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Using force tracing and nano-indentation techniques based on atomic force microscopy, the promoting effect of Tf on T7-modified nano-drug transport was investigated at a single-particle and single-cell level in real time.

We investigated the time it takes 54,146 English learners (ELs) in Michigan public schools to attain English proficiency, and how their diversity factors affect that time. We used discrete-time survival analysis to analyze the ELs from kindergarten until fifth grade. Survival analysis often concerns time from treatment until death: Here, “survival” is time from EL-program entry until proficiency, indicated via testing. Half attained proficiency in five years, with writing being their biggest barrier. Time to proficiency was substantially related to some factors (i.e., disability status, home language, retention status) but not others (i.e., home English use, instructional programming). EL education policy often assumes that theoretically, ELs become proficient in three to five years. Our analyses disaggregate this assumption.

The purpose of this study was to investigate the physiological recovery effects of olfactory, visual and olfactory–visual stimuli associated with garden plants. In a randomized controlled study design, ninety-five Chinese university students were randomly selected to be exposed to stimulus materials, namely the odor of Osmanthus fragrans and a corresponding panoramic image of a landscape featuring the plant. Physiological indexes were measured by the VISHEEW multiparameter biofeedback instrument and a NeuroSky EEG tester in a virtual simulation laboratory. The results showed the following: (1) In the olfactory stimulation group, from before to during exposure to the stimuli, the subjects’ diastolic blood pressure (DBP) (ΔDBP = 4.37 ± 1.69 mmHg, p < 0.05) and pulse pressure (PP) values increased (ΔPP = −4.56 ± 1.24 mmHg, p < 0.05), while their pulse (p) values decreased (ΔP = −2.34 ± 1.16 bmp, p < 0.05) significantly. When compared to the control group, only the amplitudes of α and β brainwaves increased significantly (Δα = 0.37 ± 2.09 µV, Δβ = 0.34 ± 1.01 µV, p < 0.05). (2) In the visual stimulation group, the amplitudes of skin conductance (SC) (ΔSC = 0.19 ± 0.01 µΩ, p < 0.05), α brainwaves (Δα = 6.2 ± 2.26 µV, p < 0.05) and β brainwaves (Δβ = 5.51 ± 1.7 µV, p < 0.05) all increased significantly relative to the control group. (3) In the olfactory–visual stimulus group, DBP (ΔDBP = 3.26 ± 0.45 mmHg, p < 0.05) values increased, and PP values decreased (ΔPP = −3.48 ± 0.33 bmp, p < 0.05) significantly from before to during exposure to the stimuli. The amplitudes of SC (ΔSC = 0.45 ± 0.34 µΩ, p < 0.05), α brainwaves (Δα = 2.28 ± 1.74 µV, p < 0.05) and β brainwaves (Δβ = 1.4 ± 0.52 µV, p < 0.05) all increased significantly relative to the control group. The results of this study show that the interaction of olfactory and visual stimuli associated with a garden plant odor landscape was able to relax and refresh the body to a certain extent, and this physiological health effect was greater with regards to the integrated response of the autonomic nervous system and central nervous system than the effect of only smelling or viewing the stimuli. In the planning and designing of plant smellscapes in garden green space, it should be ensured that plant odors and corresponding landscapes are present at the same time in order to ensure the best health effect.

Second language (L2) teachers may shy away from self-assessments because of warnings that students are not accurate self-assessors. This information stems from meta-analyses in which self-assessment scores on average did not correlate highly with proficiency test results. However, researchers mostly used Pearson correlations, when polyserial could be used. Furthermore, self-assessments today can be computer adaptive. With them, nonlinear statistics are needed to investigate their relationship with other measurements. We wondered, if we explored the relationship between self-assessment and proficiency test scores using more robust measurements (polyserial correlation, continuation-ratio modeling), would we find different results? We had 807 L2-Spanish learners take a computer-adaptive, L2-speaking self-assessment and the ACTFL Oral Proficiency Interview – computer (OPIc). The scores correlated at .61 (polyserial). Using continuation-ratio modeling, we found each unit of increase on the OPIc scale was associated with a 131% increase in the odds of passing the self-assessment thresholds. In other words, a student was more likely to move on to higher self-assessment subsections if they had a higher OPIc rating. We found computer-adaptive self-assessments appropriate for low-stakes L2-proficiency measurements, especially because they are cost-effective, make intuitive sense to learners, and promote learner agency.

In this work, the nano-g-C3N4/UiO-66-NH2 composite was prepared by one-step solvothermal method. The as-prepared composite was characterized by scanning electron microscopy, Brunner-Emmet-Teller measurement, energy dispersive spectrometer, X-ray diffraction, and Fourier transform infrared spectroscopy. By using nano-g-C3N4/UiO-66-NH2 composite as sorbent, a dispersive solid-phase extraction coupled with high-performance liquid chromatography was developed to sensitive analysis of food colorants including tartrazine, amaranth, carmine, sunset yellow, allura red and bright blue. The experiment parameters including the amount of sorbent, adsorption time, the pH of adsorption solution, desorption time, desorption solvent, the pH of desorption solution as well as the proportion between desorption solvent and buffer solvent were investigated. Under the optimized conditions, the limits of detection (S/N = 3) and limits of quantitation (S/N = 10) were determined in the ranges of 0.08–0.8 and 0.2–2.0 ng/mL, respectively. With the developed sample pretreatment method, carmine and brilliant blue were determined from blueberry juice by HPLC-DAD. The contents were calculated as1.53 μg/mL and 0.17 μg/mL, respectively.

Tourists have been attracted to world heritage sites (WHSs) by their Outstanding Universal Value (OUV). In view of the Stimulus-Organism-Response (S-O-R) framework and the theory of attitude and behavior, by employing 563 tourist samples from Mount Sanqingshan National Park, and using structural equation modeling, we examine tourist behavioral intention for heritage conservation, and the following conclusions were drawn: (1) the S-O-R theory revealed the behavioral intentions of tourists to protect WHSs; (2) as a stimulus, tourists’ value perception and destination attachment were positively affected by the OUV attractiveness, and their perceived value had a positive influence on heritage conservation, although the hypothesis of destination attachment to heritage conservation was not supported; (3) heritage-conservation education and knowledge positively influenced tourists’ behavioral intentions towards heritage protection, and tourists’ heritage protection attitude had a positive influence on their behavioral intention; and (4) a framework of the influence mechanism for tourists’ heritage conservation based on the S-O-R theory was proposed, while tourists’ cognitive and affective attitudes impacted on heritage protection intention which, in turn, further enhanced the tourists’ perception of the OUV. Conclusively, the measures and implications were proposed for improving conservation and management of WHSs, in particular to achieve the sustainable development of the tourist industry and world heritage sites.

The pursuit of tranquility experience has emerged as a new demand in tourism, but the perception of tranquility in tourism remains understudied. Although there are tools in the psychology and acoustics to measure tranquility perception, they are not suitable in tourism research. Therefore, this paper attempts to explore two contextual tourists’ perceptions scale of tranquility by analyzing two distinct destinations. Visual, auditory, and tactile involvement were introduced into the scale construction. A total of 1012 samples were collected from rural tranquil area and desert tranquil area. Following dimension construction and item production, EFA, CFA, reliability and validity tests were performed. Finally, a five-dimensional tranquility perception scale was developed. This study enriches the current themes and perspectives of multisensory involvement in the tranquility research and directs for further research on tourism, culture and tranquility experience.

Herein, a new gas-cycle-assisted (GCA) headspace solid-phase microextraction (HS-SPME) device was designed to rapidly extract organic pollutants with high Kow and boiling points, which have difficulty in volatilization from matrix to headspace. Organic pollutants, including three polycyclic aromatic hydrocarbons (PAHs), four polychlorinated biphenyls (PCBs), and five phthalate esters (PAEs), were selected to evaluate the performance of GCA HS-SPME. Compared with conventional HS-SPME, the equilibrium times of GCA HS-SPME for extraction of PAHs, PCBs, and PAEs were greatly shortened from 70-90 to 5-11 min. Moreover, the limits of detection for analysis of PAHs were achieved at pg mL-1 level by GCA HS-SPME coupled with gas chromatography-flame ionization detection.

Myocardial injury is a serious complication of sepsis. The present study aimed to identify potential biomarkers of sepsis-induced myocardial injury. Differentially expressed genes (DEGs) in patients and mice with sepsis-induced myocardial injury were identified via bioinformatic analysis. The identified DEG was tested in elderly patients with sepsis-induced myocardial injury. We identified 19 co-expressed DEGs. The most significant DEG was eotaxin-1/CCL11. We enrolled 25 controls without infections and 28 patients with sepsis-induced myocardial injury. Six of patients died within 30 days. Circulating eotaxin-1/CCL11 levels were significantly higher in patients with sepsis-induced myocardial injury than controls and were higher in non-survivors than survivors (both P < 0.01). Eotaxin-1/CCL11 was positively correlated with troponin I (r=0.48, P=0.01), B-type natriuretic peptide (BNP, r=0.44, P=0.02), and white blood cell (WBC) count (r=0.41, P=0.03). For the prediction of 30-day mortality, eotaxin-1/CCL11 had the greatest discriminatory ability (AUC 0.97) compared with troponin I (AUC 0.89), BNP (AUC 0.80), and WBC count (AUC 0.86). Taken together, eotaxin-1/CCL11 was upregulated in sepsis-injured myocardium and circulating eotaxin-1/CCL11 was a biomarker for predicting severity and mortality of elderly patients with sepsis-induced myocardial injury. These results suggest that eotaxin-1/CCL11 may become a useful biomarkers and potential therapeutic target for sepsis-induced myocardial injury.

Owing to their structural and functional tunability, the preparation of multivariate metal-organic frameworks (MTV-MOFs) and investigation of their potential application has become a hot topic in fields of environment and energy. To achieve more adsorption and removal performance, a series of multivariate Zr-MOFs (TCPP@MOF-808s) were prepared via mixed-ligands strategy for the first time. The morphology, as well as adsorption and removal properties of TCPP@MOF-808s can be controlled by adjusting ratio of the linkers. 57%TCPP@MOF-808 could provide ideal appearance with excellent stability. By using 57%TCPP@MOF-808 as sorbent, a dispersive solid-phase extraction (dSPE) was developed for extraction of endocrine disrupting compounds (EDCs) including BPA, 17β-E2, 17α-E2, E1, and HEX from environmental water prior to HPLC analysis. The pseudo-second-order model can describe the adsorption kinetic data well. Using Langmuir isotherm model, the maximum adsorption capacities of BPA, 17β-E2, 17α-E2, and E1 were calculated as 94.34, 104.17, 109.89, and 121.95 mg·g-1, respectively. The LODs for the analysis of EDCs with HPLC-DAD by using 57%TCPP@MOF-808 as sorbent were achieved in the range of 0.01-0.03 ng·mL-1. The recoveries were obtained in the range of 74.63-98.00%. Enrichment factors were calculated in the range of 146-312. This work provides an effective strategy for design and preparation of multifunctional nanomaterials to improve their potential applications in the detection of environmental pollutants.

In order to obtain a stable, biodegradable and cost-effective antibacterial food package materials, this study developed a facile route to immobilize epsilon-poly-L-lysine (EPL) on films. Cellulose films were prepared via a sol-gel transition method and activated by epoxy chloropropane (ECH) to form epoxide group. EPL was covalently immobilized on the surface of the cellulose films (ECFs) by reacting the amino groups of the EPL molecules with the epoxy groups of the epoxidized cellulose films. The structure, morphology and properties of films were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, universal material testing machine, ultraviolet-visible spectrophotometer and static water contact angle. The results showed that EPL was immobilized successfully in the cellulose films. ECFs exhibited 80% transmittance through 300 nm to 1100 nm and the excellent thermal degradation temperature of 240°C. Moreover, good antimicrobial activity against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus and Alicyclobacillus acidoterrestris were confirmed within 12 h, which is expected to provide a novel material for potential applications in the food industry.

As a type of environmental endocrine disrupting chemicals, bisphenols (BPs) have a certain embryonic toxicity and teratogenicity, which can significantly increase the risks of breast cancer, prostate cancer, leukemia and other cancers. In this work, stable multivariate metal-organic frameworks (UiO-66-NH2/TCPPx) were synthesized via in situ one-pot method and used as miniaturized dispersive solid-phase extraction (dμSPE) sorbents for extraction of trace BPs from environmental samples. The phase purity, crystal morphology and physical properties of UiO-66-NH2/TCPPx samples were varied by adjusting the mass ratio of TCPP. The extraction performance of UiO-66-NH2/TCPPx samples were investigated and UiO-66-NH2/TCPP1.0 exhibited the highest adsorption efficiency. Besides, UiO-66-NH2/TCPP1.0 possessed excellent recycling stability for the adsorption and desorption of BPs more than 20 cycles. The experimental parameters including amount of adsorbent, adsorption time, sample solution pH, temperature, desorption time and desorption solvents which affecting the efficiency of dμSPE were studied, respectively. Good linearity (R2 > 0.9992) in range of 0.1–200 ng mL−1 was obtained. The detection limits (S/N = 3) and quantification limits (S/N = 10) were achieved at 0.03–0.08 ng mL−1 and 0.1–0.5 ng mL−1, respectively. The relative standard deviations (RSDs) of intra-day and inter-day ranged from 2.5 to 5.5% and 1.1–6.8%. Enrichment factors were calculated in the range of 303–338. The obtained recoveries of bisphenol F (BPF), bisphenol A (BPA), bisphenol B (BPB) and bisphenol AF (BPAF) were 81.26–91.03% (RSDs = 0.96–6.47%), 82.2–97.27% (RSDs = 0.45–6.15%), 87.56–97.26% (RSDs = 1.1–6.22%) and 82.2–100.8% (RSDs = 0.46–4.07%). The UiO-66-NH2/TCPP1.0 can be employed as potential dμSPE sorbents for the enrichment of trace BPs in the environmental samples.

Vesicular trafficking is an important dynamic process that facilitates intracellular transport of biological macromolecules and their release into the extracellular environment. However, little is known about whether or how plant viruses utilize intracellular vesicles to their advantage. Here, we report that southern rice black‐streaked dwarf virus (SRBSDV) enters intracellular vesicles in epithelial cells of its insect vector by engaging VAMP7 and Vti1a proteins in the soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (SNARE) complex. The major outer capsid protein P10 of SRBSDV was shown to interact with VAMP7 and Vti1a of the white‐backed planthopper and promote the fusion of vesicles into a large vesicle, which finally fused with the plasma membrane to release virions from midgut epithelial cells. Downregulation of the expression of either VAMP7 or Vti1a did not affect viral entry and accumulation in the gut, but significantly reduced viral accumulation in the haemolymph. It also did not affect virus acquisition, but significantly reduced the virus transmission efficiency to rice. Our data reveal a critical mechanism by which a plant reovirus hijacks the vesicle transport system to overcome the midgut escape barrier in vector insects and provide new insights into the role of the SNARE complex in viral transmission and the potential for developing novel strategies of viral disease control., The major outer capsid protein P10 of southern rice black‐streaked dwarf virus interacts with VAMP7 and Vti1a proteins in the SNARE complex in midgut epithelial cells of the white‐backed planthopper to promote vesicle fusion and virion release.

Catalytic aquathermolysis in situ upgrading and reducing the viscosity of heavy oil in the reservoir remarkably enhances the recovery and is considered as a promising technology. However, the low c...

Using MIL-101(Fe) as the source of carbon and Fe, a magnetic porous carbon (MPC) material with Fe3C nanoparticles encapsulated in porous carbon was prepared through one-pot pyrolysis under N2 atmosphere. With MPC as adsorption material, a stir bar sorptive-dispersive microextraction (SBSDME) method was proposed to extract and preconcentrate sulfonamides (SAs) prior to HPLC-DAD determination. To investigate their extraction ability, different MPC materials were prepared under different carbonization temperatures (600, 700, 800, 900, and 1000 °C). The material prepared under 900 °C (MPC-900) exhibited the highest extraction ability for SAs. The as-prepared MPC materials were also characterized by Raman spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, zeta potential, and other techniques. The main parameters that affect extraction were systematically studied. Under optimal conditions, favorable linearity (R2 ≥ 0.9938) and detection limits (0.02–0.04 ng mL−1) of sulfonamides were obtained. The average recoveries for spiked milk and lake water samples ranged from 76.9 to 109% and from 75.4 to 118% with RSDs of 3.10–9.63% and 1.71–11.3%, respectively. Sulfameter and sulfisoxazole were detected in milk sample. Sulfisoxazole was detected in the lake water sample. The MPC-900 material demonstrated excellent reusability. It can be reused 24 times with peak areas having no obvious decline. The method can be applied to extract ultra-trace compounds in complex sample matrices.

Novel coronavirus pneumonia has had a significant impact on people's lives and psychological health. We developed a stage model to analyse the spatial and temporal distribution of public panic during the two waves of the coronavirus disease 2019 (COVID-19) pandemic. We used tweets with geographic location data from the popular hashtag ‘Lockdown Diary’ recorded from 23 January to April 8, 2020, and ‘Nanjing Outbreak’ recorded from 21 July to 1 September 2021 on Weibo. Combining the lexicon-based sentiment analysis and the grounded theory approach, this panic model could explain people's panic and behavioural responses in different areas at different stages of the pandemic. Next, we used the latent Dirichlet allocation topic model to reconfirm the panic model. The results showed that public sentiments fluctuated strongly in the early stages; in this case, panic and prayers were the dominant sentiments. In terms of spatial distribution, public panic showed hierarchical and neighbourhood diffusion, with highly assertive expressions of sentiment at the outbreak sites, economically developed areas, and areas surrounding the outbreak. Most importantly, we considered that public panic was affected by the 17 specific topics extracted based on the perceived and actual distance of the pandemic, thus stimulating the process of panic from minimal, acute, and mild panic to perceived rationality. Consequently, the public's behavioural responses shifted from delayed, negative, and positive, to rational behavioural responses. This study presents a novel approach to explore public panic from both a time and space perspective and provides some suggestions in response to future pandemics.

The monodispersed mesoporous SiO2@metal-organic framework (MSN@MIL-101(Fe)) composites were prepared by grafting MSN-NH2 onto MIL-101(Fe) particles with a solvothermal method. The adsorption ability of the composites was greatly improved compared to that of pristine MSNs or MIL-101(Fe) for phytohormones (Phys). The MSN@MIL-101(Fe) composites were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectrometer, and mapping analysis. Using MSN@MIL-101(Fe) composites as sorbent, a dispersive solid-phase extraction procedure (dSPE) was developed to extract three endogenous Phys (abscisic acid (ABA), indole-3-aceticacid (IAA), and indole-3-butyric acid (IBA)) and two exogenous Phys (1-naphthylacetic acid (1-NAA) and 2-naphthylacetic acid (2-NAA)) prior to HPLC-DAD analysis. The experimental parameters including sample volume, sorbent amount, adsorption time, adsorption pH, desorption time, and desorption solvent on extraction efficiency were optimized and evaluated. Under optimized conditions, the working range of 0.08 to 0.45 ng mL−1 with enrichment factors from 144 to 207 were achieved. The linear range is 0.75–200 ng mL−1 for IAA, 0.20–200 ng mL−1 for ABA, and 1.0–200 ng mL−1 for IBA, 1-NAA, and 2-NAA. With MSN@MIL-101(Fe) as sorbent for extraction of Phys and determination by HPLC-DAD, two endogenous Phys (IAA and ABA) were detected from mung bean sprouts which were made in a laboratory, and the results were further confirmed by high-resolution mass spectrometry. The composites can be applied to extract other small molecules, which have similar chemical structures with Phys in biological, environmental, and food samples.

Almost all insects harbor commensal bacteria in the alimentary canal lumen or within cells and often play a pivotal role in their host’s development, evolution, and environmental adaptation. However, little is known about the alimentary canal microbiota and their functions in sap-sucking insect pests of crops, which can damage plants by removing plant sap and by transmitting various plant viruses, especially in the small brown planthopper, Laodelphax striatellus. In this study, we characterized the alimentary canal microbiota of L. striatellus collected from seven regions in China by sequencing 16S rDNA. The insects harbored a rich diversity of microbes, mainly consisted of bacteria from phyla Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, and Tenericutes. The composition and abundance of microbiota were more similar as the geographic distance decreased between the populations and clustered by geographic location into three groups: temperate, subtropical, and tropical populations. Although the abundance and species of microbes differed among the populations, the various major microbes for each population performed similar functions based on a clusters of orthologous group analysis. Greater diversity in ecological factors in different regions might lead to higher microbial diversity, thus enabling L. striatellus to adapt or tolerate various extreme environments to avoid the cost of long-distance migration. Moreover, the abundance of various metabolic functions in the Kaifeng populations might contribute to higher fecundity in L. striatellus.

The monodispersed mesoporous SiO

A two-dimensional nitrogen-rich carbon nitrogen (C3N5) material was prepared via a facile high temperature thermal polymerization. For the first time, the C3N5 was used as fiber coating of solid-phase microextraction (SPME) to extract and preconcentrate polychlorinated biphenyls (PCBs) before gas chromatography (GC) analysis. The X-ray diffraction, N2 adsorption-desorption, Fourier transform-infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy were performed to investigate structure, functional groups, thermal stability, bonding type, element composition, and atomic ratio of C3N5. The two-dimensional planar stacking structure was further verified by scanning electron microscopy and transmission electron microscopy. Five PCBs including PCB-4, PCB-12, PCB-29, PCB-52 and PCB-101 were selected as targets to evaluate performance of SPME fiber. Under the optimal conditions, the method showed a good linear range from 0.01 to 1000 ng/mL with the correlation coefficients (R2) higher than 0.9990. Enrichment factors of the method were obtained from 2045 to 3080. The limits of detection (LODs, S/N = 3) and limits of quantification (LOQs, S/N = 10) were calculated as 0.0031–0.0111 ng/mL and 0.01–0.05 ng/mL, respectively. The precisions of intra-day and inter-day were obtained with the relative standard deviations (RSDs) at 1.5–6.6% and 0.8–6.9%, respectively. The fiber-to-fiber producibility was achieved with RSDs ranged from 3.5% to 11.4%. The method was applied to detect PCBs in river water and soil samples. The contents were calculated at 0.040–0.147 ng/mL in water and 0.520–3.218 ng/g in soil. The C3N5 as SPME fiber coating material may be applied to extract and preconcentrate other environmental pollutants which have similar chemical structures with PCBs.

While protective measures in response to infectious diseases may reduce the freedom of tourists (regarding their behaviors), few studies have documented the effects of destination protective measures on the self-protective behaviors of tourists. By applying the protection motivation theory, this study examines the effects of perceived destination protective supports on the social distancing intentions of tourists during the COVID-19 pandemic. The results reveal significant relationships among perceived destination support, coping appraisal, threat appraisal, and the social distancing intentions of tourists. Moreover, two cognitive appraisals—toward the pandemic—partially mediate the relationship between perceived destination support and social distancing intention, and this mediational process is ‘intervened’ with by social norms. This has implications on whether tourist destinations apply more rigorous social distancing polices during the COVID-19 pandemic, to enhance the coping confidence behaviors of tourists, without causing anxiety and fear, and to achieve the goal of enhancing tourists’ intentions to protect themselves.

The success of test reform relies considerably on how stakeholders understand and accept the revised test (Green & Andrade, 2010). This study provided an opportunity for students and teachers to share their perceptions of a recently revised English test in China, the Test for English Majors Grade Four (TEM4). In addition, this study examined how stakeholders’ perceptions of the test varied across institutions of different academic rankings. Survey data were collected from 496 students and 79 teachers, of whom 32 students and 12 teachers participated in a post-survey interview. Findings indicate that although stakeholders were overall positive about the revised TEM4, their perceptions were qualified by concerns with content representation and test difficulty. In addition, the data suggest that the revised TEM4 was associated with context-varying washback effects and negative psychological impacts. These findings highlight the important contribution that students' and teachers' perceptions may have in the test reform process.

The Al-doped mesoporous crystalline material-41 (Al-MCM-41) composite was prepared and applied as fiber coating material of headspace solid-phase microextraction (HS-SPME) for extraction of polycyclic aromatic hydrocarbons (PAHs) from human urine. Five PAHs including acenaphthene, fluorene, phenanthrene, anthracene, and pyrene are chosen as target analytes to evaluate the performance of the material by GC-FID analysis. The mesoporous Al-MCM-41 composite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption measurement, and thermogravimetric analysis. The parameters affecting the extraction efficiency of HS-SPME were investigated. Under the optimal conditions, the method exhibits ideal linearity for target analytes in the range of 0.3–600 ng⋅mL-1 with the coefficients (R2) equal or higher than 0.9906. The enrichment factors are calculated from 540 to 1760. The limits of detection (LODs) and limits of quantitation (LOQs) are between the ranges of 0.06–0.18 and 0.3–0.9 ng⋅mL-1, respectively. The relative standard deviations (RSDs) (n = 5) of intra-day and inter-day are in the ranges of 1.08–7.49% and 2.84–18.3% respectively. The fiber-to-fiber reproducibility (n = 3) is in the range of 6.47–13.9%. The method was successfully applied for the analysis of PAHs in human urine with reasonable recoveries which is ranging from 73.29 to 116.1%.

Utilizing time-varying VAR model and impulse response analysis, we examine the dynamic impact of volatility from foreign companies listed and their contribution to the main stock market in Japanese, Korean, Hong Kong and Singapore markets during the period of 20002018. We find that the host markets have a positive response to volatility effects of foreign companies, more specifically, the increase of the foreign company volatility will cause the increase of the host market volatility. Results show that volatility of foreign companies from mature markets did not cause more volatility in host markets. Interestingly, foreign companies from emerging markets will bring stronger volatility spillover to host markets.

Lithium dendrites limit the application of lithium metal as anode, and poor interfacial stability restricts the nickel-rich lithium nickel cobalt manganese oxides as cathode. Herein, diphenyl sulfone (DPS) and bis(4-florophenyl) sulfone (BFS) are proposed as bifunctional electrolyte additives. In the Li||Li symmetrical half-batteries, with 0.5 wt % DPS, high cycle stability for 360 h at the current density of 1 mA cm−2 is realized by forming a dense and smooth LiF-rich solid electrolyte interphase (SEI). In the Li||LiNi0.8Mn0.1Co0.1O2 (NMC811) battery, from the long-term cycle tests at 5C after 500 cycles, the capacity retention loss of 0.05% per cycle is found by addition of 0.5 wt% DPS, which is much lower than that with 0.5 wt% of BFS (0.08%) and no additives (0.16%). Proper content of LiF, Li2SO3 and ROSO2Li caused by DPS are beneficial to form a stable solid electrolyte interphase film for the Li||NMC batteries, which facilitates lithium ion transport, and inhibits electron transfer. Therefore, Li||NMC batteries with additives exhibit longer cycle life, higher capacity retention and better fast charging performance than that without any additive.

Conventional dual-ion conductive gel polymer electrolytes (GPEs) attracted tremendous interest for their combined advantages of liquid and solid electrolytes. However, their cycling performance usually degrades due to the concentration polarization of anions. Single lithium ion gel polymer electrolytes (SLIGPEs), which have anions covalently bonded to the polymer or inorganic backbone, can suppress the motion of anions by the interactions between the pedant anions and mobile ions. Especially, Li+ deposition in SLIGPEs can be regulated uniformly to avoid lithium dendrite growth. Herein, novel 3D-structured SLIGPEs were prepared by in-situ crosslinking of lithium (4-styrenesulfonyl) (trifluoromethanesulfonyl) imide (LiSTFSI) with polyethylene glycol dimethacrylate (PEGDMA), soaked with liquid electrolyte. The obtained SLIGPEs not only promote the absorption of liquid electrolyte and accelerate the transport of Li+, but also show a high limitation for the migration of anions, proved by high ionic conductivity (2.74 × 10−5 S cm−1 at room temperature) and high lithium ion transference number (0.622) of SLIGPE-3.5, respectively. The long cycle life (cycling for over 600 h under 0.05 mA cm−2 and 0.1 mA cm−2) of symmetric lithium batteries with SLIGPEs as both separator and electrolyte exhibits good interfacial stability between SLIGPEs and electrodes. Meanwhile, LiFePO4/SLIGPE-2/Li shows a specific discharge capacity of 132.1 mAh g−1 at 0.1 C, 80.0% of the capacity retention ratio and 99.0% of the coulombic efficiency after 150 cycles at room temperature. Moreover, confirmed by SEM, lithium dendrite growth is significantly suppressed during repeated Li plating/stripping cycles. Density functional theory calculations (DFT) confirm the mutual interactions between STFSI− pendants and ions in electrolytes and that between PEO segments and ions. We believe that these in-situ SLIGPEs with superior performances have great potential for the application in lithium metal batteries.

In this work, we define cost-free learning (CFL) formally in comparison with cost-sensitive learning (CSL). The main difference between them is that a CFL approach seeks optimal classification results without requiring any cost information, even in the class imbalance problem. In fact, several CFL approaches exist in the related studies, such as sampling and some criteria-based pproaches. However, to our best knowledge, none of the existing CFL and CSL approaches are able to process the abstaining classifications properly when no information is given about errors and rejects. Based on information theory, we propose a novel CFL which seeks to maximize normalized mutual information of the targets and the decision outputs of classifiers. Using the strategy, we can deal with binary/multi-class classifications with/without abstaining. Significant features are observed from the new strategy. While the degree of class imbalance is changing, the proposed strategy is able to balance the errors and rejects accordingly and automatically. Another advantage of the strategy is its ability of deriving optimal rejection thresholds for abstaining classifications and the "equivalent" costs in binary classifications. The connection between rejection thresholds and ROC curve is explored. Empirical investigation is made on several benchmark data sets in comparison with other existing approaches. The classification results demonstrate a promising perspective of the strategy in machine learning., Comment: Classification, class imbalance, cost-free learning, cost-sensitive learning, abstaining, mutual information, ROC

In the context of the class imbalance problem, most existing approaches require the knowledge of costs for reaching the reasonable classification results. If the costs are unknown, some approaches can not work properly. Moreover, to our best knowledge, none of the cost-sensitive approaches is able to process the abstaining classifications when costs are unknown for errors and rejects. Therefore, the challenge above forms the motivation of this work. Based on information theory, we propose a novel cost-free learning approach which targets the maximization of normalized mutual information between the target outputs and the decision outputs of classifiers. Using the approach, we can deal with classifications with/without rejections when no cost terms are given. While the degree of class imbalance is changing, the proposed approach is able to balance the errors and rejects accordingly and automatically. Another advantage of the approach is its ability of deriving optimal reject thresholds for abstaining classification and the "equivalent" costs for binary probabilistic classification. Numerical investigation is made on several benchmark data sets and the classification results confirm the unique feature of the approach for overcoming the challenge.