Search Results (24)

Dendrobium stem is a valuable food with medicinal and edible properties. Due to its high medicinal value and price, closely related Dendrobium varieties are often sold as imitations on the market. Therefore, there is an urgent need to develop new methods that can quickly identify Dendrobium stem and its closely related species. The Heracles Neo ultra-fast gas phase electronic nose was used in this study to determine and analyze the composition and contents of volatile organic compounds (VOCs) in Dendrobium stem and samples of five other species closely related to it. A total of 20 VOCs were identified, and a fingerprint map of the VOCs was constructed. Principal component analysis (PCA), Euclidean distance, and other methods were used to comprehensively process and analyze the obtained VOC information. The AroChemBase database was also used for qualitative analysis of the compounds. The results showed that there are significant differences in the odor fingerprint spectra of Dendrobium stem and the five other closely related species. The main types of compounds in Dendrobium stem and its five closely related species were organic esters, aldehydes, ketones, and olefins. Among them, 3-methylbutanal and n-butanol were characteristic compounds of the Dendrobium stem sample, while the VOCs acetonitrile and trometamol were present in the five related Dendrobium species samples. The Heracles Neo ultra-fast gas phase electronic nose can quickly and accurately identify Dendrobium stem and its five closely related species. It can also be used for the quality evaluation of Dendrobium stem, providing a theoretical reference for reducing the phenomenon of medicinal confusion in the Dendrobium stem market. Full article

(1) Background: The adulteration of cosmetics has become increasingly common, which seriously harms ordinary consumers. The counterfeit cosmetics pointed out in this study mainly refer to imitating genuine products in terms of ingredients and packaging. Ordinary consumers cannot distinguish their authenticity solely based on appearance and daily use. If there is a convenient and low-cost detection method that can expose this phenomenon of adulteration, it will be able to expose adulteration and protect the interests of consumers quickly and conveniently. (2) Methods: MALDI-TOF, GC-MS, and mid-IR were used to develop low-cost and fast methods for identifying the authenticity of cosmetics. Five types of liquid and five types of emulsion cosmetics purchased from container and wholesale markets were analyzed using the three instruments mentioned above, and their spectra and acquired data were carefully compared to determine their authenticity. MALDI-TOF and GC-MS directly tested cosmetic samples, and mid-IR spectroscopy tested the ink on the outer packaging of cosmetics. (3) Results: The data procured by MALDI-TOF can provide a representation of its product attributes; two liquid samples and one paste sample demonstrated inconsistent test outcomes with the corresponding reference samples, suggesting contamination. The results of GC-MS can illustrate the substance count within cosmetic samples; the comparison outcomes of the total ion chromatogram indicate that one paste sample was a counterfeit. The results attained from mid-IR were consonant with those acquired from the MALDI-TOF analysis and GC-MS. (4) Conclusions: These three newly developed techniques can all be effectively utilized for the task of detecting cosmetic adulteration and quality control in the manufacturing process. With regard to user-friendliness and rapidity, both MALDI-TOF and mid-IR outperform GC-MS, demonstrating consistently superior levels of detection. Conversely, GC-MS has unique advantages in identifying emulsion cosmetics containing a high amount of weak polarity and volatile substances. Consequently, these corresponding methods could serve as efficient and cost-effective ways to detect authenticity issues in real-world cosmetic products. Full article

Diverse chiral structures observed in nature find applications across various domains, including engineering, chemistry, and medicine. Particularly notable is the optical activity inherent in chiral structures, which has emerged prominently in the field of optics. This phenomenon has led to a wide range of applications, encompassing optical components, catalysts, sensors, and therapeutic interventions. This review summarizes the imitations and applications of naturally occurring chiral structures. Methods for replicating chiral architectures found in nature have evolved with specific research goals. This review primarily focuses on a top-down approach and provides a summary of recent research advancements. In the latter part of this review, we will engage in discussions regarding the diverse array of applications resulting from imitating chiral structures, from the optical activity in photonic crystals to applications spanning light-emitting devices. Furthermore, we will delve into the applications of biorecognition and therapeutic methodologies, comprehensively examining and deliberating upon the multifaceted utility of chiral structures. Full article

The same people exhibit various adoption behaviors for the same information on various networks. Previous studies, however, did not examine the variety of adoption behaviors on multi-layer networks or take into consideration this phenomenon. Therefore, we refer to this phenomenon, which lacks systematic analysis and investigation, as behavioral adoption diversity on multi-layered networks. Meanwhile, individual adoption behaviors have LTI (local trend imitation) characteristics that help spread information. In order to study the diverse LTI behaviors on information propagation, a two-layer network model is presented. Following that, we provide two adoption threshold functions to describe diverse LTI behaviors. The crossover phenomena in the phase transition is shown to exist through theoretical derivation and experimental simulation. Specifically, the final spreading scale displays a second-order continuous phase transition when individuals exhibit active LTI behaviors, and, when individuals behave negatively, a first-order discontinuous phase transition can be noticed in the final spreading scale. Additionally, the propagation phenomena might be impacted by the degree distribution heterogeneity. Finally, there is a good agreement between the outcomes of our theoretical analysis and simulation. Full article

Inspired by the observation that pathologists pay more attention to the nuclei regions when analyzing pathological images, this study utilized soft segmentation to imitate the visual focus mechanism and proposed a new segmentation–classification joint model to achieve superior classification performance for breast cancer pathology images. Aiming at the characteristics of different sizes of nuclei in pathological images, this study developed a new segmentation network with excellent cross-scale description ability called DIU-Net. To enhance the generalization ability of the segmentation network, that is, to avoid the segmentation network from learning low-level features, we proposed the Complementary Color Conversion Scheme in the training phase. In addition, due to the disparity between the area of the nucleus and the background in the pathology image, there is an inherent data imbalance phenomenon, dice loss and focal loss were used to overcome this problem. In order to further strengthen the classification performance of the model, this study adopted a joint training scheme, so that the output of the classification network can not only be used to optimize the classification network itself, but also optimize the segmentation network. In addition, this model can also provide the pathologist model’s attention area, increasing the model’s interpretability. The classification performance verification of the proposed method was carried out with the BreaKHis dataset. Our method obtains binary/multi-class classification accuracy 97.24/93.75 and 98.19/94.43 for 200× and 400× images, outperforming existing methods. Full article

Until now, the phenomenon of radiatively driven convection (RDC) in ice-covered lakes has not been sufficiently studied, despite its important role in the functioning of aquatic ecosystems. There have been very few attempts to numerically simulate RDC due to the complexity of this process and the need to use powerful computing resources. The article presents the results of Large Eddy Simulations (LES) of RDC with periodic external energy pumping, which imitates the diurnal variations in solar radiation in the subglacial layer of lakes in spring. The research is aimed at numerically studying the initial stages in the formation and development of a convective mixed layer (CML). A numerical calculation was carried out for three variants of external energy pumping that differed in intensity. A diurnal acceleration and suppression of RDC due to a change in external pumping was revealed for all three variants. The results of numerical simulations provide estimates of such integral parameters of RDC development as the rate of deepening of the lower boundary of the CML, and the rate of water temperature rise within this layer. It was shown that as the cumulative heating of the CML increases over several days, daily increments in temperature and depth slowed down; that is, the dependence of the integral RDC parameters on external pumping was nonlinear. The LES results on RDC parameters were in good agreement with our observational data. Full article

In view of current research on the cracking mechanism of high-energy gas on coal, little attention has been paid to imitating the law of explosive blasting and cracks propagation, and the influence of joint on cracks propagation in the process of high-energy gas impact permeability enhancement has not been taken into account. In this paper, the effects of joint dip angles and joint lengths on cracks size propagation are studied by using a similar simulation test and RFPA2D-dynamic numerical simulation software. In the process of impact permeability enhancement of high-energy gas, the extension direction of the cracks is approximately parallel to the joint, and with the increase in the dip angle and length, the higher the number of cracks, the larger the extension range, and the closer it is to the permeability enhancement holes, the fracture network is formed. When the dip angle of the joint is 30°, the impact permeability enhancement effect results in an obvious zoning phenomenon. When the joint dip angle is 60° and 90°, there is a higher number of cracks and the cracks network is formed, and with the increase in the dip angle, the more the cracks develop and the better the impact permeability enhancement effect. Full article

Cavitation is a destructive hydraulic phenomenon; it causes damage to small hydraulic machinery and large water-conservancy projects, and cavitation and cavitation corrosion problems are long-standing problems for hydraulic machinery experts. Micro-textures are often machined onto the end face near the indirect contact point to increase the oil film bearing capacity and reduce the transfer torque in hydraulic machinery, but the pressure disturbance caused by the texture dimple and boundary can induce cavitation. To delay or eliminate cavitation on the textured surface of equipment such as mechanical seals and dynamic bearings, the cavitation effect of a cylindrical texture on a rotating frictional pair was investigated from theoretical, imitational, and experimental perspectives. Low pressure is extremely important for inducing cavitation; once cavitation conditions are met, a full bubble can be formed in about 0.015 s. Cavitation mainly occurs at the outer radius of the rotating end face, i.e., in the high-speed region. There is a mutual mass transfer between gas and liquid phases when cavitation occurs, but the generation of cavitation bubbles is faster than its collapse, thus causing an increasing cavitation region. Full article

By introducing network game theory, this paper analyzes the internal relationship and interaction mechanism among environmental governance, local government competition, and agricultural carbon peak level. On the basis of theoretical analysis, a spatial panel model is constructed using panel data from 30 provincial-level regions in China for empirical analysis. The research finds that local governments have positive competition with respect to the agricultural carbon peak, they adopt complementary carbon peak competition strategies, and they are more inclined to take geographical distance to adjacent regions as the yardstick in the competition with respect to the agricultural carbon peak strategy. That is, when the carbon peak level of surrounding provinces increases, the carbon peak level of the region will also increase. Thus, there is a phenomenon of mutual imitation and convergence between neighboring provinces. Environmental governance has a significant positive direct effect and a positive spatial spillover effect. From the perspective of coefficient, its direct effect is significantly greater than the spatial spillover effect. Therefore, more attention should be paid to local environmental governance to promote the improvement of the agricultural carbon peak level. Furthermore, the agricultural industrial structure, fiscal decentralization, agricultural public investment, regional industrial structure, and the proportion of the rural population have significant spatial spillover effects. The agricultural industrial structure and fiscal decentralization are significantly positively correlated with the peak level of agricultural carbon while the proportion of the rural population is significantly negatively correlated with the peak level of agricultural carbon. The research results have important theoretical value for expanding the research in the field of agricultural carbon emissions and provide important practical reference for China to successfully achieve the goal of agricultural carbon peak and promote the high-quality development of agriculture Full article

With the expedition of the Portuguese explorer Jorge Álvares in 1513, Portugal took the first step toward discovering the new world. Since then, the Portuguese have become messengers between Asia and Europe. They successfully created a unique image of China in Portuguese territory by accepting and spreading Chinese culture. However, people see what they can and what they want to see, which depends greatly on their cultural and philosophical perspectives. Therefore, when the Portuguese adopted and used Chinese traditional representations to create art through the prism of their own cultural and philosophical values, their subjective perspectives became involved, which could be reflected in their artistic creations. By decoding the shanshui motif on Chinese porcelain and Portuguese faience, this study aims to discuss the differences between Chinese and Portuguese views and explore what is beyond representations, which is related to aesthetic and cultural perspectives. This indicates that imitation without understanding and modification without intention give rise to a new aesthetic value, a distinct cultural phenomenon, and a mixed heritage where two worlds subtly intersect. Full article

We study the contrarian voter model for opinion formation in a society under the influence of an external oscillating propaganda and stochastic noise. Each agent of the population can hold one of two possible opinions on a given issue—against or in favor—and interacts with its neighbors following either an imitation dynamics (voter behavior) or an anti-alignment dynamics (contrarian behavior): each agent adopts the opinion of a random neighbor with a time-dependent probability $p\left(t\right)$, or takes the opposite opinion with probability $1-p\left(t\right)$. The imitation probability $p\left(t\right)$ is controlled by the social temperature T, and varies in time according to a periodic field that mimics the influence of an external propaganda, so that a voter is more prone to adopt an opinion aligned with the field. We simulate the model in complete graph and in lattices, and find that the system exhibits a rich variety of behaviors as T is varied: opinion consensus for $T=0$, a bimodal behavior for $T<T_c$, an oscillatory behavior where the mean opinion oscillates in time with the field for $T>T_c$, and full disorder for $T\gg 1$. The transition temperature $T_c$ vanishes with the population size N as $T_c\simeq 2/lnN$ in complete graph. In addition, the distribution of residence times $t_r$ in the bimodal phase decays approximately as $t_r^{-3/2}$. Within the oscillatory regime, we find a stochastic resonance-like phenomenon at a given temperature $T^{*}$. Furthermore, mean-field analytical results show that the opinion oscillations reach a maximum amplitude at an intermediate temperature, and that exhibit a lag with respect to the field that decreases with T. Full article

In the beauty industry, the use of one-person media is making new, more active relationships that differ from those of past online services and information sharing. Therefore, in this study, we developed conformity appeal attributes in one-person media, identifying their effects on information diffusion behavior through social conformity and collaborative innovation networks, to investigate the social contagion effect of information in beauty-focused one-person media and develop a model by connecting them to the conformity threshold of individuals influenced by others. In this study, a total of 694 complete samples of experienced consumers in the beauty-focused one-person media category were selected, and research questions were verified through reliability and validity tests, path analysis, and measurement model analysis. The research results are as follows. First, conformity appeal attributes of beauty-focused one-person media in terms of information cascade, utility value efficiency, reference group influence, and subnetwork structure significantly affected social imitation conformity. However, only subnetwork structure significantly affected social connection conformity. Similarly, only reference group influence and subnetwork structure significantly affected social comparative conformity. Second, social imitation conformity, social connection conformity, and social comparative conformity in beauty-focused one-person media significantly affected cocreation. Third, cocreation in beauty-focused one-person media significantly affected information diffusion behavior. The detailed use of the conformity appeal attribute factors shown in the above results will be combined with functional changes for online and mobile services of beauty companies, and it will be a driving force to create new value for the network. Moreover, the results of this study not only enable social connection among members within the reference group of beauty-focused one-person media but are also applied as an effective phenomenon to explain the continuous maintenance, reinforcement, and expansion of these relationships, thereby enabling researchers to achieve theoretical expansion and evaluation of relevant variables. Full article

As an emerging industry, e-cigarettes have been greatly prosperous globally in recent years. In China, Shenzhen is the center of e-cigarette production, and a complete business ecosystem has been built at this point. To explore the phenomenon of the agglomeration of e-cigarette enterprises in Shenzhen, the business ecosystem structure and evolution path of e-cigarette industrial clusters in Shenzhen (the Shenzhen e-cigarette industry) are illustrated in this study from an ecological perspective, and the development characteristics of the Shenzhen e-cigarette industry as well as the interspecies relationships among enterprises were studied based on the population life history theory. Eight representative firms were also selected here. Their patent information was collected and classified to investigate niche characteristics using Levins’ niche breadth and niche overlap index. The results indicate that, after a long-term evolution, the Shenzhen e-cigarette industry has preliminarily built a business ecosystem with a unique structure. The developmental process is accompanied by the transformation of the development pattern from imitation to innovation and the enterprise populations have achieved coevolution through mutualistic symbiosis. In the area of technological innovation, niche-widening and -separation strategies are employed by the e-cigarette enterprises. The above reasons explain the boom of the Shenzhen e-cigarette industry and why Shenzhen is becoming the center of e-cigarette production. Full article

Research on radicalization became relevant to the study of terrorism and violent extremism just two decades ago. The accumulated empirical data on terrorism have led researchers and experts to understand that radicalization is a predictor of violent actions by terrorists, violent extremists, and lone actors. Violent incidents committed by school shooters are not terrorist crimes, but there is good reasons for inclusion as terrorist crimes since they have similar mechanisms. The article aims to create a conceptual model of school-shooter radicalization and determine the distinguishing features of the process. The paper presents a theoretical and methodological base of content analysis concepts, political models, and terrorist radicalization on the different levels of study. Based on the content analysis results, we identify the significant gaps in the research field, consider the radicalization phenomenon in detail, substantiated the qualitative aspects of the school shooters radicalization, and propose a conceptual scheme. Psychological, behavioral, cognitive aspects of the school shooters radicalization reflect a holistic picture of the relationship between the process phases and changes in the parameters of the object’s state. The aspects of radicalization and this phenomenon’s qualitative properties are interpreted as the determinants of the conceptual model. The model includes five stages, each of which is considered to be one of the components for the formation and acceptance of the idea of a violent way to solve a problem, but certainly do not act individually as the only component that leads to the actual implementation of the incident of a school shooting. An in-depth study of online social connections and warning signs, mobilization factors, behavioral trajectories, and imitation mechanisms can help scientists understand why school shooters are increasingly motivated to use violent means to achieve personal goals. We have outlined the possibilities and prospects of the model’s application and directions for future research. Full article

The frequency of occurrence of step length in the migratory behaviour of various organisms, including humans, is characterized by the power law distribution. This pattern of behaviour is known as the Lévy walk, and the reason for this phenomenon has been investigated extensively. Especially in humans, one possibility might be that this pattern reflects the change in self-confidence in one’s chosen behaviour. We used simulations to demonstrate that active assumptions cause changes in the confidence level in one’s choice under a situation of lack of information. More specifically, we presented an algorithm that introduced the effects of learning and forgetting into Bayesian inference, and simulated an imitation game in which two decision-making agents incorporating the algorithm estimated each other’s internal models. For forgetting without learning, each agents’ confidence levels in their own estimation remained low owing to a lack of information about the counterpart, and the agents changed their hypotheses about the opponent frequently, and the frequency distribution of the duration of the hypotheses followed an exponential distribution for a wide range of forgetting rates. Conversely, when learning was introduced, high confidence levels occasionally occurred even at high forgetting rates, and exponential distributions universally turned into power law distribution. Full article