Search

In recent years, image recognition technology based on deep learning has become a research hotspot in smart agriculture. Aiming at the problem of dataset insufficient in fine-grained fruit object detection, a class mixed fine-grained fruit image object detection dataset ZFruitis constructed covering clean, natural and complex backgrounds. At the same time, in view of the current fruit image detection and recognition algorithm with high complexity, large parameters, and difficulty in high precision and lightweight detection of fine-grained fruits in different environments, this paper proposes a lightweight fruit recognition network model DGCC-Fruitbased on YOLOv5. Firstly, a GC-based low-cost feature extraction network is proposed by integrating the GhostBottleneck module and the coordinate attention mechanism (CA), which enhances the fine-grained feature extraction capability; secondly, a new feature fusion network is constructed by introducing CARAFE content-aware upsampling operator to make full use of deep semantic information to improve the detection performance of fine-grained fruit images; finally, the model is further optimized by the knowledge distillation strategy. Taking the smallest-scale model as an example, the experimental results on the self-made dataset ZFruitand the public dataset VOC2007show that our DGCCn-Fruit network has better performance than the original YOLOv5n (ZFruit: + 2.1% mAP@.5, + 1.9% mAP@.5:.95; VOC2007: + 5.4% mAP@.5, + 5.5% mAP@.5:.95), with a reduction of about 14% in the parameters and 11% in the model size.

Based on the economic system reform of the Party since the founding of the People's Republic of China, this paper analyzes the development of China' s sports industry by using the methods of literature review and logical analysis. The findings of this paper include : under the correct leadership of the Communist Party of China, the development of sports industry in China has experienced four phases ' these are the period of gestation and reserve at the beginning of the founding of New China ' the period of initial development after the reform and opening up, the period of deep exploration at the turn of the 20th and 21st century'and the period of reform and innovation after the CPC's 18th National Congress. According to this tortuous development course of China' s sports industry, this paper concludes the CPC's basic experience of leading the development of China' s sports industry, including grasping the historical orientation of China' s social development' emphasizing the leading role of the CPC's guiding principles of economic construction ' and establishing the people-centered outlook of sports industry development. By examining the current complex situation at home and abroad, it suggests that the future development of China's sports industry should take the initiative to follow the major national strategic deployment ' further utilize the leading role of the market ' and effectively improve the transformation of scientific and technological innovation. [ABSTRACT FROM AUTHOR]

Identifying excellent natural variations is the foundation for breeding. Several major genes of quantitative trait loci for chilling tolerance at seedling stage (qCTS) have been identified. However, less is known the dual elite modules for the tolerance. Here, we reported that the major gene of qCTS1-2, Chilling-tolerance in Geng/japonica rice 4(COG4), encoding the transcription factor ENAC1, coupled with OsbZIP23to positively regulate chilling tolerance. The haplotype analysis and geographical distribution showed that most of chilling-tolerant japonicavarieties carried Var9(CT) at −317 in COG4(COG4jap). The COG4jappromoter was preferentially bound by cold-induced OsbZIP23 to cause a higher expression of COG4japcompared to COG4ind, which promotes multiple pathways for the tolerance. Both of COG4japand OsbZIP23japwere artificially selected and retained in japonicavarieties during domestication. These results not only unveil the regulatory mechanism of OsbZIP23jap-COG4japmodule, but also provide valuable variations for molecular design breeding.

The current study explored the thematic framing of the 2022 Beijing Winter Olympics on X (Twitter), examining how these thematic frames and audience engagement varied across various content creator tiers—mega, macro, micro, and nano content creators—throughout the year surrounding the event. Through the lens of the framing theory, we employed LDA topic modeling and identified three dominant thematic frames: athletic achievements and competition results, international participation dynamics including boycotts and diplomatic engagements, and geopolitical undertones reflecting on the host nation and global conflicts. A noticeable relationship between thematic frames and engagement levels was observed consistently across creator tiers, with athleticism and contest outcomes garnering sustained attention, underscoring its pivotal role in event discussions. Moreover, our findings revealed unique engagement patterns across creator tiers. Mega creators amplified reactions to sports achievements. Macro creators displayed varied engagement, suggesting responsiveness to ongoing events. Micro creators saw fluctuating engagement with a focus on geopolitical issues. Nano creators actively engaged with both sports achievements and political discussions. Overall, the study illuminates the complexities of media representations and audience perceptions, while dissecting the impactful role played by different tiers of content creators in driving public engagement with a global sporting spectacle.

Purpose: The purpose of this paper is to analyze fans’ perceptions of the corporate social responsibility (CSR) activities of a professional football club, specifically whether or not perceived CSR performances are then likely to influence patronage intentions of the fans in relation to the football club. Design/methodology/approach: The paper uses the example of a professional football club in China as a case study for data analysis. Based on a sample of 451 home team fans, analysis was conducted through calculation of descriptive statistics, and exploratory factor analysis. Regression analysis was conducted to determine the impact of perceived CSR performance on fans’ patronage intentions. Findings: The results revealed that factor 3 (“CSR to customer and employee”) and factor 4 (“Community development and youth education”) were significantly predictive of all the three patronage intention variables, i.e. repeat purchase, word-of-mouth and merchandise consumption. In addition, factor 2 (“charity”) would also affect merchandise consumption intention, but have no effect on any other dimensions. Originality/value: A scale measuring perceived CSR performance in professional football clubs by the fans in the Chinese context has been developed. In addition, the authors have identified that the two main CSR factors that would influence fans’ patronage intentions are: “CSR to the customer and employee” and “community development and youth education.” Thus, if football clubs are to use CSR strategically to leverage spend, then it is these two areas that they should focus on, explicitly in relation to CSR activities. This paper adds value to an area that is currently under-researched in respect of CSR activities in Chinese professional football.

Nonlinear optical refractive index changes (RICs) with polaron effects are studied in this Letter. The energy levels and wave functions of the polaron Schrödinger equation are calculated and brought into the nonlinear RICs to analyze the difference between the effects of the presence and absence of polarons, as well as the specific representation of RICs with polarons.

In this paper, the energy levels and the wave functions of the Schrödinger equation with position-dependent mass are theoretically deduced, and they are brought into nonlinear optical third-harmonic generation. We find that the peak of the third-harmonic coefficient becomes larger and a blueshift occurs under the condition of variable mass. Moreover, with the increment of mass variable k, the energy interval E_ij decreases, which makes the coefficients suffer a redshift, and the absolute value of the matrix elements product |M_12M_23M_34M_41| presents different monotonicity, which makes the peak value of the coefficient change regularly.

Purpose: Using Beijing’s bid for the 2022 Winter Olympic Games as an example, the purpose of this paper is to explore the expected social impact of mega-sporting events, as perceived by non-host city residents, and the way in which this perception affects attitudes toward bidding. Design/methodology/approach: An empirical survey study was conducted in which data were collected from residents in Shanghai, comprising a sample of 483 respondents. An exploratory factor analysis identified 40 items loaded on eight distinctive factors that underlie the expected social impact of the 2022 Winter Olympic Games. A multiple regression analysis was conducted to determine the effect of the perceived impact on residents’ attitudes toward the bid to host the Olympics. Findings: Among the eight identified impact factors, six were found to be positive and two negative. While all factors were significantly higher above the point of indifference, perceived positive impact factors tended to outweigh those that were negative. In addition, seven out of the eight factors were found to be significantly predictive of support for Beijing’s bidding: while the effect of “tourism and environment,” “social capital and psychic income,” “international cooperation and exchange,” “infrastructure,” “national image,” and “sport development” was positive, the effect of the “higher living cost” factor was negative with regard to the support of the bidding. This study seeks to contribute by taking a non-host community perspective. Originality/value: A growing body of literature has documented perspectives on events and their specific timing during event cycles, i.e., during the bidding stage. In addition, it also offers insight into the perception and attitudes of citizens from emerging markets toward event bidding and hosting, both of which play an increasingly important role in global sports but, on the whole, remain relatively under researched.

Purpose: The purpose of this paper is to develop a scale to measure the legacy of psychic income associated with the Olympic Games. Design/methodology/approach: Using the 2008 Beijing Games as an example, data were collected from Beijing residents through structured questionnaires. A scale of measuring psychic income (SPI) was developed through conducting a confirmatory factor analysis (CFA) based on a sample of 375. Findings: In the CFA estimation, a seven-factor SPI was identified with 24 pertinent items retained. This seven-factor model displays good fit to the data, construct validity, and reliability. Originality/value: Despite the importance of psychic income widely recognized in the existing literature, there has been a lack of valid scales to measure major sports events psychic income in general and Olympic psychic income in particular. This paper develops a multidimensional scale from the host community perspective, which can provide academics and local organizers with a reliable and valid tool to assess Olympic psychic income.

Purpose: Growth of China’s sport industry has brought tremendous opportunities to sport and non-sport organizations domestically and globally; nonetheless, the enlargement has also raised many challenges. To a great extent, China has chartered into unprecedented new sport business territories. Because of social, cultural, historical, and governmental differences, many theories and knowledge, professional experiences, best practices, and lessons learned in Western countries may or may not be directly applicable to the diverse setting(s) in China. Until now, only limited empirical evidence is available to address these challenges. Thus, formulating a special issue in the International Journal of Sports Marketing and Sponsorshipto examine contemporary subject matters and concerns would be significantly meaningful to help understand, stimulate, and improve sport business operations in China, provide guidance to transnational organizations for doing sport-related business in China, offer constructive suggestions for Chinese corporations going global, and ultimately build up theories and best practices to address unique perspectives of China’s sport industry. The paper aims to discuss these issues. Design/methodology/approach: This paper is conceptual and presents a review of literature. Findings: In addition to this leading paper, there are a total of eight manuscripts selected for this special issue inquiring on contemporary matters and development of China’s sport industry, including four short articles that were formulated based on qualitative research information derived from case studies and interviews and four full-length articles that adopted a quantitative research protocol or a mixed research design involving both qualitative and quantitative information. Research limitations/implications: While it is impossible to capture all contemporary topics in the development of China’s sport industry within one journal issue, articles selected in this special issue of the International Journal of Sports Marketing and Sponsorshiphave provided useful highlights into some of the critical issues faced by the industry and research directions by academicians. It is sincerely expected that studies in this special issue would help inspire more scholarly inquires and ultimately improve the continued formulation and advancement of a strong sport industry in China. Practical implications: While it is impossible to capture all contemporary topics in the development of China’s sport industry within one journal issue, articles selected in this special issue of the International Journal of Sports Marketing and Sponsorshiphave provided useful highlights into some of the critical issues faced by the industry and research directions by academicians. It is sincerely expected that studies in this special issue would help inspire more scholarly inquires and ultimately improve the continued formulation and advancement of a strong sport industry in China. Social implications: While it is impossible to capture all contemporary topics in the development of China’s sport industry within one journal issue, articles selected in this special issue of the International Journal of Sports Marketing and Sponsorshiphave provided useful highlights into some of the critical issues faced by the industry and research directions by academicians. It is sincerely expected that studies in this special issue would help inspire more scholarly inquires and ultimately improve the continued formulation and advancement of a strong sport industry in China. Originality/value: While it is impossible to capture all contemporary topics in the development of China’s sport industry within one journal issue, articles selected in this special issue of the International Journal of Sports Marketing and Sponsorshiphave provided useful highlights into some of the critical issues faced by the industry and research directions by academicians. It is sincerely expected that studies in this special issue would help inspire more scholarly inquires and ultimately improve the continued formulation and advancement of a strong sport industry in China.

We report an all-normal-dispersion, low-repetition-rate, high-energy, twin-pulse, passively mode locked ytterbium-doped fiber laser. The mode-locking mechanism of the laser is based on nonlinear polarization evolution and strong pulse shaping with a cascade long-period fiber grating bandpass filtering in a highly chirped pulse. The laser generates a highly stable twin-pulse group with 248?ps and 296?ps duration simultaneously and maximum pulse energy of 26.8?nJ—each pulse at a 2.5445?MHz repetition rate. Energy quantization is observed, which demonstrates the nonparabolic nature of these pulses. The laser can also work in third-harmonic mode locking with 17.8?nJ energy (at a repetition rate of 7.65?MHz and pulse width of 780?ps).

In this paper we investigated the THz radiation dynamics in InAs using the ensemble Monte Carlo method. Our simulations indicated that THz pulse shapes (temporal waveforms) are closely related with the pump laser fluence. The sharp, negative peak of a THz pulse may result from the electron intervalley transfers from center valley to satellite valleys. Our numerical results show that higher laser fluence is an advantage in enhancing the output of high frequency components. The spato-temporal distributions of photo-Dember fields on the semiconductor surface were also analyzed.

By introducing into the hot electron model, the authors have analyzed the THz radiation, which is excited by femtosecond laser from Large-Aperture InP photoconducting antennas biased electric field. Theoretic simulation shows that the departure of detected electric field from linear relationship with biased electric field comes from the high field effect of the transport process of free carriers.

An ensemble Monte Carlo simulation method has been used to study THz-pulse generation from semiconductor GaAs surface excited by a femtosecond laser pulse and biased in high electrical field near 100kV/cm. Electron transport is simulated using the three-valley conduction band model and taking into account acoustic, optical (polar and nonpolar) and intervalley phonon scattering mechanisms. Our simulations show that the THz temporal waveforms have a close relationship with the biased external field and the THz radiation is saturated with the increase of the biased field, these findings have not been exploited by the existing theoretical analyses. Power spectra show that the higher biased electrical field benefits the frequency extension for the THz radiation.

Through theoretical modeling, we find that the dynamics of photogenerated carriers play a very important role in shaping the temporal waveform of terahertz (THz) radiation pulses emitted from biased low-temperature (LT)-grown GaAs antenna. Our modeling gives successful analyses for the sharp and short, slow and long negative parts of temporal THz waveforms. By including intraband, carrier relaxation effects in the modeled mobility, we find an obvious dependence of the THz conversion efficiency on the material of THz emitter and experimental parameters such as the optical duration, the center wavelength, and the fluence of the laser pulses. Our research also shows that electron-hole and electron-electron collisions in LT-GaAs contribute to the saturation phenomenon with an increase of laser fluence.

The processes of electro-optical (EO) sampling of terahertz (THz) pulse were studied theoretically by considering the finite optical probe width and the double-sampling within the same THz pulse. The dependence of THz time-domain waveforms on the crystal thickness and optical width in EO sampling was revealed. Furthermore, the optimal thickness was analyzed, which shows whether or not an antireflection film coated for the optical probe beam is needed.

By means of an iteration method and taking into account the broadening of the infrared pumping laser, the spectrum of a miniature, optically pumped, superradiant NH3submillimeter-wave(SMMW) gas laser pumped by CO2-10R(8) has been calculated and studied by solving density matrix equations. Experimentally, the interferogram of miniature SMMW laser pumped by a TEA-CO2laser with 10R(8) line is measured. This is the first time that the theoretical spectrum has been in good agreement with experimental results.