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Elevation response of above-ground net primary productivity for Picea crassifolia to climate change in Qilian Mountains of northwest China based on tree rings

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Journal of Geographical Sciences 2024年第1期34卷 146-164页

作者： WU Xuan JIAO Liang DU Dashi XUE Ruhong WEI Mengyuan ZHANG Peng College of Geography and Environment Science Northwest Normal UniversityLanzhou 730070China Key Laboratory of Resource Environment and Sustainable Development of Oasis Northwest Normal UniversityLanzhou 730070China

Current ecosystem models used to simulate global terrestrial carbon balance generally suggest that terrestrial landscapes are stable and mature,but terrestrial net primary productivity(NPP)data estimated without accounting for disturbances in species composition,environment,structure,and ecological characteristics will reduce the accuracy of the global carbon ***,the steady-state assumption and neglect of elevation-related changes in forest NPP is a *** Qilian Mountains are located in continental climate zone,and vegetation is highly sensitive to climate *** quantified aboveground biomass(AGB)and aboveground net primary productivity(ANPP)sequences at three elevations using field-collected tree rings of Picea crassifolia in Qilian Mountains of northwest *** results showed that(1)There were significant differences between AGB and ANPP at the three elevations,and the growth rate of AGB was the highest at the low elevation(55.99 t ha^(–1)10a^(–1)).(2)There are differences in the response relationship between the ANPP and climate factors at the three elevations,and drought stress is the main climate signal affecting the change of ANPP.(3)Under the future climate scenario,drought stress intensifies,and the predicted decline trend of ANPP at the three elevations from mid-century to the end of this century is–0.025 t ha^(–1)10a^(–1),respectively;–0.022 t ha^(–1)10a^(–1);At–0.246 t ha^(–1)10a^(–1),the level of forest productivity was significantly *** results reveal the elevation gradient differences in forest productivity levels and provide key information for studying the carbon sink potential of boreal forests.

关键词： global climate change tree ring aboveground net primary productivity aboveground biomass drought stress Qilian Mountains

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Radial growth in Qinghai spruce is most sensitive to severe drought in the Qilian Mountains of northwest China

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Journal of Forestry Research 2024年第3期35卷 73-86页

作者： Xuge Wang Liang Jiao Ruhong Xue Peng Zhang Dashi Du Mengyuan Wei Qian Li College of Geography and Environmental Science Northwest Normal UniversityNo.967Anning East RoadLanzhou 730070People's Republic of China Key Laboratory of Resource Environment and Sustainable Development of Oasis Northwest Normal UniversityLanzhou 730070Gansu ProvincePeople's Republicof China

Global warming and frequent extreme drought events lead to tree death and extensive forest decline,but the underlying mechanism is not *** drought years,cambial development is more sensitive to climate change,but in different phenological stages,the response rela-tionship is ***,the dynamic relationship between tree radial growth and climatic/environmental fac-tors needs to be *** thus continuously monitored radial growth of Qinghai spruce(Picea crassifolia Kom.)and environmental factors from January 2021 to November 2022 using point dendrometers and portable meteorological weather stations in the central area of the Qilian *** relationship and stability between the radial growth of Qinghai spruce and environmental factors were compared for different levels of drought in 2021 and *** year 2022 had higher temperatures and less precipitation and was drier than *** with 2021,the growing period in 2022 for Qinghai spruce was 10 days shorter,maximum growth rate(Grmax)was 4.5μm·d^(-1) slower,and the initiation of growth was 6 days *** of Qinghai spruce was always restricted by drought,and the stem radial increment(SRI)was more sensitive to precipitation and air relative *** changes in cumulative radial growth were divided into four phenological stages according to the time of growth onset,cessation,and maximum growth rate(Grmax)of Qinghai *** responses of SRI to climate change were stronger in Stage 3 and Stage 4 of 2021 and stronger in Stage 1(initiation growth stage)and Stage 3 of *** results provide important information on the growth of the trees in response to drought and for specific managing forests as the climate warms.

关键词： Picea crassifolia Radial growth dynamics Severe drought Response stability Point dendrometer

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Linkage between precipitation isotopes and water vapor sources in the monsoon margin:Evidence from arid areas of northwest China

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Journal of Arid Land 2024年第3期16卷 355-372页

作者： CHEN Fenli ZHANG Qiuyan WANG Shengjie CHEN Jufan GAO Minyan Mohd Aadil BHAT College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730000China Key Laboratory of Resource Environment and Sustainable Development of Oasis of Gansu Province Northwest Normal UniversityLanzhou 730000China School of Ocean and Earth Science Tongji UniversityShanghai 200092China

The isotope composition in precipitation has been widely considered as a tracer of monsoon *** with the coastal region,the monsoon margin usually has limited precipitation with large fluctuation and is usually sensitive to climate *** water resource management in the monsoon margin should be better planned by understanding the composition of precipitation isotope and its influencing *** this study,the precipitation samples were collected at five sampling sites(Baiyin City,Kongtong District,Maqu County,Wudu District,and Yinchuan City)of the monsoon margin in the northwest of China in 2022 to analyze the characteristics of stable hydrogen(δD)and oxygen(δ18O)*** analyzed the impact of meteorological factors(temperature,precipitation,and relative humidity)on the composition of precipitation isotope at daily level by regression analysis,utilized the Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)-based backward trajectory model to simulate the air mass trajectory of precipitation events,and adopted the potential source contribution function(PSCF)and concentration weighted trajectory(CWT)to analyze the water vapor *** results showed that compared with the global meteoric water line(GMWL),the slope of the local meteoric water line(LMWL;δD=7.34δ^(18)O-1.16)was lower,indicating the existence of strong regional evaporation in the study *** significantly contributed toδ18O value,while relative humidity had a significant negative effect onδ18O *** the backward trajectory analysis,we found eight primary locations that were responsible for the water vapor sources of precipitation in the study area,of which moisture from the Indian Ocean to South China Sea(ITSC)and the western continental(CW)had the greatest influence on precipitation in the study *** hydrogen and oxygen isotopes in precipitation are significantly influenced by the sources and transportation paths of air *** addition,the r

关键词： water vapor monsoon margin stable water isotope transport trajectory air mass d-excess δ18O δD

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Selenium nanoparticles in aquaculture: Unique advantages in the production of Se-enriched grass carp(Ctenopharyngodon idella)

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Animal Nutrition 2024年第1期16卷 189-201页

作者： Chao Zhu Zifang Wu Qimin Liu Xiaolin Wang Lijuan Zheng Shuyang He Fangxia Yang Hong Ji Wuzi Dong College of Animal Science and Technology Northwest A&F University Biology Research Centre of Qin Mountains Wildlife Northwest A&F University College of Forestry Northwest A&F University

The production of selenium-enriched fish can contribute to alleviating selenium deficiency in human diets. However, it is still unclear which selenium source, as an additive, can efficiently and costeffectively produce high-quality selenium-enriched fish. This study evaluated the effects of selenium nanoparticles（SeNP）, selenite, and selenomethionine（SeMet） on the growth, antioxidant capacity, selenium content, selenium speciation, and meat quality of grass carp. Ten diets were prepared, including a basal diet（BD） and three concentrations（0.1, 0.3, and 0.9 mg/kg） of SeNP, selenite, and SeMet. A total of600 fish（250.79 ± 1.57 g） were randomly assigned to 30 tanks（3 tanks/group）. Fish were fed the experimental diet three times daily for 60 d. In this study, SeNP most significantly promoted the growth and antioxidant capacity of grass carp, with 0.3 mg/kg SeNP identified as the optimal additive concentration. Additionally, SeNP demonstrated equally excellent bioavailability as SeMet and significantly increased the content of SeMet in grass carp（Ctenopharyngodon idella） muscle. Furthermore, compared to SeMet and selenite, dietary SeNP could more significantly enhance the content of selenocysteine（SeCys2） and methylselenocysteine（MeSeCys） in grass carp muscle tissue. In addition, we have demonstrated that SeCys2and MeSeCys promote apoptosis of cancer cells（HeLa） through the mitochondrial apoptotic pathway（involving Bax and Bcl-2）. Furthermore, as an additive, 0.3 mg/kg SeNP significantly improved the flesh quality of grass carp by reducing crude fat and heavy metal content, as well as increasing the levels of eicosapentaenoic acid（EPA） and docosahexaenoic acid（DHA） and the ratio of n-3/n-6 polyunsaturated fatty acid（PUFA）. In summary, SeNP is the most suitable additive for producing selenium-enriched fish.

关键词： Selenium nanoparticle Speciation analysis Grass carp Selenium additive

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Preparation of PrFe_(x)Co_(1-x)O_(3)/Mt catalyst and study on degradation of 2-hydroxybenzoic acid wastewater by catalytic wet peroxide oxidation

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Chinese Journal of Chemical Engineering 2024年第1期65卷 286-297页

作者： Binxia Zhao Yijia Gao Tiancheng Hun Xiaoxiao Fan Nan Shao Xiaoqian Chen School of Chemical Engineering Northwest UniversityXi'an 710069China

In this study,the perovskite nanocomposite PrFe_(x)Co_(1-x)O_(3)(Pr(S))was successfully synthesized by the sol-gel method;PrFe_(x)Co_(1-x)O_(3)/Al-pillared montmorillonite(Pr(S)/Mt)catalysts were prepared by impregnation(D)method and solid-melting(G)method,respectively,with Pr(S)as the active component and Al-pillared montmorillonite as the *** catalysts were applied to treat the 2-hydroxybenzoic acid(2-HA)-simulated wastewater by catalytic wet peroxide oxidation(CWPO)technique,and the chemical oxygen demand(COD)removal rate and the 2-HA degradation rate were used as indicators to evaluate the catalytic *** results of the experiment indicated that the solid-melting method was more conducive to preparing the catalyst when the Co/Fe molar ratio of 7:3 and the optimal structural properties of the catalysts were *** influence of operating parameters,including reaction temperature,catalyst dosage,H_(2)O_(2)dosage,pH,and initial 2-HA concentration,were optimized for the degradation of 2-HA by *** results showed that 97.64%of 2-HA degradation and 75.23%of COD removal rate were achieved under more suitable experimental *** addition,after the catalyst was used five times,the degradation rate of 2-HA could still reach 76.93%,which implied the high stability and reusability of the *** high catalytic activity of the catalyst was due to the doping of Co into PrFeO_(3),which could promote the generation of HO·,and the high stability could be attributed to the loading of Pr(S)onto Al-Mt,which reduced the leaching of reactive *** study of reaction mechanism and kinetics showed that the whole degradation process conformed to the pseudo-firstorder kinetic equation,and the Langmuir-Hinshelwood method was applied to demonstrate that catalysis was dominant in the degradation process.

关键词： Montmorillonite Perovskite Catalytic wet peroxide oxidation(CWPO) 2-Hydroxybenzoic acid

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Ecological Network Resilience of Shiyang River Basin: An Arid Inland Watershed of northwest China

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Chinese Geographical Science 2024年第5期34卷 951-966页

作者： HE Yangxi LIU Chunfang NI Bowen LIAN Hugang School of Management Northwest Normal UniversityLanzhou 730070China Research Center of Land Use and Comprehensive Improvement Engineering of Gansu Province Lanzhou 730070China

Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem *** assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid *** River Basin is an arid watershed in northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)*** results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial ***,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river ***,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.

关键词： Ecological Network Resilience(ENR) Complex Adaptive System(CAS) element-structure-function Shiyang River Basin northwest China

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General multi-attack detection for continuous-variable quantum key distribution with local local oscillator

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Chinese Physics B 2024年第5期33卷 255-262页

作者：康茁刘维琪齐锦贺晨 School of Information Science and Technology Northwest UniversityXi'an 710127China

Continuous-variable quantum key distribution with a local local oscillator(LLO CVQKD)has been extensively researched due to its simplicity and *** practical security of an LLO CVQKD system,there are two main attack modes referred to as reference pulse attack and polarization attack ***,there is currently no general defense strategy against such attacks,and the security of the system needs further ***,we employ a deep learning framework called generative adversarial networks(GANs)to detect both *** first analyze the data in different cases,derive a feature vector as input to a GAN model,and then show the training and testing process of the GAN model for attack *** proposed model has two parts,a discriminator and a generator,both of which employ a convolutional neural network(CNN)to improve *** results show that the proposed scheme can detect and classify attacks without reducing the secret key rate and the maximum transmission *** only establishes a detection model by monitoring features of the pulse without adding additional devices.

关键词： CVQKD generative adversarial network attack classification

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Higher-dimensional integrable deformations of the classical Boussinesq-Burgers system

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Communications in Theoretical Physics 2024年第6期76卷 1-12页

作者： Xiaoyu Cheng Qing Huang School of Mathematics Northwest UniversityXi'an 710127China

In this paper,the(1+1)-dimensional classical Boussinesq-Burgers(CBB)system is extended to a(4+1)-dimensional CBB system by using its conservation laws and the deformation *** Lax integrability,symmetry integrability and a large number of reduced systems of the new higher-dimensional system are ***,for illustration,an exact solution of a(1+1)-dimensional reduced system is constructed from the viewpoint of Lie symmetry analysis and the power series method.

关键词： classical Boussinesq-Burgers system higher-dimensional system deformation algorithm Lax pair conservation law

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Blockchain-Based Certificateless Bidirectional Authenticated Searchable Encryption Scheme in Cloud Email System

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3287-3310页

作者： Yanzhong Sun Xiaoni Du Shufen Niu Xiaodong Yang College of Mathematics and Statistics Northwest Normal UniversityLanzhou730070China College of Computer Science and Engineering Northwest Normal UniversityLanzhou730070China

Traditional email systems can only achieve one-way communication,which means only the receiver is allowed to search for emails on the email *** this paper,we propose a blockchain-based certificateless bidirectional authenticated searchable encryption model for a cloud email system named certificateless authenticated bidirectional searchable encryption(CL-BSE)by combining the storage function of cloud server with the communication function of email *** the new model,not only can the data receiver search for the relevant content by generating its own trapdoor,but the data owner also can retrieve the content in the same ***,there are dual authentication functions in our ***,during encryption,the data owner uses the private key to authenticate their identity,ensuring that only legal owner can generate the keyword ***,the blockchain verifies the data owner’s identity by the received ciphertext,allowing only authorized members to store their data in the server and avoiding unnecessary storage space *** obtain a formal definition of CL-BSE and formulate a specific scheme from the new system *** the security of the scheme is analyzed based on the formalized security *** results demonstrate that the scheme achieves multikeyword ciphertext indistinguishability andmulti-keyword trapdoor privacy against any adversary *** addition,performance evaluation shows that the new scheme has higher computational and communication efficiency by comparing it with some existing ones.

关键词： Cloud email system authenticated searchable encryption blockchain-based designated server test multi-trapdoor privacy multi-ciphertext indistinguishability

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Resilience Augmentation in Unmanned Weapon Systems via Multi-Layer Attention Graph Convolutional Neural Networks

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Computers, Materials & Continua 2024年第8期80卷 2941-2962页

作者： Kexin Wang Yingdong Gou Dingrui Xue Jiancheng Liu Wanlong Qi Gang Hou Bo Li northwest Institute of Mechanical and Electrical Engineering Xianyang712099China

The collective Unmanned Weapon System-of-Systems(UWSOS)network represents a fundamental element in modern warfare,characterized by a diverse array of unmanned combat platforms interconnected through hetero-geneous network *** its strategic importance,the UWSOS network is highly susceptible to hostile infiltrations,which significantly impede its battlefield recovery *** methods to enhance network resilience predominantly focus on basic graph relationships,neglecting the crucial higher-order dependencies among nodes necessary for capturing multi-hop meta-paths within the *** address these limitations,we propose the Enhanced-Resilience Multi-Layer Attention Graph Convolutional Network(E-MAGCN),designed to augment the adaptability of *** approach employs BERT for extracting semantic insights from nodes and edges,thereby refining feature representations by leveraging various node and edge ***,E-MAGCN integrates a regularization-based multi-layer attention mechanism and a semantic node fusion algo-rithm within the Graph Convolutional Network(GCN)*** extensive simulation experiments,our model demonstrates an enhancement in resilience performance ranging from 1.2% to 7% over existing algorithms.

关键词： Resilience enhancement heterogeneous network graph convolutional network

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