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Previous studies have suggested that physical activity may decrease academic procrastination; however, few studies have explored the underlying mechanisms of how physical activity exerts an effect on academic procrastination. This study aimed to examine the mediating effects of self-control and self-efficacy in the relationship between physical activity and academic procrastination among Chinese university students. Methods: A cross-sectional design was used in this study. The sample comprised 564 university students from a university in Zhejiang, China. The physical activity rating scale-3 (PARS-3), self-control scale (SCS), generalized self-efficacy scale (GSES), and procrastination assessment scale-students (PASS) were used to investigate university students’ physical activity, self-control, self-efficacy, and academic procrastination respectively. The Percentile-Bootstrap technique was performed to examine the mediating effects of self-control and self-efficacy on the association between physical activity and academic procrastination. Results: Physical activity significantly predicted higher levels of self-control and self-efficacy, as well as lower levels of academic procrastination. Self-control and self-efficacy were significant mediators between physical activity and academic procrastination. Conclusion: This study indicated that physical activity interventions targeting the improvement of self-control and self-efficacy may reduce academic procrastination in university students.

This paper is focused on a one-dimensional nonlinear variational wave equation which is the Euler–Lagrange equations of a variational principle arising in the theory of nematic liquid crystals and a few other physical contexts. We establish the local existence and uniqueness of classical solutions to its Cauchy problem with initial data given on the parabolic degenerating line.

This paper investigates the regularity of a semi-hyperbolic patch problem arising from the Riemann problem for the 2-D isentropic Euler equations. We show that the solution is uniformly C 1 , 1 6 up to the sonic curve and the sonic curve is C 1 , 1 6 , which improve the C 1 -regularity of Song et al. [20] . We introduce a novel set of change variables which allow us to establish higher regularity results based on the ideas of characteristic decomposition and the bootstrap method.

Potassium (K) is an essential macronutrient which is known to regulate key metabolic processes, modulate enzyme activity and plays a decisive role in osmotic adjustment in plants. Present work evaluates the role of K in the regulation of endogenous hydrogen sulfide (H2S) signaling in modulating the tolerance of tomato (Solanum lycopersicum L. Mill.) seedlings to osmotic stress. The findings reveal that exposure of seedlings to 15% (w/v) polyethylene glycol 8000 (PEG) led to a substantial decrease in leaf K content which was associated with reduced H+-ATPase activity. Exogenous application of K to the stressed seedlings significantly improved endogenous K content. Treatment with sodium orthovanadate (SOV, PM H+-ATPase inhibitor) and tetraethylammonium chloride (TEA, K channel blocker) suggests that exogenous K stimulated H+-ATPase activity that further regulated endogenous K content in tomato seedlings subjected to osmotic stress. Moreover, reduction in H+-ATPase activity by hypotaurine (H2S scavenger) substantiates the role of endogenous H2S in the regulation of H+-ATPase activity. Elevation in endogenous K content enhanced the biosynthesis of hydrogen sulfide (H2S) through enhancing the synthesis of cysteine, the H2S precursor. Synergistic action of H2S and K effectively neutralized osmotic stress by regulating sugar metabolism that resulted in osmotic adjustment, as witnessed by reduced water loss and improved hydration level of the stressed seedlings. Cross talk of H2S and K also assisted the seedlings in the activation of antioxidant enzymes that controlled the generation of reactive oxygen species and led to the protection against oxidative stress. The integrative role of H2S and K signaling was validated using hypotaurine (H2S scavenger) and TEA (K channel blocker) which weakened the protection against osmotic stress induced impairments. In conclusion, exogenous K and endogenous H2S regulate H+-ATPase activity which plays a decisive role in the maintenance of endogenous K homeostasis. Thus, present work reveals that K and H2S crosstalk is essential for modulation of osmotic stress tolerance in tomato seedlings.

Recently correlations between spatial species and size diversity have been found in many forest ecosystems around the world. They are likely to play a prominent role in nature's mechanisms of maintaining species and size diversity. In this study, we analysed the species population means of spatial species-mingling and size-inequality indices in 36 large forest monitoring plots from the temperate and subtropical zones in China. Based on the literature we included eleven diversity-index combinations and considered their correlations for increasing numbers of nearest neighbours. Generally, positive correlations are related to between-species population size differences whilst negative correlations reflect within-species population size differences. Our results showed that the selected species-mingling and size-inequality indices produced different correlation patterns in one and the same monitoring site. We therefore defined a species-mingling size-inequality correlation space by computing the 0.025 and the 0.975 quantiles from the correlation data of the eleven index combinations. We noticed that each observed correlation space included 1–3 combinations of five basic geometric types and can be interpreted as the unique signature of a forest ecosystem in time. The correlation space allowed us to understand more clearly at which spatial scale within-species correlation was more influential than between-species inequality and vice versa. The shape of the correlation space is interpretable and gives important clues about the forest development stage of a forest ecosystem.

The stability discrimination method of surrounding rock in vertical shaft construction and the safety technology of shaft construction under the geological condition of a super-thick crush ...

Nitrogen fertilization is common for poplar trees to improve growth and productivity. The utilization of N by poplar largely depends on fertilizer application patterns; however, the underlying regulatory hubs are not fully understood. In this study, N utilization and potentially physiological regulations of two poplar clones (XQH and BC5) were assessed through two related experiments (i: five levels of N supply and ii: conventional and exponential N additions). Poplar growth (leaf area) and N utilization significantly increased under fertilized compared to unfertilized conditions, whereas photosynthetic N utilization efficiency significantly decreased under low N supplies. Growth characteristics were better in the XQH than in the BC5 clone under the same N supplies, indicating higher N utilization efficiency. Leaf absorbed light energy, and thermal dissipation fraction was significantly different for XQH clone between conventional and exponential N additions. Leaf concentrations of putrescine (Put) and acetylated Put were significantly higher in exponential than in conventional N addition. Photorespiration significantly increased in leaves of XQH clone under exponential compared to conventional N addition. Our results indicate that an interaction of the clone and N supply pattern significantly occurs in poplar growth; leaf expansion and the storage N allocations are the central hubs in the regulation of poplar N utilization.

Hydrogen sulfide (H2S) and nitric oxide (NO) have been known to affect vast number of processes in plants under abiotic stresses. Also, calcium (Ca) works as a second messenger in plants, which underpins the abiotic stress-induced damage. However, the sequence of action of these signaling molecules against cadmium (Cd)-induced cellular oxidative damage remains unidentified. Therefore, we studied the synergistic actions and/or relationship of signaling molecules and Ca-dependent activation of tolerance mechanisms in Vigna radiata seedlings under Cd stress. The present study shows that exogenous Ca supplemented to Cd-stressed V. radiata seedlings reduced Cd accumulation and improved the activity of nitrate reductase, and L/D-cysteine desulfhydrase (LCD/DCD) that resulted in improved synthesis of NO and H2S content. Application of Ca also elevated the level of cysteine (Cys) by upregulating the activity of Cys-synthesizing enzymes serine acetyltransferase and O-acetylserine(thiol)lyase in Cd-stressed seedlings. Maintenance of Cys pool under Cd stress contributed to improved H2S content which together with Ca and NO improved antioxidant enzymes and components of ascorbate-glutathione (AsA-GSH) cycle. All these collectively regulated the activity of NADPH oxidase and glycolate oxidase, resulting in the inhibition of Cd-induced generation of reactive oxygen species. The elevated level of Cys also assisted the Cd-stressed seedlings in maintaining GSH pool which retained normal functioning of AsA-GSH cycle and led to enhanced content of phytochelatins coupled with reduced Cd content. The positive effect of these events manifested in an enhanced rate of photosynthesis, carbohydrate accumulation, and growth attributes of the plants. On the contrary, addition of NO scavenger cPTIO [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide], H2S scavenger HT (Hypotaurine) and Ca-chelator EGTA (Ethylene glycol-bis(b-aminoethylether)-N,N,N',N'-tetraacetic acid) again developed a condition similar to stress and positive effect of the signaling molecules was abolished. The findings of the study postulate that Ca in association with NO and H2S mitigates Cd-induced impairment and enhances the tolerance of the V. radiata plants against Cd stress. The results of the study also substantiate that Ca acts both upstream as well as downstream of NO signals whereas, H2S acts downstream of Ca and NO during Cd-stress responses of the plants.

Petrographic characteristics (textural properties and modal compositions) have intrinsic influences on physical and mechanical (PM) properties of weakly cemented sandstones. Sixteen sandstone samples were tested to determine the PM parameters and then thin sections from those samples were used to measure the petrographic parameters. Petrographic parameters were analyzed statistically to establish quantitative relationships between the petrographic characteristics and PM properties. Based on multiple linear regression (MLRA) and stepwise multiple regression analyses (SMRA), several multiple regression equations with significant petrographic variables were established for estimating the PM parameters of the sandstone. Results indicated that uniaxial compressive strength (UCS) and Young9s modulus (E) were closely related to mean grain size (Mz) (φ-value), non-uniform coefficient (Cu), fractal dimension (Fd), Riley sphericity (Ψp), packing proximity (Pp), floating contacts (Fl), grain-to-grain contacts (G-G), feldspar content and organic matter content. An increased percentage of grain-to-cement contacts (G-C) and reduced percentages of grain-to-matrix contacts (G-M) and organic matter content indicated a high value of Poisson9s ratio (POISS). In addition, Mz, Cu, Fd, Ψp, quartz, feldspar, and organic matter contents were found to be significant parameters for density and P-wave velocity (Vp). Furthermore, density and POISS could be predicted using the results from the MLRA and Fd was a good predictor for density, Vp, and UCS using the results from the SMRA. Additionally, it was noted that the petrographic characteristics of roof sandstones had significant influence on the overburden pressure characteristics within the coal faces in the Shendong mining area.

Based on the panel data of 30 provinces from 2000 to 2020, this paper empirically analyzes the impact of local fiscal decentralization on the return rate of China’s real economy from two dimensions, that is, income decentralization and expenditure decentralization. It is found that income decentralization and expenditure decentralization can improve the overall real economic return rate with heterogeneity in different regions. The empirical results in the central region are consistent with the core conclusions, and the regression results of expenditure decentralization in the eastern and western regions are significant, while income decentralization is not significant. With industrial structure affecting the role of fiscal decentralization, the more advanced the industrial structure, the greater role of fiscal decentralization in promoting the return rate of the real economy.

The year-after-year deepening of North China-type coal mines has resulted in frequent water inrush disasters at coal seam floors, causing significant casualties and property loss. The key factor for assessing water inrush hazards is the depth at which the coal seam floor will fail. It is therefore of great importance to predict this failure depth so as to evaluate the potential for floor water inrush incidents and establish effective controls in a timely manner. This paper takes a deep-mining mine in North China Coalfield, as an example, a comparative study is made using four methods: theoretical calculation method, back propagation neural network (BPNN) method, field measurement method, and empirical formula method. The results show that the new theoretical calculation method and the back propagation neural network method proposed in this paper are closer to the true floor failure depth under deep seam mining conditions. Therefore, this study has played an important reference role for prevention and control of water inrush from coal seam floor in deep mining.

This paper is concerned with the degenerate initial–boundary value problem to the one-dimensional nonlinear wave equation u t t = ( ( 1 + u ) a u x ) x which arises in a number of various physical contexts. The global existence of smooth solutions to the degenerate problem was established under relaxed conditions on the initial–boundary data by the characteristic decomposition method. Moreover, we show that the solution is uniformly C 1 , α continuous up to the degenerate boundary and the degenerate curve is C 1 , α continuous for α ∈ ( 0 , min ⁡ { a 1 + a , 1 1 + a } ) .

Although online gaming may lead to Internet gaming disorder (IGD), most players are recreational game users (RGUs) who do not develop IGD. Thus far, little is known about brain structural abnormalities in IGD subjects relative to RGUs. The inclusion of RGUs as a control group could minimize the potential effects of gaming experience and gaming-related cue familiarity on the neural mechanism of IGD subjects. In this study, structural magnetic resonance imaging data were acquired from 38 IGD subjects and 66 RGUs with comparable age, gender, and educational level. Group differences in cortical thickness and volume were analyzed using the FreeSurfer software. Correlations between cortical changes and addiction severity were calculated for both groups. Compared with the RGU group, the IGD group showed significantly decreased cortical thickness in the left lateral orbitofrontal cortex, inferior parietal lobule, bilateral cuneus, precentral gyrus, and right middle temporal gyrus. Moreover, significantly reduced cortical volume was observed in the left superior temporal gyrus and right supramarginal gyrus in the IGD group. Whole-brain correlational analysis indicated different correlations between the two groups. The brain regions that showed group differences were considered to be involved in cognitive control, decision making, and reward/loss processing. These functions may serve as potential mechanisms that explain why IGD individuals experience negative outcomes in frequent game playing.

This study presents an analysis of the small scale spatial patterns in natural forest plots in different parts of China. The focus of the analysis is to assess the spatial characteristics of different natural forests at a high level of resolution. The results may provide a theoretical basis for nature-approximating forest management practices in plantations established with a regular arrangement of planting points. Method Using a new measure for describing small scale forest structures, known as the Uniform Angle Index, it was possible to identify local structure units as even, random, or clustered. We analysed 11 selected natural forest plots with mapped trees with a wide geographical distribution in different regions of China. In each plot, with a known basal area density, the proportion of the total basal area was assessed that can be assigned to local structure units with specific patterns. Specifically, the basal area of each tree, and the associated local spatial pattern in the vicinity of that tree, provided the information about the distribution of local spatial patterns in the 11 natural forests. Results (1) Most trees were distributed in neighbourhoods with a random structure, regardless of whether the entire forest pattern was classified as even, random, or clustered. Less than half of the tree neighbourhoods were either clustered or evenly structured. (2) More than 50% of the basal area of the reference trees consisted of random units in all 11 natural forests. (3) Similarly, the basal areas of the random structure units occupied more than half of the total basal area. Conclusions Our findings suggest that the major part of the basal area natural forests consists of random structure units. This observation may be helpful in the design of planting patterns or harvesting schedules to improve the stability of planted monocultures.

The discovery and creation of biocatalysts for plant biomass conversion are essential for industrial demand and scientific research of the plant cell wall. α-1,2 and α-1,3-l-arabinofuranosidases are debranching enzymes that catalyzing hydrolytic release of α-l-arabinofuranosyl residues in plant cell wall. Gene database analyses shows that GH62 family only contains specific α-l-arabinofuranosidases that play an important role in the degradation and structure of the plant cell wall. At present, there are only 22 enzymes in this group has been characterized. In this study, we cloned a novel α-1,3-arabinofuranosidase gene (poabf62a) belonging to glycoside hydrolase family 62 from Penicillium oxalicum sp. 68 and expressed it in Pichia pastoris. The molecular mass of recombinant PoAbf62A was estimated to be 32.9 kDa. Using p-nitrophenyl-α-l-arabinofuranoside (pNPαAbf) as substrate, purified PoAbf62A exhibited an optimal pH of 4.5 and temperature of 35 °C. Results of methylation and 13C NMR analyses showed that PoAbf62A was exclusively α-1,3-arabinofuranosidase, specific for cleavage of α-1,3-arabinofuranosyl residues, and with the absence of activity towards α-1,2-arabinofuranose and α-1,5-arabinofuranose. Therefore, PoAbf62A exhibits high activity on sugar beet arabinan and wheat arabinoxylan, because their branched side chain are decorated with α-1,3-arabinofuranose. On the other hand, there is a lack of activity with linear-α-l-1,5-arabinan and xylan that only contained α-l-1,5-arabinofuranose or β-1,4-xylose. The α-1,3-arabinofuranosidase activity identified here provides a new biocatalytic tool to degrade hemicellulose and analyze the structure of plant cell walls.

This paper is concerned with the structure of supersonic solutions near sonic curves for a transonic small disturbance model derivable from the two-dimensional steady viscous channel flow of a reactive premixed fluid. The model is a second-order nonhomogeneous nonlinear mixed-type equation which is coupled with an ordinary differential equation for the calculation of the reactant mass fraction. We establish the existence of classical sonic-supersonic solutions to its boundary value problem with data given on a smooth sonic curve. To deal with the sonic degeneracy, we first construct a smooth solution in a partial hodograph coordinate system by using the iteration method in a weighted metric space and then express the solution in terms of the original variables.

The NAC (NAM, ATAF and CUC) gene family plays a crucial role in the transcriptional regulation of various biological processes and has been identified and characterized in multiple plant species. However, genome-wide identification of this gene family has not been implemented in Juglans mandshurica, and specific functions of these genes in the development of fruits remain unknown. In this study, we performed genome-wide identification and functional analysis of the NAC gene family during fruit development and identified a total of 114 JmNAC genes in the J. mandshurica genome. Chromosomal location analysis revealed that JmNAC genes were unevenly distributed in 16 chromosomes, the highest numbers were found in chromosomes 2 and 4. Furthermore, according to the homologues of JmNAC genes in Arabidopsis thaliana, a phylogenetic tree was constructed, and the results demonstrated 114 JmNAC genes, which were divided into eight subgroups. Four JmNAC gene pairs were identified as the result of tandem duplicates. Tissue-specific analysis of JmNAC genes during different developmental stages revealed that 39 and 25 JmNAC genes exhibited upregulation during the mature stage in walnut exocarp and embryos, indicating that they may serve key functions in fruit development. Furthermore, 12 upregulated JmNAC genes were common in fruit ripening stage in walnut exocarp and embryos, which demonstrated that these genes were positively correlated with fruit development in J. mandshurica. This study provides new insights into the regulatory functions of JmNAC genes during fruit development in J. mandshurica, thereby improving the understanding of characteristics and evolution of the JmNAC gene family.

This paper is focused on a one-dimensional nonlinear variational wave equation which is the Euler–Lagrange equations of a variational principle arising in the theory of nematic liquid crystals and a few other physical contexts. We establish the global existence of smooth solutions to its degenerate initial–boundary value problem under relaxed conditions on the initial–boundary data. Moreover, we show that the solution is uniformly C 1 , α continuous up to the degenerate boundary and the degenerate curve is C 1 , α continuous for α ∈ ( 0 , 1 2 ) .

Cellulosimicrobium cellulans employs extracellular sialidase to selectively convert polysialogangliosides to ganglioside GM1. We cloned this novel sialidase gene (ccsia) from C. cellulans sp. 21, and overexpressed recombinant sialidase (CcSia) protein in E. coli BL21 (DE3) by high cell density fermentation. The presence of an N-terminal hexa-His tag allowed for purification using nickel affinity chromatography (2.3-fold, specific activity 41.5 U/mg). As determined by gel electrophoresis and gel filtration chromatography, the molecular weight of CcSia was found to be about 75 kDa, consistent with sequence analysis (75,271 Da). CcSia transformed polysialogangliosides GD1a, GD1b and GT1b into GM1. For this reaction, the response surface approach showed that optimal conditions in a 1-L system were 2 h incubation at 32.5 °C and pH 5.2, with substrate concentrations of 10 g/L and crude enzyme concentration 1 g/L, respectively. Under above conditions, 10 g/L of ganglioside was completely converted to the product GM1 with a yield of 52%. Our studies demonstrate CcSia could be used for industrial preparation of ganglioside GM1 by the pharmaceutical industry.

The seed nutrition of crops is affected by global climate changes due to elevated CO2 and temperatures. Information on the effects of elevated CO2 and temperature on seed nutrition is very limited in spite of its importance in seed quality and food security. Therefore, the objective of this study was to evaluate the effects of elevated atmospheric CO2 and temperature on seed composition (protein, oil, fatty acids, and sugars) and mineral nutrition in two soybean cultivars under controlled environments. The treatments were ambient CO2 concentrations (360 μmol mol-1) and elevated CO2 concentration (700 μmol mol-1) as well as normal temperature (26/16°C) and elevated temperature (45/35°C). Plants were grown under greenhouse conditions until the R5 stage, and then, transferred to growth chambers until full maturity (R8). Elevated temperature or a combination of elevated temperature and elevated CO2 resulted in a decrease in seed protein and linolenic acid concentrations and an increase in oil and oleic acid in cultivars Williams 82 (MGIII) and Hutcheson (MG V). Seed sucrose, glucose, and fructose decreased, whereas raffinose and stachyose remained relatively stable. Minerals also decreased under elevated CO2 and temperature. Among those that decreased were N, P, K, Zn, Fe, and B. Natural abundance of 15N and 13C isotopes was altered only under high temperature, regardless of CO2 concentration, indicating that changes in nitrogen and carbon metabolism occurred at elevated temperature. The increase in oil and oleic acid and decrease in linolenic acid are desirable, as high oleic acid and low linolenic acid contribute to the stability and longer shelf-life of oil. The combination of low protein and high oil was due to the inverse relationship between them. This study showed that seed composition and seed mineral nutrients can be affected by elevated temperature alone or elevated CO2 and temperature. This information is beneficial for selecting varieties with high seed nutritional qualities and efficient mineral nutrient use and uptake, traits that are related to seed production, seed quality, and food security. Also, it provides further knowledge on the effect of climate change on seed quality.

The Daotanghe riverine wetland in close proximity to the Qinghai Lake was investigated to demonstrate the interrelationships between Qinghai Lake hydrodynamic processes, eolian mobility and ecological conditions during the past 1100 years in response to climate change. We used ostracod assemblages from various sites east of Qinghai Lake and from the sediment core QW15 of Daotanghe Pond and combined them with grain size and geochemical data from the same core. The statistical extraction of grain size endmembers (EM) revealed three different transportation processes responsible for pond-related fluvio-lacustrine, pure fluvial and eolian deposits. Identified seasonal effects (eolian mobility phase) and timing of ice cover are possible tracers for the competing influence between the Asian summer monsoon and the Westerlies in the Daotanghe Wetland and surrounding area. Our results show that ostracod associations and sediment properties are evidence of a fluvio-lacustrine fresh water environment without ingression of Qinghai Lake into the wetland. Hydrodynamic variations coupled with phases of eolian input indicate highly variable water budgets in response to climate-induced effective moisture supply. The Medieval Warm Period (MWP) until about 1270 CE displays generally moist and warm climate conditions with minor fluctuations, likely in response to variations in summer monsoon intensity. The three-partite period of the Little Ice Age (LIA), shows hydrologically unstable conditions between 1350 and 1530 CE with remarkably colder periods, assigned to a prolonged seasonal ice cover. Pond desiccation and replacement by fluvial deposits occurred between 1530 and 1750 CE, superimposed by eolian deposits. The phase 1730–1900 CE is recorded by the re-occurrence of a pond environment with reduced eolian input. Principal Component Analysis (PCA) on ostracod abundances shows similar trends. All three phases of the LIA developed during a weak summer monsoon influence, favoring westerly-derived climate conditions until ca. 1850 CE, in accordance with records from the adjacent regions. Seasonal freezing periods in excess of the average time of frozen water bodies also occurred in periods of the well-known grand solar minima and indicate stronger seasonality, possibly independent from variations in summer monsoon strength but with links to global northern hemispheric climate.

We investigate a one-dimensional nonlinear wave system which is the Euler–Lagrange equations of a variational principle modeling a type of cholesteric liquid crystals. Due to the chiral effect, the Lagrangian density of the variational principle includes linear terms as well as quadratic terms in derivatives of the field, which is different from the nematic liquid crystals. Moreover, the linear terms and zero term in derivatives of the field might cause the energy to be negative in some cases. By using the method of energy-dependent coordinates and the Young measure theory, we establish the global existence of weak solutions to its Cauchy problem under some conditions on the coefficients.

This paper focuses on the structure of classical sonic-supersonic solutions near sonic curves for the two-dimensional full Euler equations in gas dynamics. In order to deal with the parabolic degeneracy near the sonic curve, a novel set of dependent and independent variables are introduced to transform the Euler equations into a new system of governing equations which displays a clear regularity-singularity structure. With the help of technical characteristic decompositions, the existence of a local smooth solution for the new system is first established in a weighted metric space by using the iteration method and then expressed in terms of the original physical variables. This is the first time to construct a classical sonic-supersonic solution near a sonic curve for the full Euler equations.

Background China has a long tradition of managing planted forests. Different species of Populus, Eucalyptus, Larix, Cunninghamia and Pinus are planted to satisfy the local demand for wood products and provide ecological services at the same time. Evidence of the greater resilience of natural forests provides the motivation to develop asymmetric planting patterns, which is the focus of this study. We present a new method for designing plantation patterns that follow those observed in natural ecosystems and to maintain some regularity for operational convenience. Methods Based on the uniform angle index, we analyzed the spatial structure of six natural forests in different regions of China. The uniform angle index describes the degree of spatial uniformity of the n nearest neighbors of a given reference tree. Accordingly, we identified all possible patterns of a neighborhood group within a regular planting pattern and developed a method to optimize planting point arrangements that contain some randomness as well as a minimum degree of regularity. Results (1) There are 13 types of structural units in a regular planting, including seven random units, five even units and one cluster unit; (2) Five near-natural arrangements are presented with a minimum proportion of 50% of random units. These five arrangements represent a combination of regularity for operational convenience and asymmetry. Conclusions The new planting patterns developed in this study are expected to increase the asymmetric competition and resilience of these important ecosystems. Some experimental plantings, based on our findings, have already been established, e.g., in Pinus tabulaeformis plantations in Tianshui, Gansu Province, and in a Populus deltoides plantation in Fangshan near Beijing. Open-Access-Publikationsfonds 2019

As coal mining is extended to ever-greater depths, the factors affecting the safe mining of coal seams are becoming increasingly complicated. High-pressure confined water in the coal seam floor can pose a major threat to the safety of coal mining. Therefore, based on the analysis of various factors that affect water inrush from coal seam floors, this study develops a geological engineering model of high-pressure confined water damage assessment for coal mine face floors. The model adopts six evaluation factors: coal mining depth, coal seam thickness, thickness of the aquiclude, hydrostatic pressure, brittle-rock thickness, and the distribution of faults and folds. The comprehensive weight of the six factors is obtained through analytic hierarchy processing (AHP) and the entropy weight method (EWM) to establish an AHP–EW risk index model (AEM). AEM is applied for the evaluation of two coalfaces in a study area in North China, and the water inrush risk zonation of the coalface floors is determined. Finally, the results given with AEM are compared with those from the traditional water inrush coefficient method, and its applicability in other mining areas is also validated. The results show that the proposed model provides more accurate evaluation results than the traditional method and that its application is more practical.

Low-dimensional semiconductors exhibit remarkable performances in many device applications because of their unique physical, electrical, and optical properties. In this paper, we report a novel and facile method to synthesize In2S3 quantum dots (QDs) at atmospheric pressure and room temperature conditions. This involves the reaction of sodium sulfide with indium chloride and using sodium dodecyl sulfate (SDS) as a surfactant to produce In2S3 QDs with excellent crystal quality. The properties of the as-prepared In2S3 QDs were investigated and photodetectors based on the QDs were also fabricated to study the use of the material in optoelectronic applications. The results show that the detectivity of the device stabilizes at ~ 1013 Jones at room temperature under 365 nm ultraviolet light irradiation at reverse bias voltage.

Objective:\ud Studies have shown that males are more prevalence than females in Internet gaming disorder (IGD). This study was set to explore the sex difference on the effect of IGD in resting states of the brain.\ud \ud Methods:\ud Resting-state fMRI data were collected from 58 recreational Internet game users (RGU, male = 29) and 46 IGD subjects (male = 23). Regional homogeneity (ReHo) was used to calculate group difference between the subjects. A two-way ANOVA was used to explore the IGD-by-sex interactions. Correlations between addiction severity and the ReHo values were also calculated.\ud \ud Results:\ud Significant sex-by-group interactions were found associated with the brain features in the right posterior cingulate (rPCC), left middle occipital gyrus (lMOG), right middle temporal gyrus (rMTG), and right postcentral gyrus (rPG). Post-hoc analysis revealed that comparing with same-sex RGUs, male IGD showed decreased ReHo in the rPCC, and the ReHo in the rPCC was also negatively associated with Internet addiction test (IAT) scores for male subjects. Moreover, male IGDs showed increased ReHo, but female ones showed decreased ReHo, in both lMOG and rMTG, when comparing with same-sex RGUs.\ud \ud Conclusions:\ud Sex differences were observed in brain regions that are responsible for executive control, visual and auditory perception. These sex differences should be taken into consideration in future studies and the treatment of IGD.

Physical and petrographic properties of sedimentary rocks have great influence on their mechanical behavior. Numerous laboratory tests were conducted on intact sandstones and mudstones obtained from Jurassic weakly cemented coal-bearing strata. Several physical and mechanical parameters, particularly the rock material constant mi and the brittleness coefficient BRIT−T, were determined. The microfabric of these sedimentary rocks was also analyzed to quantify their mineral compositions and to determine quantitative relationships among mineral compositions, physical and mechanical parameters using the regression analysis. Overall, both bulk density (ρ) and P-wave velocity (Vp) exhibit positive power relationships with uniaxial compressive strength (UCS) and Young’s modulus (E), respectively. The UCS of sandstones increases with increasing quartz content and decreasing feldspar content, and the brittleness of mudstones increases with the increase of quartz and feldspar contents. In addition, the rock material constant mi presents a logarithmic correlation with the ratio of feldspar-to-quartz content for sandstones and a polynomial correlation with the ratio of clay minerals to the quartz and feldspar contents for mudstones.

One of the aims of sustainable forest management is to preserve the diversity and resilience of ecosystems. Unfortunately, changes in the soil microbial communities after forest management remain unclear. We analyzed and compared the soil microbial community of a natural Quercus aliena var. acuteserrata forest after four years of four different management methods using high-throughput sequencing technology. The forest management methods were close-to-nature management (CNFM), structure-based forest management (SBFM), secondary forest comprehensive silviculture (SFCS) and unmanaged control (CK). The results showed that: (1) the soil microbial community diversity indices were not significantly different among the different management methods. (2) The relative abundance of Proteobacteria in the SBFM treatment was lower than in the CK treatment, while the relative abundance of Acidobacteria in the SBFM was significantly higher than that in the CK treatment. The relative abundance of Ascomycota was highest in the CNFM treatment, and that of Basidiomycota was lowest in the CNFM treatment. However, the relative abundance of dominant bacterial and fungal phyla was not significantly different in CK and SFCS. (3) Redundancy analysis (RDA) showed that the soil organic matter (SOM), total nitrogen (TN), and available nitrogen (AN) significantly correlated with the bacterial communities, and the available potassium (AK) was the only soil nutrient, which significantly correlated with the composition of the fungal communities. The short-term SBFM treatment altered microbial bacterial community compositions, which may be attributed to the phyla present (e.g., Proteobacteria and Acidobacteria), and the short-term CNFM treatment altered microbial fungal community compositions, which may be attributed to the phyla present (e.g., Ascomycota and Basidiomycota). Furthermore, soil nutrients could affect the dominant soil microbial communities, and its influence was greater on the bacterial community than on the fungal community.

With the continuous increase in mining depth, mine-confined water accidents occur more frequently, which seriously threaten the safety of employees. Taking Qiuji coal mine in eastern China as an example, this paper introduces a novel method for evaluating high confined water hazard in coal seam floor. The no. 11 coal seam in Qiuji coal mine has been threatened by the underlying karst water. The water pressure of the aquifer, the aquiclude thickness, the coal seam depth and thickness, the brittle-rock thickness of the coal seam floor, and the geological structure are the important factors to control the floor water inrush. The risk of water inrush from the floor of 11 coal seam in Qiuji coal mine was evaluated using the improved analytic hierarchy process vulnerability index (IAHP-VI) method. The IAHP-VI method used the improved analytic hierarchy process to derive the weights of six factors and establish the vulnerability index model. Consequently, through data processing and spatial superposition function of GIS, the zoning map of risk assessment for high confined water hazard on the floor of the study area was obtained. The IAHP-VI method was compared to traditional water inrush coefficient method, which demonstrated the advantages of IAHP-VI method. The IAHP-VI method was more suitable for risk assessment of floor water inrush under complex geological conditions.

Vegetation distribution of the sampling areas. (DOCX 19 kb)

A novel β-1,4-xylosidase was identified from the genome of Bacteroides ovatus strain ATCC 8483 and overexpressed in Escherichia coli BL21 (DE3) cells. The molecular weight of recombinant enzyme named BoXyl43A was calculated to be 37.1 kDa. Using p-nitrophenyl-β-D-xylopyranoside (pNPβXyl) as substrate, BoXyl43A was most active at pH 7.0 and 35 °C. The enzyme could be activated by Mg2+ and Mn2+. The Km and Vmax of BoXyl43A against pNPβXyl were 1.71 ± 0.21 mM, 7.41 ± 0.81 μmol/min/mg, respectively. BoXyl43A hydrolyzed xylooligosaccharide to produce D-xylose as main product, indicating that BoXyl43A acted as an exo-β-1,4-xylosidase. The mixture of BoXyl43A and PoAbf62A (α-L-arabinofuranosidase) exhibited significant synergistic effects on the degradation of arabinoxylan. Therefore, BoXyl43A would be a useful tool to degrade hemicellulose.

Background The broad-leaved Korean pine mixed forest is an important and typical component of a global temperate forest. Soil microbes are the main driver of biogeochemical cycling in this forest ecosystem and have complex interactions with carbon (C) and nitrogen (N) components in the soil. Results We investigated the vertical soil microbial community structure in a primary Korean pine-broadleaved mixed forest in Changbai Mountain (from 699 to 1177 m) and analyzed the relationship between the microbial community and both C and N components in the soil. The results showed that the total phospholipid fatty acid (PLFA) of soil microbes and Gram-negative bacteria (G-), Gram-positive bacteria (G+), fungi (F), arbuscular mycorrhizal fungi (AMF), and Actinomycetes varied significantly (p Conclusion The total PLFAs (tPLFA) and PLFAs of soil microbes, including G-, G+, F, AMF, and Actinomycetes, were significantly affected by elevation. Bacteria were more sensitive to changes in elevation than other microbes. Environmental heterogeneity was the main factor affecting the geographical distribution pattern of microbial community structure. TOC, TN, W and RBA were the main driving factors for the change in soil microbial biomass. C fraction was the main factor affecting the biomass of fungi and bacteria and ROC was one of the main sources of the microbial-derived C pool.

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We construct a supersonic-sonic smooth patch solution for the two dimensional steady Euler equations in gas dynamics. This patch is extracted from the Frankl problem in the study of transonic flow with local supersonic bubble over an airfoil. Based on the methodology of characteristic decompositions, we establish the global existence and regularity of solutions in a partial hodograph coordinate system in terms of angle variables. The original problem is solved by transforming the solution in the partial hodograph plane back to that in the physical plane. Moreover, the uniform regularity of the solution and the regularity of an associated sonic curve are also verified.

A multifunctional β-xylosidase/α- l -arabinofuranosidase/β-glucosidase gene ( ccxyl3a ) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp. 21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95 kDa. With p -nitrophenyl-β- d -xyloside ( p NPβXyl) as a substrate, the purified protein presented an optimal pH of 8.5 and an optimal temperature of 45 °C. Moreover, CcXyl3A was activated in the presence of the metals K + and Na + . Purified CcXyl3A demonstrated multifunctional activities on p NPβXyl, p -nitrophenyl-β- d -glucoside ( p NPβGlc), and p -nitrophenyl-α- l -arabinofuranoside ( p NPαAraf). The greatest catalytic activity were found on p NPβXyl followed by p NPαAra f and p NPβGlc, respectively. Using xylooligosaccharides as substrate, CcXyl3A completely hydrolyzed xylobiose, xylotriose, xylotetraose and xylohexaose, xylose was the sole product. In addition, CcXyl3A synergistically acted with Thermomyces lanuginosus xylanase in the degradation of beechwood xylan, released xyloses from intermediate xylooligosaccharides produced by T. lanuginosus xylanase. To date, this is the first report to demonstrate the cloning and characterization of a multifunctional GH3 enzyme in C. cellulans that may have applications in hemicellulose degradation.

Uncooled infrared detectors haves some advantages such as low cost，light weight，low power consumption, and superior reliability, compared with cryogenically cooled ones．Ferroelectric uncooled focal plane array(FPA) are being developed for its AC response and its high reliability．As a key part of the ferroelectric assembly，the ROIC determines the performance of the assembly. A top-down design model for uncooled ferroelectric readout integrated circuit(ROIC) has been developed. Based on the optical，thermal and electrical properties of the ferroelectric detector，the RTIA readout integrated circuit is designed. The noise bandwidth of RTIA readout circuit has been developed and analyzed. A novel high gain amplifier, a high pass filter and a low pass filter circuits are designed on the ROIC. In order to improve the ferroelectric FPA package performance and decrease of package cost a temperature sensor is designed on the ROIC chip．At last the novel RTIA ROIC is implemented on 0.6μm 2P3M CMOS silicon techniques. According to the experimental chip test results，the temporal root mean square(RMS)noise voltage is about 1.4mV，the sensitivity of the on chip temperature sensor is 0.6 mV/K from -40°C to 60°C，the linearity performance of the ROIC chip is better than 99%．Based on the 320×240 RTIA ROIC, a 320×240 infrared ferroelectric FPA is fabricated and tested. Test results shows that the 320×240 RTIA ROIC meets the demand of infrared ferroelectric FPA.

A novel β-glucosidase gene (ccbgl1a) was cloned from the ginsenosides-transforming strain Cellulosimicrobium cellulans sp. 21. This enzyme was overexpressed in Escherichia coli, the recombinant β-glucosidase (CcBgl1A) containing N-terminal His-tag was sufficiently purified by nickel metal affinity chromatography with purification factor of 1.9-fold and specific activity of 31.5 U/mg. The molecular mass of recombinant CcBgl1A was estimated to be approximately 46 kDa. CcBgl1A exhibited optimal activity at 35 °C and pH 5.5. However, above 40 °C, the enzyme stability significantly decreased. The enzyme showed high bioconversion ability on protopanaxadiol-type ginsenosides mixture (PPDGM), which could hydrolyze the outer C-3 glucose moieties of ginsenosides Rb1, Rb2, Rc and Rd into the rare ginsenosides Gypenoside XVII (Gyp XVII), compound O, ginsenoside Mb and ginsenoside F2. Scaled-up production using 1 g of the PPDGM resulted in 292 mg Gyp XVII, 134 mg CO, 184 mg Mb, and 62 mg F2, with chromatographic purities. These results suggest that CcBgl1A would be potentially useful in the preparation of pharmacologically active minor ginsenosides Gyp XVII, CO, Mb and F2.

This paper is focused on a nonlinear variational wave equation which is the Euler–Lagrange equation of a variational principle whose action is a quadratic function of the derivatives of the field. We establish the global existence of an energy-conservative weak solution to its Cauchy problem for initial data of finite energy. The approach follows very closely the method of energy-dependent coordinates proposed by Bressan, Zhang and Zheng [6] , [7] . By introducing a new set of variables, which resolve all singularities due to the possible concentration of energy, the equation can be rewritten as a semilinear system. We construct the global weak solution by expressing the solution of the semilinear system in terms of the original variables.

This paper is concerned with a two-dimensional Riemann problem for the nonlinear wave system which gives rise to an interaction of two planar rarefaction waves. This problem comes from the expansion of a wedge of gas with constant velocity into vacuum, which is often interpreted as the dam collapse problem in hydraulics. We establish the global existence of smooth solutions in the interaction region of rarefaction waves up to a non-trivial vacuum boundary.