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Controllable release of chemotherapeutic drugs in tumor sites remains a big challenge for precision therapy. Herein, we developed acidity/carbon dioxide (H

Circular RNA (circRNA) is a covalently closed-loop non-coding RNA that exists widely in the transcriptome of eukaryotic cells. It participates in a variety of pathophysiological processes by acting as a microRNA sponge, regulating the level of protein transcription, and interacting with RNA binding proteins. CircRNA is enriched in the cortex, hippocampus, brain white matter, and photoreceptor neurons of aging bodies, and they can be used as a biomarker for neural senescence. The expression levels of circRNA in peripheral blood and synapses in Alzheimer's disease (AD) patients are increased, which are involved in the occurrence and prognosis of AD. Different circRNAs such as HDAC9, Homer1, Cwc27, Tulp4, and PTK2 can lead to AD pathological changes via increasing amyloid-β deposition, promoting tau protein hyperphosphorylation, aggravating neuroinflammation and mitochondrial dysfunction, which result in the cognitive decline.环状RNA(circRNA)是普遍存在于真核细胞转录组中的共价闭环非编码RNA，其通过充当微RNA海绵、调节蛋白质转录水平、与RNA结合蛋白质作用等参与机体的多种病理、生理过程。CircRNA富集于衰老机体的皮层、海马体、大脑白质及光感受器神经元中，可作为神经衰老的生物标志物。CircRNA在阿尔茨海默病(Alzheimer’s disease，AD)患者外周血及神经突触中的表达水平增高，参与AD的发生与转归。不同的circRNA[如HDAC9、HOMER1、Cwc27、Tulp4、PTK2]可通过增加β-淀粉样蛋白沉积、促进tau蛋白过度磷酸化、加重神经炎症及引发线粒体功能障碍等导致患者出现AD病理改变，从而诱发认知功能下降。.

There are increasing numbers of studies investigating the potential link between microRNAs (miRNAs) and type 2 diabetes mellitus (T2DM) risk. Based on the prior evidence and the differentially expressed candidate plasma exosome miRNAs in our established discovery study, the current meta-analysis studied miR-126 and miR-122 specifically. The purpose of the present study was to systematically and quantitatively evaluate the relationship of miR-126 and miR-22 expression level with T2DM risk as well as related glucose metabolism parameters. Moreover, the present study was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline (PRISMA 2020 statement). PubMed, Embase, Web of Science, Cochrane and Chinese National Knowledge Infrastructure electronic databases were used to identify eligible original studies prior to May 3, 2022. The random-effects models were employed to explore the overall effect estimates [odds ratio (OR) and 95% confidence interval (CI), or correlation coefficient (r, 95% CI)]. The subgroup analyses were conducted to examine the potential sources of heterogeneity. The potential publication bias was assessed by the Begg's funnel plot and Egger's tests. A total of 46 articles were included in the present meta-analysis. The results revealed that higher exposure level of miR-126 was related to lower T2DM risk in 5 analytical epidemiological studies [OR=0.73, 95% CI: (0.55, 0.96)], lower fasting blood glucose (FBG) [N=22, r=-0.26, 95% CI: (-0.42, -0.10)], and lower homeostasis model assessment of insulin resistance (HOMA-IR) index [N=9, r=-0.28, 95% CI: (-0.52, -0.05)]. Besides, positive correlations were observed between miR-122 expression and FBG [N=10, r=0.34, 95% CI: (0.20, 0.48)], as well as HOMA-IR index [N=9, r=0.40, 95% CI: (0.16, 0.64)]. The relationship of miR-126 and miR-122 expression with T2DM risk and these glucose metabolism parameters may be influenced by study types, sample size, different source and mean age of participants. In conclusion, in the general healthy population, higher miR-126 expression was related to lower T2DM risk, FBG level and HOMA-IR index; higher miR-122 expression was closely correlated with higher FBG level and HOMA-IR index. These findings have notable clinical and public health implications for screening and control glucose metabolic disorders, insulin resistance and T2DM development.

Glucose oxidase (GOx)-based nanotheranostic agents hold great promise in tumor starvation and its synergistic therapy. Self-assembled plasmonic gold vesicles (GVs) with unique optical properties, large hollow cavity, and strong localized surface plasmon resonance, can be used as multi-functional nanocarriers for synergistic therapy. Herein, GOx-loaded GVs (GV-GOx) were developed for light-triggered GOx release as well as enhanced catalytic activity of GOx, achieving programmable photothermal/starvation therapy. Under near-infrared laser irradiation, the GV-GOx generated strong localized hyperthermia due to plasmon coupling effect of GVs, promoting the release of encapsulated GOx and increasing its catalytic activity, resulting in enhanced tumor starvation effect. In addition, the high photothermal effect improved the cellular uptake of GV-GOx and allowed an efficient monitoring of synergistic tumor treatment via photoacoustic/photothermal duplex imaging in vivo . Impressively, the synergistic photothermal/starvation therapy demonstrated complete tumor eradication in 4T1 tumor-bearing mice, verifying superior synergistic anti-tumor therapeutic effects than monotherapy with no apparent systemic side effects. Our work demonstrated the development of a light-triggered nanoplatform for cancer synergistic therapy.

Fossil energy supports the development of human society but is facing depletion because of industrialization. In order to solve the formidable problem in compatibility and coordination between energy utilization and the environment and accelerate the development of sustainable energy, it is pressing to realize the transition from fossil to sustainable energy as soon as possible to solve common challenges in human development. Energy technology revolution will bring new opportunities and challenges in the development of the engineering thermophysics discipline. According to urgent needs for energy, power and environmental issues and new progress in discipline development, the Chinese Society of Engineering Thermophysics is aiming for constructing a sustainable energy system and carrying out strategic research on the development of an energy paradigm and frontier growth point of the engineering thermophysics discipline in China. The new integrated development paradigm of energy, resources, and environment provides a promising support for the realization of a sustainable energy strategy. Key objectives of the new development paradigm is to open up new channels of sustainable energy, carry out an energy diversification strategy, and try to solve the formidable problems in compatibility and coordination between energy utilization and the environment, including clean utilization of traditional fossil energy sources, development of green energy, and integration of energy resources into the environment. Important research directions for future development in the engineering thermophysics discipline include: thermophysical properties of an environment friendly working medium; modern analysis methods for new energy sources; combustion under extreme conditions; theories and methods for efficient, clean, and low carbon conversion of fuels; efficient conversion and utilization of solar energy; regional, intelligent, and diversified utilization of wind energy; new methods and mechanisms for efficient and low-cost utilization of biomass; comprehensive cascade utilization of chemical and physical energy sources of fuels; distributed energy system with multiple energy source complementation and its optimization integration theory; energy consumption minimization principle on CO2 capture based on comprehensive cascade utilization of energy; and novel high-efficiency energy storage method based on entropy principle.

Disturbance by rodents alters the morphologies and nutrients of plants as well as the physical-chemical properties of the soils. Changes in plants are considered to be mechanisms of defense against the disturbance by rodents. Rodents gnaw on the assimilating branches of Haloxylon ammodendron (CA Mey.) Bunge and burrow under the bushes in the desert ecosystems of Xinjiang, China. However, eco-physiological responses of different age groups of H. ammodendron to the disturbance by rodents are not well understood. In this study, soil physical-chemical properties under the shrubs and the above-ground morphological, physiological and biochemical features of assimilating branches of H. ammodendron of different age groups (i.e., young, 30–100 cm; middle-aged, 100–200 cm; and mature, >200 cm) in burrowed and non-burrowed (control) areas were studied in 2018. We found that disturbance by rodents significantly increased the crown width and total branching rates of young and middle-aged H. ammodendron. Photosynthetic pigment contents of assimilating branches of H. ammodendron were significantly reduced under the disturbance by rodents. In term of plant nutrients, the main differences among different age groups of H. ammodendron under the disturbance by rodents occurred in the total soluble sugar and reducing sugar contents that decreased in young plants, increased in middle-aged plants, and did not affect in mature plants. Crude protein and phosphorus contents significantly increased, while crude fiber and calcium contents significantly decreased in young plants. Crude fat and calcium contents significantly decreased in middle-aged plants. Soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN) and available potassium (AK) contents in the topsoil (0–20 cm), which are conducive to forming “fertile islands”, also increased under the disturbance by rodents. In particular, soil AN and AK were the major factors affecting the above-ground morphological characteristics of H. ammodendron in burrowed areas. Overall, the response and defense strategies of H. ammodendron to the disturbance by rodents differed among different age groups, and the effect of the disturbance by rodents on H. ammodendron gradually weakened with the increasing plant age.

A novel antibacterial hydrogel was prepared through the addition of IT to a chitin (CT) and polyvinyl alcohol (PVA) hydrogel, creating a promising material for wound dressings. The addition of nano particles IT endowed the anti-bacterial activity of hydrogel as well as had a positive impact on the mechanical properties of the hydrogels. The structure of the prepared hydrogel dressing was characterized by FTIR, XPS, XRD, SEM and TEM. The composite hydrogel exhibited excellent anti-bacterial activity under the visible light. Cytotoxicity tests (L929 fibroblast cells) showed all samples achieving up to 80% cell viability. Furthermore, compared with conventional dressings, wound healing test revealed that CT/PVA/IT hydrogel could accelerated wound healing in vivo, wound closure rates reached 95.5% after 10 days. This study suggests that the novel hydrogel has considerable potential for applications in wound dressings.

The influence of the inlet and outlet heights of the flow channel on the performance of a proton exchange membrane fuel cell was studied with a three-dimensional fuel cell mathematical model. The numerical results were used as the basic training data of a three-layer back-propagation artificial neural network (ANN) model in which the inlet and outlet heights of the flow channel as well as the cell voltage were set to be the input variables while cell current density is the output variable. Then, applying the Bagging ensemble learning method to integrate the neural network model, a fuel cell performance prediction method is constructed. It was shown that as compared with the ANN model, the Bagging neural network model exhibited higher prediction accuracy and less requirements of model training data. It also can be applied for rapid prediction of fuel cell performance in a wide range of conditions beyond the training data, showing the robustness of the proposed Bagging neural network ensemble model.

Background The measures of socioeconomic status (SES) differed across divergent researches and rare of them focused on rural population. This research, thus, presented a novel measure of SES among rural population and then estimated its association with type 2 diabetes mellitus (T2DM). Methods All participants were farmer and enrolled from the Henan Rural Cohort study. SES of individual was assessed by SES-score, a composite index derived from three SES-related indicators (education level, average monthly income, and marital status). Binary logistic regression was employed to examine the independent association between SES-score and T2DM as well as the combined effects of SES and age on T2DM. To detect the gender differences, all analyses were stratified by gender. Results Among 39259 rural participants, the means (SDs) SES-score of total population, men, and women were 3.47 (1.54), 3.72 (1.49), and 3.31 (1.57), respectively. The SES-score decreased with age and men always had a higher score than women. The prevalence of T2DM decreased with increasing SES-score among women (14.87–4.47%, P trend P trend

Background The study aimed to investigate the independent and combined effects of midpoint of sleep and night sleep duration on type 2 diabetes mellitus (T2DM) in areas with limited resources. Methods A total of 37,276 participants (14,456 men and 22,820 women) were derived from the Henan Rural Cohort Study. Sleep information was assessed based on the Pittsburgh Sleep Quality Index. Logistic regression models and restricted cubic splines were used to estimate the relationship of the midpoint of sleep and night sleep duration with T2DM. Results Of the 37,276 included participants, 3580 subjects suffered from T2DM. The mean midpoint of sleep among the Early, Intermediate and Late groups were 1:05 AM ±23 min, 1:56 AM ±14 min, and 2:57 AM ±34 min, respectively. Compared to the Intermediate group, adjusted odds ratios (ORs) and 95% confidence interval (CI) of T2DM were 1.13 (1.04–1.22) and 1.14 (1.03–1.26) in the Early group and the Late group. Adjusted OR (95% CI) for T2DM compared with the reference (7- h) was 1.28 (1.08–1.51) for longer (≥ 10 h) night sleep duration. The combination of late midpoint of sleep and night sleep duration (≥ 9 h) increased 38% (95% CI 10–74%) prevalence of T2DM. These associations were more obvious in women than men. Conclusions Late and early midpoint of sleep and long night sleep duration were all associated with higher prevalence of T2DM. Meanwhile, midpoint of sleep and night sleep duration might have combined effects on the prevalence of T2DM, which provided potential health implications for T2DM prevention, especially in rural women. Trial registration The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015-07-06.

Objectives: The study aimed to explore the association between Ideal cardiovascular health (ICH) and health-related quality of life (HRQoL) using the European Quality of Life Five Dimension Five Level Scale (EQ-5D-5L) among rural population. Methods: This study included 20683 participants aged 18 to 79 years from “the Henan Rural Cohort study”. The ICH scores was evaluated by summing the total number of ICH metrics for each participant. Generalized linear and Tobit regression models were employed to explore the associations of ICH with EQ-5D-5L utility scores and visual analogue scale (VAS) scores, respectively. Results: The mean EQ-5D-5L utility scores and VAS scores were 0.962 ± 0.095 and 79.52 ± 14.02, respectively. Comparing with poor CVH participants (EQ-5D-5L utility scores and VAS scores: 0.954±0.111 and 78.44±14.29), people with intermediate and ideal CVH had higher EQ-5D-5L utility scores (0.969±0.079 and 0.959±0.099) and VAS scores (80.43±13.65and 79.28±14.14). ICH scores were positively correlated with EQ-5D-5L utility scores (0.007(0.004, 0.009)) and VAS scores (0.295(0.143, 0.446)), respectively. Conclusions: Higher ideal cardiovascular health scores is positive associated with better health-related quality of life in rural population, which suggests that improvement of cardiovascular health may help to enhance health-related quality of life in rural population among rural population.

Background: The study aimed to explore the independent and combined associations of midpoint of sleep and night sleep duration with type 2 diabetes mellitus (T2DM) in areas with limited resources.Methods: A total of 37,276 participants (14,456 men and 22,820 women) were derived from the Henan Rural Cohort. Information on sleep were collected using the Pittsburgh Sleep Quality Index. Logistic regression models and restricted cubic splines were used to estimate the relationship of the midpoint of sleep and night sleep duration with T2DM.Results: Of the 37276 included participants, 3580 subjects suffered from T2DM. The mean midpoint of sleep among Early, Intermediate and Late groups were 1.09 ± 0.39, 1.93 ± 0.24 and 2.95 ± 0.56, respectively. Compared to Intermediate group, adjusted odd ratios (ORs) and 95% confidence interval (CI) of T2DM were 1.13 (1.04-1.22) and 1.16 (1.05-1.28) in Early group and Late group. Adjusted OR (95% CI) for T2DM compared with reference (7- h) was 1.27 (1.08-1.50) for longer (≥10 h) night sleep duration. The combination of late midpoint of sleep and night sleep duration (≥9 h) increased 39% (95% CI: 11%-75%) prevalence for T2DM. These associations were more obvious in women than men.Conclusions: Late and early midpoint of sleep and long night sleep duration were all associated with the higher odds of T2DM. Meanwhile, midpoint of sleep and night sleep duration might be jointly associated with a higher prevalence of T2DM. Sleep may be a modifiable behavior that has potential health implications for T2DM.Clinical Trail Registration: The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015-07-06.

Additional file 1: Supplementary Table 1. The demographic characteristics of subjects according to midpoint of sleep. Supplementary Table 2. Comparison of bedtime, wake-up time and sleep duration across 3 categories of the midpoint of sleep. Supplementary Table 3. Subgroup analysis of the association of midpoint of sleep and night sleep duration with T2DM.

Background: The study aims to evaluate the efficacy and safety of probiotic therapy for coronavirus disease 2019 with diarrhea. Methods: The following electronic bibliographic databases will be searched to identify relevant studies from December 2019 to December 2020: MEDLINE, PubMed, Embase, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Chinese Technical Periodicals, Wan-fang data, Chinese Biological Medicine Database, and other databases. The search results will not be restricted by language, all included articles were randomized controlled trial. Two independent researchers will conduct article retrieval, de-duplication, filtering, quality assessment, and data analysis through the Review Manager (V.5.3). Meta-analysis, subgroup analysis and/or descriptive analysis were performed on the included data. Results: High-quality synthesis and/or descriptive analysis of current evidence will be provided from outcomes. Conclusion: This study will provide the evidence of whether probiotics is an effective and safe intervention for coronavirus disease 2019 with diarrhea. PROSPERO registration number: CRD42020192657.

Evidence from numerous epidemiological studies for the relationship between mental disorder and sleep quality was inconclusive and few studies assessed the modification effect of exposure to ambient air PM

Background Ferula sinkiangensis is an increasingly endangered medicinal plant. Arbuscular mycorrhiza fungi (AMF) are symbiotic microorganisms that live in the soil wherein they enhance nutrient uptake, stress resistance, and pathogen defense in host plants. While such AMF have the potential to contribute to the cultivation of Ferula sinkiangensis, the composition of AMF communities associated with Ferula sinkiangensis and the relationship between these fungi and other pertinent abiotic factors still remains to be clarified. Results Herein, we collected rhizosphere and surrounding soil samples at a range of depths (0–20, 20–40, and 40–60 cm) and a range of slope positions (bottom, middle, top). These samples were then subjected to analyses of soil physicochemical properties and high-throughput sequencing (Illumina MiSeq). We determined that Glomus and Diversispora species were highly enriched in all samples. We further found that AMF diversity and richness varied significantly as a function of slope position, with this variation primarily being tied to differences in relative Glomus and Diversispora abundance. In contrast, no significant relationship was observed between soil depth and overall AMF composition, although some AMF species were found to be sensitive to soil depth. Many factors significantly affected AMF community composition, including organic matter content, total nitrogen, total potassium, ammonium nitrogen, nitrate nitrogen, available potassium, total dissolvable salt levels, pH, soil water content, and slope position. We further determined that Shannon diversity index values in these communities were positively correlated with total phosphorus, nitrate-nitrogen levels, and pH values (P P Conclusion In summary, our data revealed that Glomus and Diversispora are key AMF genera found within Ferula sinkiangensis rhizosphere soil. These fungi are closely associated with specific environmental and soil physicochemical properties, and these soil sample properties also differed significantly as a function of slope position (P Ferula sinkiangensis, offering a theoretical basis for further studies of their development.

Background: The American Heart Association define a new concept of ideal cardiovascular health (ICH), which was widely used. However, the prevalence of ICH according to the definition of Chinese rural population is unclear. The study aimed to estimate prevalence and influencing factors of ICH in rural areas of China.Methods: This study included 35081 participants (13711 men and 21370 women)aged 18 to 79 years from “the Henan Rural Cohort study”. The cardiovascular health (CVH) metrics, the ICH scores, the ideal health behaviors (IHB) scores and ideal health factors (IHF)scores were evaluated in Chinese rural adults. Each CVH metrics divided into ideal and non-ideal including diet, physical activity, smoking, BMI, blood pressure, total cholesterol and fasting plasma glucose. The influencing factors of ideal CVH (ICH scores≥5), ideal HB (IHB scores>3) and ideal HF (IHF scores>3) were explored by logistic regression analysis.Results: The age-standardized mean scores of the ICH was 4.30(3.62 in men and4.69 in women). Prevalence of ICH metrics about ideal physical activity was the highest (91.37%), while about ideal diet was lowest (0.48%).The age-standardized prevalence of population who with 7 scores of ICH was 0.10% (0.07% in men and 0.11% in women). The age-standardized prevalence of Ideal CVH (ICH scores≥5) was 48.86% (28.26% in men and 60.70% in women). The age-standardized prevalence of 4 of IHB scores and 4 of IHF scores were 0.16% (0.17% in men and 0.16% in women) and 33.26% (10.06% in men and 46.60% in women), respectively. Further, apart from IHB scores, age had an inverse relationship with the ICH scores and IHF scores in total populations and women. Much older, men, low family income, current drinking and abdominal obesity were independently associated with ICH in Chinese rural adults.Conclusions: The percentage of ideal cardiovascular health is extremely low in rural China. There is an increasing need for primordial prevention of unhealthy lifestyles and monitoring high risk factors to promote cardiovascular health in rural China.Clinical Trial Registration The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015-07-06.http://www.chictr.org.cn/showproj.aspx?proj=11375

We investigated the rhizospheric arbuscular mycorrhizal (AM) fungi from the three medicinal licorice plants, i.e., Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat., and Glycyrrhiza glabra L. The AM fungi were reported to be affected by the host plant species as well as soil depth, physical, and chemical properties. We collected the rhizosphere from these licorice plants, from the soil layer with a depth of 0-20 cm, 20-40 cm, and 40-60 cm in the Xinjiang region. Furthermore, we employed the Illumina Miseq high-throughput sequencing platform to investigate the structure and diversity of these AM fungal communities. The soil physical and chemical properties were also evaluated to determine the relationship between the medicinal Glycyrrhiza rhizospheric AM fungi and the associated soil factors. In order to provide a reference for revealing the role of arbuscular mycorrhizal fungi in increasing the content of active components in cultivated licorice root, we isolated a total of 34 AM fungi that encompassed a phylum, a class, five (orders, families, and genus), and the Glomus and Paraglomus emerged as the dominant genus. We observed the highest diversity in the AM fungi in Glycyrrhiza uralensis Fisch. The Glycyrrhiza inflata showed the highest richness, whereas the Glycyrrhiza glabra showed the lowest richness and diversity in each soil layer. The plant species influenced the AM fungi more than the soil depth. The total phosphorus, available phosphorus, and organic matter in the soil prominently impacted the distribution of soil AM fungi. In contrast, the soil ammonium and nitrogen content had the lowest-impact on the AM fungi distribution. The genus Glomus was was found to be positively correlated with total phosphorus (P

Additional file 1: Table S1. The relationships between alpha diversity indices and abiotic factors. Spearman correlation analyses of the relationships between alpha diversity indices and abiotic factors in all samples. Only variables with significant relationships are shown. ** P

In this paper, we investigate fully discrete schemes for the Allen-Cahn and Cahn-Hilliard equations respectively, which consist of the stabilized finite element method based on multiscale enrichment for the spatial discretization and the semi-implicit scheme for the temporal discretization. With reasonable stability conditions, it is shown that the proposed schemes are energy stable. Furthermore, by defining a new projection operator, we deduce the optimal \begin{document}$ L^2 $\end{document} error estimates. Some numerical experiments are presented to confirm the theoretical predictions and the efficiency of the proposed schemes.

Nanostructured surface is an important way to improve the efficiency of solar energy by absorbing more solar irradiance. However, due the bandgap of semiconductor material, more absorbed irradiance results in more waste heat. As for photovoltaic-thermoelectric (PV-TE) hybrid system, more waste heat reduces the efficiency of PV module due to the increased temperature, but is beneficial for TE module. There are complex and coupling physical processes (near-field optics, photovoltaic conversion, thermoelectric effects, and heat transfer) in the PV-TE hybrid system. Therefore, a multi-physics coupling mathematic model is developed for investigating the effect of full-spectrum characteristics of nanostructure on the PV-TE hybrid system performances. At first, the full-spectrum characteristics of nanostructure is found and summed up. As an example, the II set of the cone nanostructures have two cone nanostructure (Ⅱ-1 cone nanostructure and Ⅱ-2 cone nanostructure) with different dimensions. They have the same average reflectance of the wavelength range from 0.35 μm to 1.1 μm (0.05), however the average reflectance of the wavelength range from 1.1 μm to 2.5 μm (Ra,1.1-2.5) of the Ⅱ-1 cone nanostructure is 74.8% lower than that of the Ⅱ-2 cone nanostructure, which results in that the output power density of the PV-TE hybrid system with the II-2 cone nanostructure being 8.4 W/m2 more than that with the II-1 cone nanostructure when the concentration ratio is 10. Thus, the cone nanostructures with as high Ra,1.1-2.5 as possible are more beneficial for the hybrid system. Then, by optimizing the heat transfer structure of the PV-TE hybrid system, the output power density is increased by 9.1%. At last, through dynamic analysis, it is found that the annual power generation per square meter of the PV-TE hybrid system with II-2 cone nanostructure is about 17 kW·h/m2 greater than that with the II-1 cone nanostructure. As a result, combined with the structural analysis of the cone nanostructure, the bottom diameter should be as short as possible for the cone nanostructure.

A cooling simulation device utilizing multiple impinging jets is built for ground cooling simulation tests of high speed flight vehicles. To help the design of the device and supply a relatively uniform heat flux on the test piece surface, a three-dimensional numerical study is performed in this paper to investigate the effects of nozzle arrangement on the convective heat transfer uniformity of the impinging jets. A simplified physical model with the size of 200 mm × 200 mm × 50 mm is built and the shear-stress transport (SST) k-ω turbulence model is used in the calculation. The nozzle quantity is varied from 8 × 8 to 32 × 32 for uniform nozzle arrays with a fixed total area of the nozzles. The corresponding numerical results of uniform nozzle arrangements are analyzed in details. Based on the 16 × 16 uniform arrangement results, the effects of diameter varying nozzle arrangements on heat transfer uniformity are further examined. Finally, an overall performance evaluation indicator named QU ratio is used in the optimization of nozzle arrangement, which proves to be effective and convenient in practice.

The condensation process of the multiple-atom and polar water molecular at a solid wall is studied. It is found that a monomolecular layer structure is existed on the wall surface and the intensity of solid-liquid potential can be revealed by the monomolecular density peak. At high-temperature conditions, liquid drop in vapor and bubble near wall can be observed. The solid-liquid potential energy on monomolecular layer structure has a greater impact than on gas-liquid interface. The simulated densities in the vapor region are consistent with the macroscopic values by refprop8.0, while in the liquid region the simulated densities are a bit lower than the macroscopic ones. Besides, the solid-liquid-gas three-phase model consisting of argon, water, freon and copper was constructed using Materials Studio software, and their interface characteristics are studied.

In this paper, the studies on the characteristics with time and failure criterion in the solar molten salt cavity receiver are carried out based on the coupled photon-thermal-stress integration method. Especially, the truly non-uniformed solar heat flux in the cavity receiver with different time are simulated using the optical simulation approach coupling the Monte Carlo ray tracing and Gebhart methods proposed by our team. Besides, the complex coupled heat transfer process of conduction, convection and radiative in the receiver are also comprehensively considered. Based on the integrally model, the solar flux, temperature and thermal stress on the absorber surfaces with different time are obtained. Then, the influences of different tube materials, flow layouts of molten salt on the coupling performances of photon-thermal-stress conversion process are discussed. Finally, the stress failure criterion in the molten salt cavity receiver is proposed based on the fracture mechanics theory. The results show that the temperature and thermal stress are influenced significantly by the non-uniformed solar flux, the distribution of temperature and thermal stress are also extremely non-uniformed. The solar flux and thermal stress change remarkably with different time, the peak heat flux and stress are maximum at 12:00 noon, and the peak thermal stress could increase by 11% and 10% compared with 11:00 and 13:00. It is also found that the peak thermal stress would be reduced effectively when the receiver tube with better thermal conductivity property and the molten salt flow layout which is from low-flux area to high-flux area are adopted. For example, compared with 800H receiver tube, the peak thermal stress of 316H tube could be reduced by 37%. Meanwhile, the peak thermal stress of flow layout which is from low to high flux area would be 20% lower than that with the opposite layout. The fracture toughness of receiver tube, which is influenced by the molten salt corrosion, is one of the key parameters to assess stress failure. Based on the stress failure criterion of critical solar flux proposed by this paper, the critical heat flux of stress failure would exhibit a decreasing trend when the fracture toughness degradation is serious in the molten salt receiver.

Tamarix is a dominant species in the Tarim River Basin, the longest inland river in China. Tamarix plays an important role in the ecological restoration of this region. In this study, to investigate the soil bacterial community diversity in Tamarix shrubs, we collected soil samples from the inside and edge of the canopy and the edge of nebkhas and non-nebkhas Tamarix shrubs located near the Yingsu section in the lower reaches of Tarim River. High throughput sequencing technology was employed to discern the composition and function of soil bacterial communities in nebkhas and non-nebkhas Tamarix shrubs. Besides, the physicochemical properties of soil and the spatial distribution characteristics of soil bacteria and their correlation were analyzed. The outcomes of this analysis demonstrated that different parts of Tamarix shrubs had significantly different effects on soil pH, total K (TK), available K (AK), ammonium N (NH4+), and available P (AP) values (P < 0.05), but not on soil moisture (SWC), total salt (TDS), electrical conductivity (EC), organic matter (OM), total N (TN), total P (TP), and nitrate N (NO3−) values. The soil bacterial communities identified in Tamarix shrubs were categorized into two kingdoms, 71 phyla, 161 classes, 345 orders, 473 families, and 702 genera. Halobacterota, unidentified bacteria, and Proteobacteria were found to be dominant phyla. The correlation between the soil physicochemical factors and soil bacterial community was analyzed, and as per the outcomes OM, AK, AP, EC, and NH4+ were found to primarily affect the structure of the soil bacterial community. SWC, TK and pH were positively correlated with each other, but negatively correlated with other soil factors. At the phyla level, a significantly positive correlation was observed between the Halobacterota and AP, OM as well as Bacteroidota and AK (P < 0.01), but a significantly negative correlation was observed between the Chloroflexi and AK, EC (P < 0.01). The PICRUSt software was employed to predict the functional genes. A total of 6,195 KEGG ortholog genes were obtained. The function of soil bacteria was annotated, and six metabolic pathways in level 1, 41 metabolic pathways in level 2, and 307 metabolic pathways in level 3 were enriched, among which the functional gene related to metabolism, genetic information processing, and environmental information processing was found to have the dominant advantage. The results showed that the nebkhas and canopy of Tamarix shrubs had a certain enrichment effect on soil nutrients content, and bacterial abundance and significant effects on the structure and function of the soil bacterial community.

In this study, two typical components in industrial flue gas (SiO 2 solid particle and H 2 O vapor) was selected as a solid-gas system, the transport properties were investigated by equilibrium molecular dynamics (EMD) simulation with three different concentrations of solid phase systems established over the actual temperature range (1000–1400 K) of industrial flue gas. The number of hydrogen bonds was counted and the radial distribution function in the system was obtained to analyze the microstructure of the system. The thermal conductivity, viscosity and diffusion coefficient were calculated and the effects of temperature and solid concentration on the transport properties were investigated. The predicted values of transport properties are in good agreement with the available experimental data. The results show that with the diffusion of water molecules, polar water molecules form hydrogen bonds with silica and other water molecules, and as the temperature increases, the average number of hydrogen bonds of water molecules decreases and the stability of the system decreases. Simultaneously, with the increase of temperature, the thermal conductivity and viscosity of the system increase, when the concentration of the solid phase in the system increases, both the thermal conductivity and the viscosity increase at the same temperature. This study improves the understanding of transport characteristics of industrial flue gas from the microscopic point of view, which is significant to the dust purification and waste heat recovery technologies.

The problem of high exhaust temperature universally exists around the industrial boilers, which causes enormous loss of energy. Different kinds of heat exchangers are widely used in the waste heat recovery systems to recover waste energy from different heat sources. However, considering the heat exchangers mainly work in dusty environment, such as in the tail of large boiler, fly ash fouling on heat exchangers is a major problem in waste heat recovery systems, which can lead to significant efficiency deterioration. Besides, the fouling may also lead to failure of the systems with serious economic consequence. The H-type finned tube heat exchanger is a new type of heat exchanger which have been widely used in waste heat recovery systems in recent years, because of their excellent anti-wear and anti-fouling performance. In this paper, a numerical model was developed to investigate the fouling characteristics of two kinds of H-type finned tube heat exchangers used in the waste heat recovery systems. Firstly, a fouling model which contains a deposition process and a removal process is developed. The deposition process is determined by the energy balance on the particles and the removal process is determined by the the local wall shear stress and the fouling thickness on the fin surface. As the flow field directly affects the particle motion, the fluid flow characteristics of the two kinds of heat exchangers are calculated, and the discrete phase model (DPM) was employed to trace the fly ash particles in the flow field during the fouling process. Since the simulation time is much smaller in magnitude than the real time in fouling process, it is impossible to simulate the whole real fouling time period (hours) with a small time step size. In order to obtain a reliable result, it is necessary to enlarge the simulation time and results to the real time scale. In this paper, a fouling time ratio is proposed by considering the volume difference between the simulated deposit layer and the real deposited particles and the concentration difference of injected particles between the simulation and real situation. According to the fouling time ratio, we can enlarge the simulation time and results to the real time scale. Then the real-time fouling characteristics of the two kind of H-type finned tube heat exchangers are investigated and the effects of inlet velocity, particle diameter on the fouling results are also studied. The results show that, the fouling mainly occurred in the flow stagnation region and the recirculation region of the H-type finned tube. The net fouling mass increases with the operating time, showing an asymptotic characteristic of growth, and finally will reach a stable value, which corresponds to the asymptotic fouling resistance. The increase in inlet velocity and particle diameter would lead to a rapidly decrease in fouling results. The anti-fouling performance of double H-type finned tubes shows slightly better than that of single ones, but the advantages decreases with the increase in inlet velocity and particle diameter.