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We formulate and analyze a new financial chaotic model in fractional stochastic differential equation in Atangana-Baleanu operator. The model is constructed initially in integer case and then the application of fractional and stochastic approach are used for the model generalization. We study with care some of the mathematical results for the model in integer case by identifying the suitable values of parameters and initial values for the state variables for which the model behaves chaotic. Further, using the concept of stochastic differential equation, the model is further extended to the stochastic fractional differential equations. The equilibriums possibly the model posses are shown and analyzed. Lyapanove exponent are investigated for the model. We give a new method that is introduced recently in literature to find the model solution numerically for the case of fractional stochastic differential equation. We obtained many interesting graphical results for the model by considering different scenarios.

When the lander approaches the lunar surface, the rocket exhaust will erode the surface and eject massive high-speed dust, which could damage the payloads on the lander or interfere with subsequent surface operations. This process also provides a unique opportunity to study the plume–dust interaction and the wind erosion on the surface of airless body such as the Moon. Previously, limited knowledge was obtained from Apollo landing images and a simplified erosion model is built to study the erosion process. With high-quality data acquired in the landing process of Chang’E-4 (CE-4) mission, for the first time, we aim to quantify the dust ejection angle and erosion depth for a low-thrust lander, test the effectiveness of the current erosion model, and provide reference information for future landing missions. We use image measurement methods to extract key parameters such as dust ejection angle and erosion depth from the landing image of CE-4. For comparison with the observation, we also employ an erosion model to estimate the erosion thickness. The dust appears at about 7 s before the lander touch the surface, with a height of 13 m above the surface. When the nozzle altitude was about 0.6 m, the dust ejection angle is measured to be above 7°, while the dust ejection angle calculated by the particle trajectory method is less than 4.3°for particle sizes smaller than 1 mm. For the first time, an average erosion depth of 0.7 cm is measured between 1.12 m and 2 m from the nozzle centerline for a low-thrust lander. The measurement corresponds to an erosion time duration from 1.1 s before landing to 0.4 s after landing. The measured erosion range using CE-4 data is much larger than the estimated erosion radius given by the previous erosion model. It indicates that the dust’s angular distribution, local topography of the landing area, and other factors are important in improving the precision of the erosion model.

A decalcified sponge-like nitrogen-doped porous carbon (DFSC) derived from fish scales has been synthesized via decalcification, pre-carbonization, and KOH activation processes. The synthesized carbon possesses high surface area of 2520.9 m2 g−1, large pore volume of 1.40 cm3 g−1, moderate nitrogen content, and hierarchical porous structure, which was used to prepare DFSC/S composite as cathode material in lithium-sulfur (Li-S) batteries. The DFSC/S composite delivered a better discharge specific capacity of 473.9 mAh g−1 after 500 cycles at 0.1 C, and the decay rate per cycle was 0.83%. Even at a higher rate of 0.5 C, the capacity retention of DFSC/S composite was 446.3 mAh g−1 after 400 cycles. The superior performance of the DFSC/S composite was attributed to the highly porous structure, which not only can provide sufficient accommodation space, but also can improve the infiltration of electrolyte, facilitating rapid Li+ ion transfer in Li-S batteries. The moderate nitrogen doping in carbon matrix can strengthen the chemical adsorption of polysulfides. Therefore, DFSC/S composite is a promising cathode material to improve the electrochemical performance of Li-S batteries.

Two rice cultivars (Xiushui 09 and Chunyou 84) were used to evaluate the effects of various soil oxygen (O2) conditions on soil nitrogen (N) transformation, absorption and accumulation in rice plants. The treatments were continuous flooding (CF), continuous flooding and aeration (CFA), and alternate wetting and drying (AWD). The results showed that the AWD and CFA treatments improved soil N transformation, rice growth, and N absorption and accumulation. Soil NO3– content, nitrification activity and ammonia-oxidising bacteria abundance, leaf area, nitrate reductase activity, and N absorption and accumulation in rice all increased in both cultivars. However, soil microbial biomass carbon and pH did not significantly change during the whole period of rice growth. Correlation analysis revealed a significant positive correlation between the nitrification activity and ammonia-oxidising bacteria abundance, and both of them significantly increased as the total N accumulation in rice increased. Our results indicated that improved soil O2 conditions led to changing soil N cycling and contributed to increases in N absorption and accumulation by rice in paddy fields. Keywords: ammonium-nitrogen content, nitrate-nitrogen content, nitrification activity, nitrate reductase activity, rhizosphere oxygen condition, ammonia-oxidising bacteria abundance, rice, nitrogen use efficiency

China first in-situ lunar dust experiment is performed by a lunar dust detector in Chang’E-3 mission. The existed dust (less than 20 µm in diameter) properties, such as levitation, transportation and adhesion, are critical constraints for future lunar exploration program and even manned lunar exploration. Based on the problems discussed above, the in-situ lunar dust detector is originally designed to characterize dust deposition properties induced by lander landing as a function of environmental temperature, solar incident angle and orbit short circuit current on the northern Mare Imbrium, aiming to study lunar dust deposition properties induced by lander landing in depth. This paper begins with a brief of introduction of Chang’E-3 lunar dust detector design, followed by a series of experimental analysis of this instrument under different influencing factors, and concludes with lunar dust mass density deposition amount observed on the first lunar day is about 0.83 mg/cm2, which is less than that observed in Apollo 11 mission because the landing site of Chang’E-3 has the youngest mare basalts comparing with previous Apollo and lunar landing sites. The young geologic environment is less weathered and thus it has thinner layer of lunar dust than Apollo missions’; hence, the amount of kicked-up lunar dust in Chang’E-3 mission is less than that in Apollo 11 mission.

It had been proven that carbon aerogel (CA) can effectively improve the conductivity of sulfur (S) and suppress the shuttle effect of polysulfides in Li-S batteries, due to its outstanding electrical conductivity and micropore-rich structure. However, the microstructure of CA was easy to collapse and shrink during carbonization, resulting in a dramatically drop in specific surface area and porosity. Herein, graphene nanosheets (GNs) were introduced in CA to reinforce the structural stability. As-prepared CA/GNs composites were fabricated from in-situ polymerization of resorcinol (R) and formaldehyde (F) in graphene oxide (GO) solution. It was found that the mass concentration of the GO solution had a significantly positive effect on hierarchical porous structure of the CA/GNs composites, which presented improve the electrochemical performances due to the combination of micro-, meso- and macro-pores. It is worth noting that the CA/GNs0.1 sample, obtained from 10 wt % GO solution, possessed the largest specific surface area of 665.477 m2 g−1 and the largest pore volume of 0.912 cm3 g−1. Especially, after incorporated with moderate amount of S (58.86 wt %), the CA/GNs0.1/S cathode exhibited the best electrochemical performances (initial discharging capacity of 1501 mAh g−1 at 0.1C and reversible capacities of 471 mAh g−1 after 100 cycles and 341 mAh g−1 after 500 cycles at 1C). This was attributed to the tunable hierarchical porous microstructure of the CA/GNs0.1 sample. Unfortunately, when increased the S content to 68.39 wt %, the electrochemical performance deteriorated in all aspects because of their sluggish reaction kinetics. These all results suggested that introducing GNs can feasibly enhance the performance of CA as matrix in Li-S batteries.

To complement shortages of discrete sampling data and improve the detection accuracy of droplet deposition in unmanned aerial vehicle (UAV) spraying, we developed a new spray deposition pattern measurement system (SDPMS) based on a fluorescent tracer and spectral analysis. Then, we evaluated the system performance in two field spraying experiments in comparison with water-sensitive paper results. The system comprises a fluorescence scanner and spectral analysis program. The fluorescence scanner includes an ultraviolet light, spectrometer, far end controller, stepping motor, and sample reel. First, 1.0% fluorescent tracer solution is sprayed, and the droplets are collected on a paper strip. Then, the paper strip is scanned with the fluorescence scanner, and a set of fluorescence intensity values is collected and processed by the spectral analysis program. Finally, the spray deposition pattern is calculated. The experimental results showed that the spray deposition pattern from the SDPMS had a 0.89 correlation coefficient with that of water-sensitive paper. A linear regression model between fluorescence intensity and deposit coverage was constructed, with a coefficient of determination of 0.91 (F = 61.8845, P

A nano-magnesium nickel oxide-mesoporous carbon/sulfur composites (Mg0.6Ni0.4O-MPC/S) was designed and prepared for lithium-sulfur (Li-S) batteries. With a specific surface area as high as 1001.2 m2 g−1 and a unique porous structure, MPC in the composites can not only absorb the polysulfides generated during charge-discharge process to slow down the shuttle effect, but provide Li+ with a transmission channel. Nano-Mg0.6Ni0.4O (40 nm) particles, as an additive fabricated by self-propagating high temperature synthesis, can promote chemical bond dissociation with polysulfides and accelerate the electrochemical reaction rate. The composites loaded with 59 wt% sulfur exhibit a high initial capacity of 1360 mAh g−1 at 0.1 C and 695 mAh g−1 after 100 cycles, proving that the synergistic effect between MPC and nano-Mg0.6Ni0.4O leads to good cycle stability of the batteries.

Unmanned helicopters are widely used in agricultural spray applications; however, there is a lack of high-accuracy field data on the complex downwash flows caused by such helicopters to support efficient spraying. Therefore, we aimed to collect high-accuracy reference data by developing an ultrasonic anemometer array and related software to measure the downwash flow velocity field of a common agricultural unmanned helicopter (Copterworks AF-25B) during outdoor hovering and forward flight. Differential GPS and image scaling were used to determine the exact position and velocity of the helicopter to ensure repeatability of the tests. When the hovering height of the rotor above the ground plane was y/R = 2.5 (where y is the height above ground level and R is the radius of the rotor), the maximum downwash velocity reached 7 m s-1 at x/R = 0.5 (where x is the radial distance from the axis of the rotor). In addition, we obtained the spatial distribution of the turbulence kinetic energy. The attached flow velocity in the near-ground boundary layer increased radially and reached a maximum of 3 m s-1 at x = 3.6 m, after which it decreased. Comparatively, the maximum downwash velocity during forward flight occurred between x/R = 0.5 and 1.5 and was only about 3 m s-1, which was less than half the maximum downwash velocity while hovering. In addition, the circulation flow below the rotor tips had a velocity of 1.5 m s-1. The downwash flow lasted more than 1 s as the helicopter passed over a given point on the ground, the downwash velocity decreased from 3 m s-1 to 1.5 to 2.5 m s-1, and the symmetry of the flow field was not maintained. This study is the first application of an ultrasonic anemometer array to measure the airflow around an unmanned helicopter and provides high-accuracy field data that can be used as a reference for future indoor and simulation studies. Keywords: Agricultural unmanned helicopter, Downwash flow velocity field, Forward flight, Hovering, Ultrasonic anemometer.

34CrMo4 steel is widely used for drill stem in oil exploration, because of its excellent properties, such as favorable hardenability, shock absorption, less tendency of temper brittleness, and eminent wear resistance. In this study, the main works are residual stress test and microstructure characterization of 34CrMo4 steel upon various shot peening treatments. The residual stress distribution with effect depth was studied upon the shot peening. Face-to-face paste sample preparation method is required for continuous observation for microstructure evolution of shot-peened specimen from the treat surface to matrix. Grain refinement, lath structure, and precipitates are clearly observed in the gradient deformation layer.

To compare the heterosis levels among various groups of parental lines used extensively in China, identify foundational heterotic groups in parental pools and understand the relationship between genetic distance and heterosis performance, 16 parental lines with extensive genetic variation were selected from various sub-groups, and 39 hybrid combinations were generated and evaluated in Fujian and Hainan Provinces of China. The main results were as follows: (1) The 16 parental lines can be grouped into 7 sub-groups consisting of 1 maintainer sub-group and 6 restorer sub-groups; (2) Mean grain yield of the restorer lines was higher than that of the maintainer lines, and mean yield of parental lines was higher than that of the hybrid combinations; (3) The two best heterotic patterns were II-32A × G5 and II-32A × G6, moreover, the order of restorer sub-groups according to grain yield, from the highest to lowest, was G7, G6, G5, G4, G3 and G2; High specific combining ability values were observed for combinations of II-32A × G5, II-32A × G6 and Tianfeng A × G7; (4) Hybrid combinations derived from II-32A crossed with 13 restorer lines had higher yield trait values (mid-parent heterosis, better-parent heterosis, standard heterosis over check and specific combining ability) than any other combinations; (5) Genetic distance was positively correlated with panicle number, grain length and length-to-width ratio (P

Azoxystrobin (AZ) is a broad-spectrum systemic fungicide that widely used in the world. The present study investigated the toxicity effects on zebrafish after short-term exposure of AZ. Results demonstrated that the larval stage was most susceptible to AZ in the multiple life stages of zebrafish, with 96 h-LC50 value of 0.777 mg/L. Zebrafish larvae were exposed to different AZ concentrations (0, 0.1, 1, 10, 100 μg/L) and examined on 24, 48 and 72 h. It was found that AZ induced ROS accumulation, increased GST, GPX and POD activity and the transcriptions of antioxidant and stress response related genes, while the opposite trend occurred for SOD and CAT activity in 24-h or 48-h exposure period. The increased E2 and VTG levels in zebrafish larvae, and altered transcription levels of regulatory and steroidogenic genes in the hypothalamus-pituitary-gonad (HPG) axis indicated the endocrine disruption capacity of AZ. The transcripts of mdm2, p53, ogg1, bcl2, bbc3, cas8 and cas9 involved in cell apoptosis, and the mRNA levels of cytokines and chemokines such as cxcl-c1c, ccl, il-1β, il-8, ifn, and tnfα were in accordance with the trends of the examined genes involved in oxidative stress and endocrine system. The results suggested that short-term exposure to AZ might impose ecotoxicological effects on zebrafish larvae, and the information presented here also provide molecular strategies and increase mechanistic understanding of AZ-induced toxic response, and help elucidate the environmental risks of AZ.

A series of banana peels derived porous carbon (BPPC) materials were fabricated by pyrolysis carbonization with different numbers of KOH activation. The Brunauer–Emmett–Teller tests indicated the number of activation effectively improves the specific surface area and pore volume of the BPPC. Amongst, the BPPC-2 (activated twice) possesses ultrahigh specific surface area (2044.57 m2 g−1) and large pore volume (2.40 cm3 g−1) on account of the improved hierarchical porous microstructure. After S loading process, the resultant C/S composites were introduced as cathode material in Li–S batteries. The S/BPPC-2 composite cathode exhibited a higher initial specific capacity (1481.54 mAh g−1 at 0.1 C) and a better reversible capacity (351 mAh g−1 after 300 cycles at 1 C) than those of others. It also exhibited excellent high rate performance even at 5 C. The enhanced electrochemical performances were ascribed to the improved specific surface area and larger pore volume of the BPPC-2, which effectively facilitated the intimate contact between sulfur and the conductive matrix, accommodating severe volume change. Besides, the micro/mesopores provided high adsorption power to inhibit the dissolution of polysulfides. This research suggested that the activation number played a key role in improving the electrochemical performance of composite cathode in Li–S batteries.

Nitrogen and sulfur dual-doped graphene (NSG) synthesized by a simple and low-cost one-pot microwave assisted method is applied to immobilize sulfur by the mean of an in situ sulfur deposition approach. Images of scanning electron microscope (SEM) and transmission electron microscope (TEM) show that nano-sulfur (2–20 nm) is wrapped by the transparent NSG nanosheets with wrinkled and folded features. The application of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) confirmed the structure and composition of the obtained nitrogen and sulfur dual-doped graphene/sulfur (NSG/S) composites as well. The heteroatom doping content was controlled by adjusting the amount of thiourea. The XPS analysis results indicate that pyridinic-N and pyrrolic-N are dominant among the product, thereby improving the cycle life of the lithium sulfur batteries. The NSG-4/S composites with sulfur loading of 68 wt% exhibits a remarkably higher reversible specific capacity of 1583 mAh g−1, impressive rate capability, splendid specific discharge capacity of 819 mAh g−1 at 0.1 C after 100 cycles and long cycle stability of 640 mAh g−1 after 200 cycles at 1 C.

The top-of-the-atmosphere (TOA) reflectances of the Visible Infrared Imaging Radiometer (VIIRS) M9 channel and the Moderate Resolution Imaging Spectroradiometer (MODIS) 26 channel have been simulated using the libRadtran radiative transfer model and the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) Vertical Feature Mask data. The simulated data were analyzed to quantify the performance differences between the VIIRS M9 and the MODIS 26 channels. Analysis of simulated clear-sky TOA reflectances showed that compared MODIS channel 26, the VIIRS M9 channel always performs better in reducing background reflectance regardless of latitude, season, surface type, vapor content or surface elevation. For mid-latitude, sub-Arctic and tropical regions the VIIRS M9 channel reduce the background reflectance by approximately 66.7%, 52.6% and 41.5%, respectively over the surface type of sandstone, compared to MODIS channel 26. Simulations for cloudy skies showed that both stratus and cumulus clouds contribute less to VIIRS M9 and MODIS band 26 TOA reflectances. Analysis of observed MODIS, VIIRS and CALIOP data was consistent with the simulated results. The VIIRS M9 decreases clear-sky background reflectance by as much as 35.96% and non-cirrus cloud reflectance by 29.86% compared with the MODIS channel 26. The observed reflectances of MODIS and VIIRS cirrus channels for clear-sky, non-cirrus cloud, and cirrus cloud are 0.0133 and 0.0095, 0.020 and 0.015, 0.084 and 0.067 respectively.

Salicylic acid (SA) is an important phytohormone. It plays an essential role in regulating many physiological processes of plants. Most of the conventional methods for SA detection are based on in vitro processes. More attention should be paid to develop in vivo methods for SA detection. In this work, Pt nanoflowers and GO were simultaneously electrodeposited and reduced on a Pt wire microelectrode in one step. The Pt nanoflowers/ERGO modified Pt microsensor demonstrated high sensitivity and selectivity for SA. SA could be detected from 100 pM to 1 μM with a detection limit of 48.11 pM. Then this microsensor was used to detect SA in the stem of sunflower seedlings under different salt stresses in vivo. The result showed that with the increasing concentration of salt, SA levels decreased. Our result was also confirmed by UPLC-MS and gene expression analysis. To the best of our knowledge, this is the first report of in vivo detection of SA in plants using the Pt nanoflowers/ERGO modified Pt microelectrode. It is foreseeable that our strategy could pave the way for the in vivo detection of phytohormones in plants.

The new principle and technique to tune biodegradation rates of biomaterials is one of the keys to the development of regenerative medicine and next-generation biomaterials. Biodegradable stents are new-generation medical devices applied in percutaneous coronary intervention, etc. Recently, both corrodible metals and degradable polymers have drawn much attention in biodegradable stents or scaffolds. It is, however, a dilemma to achieve good mechanical properties and appropriate degradation profiles. Herein, we put forward a metal-polymer composite strategy to achieve both. Iron stents exhibit excellent mechanical properties but low corrosion rate in vivo. We hypothesized that coating of biodegradable aliphatic polyester could accelerate iron corrosion due to the acidic degradation products, etc. To demonstrate the feasibility of this composite material technique, we first conducted in vitro experiments to affirm that iron sheet corroded faster when covered by polylactide (PLA) coating. Then, we fabricated three-dimensional metal-polymer stents (MPS) and implanted the novel stents in the abdominal aorta of New Zealand white rabbits, setting metal-based stents (MBS) as a control. A series of in vivo experiments were performed, including measurements of residual mass and radial strength of the stents, histological analysis, micro-computed tomography, and optical coherence tomography imaging at the implantation site. The results showed that MPS could totally corrode in some cases, whereas iron struts of MBS in all cases remained several months after implantation. Corrosion rates of MPS could be easily regulated by adjusting the composition of PLA coatings.

Eu 2+ doped Sr 2- x Ba x Si 5 N 8 phosphors were synthesized at 1610 ℃ for 4 h via the solid-state reaction method. The XRD results confirm that the complete solid solutions are formed. With the increase of x, the emission spectra show an obvious blue-shift from 610 nm to 585 nm under the excitation of 460 nm. The color tone can be tuned from yellow to red. The corresponding mechanism for the blue-shift of peak-wavelength is studied in detail. The results of decomposed Gaussian spectra and fluorescence lifetime show that the local coordination structure surrounding activator ions changes with increasing x value. It is found that the probability of Eu occupying Sr1 and Sr2 site is dependent on Ba/Sr ratio. The variation of thermal quenching properties and the corresponding mechanism is discussed in detail. The results indicate that Eu 2+ doped Sr 2- x Ba x Si 5 N 8 is a promising orange red-emitting phosphor for near UV or blue light-pumped white light-emitting-diodes ( w LEDs).

The effects of the aldehydes crosslinkers on properties of the BC/PVA nanocomposite hydrogels were investigated. BC as the reinforcement and PVA as the matrix materials of the BC/PVA nanocomposite hydrogels, the hydrogels were prepared in coagulating bath of sodium sulfate and cross-linked with kinds of aldehydes. The hydrogels were characterized by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), Equilibrium swelling ratio (ESR) tests, mechanical properties tests, thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) analysis. It was found that the dialdehyde (glyoxal, glutaraldehyde) crosslinkers were more efficient than monoaldehyde (formaldehyde, acetaldehyde) crosslinkers. The ESR, mechanical properties of the BC/PVA nanocomposite hydrogels were obviously influenced by aldehydes crosslinkers. However, their thermo stability and crystallinity were scarcely influenced. The nanocomposite hydrogels described in this study provides information for further development and optimization of a variety of nanofiber-polymer matrix composite hydrogels.

Although the carbendazim is widely used to manage spot blight in celery cultivation, information on residues identified is of interest. In this study, we examined the dissipation and residual amounts of carbendazim in celery and soil under different cultivation methods when using the suggested dose and ten times of that and the bioconcentration factor of carbendazim for celery. The results showed that when celery leaves were sprayed with the suggested dose, the half-lives in a celery field and greenhouse were 2.75 days and 3.29 days, respectively. When the soil matrix was sprayed with the recommended dose before cultivation, the half-lives of carbendazim residues were 16.86 days and 11.97 days. We also conducted a long-term dietary risk assessment using the corresponding criteria. The results showed that, in China, the use of carbendazim at a dose of 0.022 g/m2 is safer and more reasonable when the harvest interval is 28 days.

Monitoring the cotton budding rate is important for growers so that they can replant cotton in a timely fashion at locations at which cotton density is sparse. In this study, a true-color camera was mounted on an unmanned aerial vehicle (UAV) and used to collect images of young cotton plants to estimate the germination of cotton plants. The collected images were preprocessed by stitching them together to obtain the single orthomosaic image. The support-vector machine method and maximum likelihood classification method were conducted to identify the cotton plants in the image. The accuracy evaluation indicated the overall accuracy of the classification for SVM is 96.65% with the Kappa coefficient of 93.99%, while for maximum likelihood classification, the accuracy is 87.85% with a Kappa coefficient of 80.67%. A method based on the morphological characteristics of cotton plants was proposed to identify and count the overlapping cotton plants in this study. The analysis showed that the method can improve the detection accuracy by 6.3% when compared to without it. The validation based on visual interpretation indicated that the method presented an accuracy of 91.13%. The study showed that the minimal resolution of no less than 1.2 cm/pixel in practice for image collection is necessary in order to recognize cotton plants accurately.

Geographic Object-Based Image Analysis and linear unmixing are common methods in image classification. The purpose of this study is to analyze the classification efficiency by integrating these two methods in the mountain area. This research selected Jiangle County, Fujian, as a study area. Two Landsat8 OLI images, which covered the county, were used. Linear spectral mixture model, multi-scale segmentation, and decision tree were applied in the classification. After image preprocessing, linear spectral mixture model was used to unmix the image into three fraction images-vegetation, shade, and soil. The principal component analysis and tasseled cap transformation were used to derived three principal components and the brightness, wetness, and greenness. Multi-scale segmentation is applied by eCognition. Under scale 40, the image was divided into vegetation and non-vegetation area, then under scale 20, the vegetation area was divided into different types by integrating the fraction with different methods. The accuracy assessment of the classification map was done using the forestry resource survey and the high-resolution image of Google Earth. This study indicated that the unmixed bands could improve the classification accuracy. The overall classification accuracy was 92.40% with a Kappa coefficient of 0.9032. Therefore, there is a conclusion that this approach is an efficient way to classify different plantation.

CaCO3-templating is a strategy for synthesizing porous carbon (PC) materials that has been widely used for decades. In this work, a modified template-removal process, soaking the pyrolysis product by hydrochloric acid solution, was proposed to optimize the graphitization degree, morphology, specific area, and pore size distribution of the products. The tests results demonstrated that the PC product obtained by a modified template method (M-TC) exhibited a transformation in microstructure such as an enhanced specific surface area and more plentiful hierarchical pores as compared with those PC materials obtained by conventional strategy. The potential formation mechanisms are proposed as well. When the M-TC sample loaded sulfur was applied as a cathode material for a Li-S battery, it delivered a high initial discharge capacity (1475 mAh g−1) and a stable discharge capacity (874 mAh g−1) after 50 cycles at 0.1 C. The modified template-removal strategy could bring inspirations on synthesis design and extend potential applications of commercial PC materials.

Non-destructive testing of plant organs, tissues, and cells has important implications in studying the immediate physiological status of plants. The portable dynamic ion flux test equipment (PDIFTE) was developed based on Fick’s first law of diffusion and the Nernst equation to achieve the ion flux measurement in pmol cm−2s−1. This equipment integrates micro-imaging, micro-signal processing, automation and control, and biosensor technologies with the original signal acquisition and conditioning module, the motion control module, the macro 3D automatically control platform, micro digital imaging system, electrostatic shielding coating, ion-selective microelectrode, and other components. PDIFTE can detect H+, K+, Na+, Mg2+, Ca2+, Cd2+, Cl−, \( {\text{NO}}_{3}^{ - } \), and \( {\text{NH}}_{4}^{ + } \). This device can be used in the physiological mechanism research of salt-resistant, drought-resistant, cold-tolerant, heavy metal-resistant, and disease-resistant plants. It can also be used in the research on plant nutrition, ion channel-related gene function, and crop resistant breeding screening.

In this study, 33 pieces of WSP were placed along three lines in a paddy. An M-18B Dromader AG aircraft flew and sprayed over the field, and the spray deposits were collected by water sensitive paper. Seven greyscale parameters were used to compare the color depth, deviation and homogeneity of digital water sensitive images. The greyscale images were converted to binary images with five threshold selection methods. The results of recognition of seven greyscale parameters and five threshold methods were compared to analyze the droplets in different scanned images on water sensitive paper. The effects of the threshold on the computation of deposit density and the stain size were evaluated. The most suitable grey scale was found to be luminosity. Finally, a manual validation was performed, and the relationship between the threshold and the stain size of was analyzed.

Charged dust widely exists on the surface of the moon, which is considered to be closely related with many natural phenomena. China's Chang’E-5 lunar mission plans to monitor the charged characteristics of electrostatically levitated dust on the lunar surface in an economical and effective way. The designed detector consists of two probes, the reference probe and the measuring probe. Each single probe consists of two grids and a sticky quartz crystal microbalance. The sensitivity coefficient of measuring probe is SM=(8.002±0.510)×10−9g/Hz·cm2, and that of reference probe is SR=(9.137±0.369)×10−9 g/Hz·cm2 under the test. By comparing the measurement results of two sets of probes, the mass proportion of dust with different charge/mass ratio of suspended lunar dust can be obtained. These results measured on the lunar surface would be helpful for analyzing the levitation mechanisms and motion characteristics of lunar dust.

Geographical traceability is essential to the highly valued wild edible mushroom Thelephora ganbajun (T. ganbajun). This work examined the possibility of using the combination of multielement together with multivariate statistics methods, to identify the origins of 40 T. ganbajun from four sites of Yunnan province, China. Multielement analysis of thirteen elements (Mg, K, Ca, Al, Cr, Zn, As, Se, Cd, Pb, Fe, Mn, and P) were investigated by inductively coupled plasma mass spectroscopy (ICP-MS). Pearson correlation analysis was performed to check for the potential relationship between elements. Concentrations were used as chemical indicators to determine the geographical origins of T. ganbajun samples by utilizing multivariate data analysis, including principal component analysis (PCA), hierarchical cluster analysis (HCA), and linear discriminant analysis (LDA). Thirteen elements in T. ganbajun from different regions showed significant differences (p

Drought stress is a major environmental constraint for plant growth. Climate-change-driven increases in ambient temperatures resulted in reduced or unevenly distributed rainfalls, leading to increased soil drought. Carex duriuscula C. A. Mey is a typical drought-tolerant sedge, but few reports have examined the mechanisms conferring its tolerant traits. In the present study, the drought responses of C. duriuscula were assessed by quantifying activity of antioxidant enzymes in its leaf and root tissues and evaluating the relative contribution of organic and inorganic osmolyte in plant osmotic adjustment, linking it with the patterns of the ion acquisition by roots. Two levels of stress—mild (MD) and severe (SD) drought treatments—were used, followed by re-watering. Drought stress caused reduction in a relative water content and chlorophyll content of leaves, this was accompanied by an increase in the hydrogen peroxide (H2O2) and superoxide (O2−) contents in leaves and roots. Under MD stress, the activities of catalase (CAT), peroxidase (POD), and glutathione peroxidase (GPX) increased in leaves, whereas, in roots, only CAT and POD activities increased. SD stress led to an increase in the activities of CAT, POD, superoxide dismutase (SOD), and GPX in both tissues. The levels of proline, soluble sugars, and soluble proteins in the leaves also increased. Under both MD and SD stress conditions, C. duriuscula increased K+, Na+, and Cl− uptake by plant roots, which resulted in an increased K+, Na+, and Cl− concentrations in leaves and roots. This reliance on inorganic osmolytes enables a cost-efficient osmotic adjustment in C. duriuscula. Overall, this study revealed that C. duriuscula was able to survive arid environments due to an efficient operation of its ROS-scavenging systems and osmotic adjustment mechanisms.

In this work, graphene quantum dots/sulfur (GQDs/S) composite was prepared as cathode material for lithium sulfur (Li-S) batteries by a feasible chemical method. Multiple polar functional groups in GQDs can provide more active absorption sites to significantly strengthen the chemical absorption with polysulfides, suppressing the ‘shuttle effect’. In addition, the highly dispersed GQDs particles in the solution served as nucleation sites, the dissolved sulfur are reprecipitated around the GQDs, forming a dendritic interlaced network structure to prevent the aggregation of the sulfur, and further enhance the utilization of active substances. A high initial discharge capacity of 1125 mA h g−1 at 0.1C has been obtained in the GQDs/S cell, which is much higher than the initial discharge capacity of 658 mA h g−1 of GQDs/SR prepared by physical melting method. The superior performance of GQDs/S is attributed to the unique dendritic interlaced framework and multiple polar functional groups. The strong chemical effects between polar functional groups and polysulfides have been confirmed by the absorption experiment and DFT calculation. This work develops a new strategy in cathode material design for Li-S batteries.

Cyhalofop-butyl resistance in Leptochloa chinensis (L.) Nees is a threat to rice production. Qualitative changes to the acetyl-CoA carboxylase gene (ACCase) have been reported to induce cyhalofop-butyl resistance in some weed species, but the role of ACCase in cyhalofop-butyl resistance through quantitative changes remains uncertain. The accurate assessment of transcriptional changes in the functional genes associated with herbicide resistance in L. chinensis is challenging owing to the lack of available reference genes for expression normalization. Here, we selected nine candidate reference genes in L. chinensis and assessed their transcription stability in populations susceptible and resistant to cyhalofop-butyl. Transcription stability was compared under conditions of herbicide stress and control conditions using BestKeeper, NormFinder, and geNorm. Elongation factor 1 alpha, eukaryotic initiation factor 4A, and cap-binding protein CBP20 were the most stable reference genes under cyhalofop-butyl treatment. Transcription levels of ACCase were evaluated in seven resistant populations, one of which showed higher transcription than the susceptible population after 24 h cyhalofop-butyl treatment. However, the slight up-regulation of ACCase (approximately 2.0-fold) is unlikely to be responsible for the high resistance levels in these populations of L. chinensis.

A study of the velocity field of the wake of a Thrush 510G carrying out spray application close to the ground was investigated. The aircraft normally operates in extreme ground effect and wake vortices play a major role in the dispersal and deposition of pesticide spray released behind the aircraft. The evolution of wake vortices over time, and their interaction with the ground were simulated using computational fluid dynamics (CFD) techniques. The simulation was initialised with meteorological data from a field experiment. Information given by CFD simulation included the trajectory of the wake vortices as well as circulation, which indicates the strength of vortex. This information provided insights into the velocity field in the wake, including the upwash near the wing tips and the downwash in between. The effect of turbulence intensity as well as crosswind on the wake vortices and the resulting velocity field were investigated.

In order to spray herbicides accurately on targets, this study focused on spectral classification of weeds and crops for potential to rapidly detect weeds in crop fields. A 350 ~ 2500 nm FieldSpec-FR spectroradiometer was used to measure spectral responses of the canopies of the seedling vegetables, cabbage ‘8398’ and cabbage ‘Zhonggan 11’, and weeds, Barnyard grass, green foxtail, goosegrass, crabgrass, and Chenopodium quinoa, at five- and seven-week growth stages (WGS). First, the characteristic wavelengths (CW) were determined using Principal Component Analysis (PCA). Then, the plants were classified using Bayesian discriminant analysis with the reflectance of the CWs. The results of spectral analysis indicated that the different growth stages of cabbages had little influence on the spectral identification of cabbages and weeds. The eight CWs determined were used as the input to the model for Bayesian discriminant analysis to classify two varieties of cabbages and five weeds with the correct classification rate of 84.3% for model testing. When the two varieties of cabbages were considered as the same category, the correct classification rate was improved to 100%. It was concluded that Bayesian discriminant analysis could be used to identify weeds from seedling cabbages using leaf hyperspectral reflectance. Key words: Weed identification, spectrum analysis, visible and near-infrared, Bayesian discriminant, seedling weed, seedling cabbage.

Long corrosion period and slow resorption in vivo remain major limitations for iron-based bioresorbable scaffolds. This work focused on the design and characterization of a novel iron-based drug-eluting coronary scaffold (IBS scaffold) made of nitrided iron materials. The 53 μm IBS scaffold shows good device performance comparable to a current mainstream drug-eluting coronary stent (Xience Prime™) due to the good comprehensive mechanical performance of nitrided iron materials. The novel design of a zinc barrier layer makes it possible for the IBS scaffold to have ultrathin struts and thick PDLLA coating of 12 μm to maintain adequate scaffolding (125 kPa) after 3 months implantation while having a significantly shortened corrosion period (13 months). The biocorrosion and bioresorption of the IBS scaffold could be effectively evaluated using Micro-CT, OCT and MRI methods. Although complete bioresorption of the corrosion products has not been observed yet, there are no identified biological problems for the IBS scaffold after implantation in rabbit abdominal aorta up to 13 months. This study demonstrates that the IBS scaffold with novel design has significantly shortened corrosion period and less amount of corrosion products without causing any biological problems after implantation up to 13 months, therefore is promising for coronary application. Keywords: Nitrided iron, Coating design, Effective scaffolding, Shortened corrosion period, Biosafety

Unmanned helicopter-based spray systems are developing rapidly in Asia. However, droplet movement during aerial spraying remains poorly understood, owing to the complexity of downwash flow-structure development. Therefore, a computational fluid-dynamics method was used to investigate the downwash flow field of a full-scale unmanned agricultural helicopter (AF-25B; Copterworks) and the resultant movements of the spray droplets. A large-eddy simulation was performed and the lattice Boltzmann method was used to accurately capture the development of the rotor-tip vortex. To assess model performance, a hovering case with the height of 2.7 m was simulated and compared with previous field- and indoor-test results. The simulated instantaneous flow structures are qualitatively comparable with the indoor test results, supporting the reliability of the simulation method. Then, forward flight was simulated at heights of 1.5, 2.5, and 3.5 m above ground. In the forward-flight case, the flow speed on the right side was approximately 15% lower than that on the left side. The iso-surface of the vorticity was used to represent the asymmetric flow structures produced by the rotor. This flow structure was asymmetric, and the yaw angle, θ, was approximately 3–12° inclined to the right of the helicopter. When the application height was 1.5, 2.5, and 3.5 m, the angle of the edge of the flow structure, α, was about 105, 80, and 44°, respectively, and the entire flow structure width was 13, 9, and 6 m, respectively, and inversely proportional to the application heights. The temporal developments of the flow structures and droplet movements after the helicopter flew by were also simulated. The droplet expansion speed was found to have decreased when the application height increased. The droplet distribution was observed to become more asymmetric, with fewer droplets on the left side of the helicopter, when the application height was decreased. The coefficient of variation of deposition could, therefore, get reduced by the increase in the application height and cause the droplet deposit to be more uniform. However, the deposition quality may also get rapidly decreased as a consequence. A potential method to predict aerial-spray drift and deposition under complex conditions is presented in this study.

Unmanned helicopters are used widely in precision agriculture, especially in East Asia. However, the development of the downwash flow field of unmanned helicopters, which strongly influences the movement of spray droplets in the air, is poorly understood. Therefore, an indoor measurement technique was developed to investigate the downwash flow field of a 1:10 scaled unmanned agricultural helicopter (AF-25B; Copterworks). High-speed particle image velocimetry was employed to obtain the instantaneous and average velocity field of the downwash flow, with a spatial resolution less than 0.005 m and temporal resolution less than 0.001 s. Results showed that radial distance of the point at which downwash flow reached the ground was proportional to the hovering height of the helicopter at a hovering height of z/R

Fibre-reinforced polymer (FRP) is used widely in concrete structures owing to its noncorrosive, light-weight, nonmagnetic, and high tensile-strength properties. However, the FRP-reinforced concrete flexural member exhibits low ductility owing to the linear&ndash, elastic property of FRP reinforcement. Hybrid steel&mdash, FRP-reinforced concrete members exhibit good strength and ductility under flexure owing to the inelastic deformation of steel reinforcement. The existing investigations have focused on the mechanical behaviours of the hybrid steel&mdash, FRP-reinforced flexural members. Only few studies have been reported on the members under combined flexural and compression loads, such as columns, owing to the poor compressive behaviour of FRP bars. We herein propose a new type of hybrid steel&mdash, FRP-reinforced concrete&mdash, engineered cementitious composite (ECC) composite column with ECC applied to the plastic hinge region and tested it under reversed cyclic loading. The hybrid steel&mdash, FRP-reinforced concrete column was also tested for comparison. The influence of matrix type in the plastic hinge region on the failure mode, crack pattern, ultimate strength, ductility, and energy dissipation capacity, of the columns were evaluated systematically. We found that the substitution of concrete with ECC in the plastic hinge zone can prevent the local buckling of FRP bars efficiently, and subsequently improve the strength and ductility of the column substantially.

For Li-S batteries, commercial application was hindered by the insulating nature of S and the solubility of polysulfide. Porous carbon materials had proven themselves to be an ideal immobilizer host for S impregnation. Herein, carbon aerogels (CAs) with tunable pore microstructure were synthesized from resorcinol-formaldehyde reaction with increasing catalyst concentration and pyrolysis under high temperature. The results demonstrated that the catalyst concentration played a key role in tuning the porous microstructure of the CAs. In addition, potassium hydroxide (KOH) was introduced to activate the obtained CAs. The activated carbon aerogels (A-CAs) with hierarchical porous structure exhibited the highest specific surface area (1837.4 m2 g−1) and the largest total pore volume (2.276 cm3 g−1), which combined the advantages of both mesoporous and microporous. The effects of porous microstructure, specific surface area, and pore volume of the CAs and A-CAs on S incorporation were studied. The S/A-CAs exhibited significantly improved reversible capacity (1260 mAh g−1 at a rate of 0.1 C), enhanced high-rate property, and excellent cycling performance (229 mAh g−1 after 500 cycles at 1 C) as a cathode for Li-S batteries.

In vivo detecting of plants signal molecules is of great importance for the precision farming, crop management and plant phenotyping. In this work, for in vivo detecting indole-3-acetic acid (IAA), one of phytohormones, fine stainless steel (SS) wire was used as electrode material. Highly ordered nanopores, popcorn-like Au nanostructures, Pt nanoparticles and reduced graphene oxide (ERGO) nanocomposite films, and polymerized ST film (PST) were fabricated on the SS microelectrode in turn for improving the detection effect. Using the as-prepared SS microelectrode as working electrode, two untreated SS wires as reference electrode and counter electrode respectively, a disposable electrochemical microsensor for IAA were developed. The microsensor exhibited excellent selectivity and high sensitivity with low detection limit (LOD) of 43 pg mL−1. The limit of quantity (LOQ) is 143 pg mL−1. The RSD was 7% for 12 different PST/Pt-ERGO/Au/a-SS microsensors in presence of 100 µg mL−1 IAA. Using this microsensor, IAA of the stem of soybean seedlings was detected in vivo under salt stress. Our result was also confirmed by ultra-performance liquid chromatography-mass spectrum (UPLC-MS). This is the first report for the in vivo detection of IAA in plants using SS-based electrochemical microsensor. Our sensor provides an excellent sensing platform for detecting IAA in plants in vivo.

The fructosyltransferase gene was isolated and cloned from Aspergillus oryzae. The gene was 1368 bp, which encoded a protein of 455 amino acids. To analyze the activity of the expressed fructosyltransferase, the pET32a-fructosyltransferase recombined plasmid was transformed into Escherichia coli BL21. The fructosyltransferase gene was successfully expressed by Isopropyl-β-d-thiogalactoside (IPTG) induction. The molecular weight of the expression protein was about 45 kDa. The optimal conditions of protein expression were 25 °C, 0.1 mM IPTG, and 8 h of inducing time. The optimal concentration of urea dealing with inclusion body was 2.5 M. The expressed protein exhibited a strong fructosyl transfer activity. These results showed that the expressed fructosyltransferas owned transferase activity, and could catalyze the synthesis of sucrose-6-acetate.

In this study, it analyzed the common evaluating methods for the aerial spraying quality for plant protection in the field experiment. Aiming at the image processing technique to analyze the parameters of droplet deposition in water sensitive image, the disadvantages of the existing systems are discussed. The method of separating the overlapping droplet images by erosion method and calculating the droplet diameter with the image's grayscale depth is proposed. Based on this, the iDAS droplet deposition image processing system was designed. The data collected from the field experiments are compared with the Deposit Scan system developed by USDA and the results show that the system is effective and reliable. The performance of this system is better than Deposit Scan system when analyzing high coverage water-sensitive images. In the analysis of medium coverage and low coverage water-sensitivity images, the performance of these two systems is similar.

Land use and land cover change research has been applied to landslides, erosion, land planning and global change. Based on the CA-Markov model, this study predicts the spatial patterns of land use in 2025 and 2036 based on the dynamic changes in land use patterns using remote sensing and geographic information system. CA-Markov integrates the advantages of cellular automata and Markov chain analysis to predict future land use trends based on studies of land use changes in the past. Based on Landsat 5 TM images from 1992 and 2003 and Landsat 8 OLI images from 2014, this study obtained a land use classification map for each year. Then, the genetic transition probability from 1992 to 2003 was obtained by IDRISI software. Based on the CA-Markov model, a predicted land use map for 2014 was obtained, and it was validated by the actual land use results of 2014 with a Kappa index of 0.8128. Finally, the land use patterns of 2025 and 2036 in Jiangle County were determined. This study can provide suggestions and a basis for urban development planning in Jiangle County.