gannan Normal UniversityGanzhouJiangxi ProvinceChina

Body color polyphenism is common in Diaphorina *** studies compared physiological characteristics in ***,but the ecological and biological significance of its body color polyphenism remains poorly *** studied the ecological and molecular effects of stressors related to body color in *** or low temperature induced a high proportion of gray morphs,which had smaller bodies,lower body weight,and greater susceptibility to the insecticide *** performed transcriptomic and metabolomics analysis of 2 color morphs in *** expression dynamics revealed that the differentially expressed genes were predominantly involved in energy metabolism,including fatty acid metabolism,amino acid metabolism,and carbohydrate *** these genes,plexin,glycosidase,phospholipase,take out,trypsin,and triacylglycerol lipase were differentially expressed in 2 color morphs,and 6 hsps(3 hsp70,hsp83,hsp90,hsp68)were upregulated in gray *** metabolome data showed that blue morphs exhibited a higher abundance of fatty acid and amino acid,whereas the content of carbohydrates was elevated in gray *** study partly explains the body color polyphenism of *** and provides insights into the molecular changes of stress response of ***.

关键词： body color energy metabolism environmental stress phenotypic plasticity polyphenism trade-off

Facile synthesis of a tumor microenvironment-responsive nanomaterial with metallic polyphenol-encapsulated for enhanced synergistic therapy

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Journal of Rare Earths 2024年第10期42卷 1895-1902页

作者： Kaige Yu Nuo Kou Shouqiang Zhang Tianqi Cao Hanqing Wu Jing Zhou Department of Chemistry Capital Normal University College of Teacher Education Capital Normal University

The tumor microenvironment（TME） differs from normal tissue cells in its physiological and biochemical *** construction of TME-responsive nanoplatforms requires a tedious preparation process and complex multicomponent *** this work,Er@EGCG-Cu,a TME-responsive nanoplatform,was simply and rapidly synthesized by combining rare earth-doped nanomaterials（NaLuF4:Yb,Er） with EGCG-Cu which is based on the ability of metal ions to coordinate with polyphenols to form a metal-phenolic network（MPN） *** MPN structure is then destroyed under an acidic TME,releasing the chemotherapy（CT） drug EGCG,which can cause apoptosis,CuxSyis generated by combining Cu2+with H2S overexpressed in human colorectal cancer cells and can be used for photothermal therapy（PTT）.Cell experiments show that laser irradiation improves the CT/PTT synergistic effect of Er@*** study has significance for the construction of TME-responsive nanomedicines with simple and rapid preparation for synergistic therapy.

关键词： Metal-polyphenol networks Nanomaterials Rare earths Synergistic therapy Tumor microenvironment