We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Major depressive disorder (MDD) and coronary heart disease (CHD) can both cause significant morbidity and mortality. The association of MDD and CHD has long been identified, but the mechanisms still require further investigation. Seven mRNA microarray datasets containing samples from patients with MDD and CHD were downloaded from Gene Expression Omnibus. Combined matrixes of MDD and CAD were constructed for subsequent analysis. Differentially expressed genes (DEGs) were identified. Functional enrichment analyses based on shared DEGs were conducted to identify pivotal pathways. A protein-protein network was also applied to further investigate the functional interaction. Results showed that 24 overlapping genes were identified. Enrichment analysis indicated that the shared genes are mainly associated with immune function and ribosome biogenesis. The functional interactions of shared genes were also demonstrated by PPI network analysis. In addition, three hub genes including MMP9, S100A8, and RETN were identified. Our results indicate that MDD and CHD have a genetic association. Genes relevant to immune function, especially IL-17 signalling pathway may be involved in the pathogenesis of MDD and CHD.
The study aims were to present in vitro susceptibilities of clinical isolates from Gram-negative bacteria bloodstream infections (GNBSI) collected in China. GNBSI isolates were collected from 18 tertiary hospitals in 7 regions of China from 2018 to 2020. Minimum inhibitory concentrations were assessed using a Trek Diagnostic System. Susceptibility was determined using CLSI broth microdilution, and breakpoints were interpreted using CLSI M100 (2021). A total of 1,815 GNBSI strains were collected, with E. coli (42.4%) and Klebsiella pneumoniae (28.6%) being the most prevalent species, followed by P. aeruginosa (6.7%). Susceptibility analyses revealed low susceptibilities (<40%) of ESBL-producing E. coli and K. pneumonia to third-/fourth-generation cephalosporins, monobactamases, and fluoroquinolones. High susceptibilities to colistin (95.0%) and amikacin (81.3%) were found for K. pneumoniae, while Acinetobacter baumannii exhibited a high susceptibility (99.2%) to colistin but a low susceptibility to other antimicrobials (<27.5%). Isolates from ICUs displayed lower drug susceptibility rates of K. pneumoniae and A. baumannii than isolates from non-ICUs (all P < 0.05). Carbapenem-resistant and ESBL-producing K. pneumoniae detection was different across regions (both P < 0.05). E. coli and K. pneumoniae were major contributors to GNBSI, while A. baumannii exhibited severe drug resistance in isolates obtained from ICU departments.
Significant differences in life-history traits between the southern population (S) and northern (N) population of the cabbage beetle Colaphellus bowringi make it an excellent model for studying inheritance in this insect. In the present study, we observed the life-history traits of pure strains, F1, reciprocal backcross and reciprocal F2 progeny under a photoperiod of L:D 15:9 h at 22 °C. The S population had shorter larval development time, longer pupal time, higher body weight, growth rate and weight loss compared with the N population. In the F1 testing, the larval development time and body weight in hybrid populations were intermediate between the parents, and the paternal parents played a greater role in determining the larval development time, while the maternal parents exhibited a greater role in determining the body weight. The pupal time of hybrid populations was significantly shorter than that of the parents. In the reciprocal backcross testing, both father and grandfather affected the larval development time, while both mother and grandmother affected the body weight. Consistently, in the reciprocal F2 cross testing, the grandfather was more influential in determining the larval development time, and grandmother was more important in determining the body weight. In all tested populations, females had greater body weight, higher growth rate and weight loss than males. Hybridization pattern did not affect sex dimorphism and sex ratio. Overall, these findings suggest that different pathways (maternal or paternal effects) were involved in the inheritance of various life-history traits in C. bowringi.
In contemporary neuroimaging studies, it has been observed that patients with major depressive disorder (MDD) exhibit aberrant spontaneous neural activity, commonly quantified through the amplitude of low-frequency fluctuations (ALFF). However, the substantial individual heterogeneity among patients poses a challenge to reaching a unified conclusion.
Methods
To address this variability, our study adopts a novel framework to parse individualized ALFF abnormalities. We hypothesize that individualized ALFF abnormalities can be portrayed as a unique linear combination of shared differential factors. Our study involved two large multi-center datasets, comprising 2424 patients with MDD and 2183 healthy controls. In patients, individualized ALFF abnormalities were derived through normative modeling and further deconstructed into differential factors using non-negative matrix factorization.
Results
Two positive and two negative factors were identified. These factors were closely linked to clinical characteristics and explained group-level ALFF abnormalities in the two datasets. Moreover, these factors exhibited distinct associations with the distribution of neurotransmitter receptors/transporters, transcriptional profiles of inflammation-related genes, and connectome-informed epicenters, underscoring their neurobiological relevance. Additionally, factor compositions facilitated the identification of four distinct depressive subtypes, each characterized by unique abnormal ALFF patterns and clinical features. Importantly, these findings were successfully replicated in another dataset with different acquisition equipment, protocols, preprocessing strategies, and medication statuses, validating their robustness and generalizability.
Conclusions
This research identifies shared differential factors underlying individual spontaneous neural activity abnormalities in MDD and contributes novel insights into the heterogeneity of spontaneous neural activity abnormalities in MDD.
This paper explores active wake-flow control on a notchback Ahmed body using genetically inspired optimization. Hotwire and particle image velocimetry measurements record velocity data and flow structures in the wake. Pulsed jets at four actuation slots (two at the roof trailing edge, two at the side trailing edges) dynamically control the wake to minimize aerodynamic drag. The study achieves up to 9.2 % (without consideration of energy consumption) drag reduction, primarily by manipulating vortices from the roof rear end. The paper elucidates the underlying flow mechanism and evaluates various actuation strategies, highlighting how optimal control leads to reattachment of wake separation at the rear slant, diminishing the slant bubble and promoting downstream reattachment for enhanced drag reduction.
Phytoplasmas are phloem-limited bacteria that are primarily transmitted by hemipteran insects and are emerging threats to Camptotheca acuminata Decne plants due to their associations with a witches’ broom disease. Despite numerous studies, there has been no report on insect transmission of phytoplasma among C. acuminata. Here, transmission characteristics of the leafhopper, Empoasca paraparvipenis Zhang and Liu, 2008 and the phytoplasma in plant leaves through PCR quantification are described. The interaction between C. acuminata-phytoplasma and insect vectors was examined by analysing the impact on the life characteristics and progeny population in a temperature-dependent manner. Phytoplasma-infected C. acuminata plant exhibited symptoms including shorter internodes, weak and clustered branches, shrunken and yellowed leaves, and red leaf margins. The acquisition and transmission time of bacterial-infected third-instar nymphs of insect vectors were 10 (11.11%) and 30 min (33.33%), respectively. A single insect vector can infect a plant after 72 h of feeding, and the incidence rate of disease increases with the number of insects following 11–100% from single to 20 insects. The development time of the infected insect vectors (1–3 instars) was significantly shorter than that of the healthy insects, and the development duration of instar individuals was longer. In progeny populations, the higher the phytoplasma concentration (88–0% for 1–5 instars nymph, female and male adults), the shorter the development time and the longer the adult lifetime (both male and female). These findings provided research evidence of phytoplasma transmission by insect vectors; however, further investigation of the mechanisms for prevention and management of phytoplasma diseases is needed.
A high-energy picosecond 355 nm ultraviolet (UV) laser operating at 100 Hz was demonstrated. A 352 mJ, 69 ps, 1064 nm laser at 100 Hz was realized firstly by cascaded regenerative, laser diode end-pumped single-pass and side-pumped main amplifiers. The stimulated Raman scattering-based beam shaping technique, thermally induced birefringence compensation and 4f spatial filter-image relaying systems were used to maintain a relatively homogeneous beam intensity distribution during the amplification process. By using lithium triborate crystals for second- and third-harmonic generation (THG), a 172 mJ, approximately 56 ps, 355 nm UV laser was achieved with a THG conversion efficiency of 49%. To the best of our knowledge, it is the highest pulse energy of a picosecond 355 nm UV laser so far. The beam quality factor ${M}^2$ and pulse energy stability were ${M}_x^2$=3.92, ${M}_y^2$=3.71 and root mean square of 1.48%@3 hours. This laser system could play significant roles in applications including photoconductive switch excitation, laser drilling and laser micro-fabrication.
Nano-silicon has been regarded as the most promising anode material for next-generation lithium-ion batteries (LIBs). However, the preparation of nano-silicon suffers from high cost, complex procedures, and low yield, which hinders its commercial application. In this study, porous nano-silicon with particle sizes in the range of 50–100 nm was prepared through molten salt-assisted magnesiothermic reduction using porous nano-silica derived from clay minerals as the precursor. Through combining ball milling and acid activation, the synthesised nano-silica derived from montmorillonite exhibited smaller particle sizes (below 50 nm), higher specific surface area (647 m2 g–1), and total pore volume (0.71 cm3 g–1). This unique structure greatly facilitated the conversion efficiency of silica into nano-silicon by maximising the contact area between silica and magnesium powder and optimising the diffusion kinetics of magnesium atoms. When used as anodes in LIBs, the synthesised nano-silicon materials demonstrated a high specific capacity of up to 1222 mAh g–1 and an excellent capacity retention rate of 79% after 150 cycles at a current density of 0.5 A g–1. This method provides a novel approach for the cost-effective and large-scale production of nano-silicon materials for high-performance anodes.
We aimed to evaluate the association of coffee consumption with different additives, including milk and/or sweetener (sugar and/or artificial sweetener), and different coffee types, with new-onset acute kidney injury (AKI), and examine the modifying effects of genetic variation in caffeine metabolism. 194 324 participants without AKI at baseline in the UK Biobank were included. The study outcome was new-onset AKI. During a median follow-up of 11·6 years, 5864 participants developed new-onset AKI. Compared with coffee non-consumers, a significantly lower risk of new-onset AKI was found in coffee consumers adding neither milk nor sugar to coffee (hazard ratio (HR), 0·86; 95 % CI, 0·78, 0·94) and adding only milk to coffee (HR,0·83; 95 % CI, 0·78, 0·89), but not in coffee consumers adding only sweetener (HR,1·14; 95 % CI, 0·99, 1·31) and both milk and sweetener to coffee (HR,0·96; 95 % CI, 0·89, 1·03). Moreover, there was a U-shaped association of coffee consumption with new-onset AKI, with the lowest risk at 2–3 drinks/d, in unsweetened coffee (no additives or milk only to coffee), but no association was found in sweetened coffee (sweetener only or both milk and sweetener to coffee). Genetic variation in caffeine metabolism did not significantly modify the association. A similar U-shaped association was found for instant, ground and decaffeinated coffee consumption in unsweetened coffee consumers, but not in sweetened coffee consumers. In conclusion, moderate consumption (2–3 drinks/d) of unsweetened coffee with or without milk was associated with a lower risk of new-onset AKI, irrespective of coffee type and genetic variation in caffeine metabolism.
Based on a contingent valuation method survey on air quality improvement in northern China, we construct several subjective perception determinants of respondents' valuation uncertainty from both the demand and perceived supply sides. Using the individual-level uncertainty measurements initially proposed by Wang and He (2011) and their alternative transformations, we analyze how these factors of demand and perceived supply sides affect people's valuation uncertainty. Our results demonstrate the significant contribution of these determinants in explaining respondents' uncertainty. On the demand side, people who ‘don't know much’ about benefits-related factors have the highest level of uncertainty, and those claiming to ‘know nothing’ most often report the lowest level of uncertainty. On the supply side, people who either do not trust or are not satisfied with the control policies tend to be more certain of their valuation. The subsequent analyses also suggest that these results be interpreted as negative certainty, which is attributed to a lack of interest.
To address the relationship between the proportions of carbohydrates and fat and hyperglycaemia in the Chinese population.
Design:
A cross-section research involving data from the China Health and Nutrition Survey in 2009, and nutritional status and health indicators were mainly focused.
Setting:
China.
Participants:
8197 Chinese individuals aged over 16 years, including 1345 subjects who had a low-carbohydrate and high-fat diet, 3951 individuals who had a medium proportion of carbohydrate and fat diet, 2660 participants who had a high-carbohydrate and low-fat diet and 241 people who had a very-high-carbohydrate and low-fat diet.
Results:
Subjects with the high-carbohydrate and low-fat diet were significantly associated with an increased risk of hyperglycaemia (OR: 1·142; 95 % CI: 1·022, 1·276) when compared with the individuals with the medium proportion of carbohydrate and fat diet. Meanwhile, people with a very-high-carbohydrate and low-fat diet had a higher risk of hyperglycaemia (OR: 1·829; 95 % CI: 1·377, 2·429). In contrast, the association between participants with a low-carbohydrate and high-fat diet and hyperglycaemia was NS (OR: 1·082; 95 % CI: 0·942, 1·243) with adjusting a series of confounding factors. Furthermore, people with a very-high-carbohydrate and low-fat diet were significantly associated with a higher risk of hyperglycaemia in the major energy levels and social characteristics subgroup.
Conclusions:
We found the high-carbohydrate and low-fat and very-high-carbohydrate and low-fat diets were significantly associated with a high risk of hyperglycaemia. And, the association between low-carbohydrate and high-fat diets and the risk of hyperglycaemia was NS.
We report an experimental study of the formation and evolution of laminar thermal structures generated by a small heat source, with a focus on their correlation to the thermal boundary layer and effects of heating time $t_{heat}$. The experiments are performed over the flux Rayleigh number ($Ra_f$) range $2.1\times 10^6 \leq Ra_f \leq 3.6\times 10^{7}$ and the Prandtl number ($Pr$) range $28.6 \leq Pr \leq 904.7$. The corresponding Rayleigh number ($Ra= t_{heat}\,Ra_{f}/\tau _0\,Pr$) range is $900 \leq Ra \leq 4\times 10^{4}$, where $\tau _0$ is a diffusion time scale. For thermal structures generated by continuous heating (i.e. starting plumes), their formation process exists three characteristic times that are well reflected by changes in the thermal boundary layer thickness. These characteristic times, denoted as $t_{emit}$, $t_{recover}$ and $t_{static}$, correspond to the moments when the plume emission begins and completes, and when the thermal boundary layer becomes quasi-static, respectively. Their $Ra_f$–$Pr$ dependencies are found to be $t_{emit}/\tau _0\sim Ra_f^{-0.41}\,Pr^{0.41}$, $t_{recover}/\tau _0\sim Ra_f^{-0.48}\,Pr^{0.48}$ and $t_{static}/\tau _0\sim Ra_f^{-0.49}\,Pr^{0.33}$, respectively. Thermal structures generated by finite $t_{heat}$ exhibit similar evolution dynamics once $t_{heat} \ge t_{emit}$, with the accelerating stage behaving like starting plumes and the decay stage like thermals (i.e. a finite amount of buoyant fluids). It is further found that their maximum rising velocity experiences a transition in the $Ra$-dependence from $Ra$ to $(Ra\ln Ra)^{0.5}$ at $Ra \simeq 6000$; and their maximum acceleration reaches the value of starting plumes at $t_{heat}\simeq t_{recover}$, and remains unchanged for larger $t_{heat}$. In particular, the maximum rising velocity for the cases with $t_{heat} = t_{recover}$ follows a scaling relation $Ra_f^{0.37}\,Pr^{-0.37}$, in contrast to the relation $Ra_f^{0.48}\,Pr^{-0.48}$ for starting plumes. This study provides a more comprehensive understanding of laminar thermal structures, which are relevant to a range of processes in nature and laboratory systems such as Rayleigh–Bénard convection.
To examine the effectiveness of Self-Help Plus (SH+) as an intervention for alleviating stress levels and mental health problems among healthcare workers.
Methods
This was a prospective, two-arm, unblinded, parallel-designed randomised controlled trial. Participants were recruited at all levels of medical facilities within all municipal districts of Guangzhou. Eligible participants were adult healthcare workers experiencing psychological stress (10-item Perceived Stress Scale scores of ≥15) but without serious mental health problems or active suicidal ideation. A self-help psychological intervention developed by the World Health Organization in alleviating psychological stress and preventing the development of mental health problems. The primary outcome was psychological stress, assessed at the 3-month follow-up. Secondary outcomes were depression symptoms, anxiety symptoms, insomnia, positive affect (PA) and self-kindness assessed at the 3-month follow-up.
Results
Between November 2021 and April 2022, 270 participants were enrolled and randomly assigned to either SH+ (n = 135) or the control group (n = 135). The SH+ group had significantly lower stress at the 3-month follow-up (b = −1.23, 95% CI = −2.36, −0.10, p = 0.033) compared to the control group. The interaction effect indicated that the intervention effect in reducing stress differed over time (b = −0.89, 95% CI = −1.50, −0.27, p = 0.005). Analysis of the secondary outcomes suggested that SH+ led to statistically significant improvements in most of the secondary outcomes, including depression, insomnia, PA and self-kindness.
Conclusions
This is the first known randomised controlled trial ever conducted to improve stress and mental health problems among healthcare workers experiencing psychological stress in a low-resource setting. SH+ was found to be an effective strategy for alleviating psychological stress and reducing symptoms of common mental problems. SH+ has the potential to be scaled-up as a public health strategy to reduce the burden of mental health problems in healthcare workers exposed to high levels of stress.
The literature investigates trade-environment relationship at the firm level, but does not focus on the environmental effect of trade policy uncertainty. In the context of de-globalization and Sino-US trade friction, trade policy uncertainty significantly increases. How does trade policy uncertainty affect firms’ pollution emissions? In this study, we incorporate energy, pollution, and trade policy uncertainty into Melitz’s (2003) framework and construct a theoretical model to reveal the relationship between trade policy uncertainty and pollution emissions. Then, we employ the event that the USA granted permanent normal trade relationship to China as a quasi natural experiment. We use difference-in-difference-in-difference model and the data of Chinese manufacturing firms for empirical analysis. Our results indicate that the decrease in trade policy uncertainty reduces emission intensity of exporting firms, but has no significant impact on emission levels. Given that these firms do not aggravate emission levels under the condition of expanding output scale, we conclude that the decrease in trade policy uncertainty can improve environmental performance. Mechanism analysis shows an interesting finding that the decrease in trade policy uncertainty reduces emission intensity mainly by improving energy efficiency rather than improving abatement technology and optimizing energy structure. In addition, pollution reductions mainly occur in pollution-intensive and capital-intensive industries as well as coastal regions. Altogether, this study contributes to the literature on trade-environment relationship and trade policy uncertainty.
The production and industrial use of asbestos cement and other asbestos-containing materials have been restricted in most countries because of the potential detrimental effects on human health and the environment. Chrysotile is the most common form of asbestos and investigations into how to recycle this serpentine phyllosilicate mineral have attracted extensive attention. Chrysotile asbestos tailings can be transformed thermally, at high temperature, by in situ carbothermal reduction (CR). The CR method aims to maximize use of the chrysotile available and uses high temperatures and carbon to change the mineral form and structure of the chrysotile asbestos tailings. When chrysotile asbestos is employed as the raw material and coke (carbon) powder is used as the reducing agent for CR transformation, stable, high-temperature composites consisting of forsterite, stishovite, and silicon carbide are formed. Forsterite (Mg2SiO4) was the most abundant crystalline phase formed in samples heat treated below 1500ºC. At 1600ºC, forsterite was exhausted through decomposition and β-SiC formed by reduction of stishovite. A larger proportion of β-SiC was generated as the carbon content was increased. This research revealed that both temperature and carbon addition play key roles in the transformation of chrysotile asbestos tailings.
Ion adsorption-type rare earth deposits (IADs) are developed via prolonged weathering of REE-rich volcanic and metamorphic rocks. Intense magmatic activity which occurred during the Yanshanian (199.6–65.5 Ma) and Caledonian periods (542–359.2 Ma) provided an abundant material basis for the formation of IADs in South China. High concentrations of REE and the high proportion of ion-exchangeable REE were found in the Maofeng Mountain regolith, Guangzhou city. However, the geochemical patterns and mechanisms of REE enrichment in the regolith were still poorly understood. The present study investigated the regolith profile (0–8 m) developed in Maofeng Mountain based on metallogenic and geochemical characteristics, sequential extraction, and physical and chemical parameters of the regolith profile. The bedrock contained abundant REE resources (245–287 mg kg–1) and the chondrite-normalized REE patterns showed the enrichment of light REE (LREE) and negative cerium (Ce) and europium (Eu) anomalies. The distribution patterns of REE in the bedrock were inherited by the regolith. REE enrichment of the regolith occurred mainly in the completely weathered layer (B1, B2, and B3 horizons), particularly in the depth range 2.5–4.5 m (849–2391 mg kg–1). The position of REE enrichment was controlled by the soil pH (5.52–6.02), by the amount of kaolinite and halloysite, and by the permeability of the metamorphic rock. In the REE-enriched horizon (2–8 m), the REE were hosted mainly in ion-exchangeable fractions (75–2158 mg kg–1), representing 79% of the total REE. Given the pH of 4.73–6.02, REE fractionation driven by the adsorption of kaolinite was limited. Fe–Mn (oxyhydr)oxides played an important role in REE enrichment and the reducible fraction holds up to 21% (139 mg kg–1) of the total REE. The enrichment of LREE was observed in the reducible fraction potentially because of the preferential release of LREE from the LREE-bearing minerals (monazite) and then scavenged by Fe–Mn (oxyhydr)oxides. Positive Ce anomalies (Ce/Ce*: 10) were found in the reducible fraction because trivalent Ce was oxidized by Fe–Mn (oxyhydr)oxides to cerianite (CeO2). The present study helps to understand the enrichment and fractionation of REE in the IADs of South China.
The late third-millennium BC Longshan period was a crucial time for state formation in central China. During these centuries, long-distance networks expanded and shared material culture and then cultural practices spread across wider areas precipitating social and ideological developments that presaged the rise of states and cities on the Central Plain. In this research, the authors use multiple (strontium, oxygen and carbon) isotope analyses from the dental enamel of 67 individuals buried at the Xiajin cemetery, Shanxi Province. The results indicate significant long-distance migration among females during the Longshan period, which the authors interpret as evidence of exogamous marriage for political alliance-building—a phenomenon found more widely across Eurasia at the start of the Bronze Age.
COVID-19 lockdowns increased the risk of mental health problems, especially for children with autism spectrum disorder (ASD). However, despite its importance, little is known about the protective factors for ASD children during the lockdowns.
Methods
Based on the Shanghai Autism Early Developmental Cohort, 188 ASD children with two visits before and after the strict Omicron lockdown were included; 85 children were lockdown-free, while 52 and 51 children were under the longer and the shorter durations of strict lockdown, respectively. We tested the association of the lockdown group with the clinical improvement and also the modulation effects of parent/family-related factors on this association by linear regression/mixed-effect models. Within the social brain structures, we examined the voxel-wise interaction between the grey matter volume and the identified modulation effects.
Results
Compared with the lockdown-free group, the ASD children experienced the longer duration of strict lockdown had less clinical improvement (β = 0.49, 95% confidence interval (CI) [0.19–0.79], p = 0.001) and this difference was greatest for social cognition (2.62 [0.94–4.30], p = 0.002). We found that this association was modulated by parental agreeableness in a protective way (−0.11 [−0.17 to −0.05], p = 0.002). This protective effect was enhanced in the ASD children with larger grey matter volumes in the brain's mentalizing network, including the temporal pole, the medial superior frontal gyrus, and the superior temporal gyrus.
Conclusions
This longitudinal neuroimaging cohort study identified that the parental agreeableness interacting with the ASD children's social brain development reduced the negative impact on clinical symptoms during the strict lockdown.
The development of the tourism industry has led to an increasing number of tourists, demanding better service quality from scenic spots. The improvement of service quality in tourist attractions can provide tourists with a safer and more reliable travel environment, reducing their anxiety about risks and uncertainties.
Subjects and Methods
Based on the principle of random sampling, the population aged between 18 and 60 in a certain scenic area were selected and distributed a service quality demand questionnaire. It includes four criteria: safety services, navigation services, employee attitudes, and service processes. The score was filled out on a scale of 1 to 10. The higher the score, the more valued the content is by tourists. A total of 1000 demand forms were distributed, and 985 were actually collected, with a recovery rate of 98.5%. Statistical analysis was conducted on the table data using SPSS23.0 software.
Results
According to the statistical results, there is a negative correlation between the four aspects of scenic area safety services, scenic area navigation services, employee attitudes, and service processes and tourists’ psychological anxiety, with a P-value less than 0.05, indicating statistical significance.
Conclusions
By providing a sense of safety and security, accurate and complete scenic area information, friendly and enthusiastic service attitude, and convenient and efficient service processes, scenic area managers can reduce tourists’ anxiety, and improve their satisfaction and experience.
Acknowledgement
In 2019, the Youth Fund for Humanities and Social Sciences Research of the Ministry of Education (No. 19YJC790043).
Submerged vegetation plays a subtle role in exchanging the fluid mass and energy in the vegetated flow zone, where the swaying motions of flexible plants are the important source of turbulent kinetic energy production. Flume experiments were conducted to study the modes, characteristics and factors of swaying of individual submerged flexible plants. A modified plant model in a new form, representing the highly flexible vegetation with clustered leaves, was employed. A ‘rigid-like’ synchronous swaying mode and a ‘whip-like’ asynchronous flapping mode are found to appear alternately for the individual plants. The interaction between these modes depends on the resulting local flow structure affected by the plants. Compared with a plant in isolation with the same flow Reynolds number, the swaying motions of a plant within the vegetation patch are less frequent but more prone to the synchronous mode. The eigen frequency of the motions increases linearly with an increase in flow Reynolds number in the range of 2 × 104–5 × 104, but the normalised amplitude reaches a saturation at a high flow Reynolds number. Moreover, the in-line and spanwise motions have a 2 : 1 frequency ratio for an ‘8’ shaped trajectory on the horizontal plane and a 1 : 1 ratio for a ‘0’ shaped circular trajectory, or a combination of both.