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Global Value Chain Participation and Firms'Responses to Exchange Rate Fluctuations

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China & World Economy 2024年第5期32卷 53-86页

作者： Chun Jiang Fuwei Sun Zhida Zhang Center for Economic development research Wuhan UniversityChina Economics and Management School Wuhan UniversityChina

Greater participation in global value chains(GVCs)has highlighted the impact of exchange rate shocks on international *** paper examines how such participation influences firms'responses to exchange rate movements,focusing on the relationship between firms'pricing and value-added in *** study,using detailed Chinese firm-level data,demonstrates that firms with a high degree of GVC participation reacted to currency appreciation by lowering their export prices more substantially and reducing their export volumes *** is mainly attributable to the"cost-hedging effect"within the marginal cost channel and the"pricing inhibition effect"within the markup *** categorizing export firms by trade models and product types,this study further demonstrates that processing trade firms at the low end of the value chain and those with low product differentiation were more inclined to absorb exchange rate *** study adds to the existing theoretical framework and provides strong evidence for China in deepening GVC integration and supporting the development of high-quality export firms.

关键词： exchange rate elasticity exchange rate fluctuations exchange rate pass through firm response global value chain participation

Automatic modulation recognition of radio fuzes using a DR2D-based adaptive denoising method and textural feature extraction

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defence Technology（防务技术） 2024年第4期34卷 328-338页

作者： Yangtian Liu Xiaopeng Yan Qiang Liu Tai An Jian Dai Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China China research and development Academy of Machinery Equipment Beijing 100089China

The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference ***,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(SNR)of such environments is usually low,which makes it difficult to implement accurate recognition of radio *** solve the above problem,a radio fuze automatic modulation recognition(AMR)method for low-SNR environments is ***,an adaptive denoising algorithm based on data rearrangement and the two-dimensional(2D)fast Fourier transform(FFT)(DR2D)is used to reduce the noise of the intercepted radio fuze intermediate frequency(IF)***,the textural features of the denoised IF signal rearranged data matrix are extracted from the statistical indicator vectors of gray-level cooccurrence matrices(GLCMs),and support vector machines(SVMs)are used for *** DR2D-based adaptive denoising algorithm achieves an average correlation coefficient of more than 0.76 for ten fuze types under SNRs of-10 d B and above,which is higher than that of other typical *** trained SVM classification model achieves an average recognition accuracy of more than 96%on seven modulation types and recognition accuracies of more than 94%on each modulation type under SNRs of-12 d B and above,which represents a good AMR performance of radio fuzes under low SNRs.

关键词： Automatic modulation recognition Adaptive denoising Data rearrangement and the 2D FFT(DR2D) Radio fuze

Phase Transitions and Seepage Characteristics during the Depletion development of Deep Condensate Gas Reservoirs

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Energy Engineering 2024年第10期121卷 2797-2823页

作者： Qiang Liu Rujun Wang Yintao Zhang Chong Sun Meichun Yang Yuliang Su Wendong Wang Ying Shi Zheng Chen Exploration and development Technology research and development Center of Ultra-Deep Complex Oil and Gas Reservoirs Petro China Tarim Oilfield CompanyKorla841000China School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580China

Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow *** study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in *** phase behavior analysis and CMG software simulations,the study systematically investigates phase transitions,viscosity,and density changes in the gas and liquid phases under different pressure conditions,with a reservoir temperature of 165°*** research covers three crucial depletion stages of the reservoir:single-phase flow,two-phase transition,and two-phase *** findings indicate that retrograde condensation occurs when the pressure falls below the dew point pressure,reachingmaximum condensate liquid production at around *** pressure decreases,gas phase density and viscosity gradually decrease,while liquid phase density and viscosity show an increasing *** the initial single-phase flow stage,maintaining a consistent gas-oil ratio is observed when both bottom-hole and reservoir pressures are higher than the dew point ***,a sudden drop in bottom-hole pressure below the dew point triggers the production of condensate oil,significantly reducing subsequent gas and oil *** the transitional two-phase flow stage,as the bottom-hole pressure further decreases,the reservoir exhibits a complex flow regime with coexisting areas of gas and *** the subsequent two-phase flow stage,when both bottom-hole and reservoir pressures are below the dew point pressure,a significant increase in the gas-oil ratio is *** reservoir manifests a two-phase flow regime,devoid of single-phase gas flow *** lowpressure conditions in deep condensate gas reservoirs,considerations include gas injection,gas lift,and cyclic gas injection and production in surrounding ***,techniques such as hot nitrogen or CO

关键词： Deep condensate gas reservoirs depletion development phase behavior percolation laws dynamic production analysis

A dataset of lake level changes in China between 2002 and 2023 using multi-altimeter data

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Big Earth Data 2024年第1期8卷 166-188页

作者： Shanmu Ma Jingjuan Liao Ruofan Jing Jiaming Chen Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijingChina International research Center of Big Data for Sustainable development Goals BeijingChina University of Chinese Academy of Sciences BeijingChina

Lake water levels are an important indicator of water balance and water cycles,and are essential for climate and environmental change studies and water resource ***,lake level measurements are scarce or inconsistent throughout the country,and traditional gauge measurements of many lakes are not feasible,so satellite altimetry is a vital alternative to gauge lake ***,the accuracy and sam-pling frequency of lake level time series are usually low because of time and space coverage limitations;therefore,it is necessary to utilize multialtimeter data to monitor lake levels and obtain lake level changes over long time *** this study,we extracted the water level changes in 988 lakes(>10 km^(2))in China between 2002 and 2023 based on ICESat/-2,Cryosat-2,Jason-1/2/3,and Sentinel-3A/3B altimetry data using waveform retracking,lake level extraction,lake level time series construction,the fusion of multi-altimeter lake level time series,and outlier removal.A total of 55%of the lakes in this dataset have been monitored for more than 10 years,and 34%have more than 12 times the annual average water level *** the same time,in situ data from 21 lakes were used for validation,and the average root mean square error(RMSE)for each of the datasets of ICESat/-2,Cryosat-2,Jason-1/2/3,and Sentinel-3A/3B versus the in situ lake levels are 0.223 m,0.163 m,0.207 m,0.596 m,0.295 m,0.275 m,0.243 m,and 0.317 m,respectively,and the mean RMSE of the fused lake levels reaches 0.332 *** the monitoring period,the water levels in Chinese lakes generally *** overall annual average rate of change at the 20 and 10-year scales was 0.123 m/a and 0.151 m/a,respectively,among which the overall water levels in large lakes increased *** lakes with a faster rate of decline in the water level were primarily *** water storage in each lake region in China shows an upward trend,with the most significant increase in the Tibetan Plateau reg

关键词： Lake level multi-altimeter China spatiotemporal variation

Genesis and Accumulation of Paleo-Oil Reservoir in Dabei Area,Kuqa Depression,Northwest China:Implications for Tight-Gas Accumulation

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Journal of Earth Science 2024年第2期35卷 655-665页

作者： Fujie Jiang Xiao Chen Pengwei Wang Xinghe Shao Haijun Yang State Energy Center for Shale Oil research and development Beijing102206China National Key Laboratory of Oil and Gas Resources and Engineering Beijing102249China College of Geosciences China University of PetroleumBeijing102249China CNOOC International Ltd. Beijing100027China research Institute of Petroleum Exploration&Production SINOPECBeijing100083China research Institute of Petroleum Exploration and development Tarim OilfieldPetroChinaKorla841000China

Paleo-oil reservoir is of great importance to understand hydrocarbon enrichment mechanism and hydrocarbon exploration potential,but is yet poorly investigated in Kuqa *** occurrence of the paleo-oil reservoir in Dabei area was proved by quantitative grain fluorescence(QGF)and fluid inclusion *** history of the paleo-oil reservoir was reconstructed through:(1)oil-source correlation;(2)time coupling of source rock maturation,porosity evolution and migration *** impact of paleo-oil reservoir on tight-gas accumulation was consequently *** suggest that considerable oil was accumulated in the K_(1)bs reservoir with paleo oil-water contact in Dabei 2 Well and Dabei 201 Well at 5800 and 6040 m,*** oil was primarily sourced from Triassic source rocks with Jurassic source rocks of secondary importance,which was at oil generation window(0.7%–1.1%Ro)during 9–6 and 7.5–5 Ma,*** occurrence of K_(1)bs tight reservoir(porosity<12%)was about 25 Ma,while faults and associated fractures at Kelasue structural belt were developed approximately from 8 to 3.5 ***,the tight oil accumulation was formed during 8–5 *** paleo-oil reservoir in Dabei 1 gas field was destroyed by the evaporation fractionation in later stage.

关键词： Paleo-oil reservoir Dabei area Kuqa Depression Northwest China petroleum geology

Neuropeptide Y receptor Y8b(npy8br)regulates feeding and digestion in Japanese medaka(Oryzias latipes)larvae:evidence from gene knockout

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第7期25卷 605-616页

作者： Xiaodan JIA Ke LU Xufang LIANG College of Fisheries Chinese Perch Research CenterHuazhong Agricultural UniversityWuhan 430070China Engineering research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt Ministry of EducationWuhan 430070China

Neuropeptide Y receptor Y8(NPY8R)is a fish-specific receptor with two subtypes,NPY8AR and *** in expression levels during physiological processes or in vivo regulation after ventricular injection suggest that NPY8BR plays an important role in feeding regulation;this has been found in only a few fish,at *** order to better understand the physiological function of npy8br,especially in digestion,we used clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)technology to generate npy8br-/-japanese medaka(Oryzias latipes).We found that the deletion of npy8br in medaka larvae affected their feeding and digestion ability,ultimately affecting their ***,npy8br deficiency in medaka larvae resulted in decreased feed intake and decreased expression levels of orexigenic genes(npy and agrp).npy8br-/-medaka larvae fed for 10 d(10th day of feeding)still had incompletely digested brine shrimp(Artemia nauplii)in the digestive tract 8 h after feeding,the messenger RNA(mRNA)expression levels of digestion-related genes(amy,lpl,ctra,and ctrb)were significantly decreased,and the activity of amylase,trypsin,and lipase also significantly *** deletion of npy8br in medaka larvae inhibited the growth and significantly decreased the expression of growth-related genes(gh and igf1).Hematoxylin and eosin(H&E)sections of intestinal tissue showed that npy8br-/-medaka larvae had damaged intestine,thinned intestinal wall,and shortened intestinal *** far,this is the first npy8br gene knockout model established in fish and the first demonstration that npy8br plays an important role in digestion.

关键词： Neuropeptide Y receptor Y8b(npy8br) Japanese medaka(Oryzias latipes) Knockout Feeding Digestion

An Enhanced GAN for Image Generation

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Computers, Materials & Continua 2024年第7期80卷 105-118页

作者： Chunwei Tian Haoyang Gao Pengwei Wang Bob Zhang PAMI research Group University of MacaoMacao999078China School of Software Northwestern Polytechnical UniversityXi’an710129China Yangtze River Delta research Institute Northwestern Polytechnical UniversityTaicang215400China research&development Institute Northwestern Polytechnical UniversityShenzhen518057China

Generative adversarial networks(GANs)with gaming abilities have been widely applied in image ***,gamistic generators and discriminators may reduce the robustness of the obtained GANs in image generation under varying *** the relation of hierarchical information in a generation network and enlarging differences of different network architectures can facilitate more structural information to improve the generation effect for image *** this paper,we propose an enhanced GAN via improving a generator for image generation(EIGGAN).EIGGAN applies a spatial attention to a generator to extract salient information to enhance the truthfulness of the generated *** into relation the context account,parallel residual operations are fused into a generation network to extract more structural information from the different ***,a mixed loss function in a GAN is exploited to make a tradeoff between speed and accuracy to generate more realistic *** results show that the proposed method is superior to popular methods,i.e.,Wasserstein GAN with gradient penalty(WGAN-GP)in terms of many indexes,i.e.,Frechet Inception Distance,Learned Perceptual Image Patch Similarity,Multi-Scale Structural Similarity Index Measure,Kernel Inception Distance,Number of Statistically-Different Bins,Inception Score and some visual images for image generation.

关键词： Generative adversarial networks spatial attention mixed loss image generation

Unveiling vulnerable smart contracts:Toward profiling vulnerable smart contracts using genetic algorithm and generating benchmark dataset

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Blockchain(research and Applications) 2024年第1期5卷 58-84页

作者： Sepideh HajiHosseinKhani Arash Habibi Lashkari Ali Mizani Oskui Computer Science Department of Computer Science and EngineeringYork UniversityTorontoOntario M3J1P3Canada Behavior-Centric Cybersecurity Center(BCCC) School of Information TechnologyYork UniversityTorontoOntario M3J1P3Canada Financial and Crypto Advisory of Switzerland(FiCAS AG) ZugSwitzerland

Smart contracts(SCs)are crucial in maintaining trust within blockchain ***,existing methods for analyzing SC vulnerabilities often lack accuracy and effectiveness,while approaches based on Deep Neural Networks(DNNs)struggle with detecting complex vulnerabilities due to limited data *** paper proposes a novel approach for analyzing SC *** method leverages an advanced form of the Genetic Algorithm(GA)and includes the development of a comprehensive benchmark dataset consisting of 36,670 Solidity source code *** primary objective of our study is to profile vulnerable SCs *** achieve this goal,we have devised an analyzer called SCsVulLyzer based on GAs,designed explicitly for profiling ***,we have carefully curated a new dataset encompassing a wide range of examples,ensuring the practical validation of our ***,we have established three distinct taxonomies that cover SCs,profiling techniques,and feature *** taxonomies provide a systematic classification and analysis of information,improving the efficiency of our *** methodology underwent rigorous testing through experimentation,and the results demonstrated the superior capabilities of our model in detecting *** to traditional and DNN-based approaches,our approach achieved higher precision,recall,and F1-score,which are widely used metrics for evaluating model *** all these metrics,our model showed exceptional *** customization and adaptations we implemented within the GA significantly enhanced its *** approach detects SC vulnerabilities more efficiently and facilitates robust *** promising results highlight the potential of GA-based profiling to improve the detection of SC vulnerabilities,contributing to enhanced security in blockchain networks.

关键词： Smart contracts(SCs) Vulnerability Vulnerable smart contracts Vulnerability profiling Genetic algorithm

A tectono-thermal perspective on the petroleum generation,accumulation and preservation in the southern Ordos Basin, North China

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Petroleum Science 2024年第3期21卷 1459-1473页

作者： Peng Yang Zhan-Li Ren Jin-Hua Fu Hong-Ping Bao Hui Xiao Zheng Shi Kun Wang Yuan-Yuan Zhang Wen-Hui Liu Wen-Hou Li State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an710069ShanxiChina National Engineering Laboratory for Exploration and development of Low-Permeability Oil and Gas Fields Exploration and Development Research Institute of PetroChina Changqing Oilfield CompanyXi'an710018ShaanxiChina Shaanxi Key Lab of Petroleum Accumulation Geology School of Earth Science and EngineeringXi'an Shiyou UniversityXian710065ShaanxiChina Wuxi research Institute of Petroleum Geology Petroleum Exploration and Production Research InstituteSINOPECWuxi214126JiangsuChina

The southern Ordos Basin has excellent petroleum exploration ***,the tectono-thermal history and the controls on petroleum generation,accumulation and preservation conditions in southern basin are *** this study,we analyzed the present geothermal field,paleo-geothermal gradient,maturity of the hydrocarbon source rocks,uplift and cooling process and tectono-thermal evolution *** the study area,for the Ordovician,Permain and the Triassic strata,the present temperature is low(3070℃)in the southeastern area but high(80140℃)in the northwestern *** paleogeothermal gradient varied from 24℃/km to 30℃/km with a heat flow of 58—69 m W/m^(2)(i.e.,a medium-temperature basin).The paleo-temperatures are higher than the present temperatures and the maximum paleo-temperatures controlled the thermal maturity of the source *** vitrinite reflectance(Ro)values of the Triassic strata are>0.7%and the thermal maturity reached the middlemature oil generation *** Rovalues of the Permian-Ordovician strata are>1.8%and the thermal maturity reached the over-mature gas generation *** southern Ordos Basin has experienced the multiple tectonic events at the Late Ordovician Caledonian(452 Ma),Late Triassic(215 Ma),Late Jurassic(165160 Ma),End-Early Cretaceous(110100 Ma)and Cenozoic(since 40 Ma).A large-scale tectonothermal event occurred at the End-Early Cretaceous(110100 Ma),which was controlled by lithospheric extension,destruction and *** event led to the highest paleo-temperatures and thermal maturities and coeval with the peak period of petroleum generation and *** southern Ordos Basin has undergone rapid and large-scale uplift since the Late Cretaceous due to expansion of the northeastern margin of the Tibetan Plateau,uplift of the Qinling orogenic belt and thrust faulting in the Liupanshan tectonic *** southern Ordos Basin experienced tectonic overprinting that was strong in the south and weak in the *** str

关键词： Fission-track dating Vitrinitereflectance Geothermal field Tectono-thermal evolution Petroleum geology Ordos Basin