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Goosegrass is considered one of the worst agricultural weeds worldwide. Understanding its life cycle will provide useful management information. Field experiments with six emergence times (April, May, June, July, August, and September) were conducted at Anyang, China in 2015 and 2017 to clarify the growth and reproduction of goosegrass emerging at different times within a season. The result showed that plant height, dry weight, average weight per inflorescence, total inflorescence weight, average seed number per inflorescence, and total number of seeds per plant were relatively low in the April cohort, peaked with the May or June emergence cohort, and decreased thereafter. However, the earliest emergence of goosegrass in April had the highest total number of inflorescences. The plants of the May cohort produced the greatest number of seeds: 225,954 and 322,501 seeds per plant in 2015 and 2017, respectively. Delayed emergence resulted in less seed production; most plants that emerged in September did not flower or set seed. The 1,000-seed weight did not vary among the emergence cohorts. The reproductive investment was lowest for plants of the May cohort and then increased as emergence time was delayed to June, July, and August. Fresh mature seed of all emergence cohorts was extremely dormant and had low germination only up to 6% from August to November, and high germination (44% to 93%) in December. The information gained from this study indicates that weed management strategies should focus on the early-emerged seedlings such as the April and May cohorts, so as to effectively prevent goosegrass seed production, minimize the weed seed replenishment into the soil seed bank, and reduce the infestation in subsequent seasons.
Field bindweed, a member of the Convolvulaceae family, is a problematic perennial weed in cotton fields and orchards in northwest China. The species exhibits strong seed dormancy, causing delayed germination. A clear understanding of the mechanisms involved in alleviating seed dormancy is important for effective plant propagation and successful management of field bindweed. Experiments were conducted to investigate seed germination and radicle growth of field bindweed by breaking seed dormancy using mechanical scarification, sulfuric acid, hot-water scarification, cold stratification, and chemical treatment. Chemical treatments (gibberellic acid or potassium nitrate) had no effect on breaking seed dormancy, whereas mechanical scarification (sandpaper and blade) resulted in 92% to 98% seed germination, indicating that seed dormancy of field bindweed was mainly due to the presence of a hard seed coat. Seeds pretreated with 80% sulfuric acid for 15 to 60 min or 98% sulfuric acid for 15 to 30 min had germination rates above 80%, and soaking seeds in 70 C water for 4 to 16 min or in boiling water for 5 to 20s were effective in breaking seed dormancy but had no effect on the radicle growth of field bindweed. Cold stratification at 5 C for 2 to 8wk partially accelerated seed dormancy release, resulting in 53% to 67% seed germination. Results indicated that field bindweed could potentially form a persistent soil seed bank with physically dormant seed; therefore, strategies for eliminating seed production should be adopted.
It has been reported that the optimal properties of materials are usually not linear to the configuration entropy of materials; in another word, the high-entropy alloys may not have the best properties among all the alloys, including medium-entropy alloys, thus all of these alloys can be universally named as entropic alloys. For entropic alloys, the design, discovery, and optimization of new materials are more complicated than conventional materials. A technique of high-throughput processing is urgently needed to improve the efficiency. In this paper, a combined method by using multitarget deposition has been proposed for parallel preparation of high-entropy to medium-entropy alloys. Films with compositional gradient were constructed in a pseudo-ternary Ti–Al–(Cr, Fe, Ni) system in this study. To facilitate the characterization of the material library, it has been divided into 144 independent units with an area of 1 cm2 and the maximum value of compositional gradient reaches ∼13 at.%/cm. The material library exhibits a high coverage of composition, and the range of element content varies from 3.3 to 89.2 at.% on average. The stability and homogeneity of the material library were analyzed from phase structure and microtopography. Preliminary screening of the phase structure and properties were performed. The phases are mainly composed of amorphous phase and body-centered cubic phase. Hardness changes nonlinearly with compositions. The material library synthesized in this study is expected to provide an effective platform for high-throughput screening of multicomponent materials.
TiB2 particulates were formed in situ in an aluminum matrix via chemical reactions between an aluminum melt and the mixture of K2TiF6 and KBF4 salts. Different effects of Sc addition on the formation of the TiB2 particulates were revealed depending on the participation of Sc at different stages of the formation of the particulates. The metal–salt reactions resulted in boride layers along the α-Al grain boundaries in the presence of Sc, while the addition of Sc after the metal–salt reactions broke up the boride layers improving the dispersion of the TiB2 particulates to a limited degree. Sc promoted the growth of the TiB2 particulates, resulting in the coarsening of TiB2 particulates. The participation of Sc in the formation of TiB2 particulates altered the coarsening of the TiB2 particulates, resulting in different morphologies of the TiB2 particulates depending on the participation of Sc in the formation of the TiB2 particulates at different stages.
Monosized spherical Cu–20% Sn (wt%) alloy particles with diameter ranging from 70.6 to 334.0 μm were prepared by the pulsated orifice ejection method (termed “POEM”). Fully dense without pores and bulk inclusions, the cross-sectional micrographs of the spherical alloy particles indicate an even distribution of Cu and Sn. These spherical Cu–Sn alloy particles exhibit a good spherical shape and a narrow size distribution, suggesting that the liquid Cu–Sn alloy can completely break the balance between the surface tension and the liquid static pressure in the crucible micropores and accurately control the volume of the droplets. Furthermore, the cooling rate of spherical Cu–20% Sn alloy particles is estimated by a Newton’s cooling model. The cooling rate of the Cu–20% Sn alloy particle decreases gradually with the particle diameter increasing. Smaller particles have higher cooling rates and when the particle diameter is less than 70 μm, the cooling rate of particles can reach more than 3.3 × 104 K/s. The secondary dendrite arm spacing has strong dependence on particle diameter which increases gradually with the increase of particle diameter. The results demonstrate that POEM is an effective route for fabrication of high-quality monosized Cu–20% Sn alloy particles.
Interactions of fluvial and eolian processes are prominent in dryland environments and can significantly change Earth surface morphology. Here, we report on sediment records of eolian and fluvial interactions since the last glacial period, in the semiarid area of northwest China, at the limit of the Southeast Asian monsoon. Sediment sequences of last glacial and Holocene terraces of the Yellow River are composed of channel gravels, overlain by flood sands, eolian dunes, and flood loams. These sequences, dated by optically stimulated luminescence, record interlinks between fluvial and eolian processes and their response to climate change. Sedimentologic structures and grain-size analysis show flood loams, consisting of windblown sediment, deposited from floodwater suspended sediment. The gravel and sand were deposited during cold periods. During transitions from cold to warm phases, the river incised, and dunes were formed by deflation of channel and floodplain deposits (>70 and 21–16 ka). Dunes also formed at ~0.8 ka, probably after human intervention. After dune formation, flood loam covered dunes without erosion during peak discharges at the beginning of the subsequent warm period. The fluctuations of the Southeast Asian monsoon as a moisture-transporting agent have perhaps been the driving force for interactions between fluvial and eolian processes in this semiarid environment.
To understand parents’ knowledge and use of nutrition labelling and to explore its associated factors.
Two schools providing a nine-year educational programme in Putuo District, Shanghai, China, were selected for the study. Information was included on demographic data and knowledge of the Chinese Food Pagoda.
Students and their parents (n 1770) participated in a questionnaire survey.
Of questionnaires, 1766 were completed (response rate 99·8 %). Utilization rate of nutrition labelling was 19·3 %. Among 624 parents knowing nutrition labelling, 22·1 % understood all the information included, 70·7 % understood it partially and 7·2 % could not understand it at all. Use of nutrition labelling by parents was related to the following factors (OR; 95 % CI): high educational level of parent (1·465; 1·165, 1·841), parent’s knowledge of the Chinese Food Pagoda (1·333; 1·053, 1·688), parent’s consumption of top three snacks which are unhealthy (1·065; 1·023, 1·109), parent’s assumption that nutrition labelling would affect their choice of food (1·522; 1·131, 2·048), student’s willingness to learn about labels (1·449; 1·093, 1·920) and student’s knowledge and use of labels (2·214; 1·951, 2·513).
Parents’ knowledge and use of nutrition labelling are still at a lower level, and some information included in the nutrition labels is not understood by parents. The forms of the existing nutrition labelling need to be continuously improved to facilitate their understanding and usefulness. It is necessary to establish nutrition projects focusing on education and use of nutrition labels which help parents and their children make the right choices in selecting foods.
The triplite LiFeSO4F displays both the highest potential ever reported for an Fe-based compound, as well as a comparable specific energy with that of popular LiFePO4. The synthesis is still a challenge because the present approaches are connected with long time, special equipments or organic reagents, etc. In this work, the triplite LiFeSO4F powder was synthesized through an ambient two-step solid-state route. The reaction process and phase purity were analyzed, coupled with structure refinement and electrochemical test.
As a key indicator of childhood malnutrition, few studies have focused on stunting in relation to various socio-economic factors in which disadvantaged groups face in China. We conducted a community-based cross-sectional study incorporating forty-two rural counties in seven western provinces of China in 2011. In total, 5196 children aged 6–23 months were included. We used Poisson regression to examine risk factors for inadequate minimum dietary diversity (MDD) and stunting status, respectively. Overall, the proportion of children not meeting MDD was 44·5 %. Children aged 6–11 months (adjusted risk ratio (ARR)=1·39; 95 % CI 1·31, 1·49), with two siblings (ARR=1·09; 95 % CI 1·02, 1·17), delivered at home (ARR=1·30; 95 % CI 1·20, 1·41), within Yi (ARR=1·15; 95 % CI 1·04, 1·28) or Uighur groups (ARR=1·52; 95 % CI 1·36, 1·71), with an illiterate caregiver (ARR=2·12; 95 % CI 1·52, 2·96), receiving lowest income (ARR=1·32; 95 % CI 1·17, 1·50), and with breast-feeding in the last day (ARR=1·55; 95 % CI 1·44, 1·66) were more likely to have inadequate MDD. Moreover, inadequate MDD was positively associated with stunting (ARR=1·15; 95 % CI 1·01, 1·31). Other determinants for stunting were age, sex, place of delivery, minority group and income. The stunting prevalence and proportion of inadequate MDD remained high in Western China; to reduce stunting rates of ethnic minorities, further efforts addressing appropriate dietary feeding practices are needed, especially within these groups.
To explore effective ways to decrease soil CO2 emission and increase winter wheat grain yield in the North China Plain, a field experiment was conducted using two planting systems (wide-precision planting and conventional-cultivation planting) and two straw mulching rates (0 and 0.6 kg m−2) to study carbon emission, carbon cumulative emission flux, grain yield and yield carbon utilization efficiency. In the 2013–2014 and 2014–2015 winter wheat growing seasons, CO2 emission rate and cumulative CO2-C fluxes following straw mulching treatment were significantly lower than those following non-mulching treatments, whereas the yield carbon utilization efficiency was significant higher following straw mulching treatment. Straw mulching significantly reduced winter wheat grain yield, which was mainly due to the significant decrease in spike numbers and 1000-kernel weight. However, wide-precision planting system significantly increased winter wheat grain yields by increasing spike numbers under straw mulching conditions. Therefore, wide-precision planting system could compensate for the reduction in winter wheat grain yield under carbon sequestration conditions in the North China Plain.
Waist-to-height ratio (WHtR) has been reported to be more strongly associated with cardiometabolic risk factors among non-obese individuals than BMI and waist circumference (WC). A body shape index (ABSI) and body roundness index (BRI) have been proposed recently to assess obesity-related disorders or mortalities. Our aim was to compare the ability of ABSI and BRI with that of WHtR to identify cardiometabolic risk factors in Chinese adults with normal BMI and WC.
Receiver-operating characteristic curves and areas under the curve (AUC) were employed to evaluate the ability of the indices (WHtR, BRI, ABSI) to identify metabolic risk factors and to determine the indices’ optimal cut-off values. The value of each index that resulted in maximization of the Youden index (sensitivity + specificity – 1) was defined as optimal. Differences in the AUC values between the indices were also evaluated.
Individuals attending a voluntary health check-up in Beijing, China, July–December 2015, were recruited to the study.
Non-obese adults (n 1596).
Among both genders, ABSI exhibited the lowest AUC value for identifying each risk factor among the three indices; the AUC value of BRI for identifying each risk factor was very close to that of WHtR, and no significant differences were observed between the AUC values of the two new indices.
When evaluating cardiometabolic risk factors among non-obese adults, WHtR was a simple and effective index in the assessment of cardiometabolic risk factors, BRI could be used as an alternative body index to WHtR, while ABSI could not.
Much can be learned from terrestrial planets that appear to have had the potential to be habitable, but failed to realize that potential. Mars shows evidence of a once hospitable surface environment. The reasons for its current state, and in particular its thin atmosphere and dry surface, are of great interest for what they can tell us about habitable zone planet outcomes. A main goal of the MAVEN mission is to observe Mars’ atmosphere responses to solar and space weather influences, and in particular atmosphere escape related to space weather ‘storms’ caused by interplanetary coronal mass ejections (ICMEs). Numerical experiments with a data-validated MHD model suggest how the effects of an observed moderately strong ICME compare to what happens during a more extreme event. The results suggest the kinds of solar and space weather conditions that can have evolutionary importance at a planet like Mars.
The Resource Description Framework (RDF) is a flexible model for representing information about resources on the Web. As a W3C (World Wide Web Consortium) Recommendation, RDF has rapidly gained popularity. With the widespread acceptance of RDF on the Web and in the enterprise, a huge amount of RDF data is being proliferated and becoming available. Efficient and scalable management of RDF data is therefore of increasing importance. RDF data management has attracted attention in the database and Semantic Web communities. Much work has been devoted to proposing different solutions to store RDF data efficiently. This paper focusses on using relational databases and NoSQL (for ‘not only SQL (Structured Query Language)’) databases to store massive RDF data. A full up-to-date overview of the current state of the art in RDF data storage is provided in the paper.
Generally, the obvious work hardening, dynamic recrystallization (DRX), and dynamic recovery behaviors can be found during hot deformation of Ni-based superalloys. In the present study, the classical dislocation density theory is improved by introducing a new dislocation annihilation item to represent the influences of DRX on dislocation density evolution for a Ni-based superalloy. Based on the improved dislocation density theory, the peak strain corresponding to peak stress and the critical strain for initiating DRX can be determined, and the improved DRX kinetics equations and grain size evolution models are developed. The physical framework and algorithmic idea of the improved dislocation density theory are clarified. Moreover, the deformed microstructures are characterized and quantitatively correlated to validate the improved dislocation density theory. It is found that the improved dislocation density-based models can precisely characterize hot deformation and DRX behaviors for the studied superalloy under the tested conditions.
Field experiments were conducted in 2013 and 2014 to determine the influence of velvetleaf densities of 0, 0.125, 0.25, 0.5, 1, 2, 4, and 8 plants m−1 of row on cotton growth and yield. The relationship between velvetleaf density and seed cotton yield was described by the hyperbolic decay regression model, which estimated that a density of 0.44 to 0.48 velvetleaf m−1 of row would result in a seed cotton yield loss of 50%. Velvetleaf remained taller and thicker than cotton throughout the growing season. Both cotton height and stem diameter reduced with increasing velvetleaf density. Moreover, velvetleaf interference delayed cotton maturity, especially at velvetleaf densities of 1 to 8 plants m−1 of row, and cotton boll number and weight, seed numbers per boll, and lint percentage were also reduced. Fiber quality was not influenced by weed density when analyzed over 2 yr; however, fiber length uniformity and micronaire were adversely affected in 2014. Velvetleaf intraspecific competition resulted in density-dependent effects on weed biomass, ranging from 97 to 204 g plant−1 dry weight. Velvetleaf seed production per plant or per square meter was indicated by a logarithmic response. At a density of 1 plant m−1 of cotton row, velvetleaf produced approximately 20,000 seeds m−2. The adverse impact of velvetleaf on cotton growth and development identified in this study have indicated the need for effective management of this species when the weed density is greater than 0.25 to 0.5 plant m−1 of row and before the weed seed maturity.
Picoeukaryotes (<2–3 μm) perform key roles for the functioning of marine ecosystems, but little is known regarding the composition and diversity of picoeukaryotes in aquaculture areas. In this study, the Illumina MiSeq platform was used for sequencing the V4 variable region within the 18S rDNA gene to analyse genetic diversity and relative abundance of picoeukaryotic communities in the Qinhuangdao scallop cultivation area of the Bohai Sea. The community was dominated by three super groups, the alveolates (54%), stramenopiles (41%) and chlorophytes (3%), and three groups, dinoflagellates (54%), pelagomonadales (40%) and prasinophytes (3%). Furthermore, a contrasting station with open water away from the eutrophic aquaculture area was chosen. The communities collected from the two stations exhibited significant differences, with higher diversity in the aquaculture area. These results provide the first snapshot of the picoeukaryotic diversity in surface waters of the Qinhuangdao scallop cultivation area, and basic data for future studies on picoeukaryote community in an aquaculture region.
Nanosecond pulse discharges can provide high reduced electric field for exciting high-energy electrons, and the ultrafast rising time of the applied pulse can effectively suppress the generation of spark streamer and produce homogeneous discharges preionized by runaway electrons in atmospheric-pressure air. In this paper, the electrostatic field in a tube-plate electrodes gap is calculated using a calculation software. Furthermore, a simple physical model of nanosecond pulse discharges is established to investigate the behavior of the runaway electrons during the nanosecond pulse discharges with a rise time of 1.6 ns and a full-width at half-maximum of 3–5 ns in air. The physical model is coded by a numerical software, and then the runaway electrons and electron avalanche are investigated under different conditions. The simulated results show that the applied voltage, voltage polarity, and gas pressure can significantly affect the formation of the avalanche and the behavior of the runaway electrons. The inception time of runaway breakdown decreases when the applied voltage increases. In addition, the threshold voltage of runaway breakdown has a minimum value (10 kPa) with the variation of gas pressure.
X-ray powder diffraction data for piperaquine, C29H32Cl2N6, are reported [a = 15.8865(1) Å, b = 12.5975(3) Å, c = 13.2647(3) Å, β = 91.2890(1)°, unit-cell volume V = 2654.02 Å3, Z = 4, and space group P21/n]. All measured lines were indexed and are consistent with the P21/n space group. No detectable impurities were observed.
X-ray powder diffraction data for 5-Chloro-N-(4-nitrophenyl)pentanamide, C11H13ClN2O3, are reported [a = 8.036(4) Å, b = 15.972(5) Å, c = 9.829(5) Å, α = 90°, β = 104.227(2)°, γ = 90°, V = 1222.98 Å3, Z = 4, ρx = 1.3941 g cm−3 and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurities were observed.
To examine the association of 24 h urinary Na excretion and Na:K with obesity in Chinese adults.
Population-based cross-sectional study using a four-stage stratified sampling strategy.
Shandong Province, China.
Chinese adults (n 1906) aged 18–69 years who provided complete 24 h urine samples.
Odds of obesity increased significantly across increasing quartiles of urinary Na excretion (1·00, 1·54, 1·69 and 2·52, respectively, for overweight; 1·00, 1·20, 1·50, and 2·03, respectively, for obesity; 1·00, 1·44, 1·85 and 2·53, respectively, for abdominal obesity (assessed by waist circumference); and 1·00, 1·28, 1·44 and 1·75, respectively, for abdominal obesity (assessed by waist-to-height ratio); P for linear trend <0·001 for all). In addition, odds of abdominal obesity, but not odds of overweight and obesity, increased significantly with successive Na:K quartiles. Additionally, for each increment in urinary Na excretion of 100 mmol, odds of overweight, obesity, abdominal obesity (by waist circumference) and abdominal obesity (by waist-to-height ratio) increased significantly by 46 %, 39 %, 55 % and 33 %, respectively. Similarly, with a 1 sd increase in Na:K, odds of abdominal obesity (by waist circumference) and abdominal obesity (by waist-to-height ratio) increased significantly by 12 % and 15 %, respectively.
These findings suggest that 24 h urinary Na excretion and Na:K might be important risk factors for obesity in Chinese adults.