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Vegetation restoration is an effective measure for improving the function of soil ecosystems and promoting the biogeochemical cycling of carbon (C), total nitrogen (TN) and total phosphorus (TP). Here, we aimed to quantify the fine-scale (pedon scale) spatial distribution of soil C, N, P and soil physical–chemical properties in the Mu Us Desert ecosystems. We systematically evaluated the effects of A. ordosica on fine-scale (pedon scale) spatial distribution of C, TN, TP, soil-available nutrients, and liable organic carbon (LOC) and their stoichiometric characteristics in the semiarid Mu Us Desert in the 0–100-cm soil profiles at various distances from the plant. The results demonstrated that soil organic carbon (SOC), TN and LOC were decreased with increasing distance from the plant and soil depth. SOC stocks at 20 cm were 16.98% higher than those at 120 cm from the plant. SOC stocks at 20, 60 and 120 cm from the plant were increased by 71.62%, 58.14% and 46.72% compared with shifting sandy land (Sland), respectively. Microbial biomass carbon (MBC) and readily oxidised organic carbon (ROOC) were significantly affected by different soil layers and distances and their interaction (p

Oxygen-powder injection from a BOF lance has received much attention in attempts to improve refining efficiency, but knowledge of particle-induced erosion to the lance nozzle, as one of the foreseeable concerns in such a process, is still limited. Thus, numerical studies on gas-particle flow through a Laval nozzle were performed to clarify what the nozzle erosion distribution is and how it is influenced by particle motion. The results show that the most serious erosion occurs in the nozzle convergent section, where nozzle erosion can be further intensified by increasing the powder feeding rate or particle size. The powder blowing parameters have a significant influence on the erosion rate and distribution. Increasing the powder feeding rate or decreasing the particle size worsens erosion downstream of the nozzle divergent section. Therefore, in order to reduce erosion, the powder feeding rate and particle size should be smaller than 2.0 kg/s and larger than 10 μm, respectively.

Conventional laser cavities require discontinuity of material property or disorder to localize a light field for feedback. Recently, an emerging class of materials, twisted van der Waals materials, have been explored for applications in electronics and photonics. Here we propose and develop magic-angle lasers, where the localization is realized in periodic twisted photonic graphene superlattices. We reveal that the confinement mechanism of magic-angle lasers does not rely on a full bandgap but on the mode coupling between two twisted layers of photonic graphene lattice. Without any fine-tuning in structure parameters, a simple twist can result in nanocavities with strong field confinement and a high quality factor. Furthermore, the emissions of magic-angle lasers allow direct imaging of the wavefunctions of magic-angle states. Our work provides a robust platform to construct high-quality nanocavities for nanolasers, nano light-emitting diodes, nonlinear optics and cavity quantum electrodynamics at the nanoscale. Twisted photonic graphene superlattices enable the realization of high-performance room-temperature magic-angle lasers.

It is imperative to understand the influence of second-generation cryoballoon (CB-2) and contact-force sensing radiofrequency ablation (CF-RF) on clinical outcomes in atrial fibrillation (AF). This updated meta-analysis of randomized controlled trials (RCTs) examined the efficacy and safety of CB-2 vs. CF-RF in patients with AF. RCTs on the use of CB-2 vs. CF-RF in patients with AF were included. The primary outcome was the recurrence of AF, and the key secondary outcomes included serious complications, acute pulmonary vein isolation (PVI), procedure duration, and fluoroscopy time. A total of 261 articles were identified, and five studies with a total of 845 participants were included in the study. A total of 93% of participants had paroxysmal AF, 7% of participants had persistent AF, and none of participants had permanent AF. There were 499 participants in the CB-2 arm and 346 in the CF-RF arm. AF recurrence was comparable in the CB-2 group (30.3%) and the CF-RF group (29.2%) (OR = 0.93; 95%CI = 0.56–1.54; P = 0.79; I2 = 48%). There were no statistical differences in acute PVI (P = 0.92; I2 = 0%) and serious complications (P = 0.87; I2 = 47%) between the two groups. The procedure duration was shorter in the CB-2 group than in the CF-RF group (MD = − 13.39; 95%CI = − 15.58, − 7.19; P

Selenium (Se) is one of the essential elements required to maintain human health. Although various kinds of Se supplements are now available on the market, their biological activities and toxicities vary based on the transportation characteristics of Se. In this study, we compared the absorption and distribution of Se in rats administered with different Se supplements: Se-enriched Bifidobacterium longum DD98 (Se-DD98), selenized yeast (Se-Y), and sodium selenite (Na2SeO3). Se-DD98, Se-Y, and Na2SeO3 were orally administered to rats. The plasma Se content at different time points after administration was determined within 72 h. Pharmacokinetic parameters were analyzed to reveal the absorption of Se. Se-DD98, Se-Y, and Na2SeO3 were also repeatedly administered by oral gavage for 30 days, and Se content of the heart, liver, spleen, lungs, kidneys, and muscle was determined to analyze the distribution of Se. The results showed that the organic Se supplements (Se-DD98 and Se-Y) were more easily absorbed into the blood and retained longer in the plasma than the inorganic Na2SeO3 was. Moreover, Se-DD98 induced better absorption of Se in plasma than Se-Y did. Furthermore, significantly higher concentrations of Se were found in the heart, liver, spleen, kidneys, and muscle of rats administered with organic Se supplements (Se-DD98 and Se-Y) than those administered the inorganic Na2SeO3. Rats administered Se-DD98 accumulated more Se in the spleen, lung, and kidney than those administered Se-Y, while Se-Y led to higher concentration of Se in the liver compared to Se-DD98. These results suggest that the organic form of Se was better absorbed and accumulated than the inorganic form was. Se-enriched B. longum DD98 induced greater absorption of Se in plasma and accumulation of Se in several organs than the selenized yeast did, which could suggest the potential superior nutritional function of Se-DD98.

Topological insulators are materials that behave as insulators in the bulk and as conductors at the edge or surface due to the particular configuration of their bulk band dispersion. However, up to date possible practical applications of this band topology on materials' bulk properties have remained abstract. Here, we propose and experimentally demonstrate a topological bulk laser. We pattern semiconductor nanodisk arrays to form a photonic crystal cavity showing topological band inversion between its interior and cladding area. In-plane light waves are reflected at topological edges forming an effective cavity feedback for lasing. This band-inversion-induced reflection mechanism induces single-mode lasing with directional vertical emission. Our topological bulk laser works at room temperature and reaches the practical requirements in terms of cavity size, threshold, linewidth, side-mode suppression ratio and directionality for most practical applications according to Institute of Electrical and Electronics Engineers and other industry standards. We believe this bulk topological effect will have applications in near-field spectroscopy, solid-state lighting, free-space optical sensing and communication.

To investigate morphological changes of focal choroidal excavation (FCE). The medical records of 18 FCE patients (25 eyes) were retrospectively reviewed. Clinical features as well as images of ocular fundus, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and spectral domain optical coherence tomography (OCT) were analyzed. OCT images were employed as a major criterion to evaluate the changes which occurred during the follow-up. Of the 18 patients, 9 were male and 9 were female. The mean age was 41 ± 13.5 years. The follow-up period was 38.5 ± 24.7 (7–92) months. Thirteen patients were myopic. FCE appeared from slight pigment irregularity to yellowish white plaque. FFA revealed window defects corresponding to the lesions. Early-phase ICGA images showed hypofluorescence and medium to large choroidal blood vessels. Plaque- or dot-like hyperfluorescence was seen on late-phase images. OCT scans showed that 11 patients had unilateral FCE and 7 patients were bilaterally affected. Twenty-three eyes had a single FCE and the other two eyes had 2 excavations. FCE presented as confirming type in 21 eyes and non-confirming type in 3 eyes. Discontinuity of the interdigitation zone, ellipsoid zone, and retinal pigment epithelium/Bruch’s complex zone was found. The average subfoveal choroidal thickness was 312.06 ± 66.12 μm in FCE eyes. During the follow-up, choroidal neovascularization developed in 4 patients and retinal pigment epithelium discontinuity was aggravated in one eye. No remarkable changes were found in the other eyes on B scan of the OCT images, but the volume of FCE might have changed a little. FCE, both confirming type and non-confirming type, may keep stable during a long period of time. Choroidal neovascularization may develop at the site of FCE.

Fruit juice is a complex mixture, in which polyphenols are active compounds for human health. In this paper, the effects of membrane properties, such as materials and molecular weight cutoff (MWCO), on fouling behavior of four typical polyphenols in model fruit juice ultrafiltration process were investigated. Zeta potential, contact angle, SEM image, and fouling resistances were determined. Static adsorption and rejection content of polyphenols on membranes were measured. Quantitative structure-activity relationship (QSAR) model has been developed to demonstrate the relationships between rejection and molecular parameters. Results showed that materials, MWCOs, hydrophobic properties, electrical parameters, and molecular parameters are critical factors. Membranes which were hydrophobic and positively charged have higher permeate flux and lower fouling resistance. Polyphenols were adsorbed by membranes as irreversible fouling and also had an important contribution in cake layer fouling. Retention of polyphenols on polyethersulfon 5-kDa membrane was the largest, while that on PVDF 50-kDa membrane was the least. According to QSAR analysis, rejections of polyphenols were higher when the molecules have smaller dipole moment, larger connectivity index 3Xpv, and smaller 4Xpcv.

After more than 30 years of rapid urbanization, the overall urbanization rate of China reached 56.1% in 2015. However, despite China’s rapid increase in its overall rate of urbanization, clear regional differences can be observed. Furthermore, inadequate research has been devoted to in-depth exploration of the regional differences in China’s urbanization from a national perspective, as well as the internal factors that drive these differences. Using prefecture-level administrative units in China as the main research subject, this study illustrates the regional differences in urbanization by categorizing the divisions into four types based on their urbanization ratio and speed (high level: low speed; high level: high speed; low level: high speed; and low level: low speed). Next, we selected seven economic and geographic indicators and applied an ordered logit model to explore the driving factors of the regional differences in urbanization. A multiple linear regression model was then adopted to analyze the different impacts of these driving factors on regions with different urbanization types. The results showed that the regional differences in urbanization were significantly correlated to per capita GDP, industry location quotients, urban-rural income ratio, and time distance to major centers. In addition, with each type of urbanization, these factors were found to have a different driving effect. Specifically, the driving effect of per capita GDP and industry location quotients presented a marginally decreasing trend, while main road density appeared to have a more significant impact on cities with lower urbanization rates.

Urbanization has both direct and indirect impacts on land use change, and analyzing spatio-temporal characteristics of land use change is essential for understanding these impacts. By comparing Landsat TM images, this paper examines the changes of land use structure and landscape patterns in Shanghai from 1990 to 2015. It finds that the city doubled in size, with the growth of isolated construction land being most significant among eight land use types. A land use change matrix was established and landscape indices were selected to evaluate the change of spatial structure in Shanghai. In order to identify the main driving forces of city expansion in Shanghai, this research ran partial least square regression models to assess the impact of 10 social-economic factors on land use change of Shanghai from 1990 to 2015. It then conducted bivariate correlation analysis to explore the drivers of change of various land use types: urban settlement, rural settlement and isolated construction land. Besides quantitative analysis, this paper analyzes the influence of policy-dimensional factors in land use change. It concludes with future potential research topics on land use change in a rapidly urbanizing context.