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INTRODUCTION Picfeltarraenins IA, IB and IV and acteoside are the four bioactive ingredients of Picria fel-terrae Lour. Their pharmacological effects include central inhibitory, cardiovascular, anti-inflammatory, anti-pyretic, analgesic, anti-bacterial, antioxidative and anti-tumor effects. OBJECTIVE We aimed to develop an efficient micellar electrokinetic chromatography (MEKC) method modified with mixed organic solvents for the simultaneous separation and determination of the four components in Picriae Herba and its formulations. METHODS Method optimization was carried out by investigating influences of significant factors on the separation, and this method was successfully applied for the determination of the four components in Picriae Herba and its formulations. RESULTS The optimal running buffer was composed of 20 mM sodium tetraborate, 40 mM sodium cholate, 10% (v/v) methanol and 10% (v/v) isopropanol (pH 9.76). The separation voltage was 18 kV, the temperature was 25°C and the detection wavelength was 266 nm. Under the optimal separation conditions, the baseline separation of four components was achieved in less than 14 min. The correlation coefficients of the calibration curves were 0.9984-0.9995 for the analytes. The intraday and interday precision ranged from 1.5% to 2.5% and from 1.4% to 5.0%, respectively. Recoveries of analytes varied from 96.6% to 104.1%. CONCLUSION The method was proved suitable for the determination of four components in Picriae Herba and its formulations. Good performance was obtained under optimal conditions, and the method provides an effective tool for the quality control of Picriae Herba and its formulations.

The hilly area of Southwest China is a typical rice production area which is limited by seasonal droughts and low temperature in the early rice growth period. A field experiment was conducted on three typical paddy fields (low-lying paddy field, medium-elevation paddy field, and upland paddy field) in this region. Nitrogen (N) treatment (180 kg N ha−1 year−1) was compared to a control treatment (0 kg N ha−1 year−1) to evaluate the effects of integrated rice management (IRM) on rice growth, grain yield, and N utilization. Integrated rice management integrated raised beds containing plastic mulch, furrow irrigation, and triangular transplanting. In comparison to traditional rice management (TRM), IRM promoted rice tiller development, with 7–13 more tillers per cluster at the maximum tillering stage and 1–6 more tillers per cluster at the end of tillering stage. Integrated rice management significantly increased the rice aboveground biomass by 34.4%–109.0% in different growth periods and the aboveground N uptake by 25.3%–159.0%. Number of productive tillers significantly increased by 33.0%, resulting in a 33.0% increase in grain yield and 8.0% improvement of N use efficiency (NUE). Grain yields were significantly increased in all three paddy fields assessed, with IRM being the most important factor for grain yield and productive tiller development. Effects of paddy field type and N level on N uptake by aboveground plants were reflected in the rice reproductive growth period, with the effects of IRM more striking due to the dry climate conditions. In conclusion, IRM simultaneously improved rice yield and NUE, presenting a valuable rice management technique in the paddy fields assessed.

China has the world's highest nitrogen (N) application rate, and the lowest N use efficiency (NUE). With the crop yield increasing, serious N pollution is also caused. An in-situ field experiment (2011–2015) was conducted to examine the effects of three N levels, 0 (i.e., no fertilizer N addition to soil), 120, and 180 kg N ha−1 using integrated rice management (IRM). We investigated rice yield, aboveground N uptake, and soil surface N budget in a hilly region of Southwest China. Compared to traditional rice management (TRM), IRM integrated raised beds, plastic mulch, furrow irrigation, and triangular transplanting, which significantly improved rice grain yield, straw biomass, aboveground N uptake, and NUE. Integrated rice management significantly improved 15N recovery efficiency (by 10%) and significantly reduced the ratio of potential 15N loss (by 8%–12%). Among all treatments, the 120 kg N ha−1 level under IRM achieved the highest 15N recovery efficiency (32%) and 15N residual efficiency (29%), with the lowest 15N loss ratio (39%). After rice harvest, the residual N fertilizer did not achieve a full replenishment of soil N consumption, as the replenishing effect was insufficient (ranging from −31 to −49 kg N ha−1). Furthermore, soil surface N budget showed a surplus (69–146 kg N ha−1) under all treatments, and the N surplus was lower under IRM than TRM. These results indicate IRM as a reliable and stable method for high rice yield and high NUE, while exerting a minor risk of N loss. In the hilly area of Southwest China, the optimized N fertilizer application rate under IRM was found to be 100–150 kg N ha−1.

This paper studies the acoustic radiation force of a rigid sphere positioned in a fluid-filled cylindrical cavity with an abruptly changed cross-section. This cavity consists of a semi-infinite front tube and a coaxially connected semi-infinite rear tube with different cross-sectional area through a transverse planar junction. Considering a plane wave propagates along the cavity, the exact expression of the acoustic radiation force exerted on the sphere in the front tube is deduced. The effects of the distance between the sphere and the planar junction and the radius ratio of the front tube to the rear tube on acoustic radiation force are analyzed. Numerical results show that the distance influences the acoustic radiation force periodically. Both the distance and the radius ratio of the tubes affect the magnitude and the direction of acoustic radiation force. A finite element model about the calculation for the acoustic radiation force on the sphere in the fluid-filled cylindrical cavity with suddenly changed cross-section is built to validate the theoretical results. The comparison results between the theoretical computation and the finite element simulation are in good agreement with each other. This work can support future studies for the predictive control of a particle in the cavity which has an abruptly changed cross-section.

Introduction Hirsutine and hirsuteine are the main pharmacological activity ingredients of Uncaria rhynchophylla (UR), playing an important role in treating mental and cardiovascular diseases, such as Alzheimer's disease, hypertension, Parkinson's disease, potential anti-cancer activities and so on. Objective To develop a cyclodextrin-modified micellar electrokinetic capillary chromatography (CD-MEKC) method for the simultaneous separation and determination of hirsutine and hirsuteine from UR and its formulations. Methodology The optimal method was developed by investigating influences of significant factors on the separation, and this method was successfully applied for the determination of hirsutine and hirsuteine in UR and its formulations. Results The optimal background electrolyte (BGE) consisted of 40 mM sodium dihydrogen phosphate (pH 7.0), 150 mM 2,6-dimethyl-β-cyclodextrin (DM-β-CD), 3 mM mono-(6-ethylenediamine-6-deoxy)-β-cyclodextrin (ED-β-CD), and 30 mM sodium cholate (SC). Under these conditions, hirsutine and hirsuteine were successfully separated within 13 min at the separation voltage of 15 kV, temperature of 25°C and the detection wavelength of 224 nm. For the analytes, linear calibration curves were performed within the range 5.0-160.0 μg/mL. The limit of detection (LOD, S/N = 3) and the limit of quantitation (LOQ, S/N = 10) were 0.41, 1.42 μg/mL for hirsutine and 0.60, 2.17 μg/mL for hirsuteine, respectively. The recoveries of three samples were from 97.9% to 102.3%. Conclusion The method was successfully applied to the determination of hirsutine and hirsuteine in UR and its formulations. Meanwhile, it provides an effective reference of the quality control of UR and its formulations.

The incorporation of straw with a microbial inoculant (a mixture of bacteria and fungi, designed to accelerate straw decomposition) is being increasingly adopted within the agricultural sector in China. However, its effects on N and C trace gas emissions remain unclear. We conducted a field experiment to investigate the effects of different straw incorporation methods (with and without microbial inoculant) in the wheat season on nitrous oxide (N2O) and methane (CH4) emissions from a wheat-rice rotation system in China. The treatments comprised N, P, and K fertilizers only (NPK), NPK plus rice straw (NPKS), NPKS plus Ruilaite microbial inoculant (NPKSR), and NPKS plus Jinkuizi microbial inoculant (NPKSJ). Rice straw incorporation before wheat sowing significantly decreased N2O emissions during the wheat season and stimulated N2O and CH4 emissions during the subsequent rice season. Compared with the NPKS treatment, the NPKSR and NPKSJ treatments decreased N2O emissions during the wheat season, but had no effect on N2O or CH4 emissions during the subsequent rice season. Annually, the two treatments were comparable regarding N2O emissions. Although the global warming potentials of the NPKSR and NPKSJ treatments were lower than that of the NPKS treatment during the wheat season, no significant differences were observed during the subsequent rice season, or over the entire rotation cycle. The annual greenhouse gas intensity was slightly lower in the NPKSR and NPKSJ treatments than in the NPKS treatment. Overall, these results suggest that the incorporation of rice straw with a microbial inoculant in the wheat season was the best strategy tested for managing straw resources within the wheat-rice rotation system.

Ecological rice-cropping systems (ERSs) are prosperous rice ecosystems that have a profound influence on global greenhouse (GHG) effects. However, the high variation in research results requires an accurate evaluation of the ERS effects. In this study, three typical ERS modes, rice-crayfish, rice-duck, and rice-fish were selected, and a meta-analysis was conducted using the data of 34 studies to comprehensively evaluate the effects of ERSs on GHG emissions, the global warming potential (GWP), and GHG intensity (GHGI). The results showed that the ERSs reduced CH4 emissions significantly (-12.5%), but increased N2O emissions by 11.3% as compared with traditional rice-cropping systems (TRSs). Further, ERSs have slightly lower GWP, rice yield, and GHGI values (6.5%, 5.5%, and 5.6%, respectively) than TRSs. The rice-crayfish and rice-duck modes significantly alleviated the GWP by 18.0% and 11.1%, respectively, whereas the rice-fish mode enhanced the GWP by 20.8%. Moreover, the rice-duck mode significantly reduced the GHGI by 17.2%, while the ricecrayfish and rice-fish modes increased the GHGI by 9.7% and 8.8%, respectively. Further, the ERSs significantly changed the dissolved oxygen concentration in the flood water as well as the Eh, dissolved organic carbon, and ammonium nitrogen in the soil, wherein the effect sizes of the ERSs on the GHG emissions were significantly correlated with their respective increase. Considering the net ecosystem economic budget and CO2 emissions equivalent/output, ERSs were found to be effective "green technologies". Further, we found that the rice-duck ERS was a good ecological ricecropping system for global warming mitigation. Our study provided new ideas for sustainable agriculture.

In this study, a simple and sensitive cyclodextrin-modified mixed micellar electrokinetic capillary chromatography (CD-MEKC) method has been developed for the simultaneous separation and determination of Huperzine A (HupA), Huperzine B (HupB) and Huperzine C (HupC) in Huperzia serrata (H. serrata). The optimal conditions (pH 9.3) were composed of 10 mM sodium tetraborate solution, 40 mM sodium dodecyl sulfate (SDS), 50 mM sodium cholate (SC) and 3.0 mM mono-(6-ethylenediamine-6-deoxy)-β-cyclodextrin (ED-β-CD). The separation and determination process were performed on a P/ACE MDQ capillary electrophoresis system, the separation voltage was 15 kV, the temperature was 25 °C and the detection wavelength was 308 nm. Under the optimum conditions, the migration time was less than 9 min. The LOD and LOQ were between 0.38 and 0.80 μg/mL and 1.2–2.3 μg/mL, respectively. The developed method, with excellent precision and accuracy, was applied for the determination of three alkaloids in H. serrata and its formulations.

The exact equations of the axial and transverse acoustic radiation force functions of a Gaussian beam arbitrarily incident on an infinite rigid cylinder close to an impedance boundary and immersed in an ideal fluid are deduced by expressing the incident wave, the scattering wave and the boundary reflected wave in terms of the cylindrical wave function. The effects of the beam waist, the sound reflection coefficient, the cylinder position and the distance from the impedance boundary on the acoustic radiation force are studied using numerical simulations. The simulation results show that the amplitude of the acoustic radiation force function increases with beam width. Moreover, the values of the acoustic radiation force in both the axial and transverse directions reach those of a plane wave when the beam width is considerably larger than the wavelength of the Gaussian beam. The properties of the impedance boundary and the position of the cylinder in the Gaussian beam have a considerable effect on the magnitude and direction of the force. The simulation results, particularly in the case of a transverse force, indicate the presence of a negative acoustic radiation force that is related to the nondimensional frequency and position of the cylinder in the Gaussian beam.

Tillage with the incorporation of stubble is a common practice in rice cultivation, but its effect on the net global warming potential (GWP) and greenhouse gas intensity (GHGI) is poorly documented. A three-year field experiment in a double-cropping rice system was conducted to investigate the rate of sequestration of soil organic carbon, CH4 and N2O emissions, the net GWP and the GHGI. Two timings of tillage with three amounts of stubble incorporation were prepared: winter tillage (tillage after the harvest of late rice) and spring tillage (tillage before the transplantation of early rice) with no (0 t ha−1), low (3.5 t ha−1) and high (5.2 t ha−1) amounts of stubble incorporation. The results showed that the rates of sequestration of soil organic carbon with the incorporation of stubble were 0.85–1.06 t C ha−1 yr−1 for winter tillage, 67–429% higher than for spring tillage. Winter tillage significantly increased CH4 and N2O emissions in the winter fallow season relative to spring tillage, whereas it tended to decrease both emissions in the early and late rice seasons, thus playing a small part in the annual emissions. The total CH4 and N2O emissions averaged 106.5–198.2 kg ha−1 yr−1 and 114.4–229.4 g N ha−1 yr−1, respectively. Significant decreases in the net GWP (46–82%) and GHGI (49–84%) were observed when changing the tillage practices with the incorporation of stubble from spring to winter. Compared with high levels of stubble incorporation, winter tillage with low levels of stubble incorporation significantly decreased both the net GWP and the GHGI. The total grain yield was 13.0–13.3 t ha−1 yr−1 for winter tillage, 3–5% higher than for spring tillage. These findings suggest that tillage with the incorporation of stubble in the winter fallow season, particularly with 3.5 t ha−1 stubble, is an effective strategy to mitigate the net GWP and GHGI while maintaining a high grain yield in the double-cropping rice system.

Rice cultivation faces increasing challenges to enhance the net ecosystem economic budget (NEEB), which is the balance between economic benefits and environmental costs. Plastic film mulching cultivation (MC) was evaluated for its ability to decrease the global warming potential (GWP) while increasing economic benefits relative to rainfed (RF) and traditional irrigation (TI). To comprehensively assess the effect on NEEB, the CH4 and N2O emissions and grain yields in a rice-based cropping system were measured from 2010 to 2014. The effects of urease and nitrification inhibitors (UNIs) and controlled release fertilizer (CRF) were also estimated. Shifting the field management from RF to MC had unclear impact on CH4 emissions, but increased N2O emissions by 77%. In contrast, switching TI to MC caused a significant reduction (45–85%) in CH4 emissions, producing a strong decrease in GWP, although N2O emissions substantially increased (206–1153%). The decrease in CH4 emissions was attributed to the reduced dissolved organic carbon and CH4 production, whereas the increase in N2O emissions might have resulted from the higher NH4+ concentrations and more favorable soil water content. Integrated assessment showed that MC significantly enhanced NEEB by 6136–8362 CNY ha−1 y−1 relative to RF as the yields increased and input costs reduced. Although MC reduced the yields, the much lower input and GWP costs led to a substantial increase in NEEB (2607–5593 CNY ha−1 y−1) relative to TI. Under MC conditions, applying UNIs and CRF obviously increased input costs though it always tended to enhance grain yields, thus decreasing NEEB by approximately 490–960 CNY ha−1 y−1, except CP addition, which had a positive effect on NEEB. The results demonstrate that MC, particularly MC + CP, are effective management strategies to reduce the environmental costs and increase the economic benefits of rice fields suffering from a lack of water supply.

A sensitive, fast, and effective method, field-amplified sample stacking (FASS) in capillary electrophoresis, has been established for the separation and determination of corynoxine and corynoxine B. Hydroxypropyl-β-CD (HP-β-CD) and tetrabutylammonium-L-glutamic acid (TBA-L-Glu) were used as additives in the separation system. Electrokinetic injection was chosen to introduce sample from inlet at 10 kV for 50 s after a water plug (0.5 psi, 4 s) was injected to permit FASS. The running buffer (pH 6.1) was composed of 40 mM sodium dihydrogen phosphate solution, 130 mM HP-β-CD, and 10 mM TBA-L-Glu and the separation voltage was 20 kV. Under the optimum conditions, corynoxine and corynoxine B were successfully enriched and separated within 12 min and the sensitivity was improved approximately by 700-900 folds. Calibration curves were in a good linear relationship within the range of 62.5-5.00 × 103 ng/mL for both corynoxine and corynoxine B. The limits of detection (S/N = 3) and quantitation (S/N = 10) were 14.9, 45.2 ng/mL for corynoxine and 11.2, 34.5 ng/mL for corynoxine B, respectively. Finally, this method was successfully applied for the determination of corynoxine and corynoxine B in the stems with hooks of Uncaria rhynchophylla and its formulations.

An expression for the acoustic radiation force function on a solid elastic spherical particle placed in an infinite rigid cylindrical cavity filled with an ideal fluid is deduced when the incident wave is a plane progressive wave propagated along the cylindrical axis. The acoustic radiation force of the spherical particle with different materials was computed to validate the theory. The simulation results demonstrate that the acoustic radiation force changes demonstrably because of the influence of the reflective acoustic wave from the cylindrical cavity. The sharp resonance peaks, which result from the resonance of the fluid-filled cylindrical cavity, appear at the same positions in the acoustic radiation force curve for the spherical particle with different radii and materials. Relative radius, which is the ratio of the sphere radius and the cylindrical cavity radius, has more influence on acoustic radiation force. Moreover, the negative radiation forces, which are opposite to the progressive directions of the plane wave, are observed at certain frequencies.

The purpose of this study was to develop a novel, simple and precise ligand-exchange capillary electrophoresis method to separate the diastereomer pairs of four major cinchona alkaloids (quinine/quinidine and cinchonine/cinchonidine). The l-lysine and copper(II) were chosen as the ligand and the central ion, respectively. Optimal separation conditions of four alkaloids were 4.0 mM l-lys, 2.0 mM copper(II) and 30 mM NH4Ac at pH 8.9 and a applied voltage of 15 kV . Meanwhile, the first-order derivative electropherogram was used for resolving the overlapping peaks of cinchonidine and quinidine. Under the optimum condition, good linearities were obtained with correlation coefficients from 0.9908 to 0.9935. The limits of detection (LOD, S/N = 3) and the limits of quantitation (LOQ, S/N = 10) ranged from 0.24 to 0.41 μg/mL and from 0.73 to 1.35 μg/mL, respectively. The recoveries ranged between 95.38 and 106.03%. The proposed ligand-exchange capillary electrophoresis method was suitable for the quantitative determination of four cinchona alkaloids in some preparations such as Compound Quinine Injection, Tonic Water and Klorane quinine and Vitamin B complex Shampoo.

Stubble return, drainage, and tillage are common practices in rice agriculture, but their integrated effects in the winter season on greenhouse gas (GHG) emissions and soil organic carbon (SOC) and total nitrogen (STN) sequestration remain poorly known. A six-year experiment was carried out in a double-rice field to measure CH4 and N2O fluxes and SOC and STN contents, and then the net global warming potential (GWP) and yield-scaled GWP were estimated. Shifting the fields from no management in tradition to tillage in the winter season tended to reduce total CH4 emissions of double-rice seasons by 14.7%, and it significantly decreased the emissions by 28.3% under drainage conditions. An additional reduction of 27.3% was further found without returning stubble. Therefore, winter tillage and drainage substantially reduced total GWP by 28.0%, in particular, a larger decrease (47.2%) was observed by no stubble return though N2O emissions were strongly stimulated by 82.1%. Moreover, winter tillage significantly reduced SOC sequestration rate while played little role in STN sequestration rate. However, winter tillage with stubble return (2.5–4.1 t ha−1) under drainage conditions showed the largest SOC (1.58 t C ha−1 yr−1) and STN (0.15 t N ha−1 yr−1) sequestration rates. Therefore, the net GWP and yield-scaled GWP were significantly decreased by 227% and 30.5%, respectively. Overall, our results suggest that winter drainage and tillage with stubble incorporation would be an effective management strategy to promote soil C and N sequestration and mitigate GHG emissions from the double-rice fields.

This work presents a theoretical model to calculate the acoustic radiation force on a rigid cylindrical particle immersed in an ideal fluid near a boundary for an on-axis Gaussian beam. An exact solution of the axial acoustic radiation force function is derived for a cylindrical particle by applying the translation addition theorem of cylindrical Bessel function. We analyzed the effects of the impedance boundary on acoustic radiation force of a rigid cylinder immersed in water near an impedance boundary with particular emphasis on the radius of the rigid cylinder and the distance from the cylinder center to impedance boundary. Simulation results reveal that the existence of particle trapping behavior depends on the choice of nondimensional frequency as well as the offset distance from the impedance boundary. The value of the radiation force function varies when the cylinder lies at the different position of the on-axis Gaussian beam. For the particle with different radius, the acoustic radiation force functions vary significantly with frequency. This study provides a theoretical basis for acoustic manipulation, which may benefit to the improvement and development of the acoustic control technology.

Little is known about the stable carbon isotopes of methane (CH4) emitted (δ13CH4emitte4) from permanently flooded rice fields and double rice-cropping fields. The CH4 emission and corresponding δ13CH4emitte4 under various field managements (mulching, water regime, tillage, and nitrogen (N) fertilization) were simultaneously measured in three typical Chinese rice fields, a permanently flooded rice field in Ziyang City, Sichuan Province, Southwest China, a double-rice cropping field in Yingtan City, Jiangxi Province, Southeast China, and a rice-wheat rotation field in Jurong City, Jiangsu Province, East China, from 2010 to 2012. Results showed different seasonal variations of δ13CH4emitte4 among the three fields during the rice-growing season. The values of δ13CH4emitte4 were negatively correlated with corresponding CH4 emissions in seasonal variation and mean, indicating the importance of CH4 production, oxidation, and transport associated with isotopic fractionation effects to the δ13CH4emitte4. Seasonal variations of δ13CH4emitte4 were slightly impacted by mulching cultivation, tillage, and N application, but highly controlled by drainage. Meanwhile, tillage, N application, and especially mulching cultivation had important effects on seasonal mean CH4 emissions and corresponding δ13CH4emitte4, with low emissions accompanied by high values of δ13CH4emitte4. Seasonal mean values of δ13CH4emitte4 from the three fields were similar, mostly ranging from −60‰ to −50‰, which are well in agreement with previously published data. These demonstrated that seasonal variations of δ13CH4emitte4 mainly depended on the changes in CH4 emission from rice fields and further indicated the important effects of methanogenic pathways, CH4 oxidation, and CH4 transport associated with isotope fractionation effects influenced by field managements on δ13CH4emitte4.

An improved permutation entropy (PE) algorithm named coded permutation entropy (CPE) is proposed in this paper to optimize the problems existing in PE based on the secondary partitioning. The principle of CPE algorithm is given, and the performance of it for dynamical change detection is analyzed using synthetic signal, logistic map and Lorenz map. The detection ability of CPE algorithm in different signal-to-noise ratios (SNR) is studied and the algorithm complexity is discussed. The results show that CPE can accurately capture minor feature information and amplify the detection results of dynamical changes compared with PE, weighted permutation entropy (WPE) and amplitude-aware permutation entropy (AAPE), but it has less robustness to noise and requires a higher computation cost than the others. Finally, we use the new algorithm to analyze the rolling bearing fault signals. The application of actual signals illustrates that CPE performs better in detecting abnormal pulse of the rolling bearing when the embedded dimension is small. From all the analyses in this paper, we find that CPE has a better performance for dynamical change detection compared with the other three algorithms when there is a larger repetition rate of permutation pattern in the position sequences.

A simple, comprehensive and efficient capillary electrophoresis method using a dual cyclodextrin system was developed for the simultaneous determination of seven isoflavones (3'-methoxypuerarin, puerarin, 3'-hydroxypuerarin, ononin, daidzin, daidzein and genistin). Baseline separations of the seven isoflavones were achieved within 11 min with the running buffer consisting of 35 mm sodium tetraborate, 9.0 mm sulfobutylether-β-cyclodextrin and 30 mm α-cyclodextrin at pH 9.34, and peaks were detected at 254 nm. Other separation parameters included the separation voltage for 15 kV and the working temperature for 25°C. Under the optimum conditions, good linearities were obtained with linear correlation coefficients of seven isoflavones of 0.9978-0.9992. The limits of detection and the limits of quantification were 0.7-2.9 and 2.5-9.5 μg/mL, respectively. Excellent precision and accuracy were obtained. The intraday and interday precision ranged from 0.7 to 2.0% and from 0.8 to 1.9%, respectively. The recoveries of seven analytes were from 97.7 to 103.1%. This method was successfully applied to determine the seven analytes in Radix Puerariae and its preparations.

Deep learning approaches have been widely used in building automatic extraction tasks and have made great progress in recent years. However, the missing detection and wrong detection causing by spectrum confusion is still a great challenge. The existing fully convolutional networks (FCNs) cannot effectively distinguish whether the feature differences are from one building or the building and its adjacent non-building objects. In order to overcome the limitations, a building multi-feature fusion refined network (BMFR-Net) was presented in this paper to extract buildings accurately and completely. BMFR-Net is based on an encoding and decoding structure, mainly consisting of two parts: the continuous atrous convolution pyramid (CACP) module and the multiscale output fusion constraint (MOFC) structure. The CACP module is positioned at the end of the contracting path and it effectively minimizes the loss of effective information in multiscale feature extraction and fusion by using parallel continuous small-scale atrous convolution. To improve the ability to aggregate semantic information from the context, the MOFC structure performs predictive output at each stage of the expanding path and integrates the results into the network. Furthermore, the multilevel joint weighted loss function effectively updates parameters well away from the output layer, enhancing the learning capacity of the network for low-level abstract features. The experimental results demonstrate that the proposed BMFR-Net outperforms the other five state-of-the-art approaches in both visual interpretation and quantitative evaluation.

Based on permutation entropy (PE), which has been presented as a measure to characterize the complexity of nonlinear time series, phase permutation entropy (PPE) is proposed in this paper. Experiments are implemented using artificial and actual data to show the performance of PPE algorithm. The achieved results demonstrate that PPE can amplify the detection effect of dynamical changes compared with PE whether using the logistic map or actual signals. Increasing embedding dimension can improve the capability of detecting dynamical changes using PPE method. Furthermore, PPE is not sensitive to data length when embedding dimension is less than or equal to 5 and it is more susceptible to noise than PE. The results from actual signals show that PPE can be used as an effective analytical tool in the field of biomedical and engineering signals processing.

Traditional land management (no tillage, no drainage, NTND) during the winter fallow season results in substantial CH4 and N2O emissions from double-rice fields in China. A field experiment was conducted to investigate the effects of drainage and tillage during the winter fallow season on CH4 and N2O emissions and to develop mitigation options. The experiment had four treatments: NTND, NTD (drainage but no tillage), TND (tillage but no drainage), and TD (both drainage and tillage). The study was conducted from 2010 to 2014 in a Chinese double-rice field. During winter, total precipitation and mean daily temperature significantly affected CH4 emission. Compared to NTND, drainage and tillage decreased annual CH4 emissions in early- and late-rice seasons by 54 and 33 kg CH4 ha−1 yr−1, respectively. Drainage and tillage increased N2O emissions in the winter fallow season but reduced it in early- and late-rice seasons, resulting in no annual change in N2O emission. Global warming potentials of CH4 and N2O emissions were decreased by 1.49 and 0.92 t CO2 eq. ha−1 yr−1, respectively, and were reduced more by combining drainage with tillage, providing a mitigation potential of 1.96 t CO2 eq. ha−1 yr−1. A low total C content and high C / N ratio in rice residues showed that tillage in the winter fallow season reduced CH4 and N2O emissions in both early- and late-rice seasons. Drainage and tillage significantly decreased the abundance of methanogens in paddy soil, and this may explain the decrease of CH4 emissions. Greenhouse gas intensity was significantly decreased by drainage and tillage separately, and the reduction was greater by combining drainage with tillage, resulting in a reduction of 0.17 t CO2 eq. t−1. The results indicate that drainage combined with tillage during the winter fallow season is an effective strategy for mitigating greenhouse gas releases from double-rice fields.

This work reported that ionic liquid (IL) ([Bmim] [PF6 ]) and sulfobutylether-β-CD (SBE-β-CD) were used as electrolyte additives for the separation and determination of camptothecin (CPT) alkaloids by CZE. Separation parameters such as the buffer type, pH, and concentration of the running buffer, the concentration of SBE-β-CD and IL, temperature, and separation voltage were all investigated in order to achieve the maximum possible resolution. The four analytes were baseline separated within 10 min in capillary at the separation voltage of 15 kV with a running buffer consisting of 20 mM borate buffer, 20 mM IL, and 100 mM SBE-β-CD at pH 9.0. Under such conditions, good linearity about two orders of magnitudes of peak areas was achieved for the investigated CPT alkaloids with the correlation coefficients ranging from 0.9946 to 0.9985. For all analytes, detection limits (S/N = 3) and quantitation limits (S/N = 10) range from 0.05 to 0.92 μg/mL and 0.17 to 3.06 μg/mL, respectively. The proposed method has not only been successfully applied to the separation and determination of CPT alkaloids but also showed that IL seemed to be a promising additive in CZE separation.

To conserve water resources and guarantee food security, a new technology termed as "wet irrigation" is developed and practiced in rice fields; thus, its impact on radiative forcing derived from nitrous oxide (N2O) and methane (CH4) emissions merits serious attention. Dicyandiamide (DCD), a kind of nitrification inhibitor, is proposed as a viable means to mitigate greenhouse gas (GHG) emission while enhancing crop productivity. However, little is known about the response of GHG emission and grain yield to DCD application in a rice system under wet irrigation. In these regard, effects of water regime and DCD application on CH4 and N2O emissions, grain yield, global warming potential (GWP), and greenhouse gas intensity (GHGI) from rice fields were studied. For this study, a field experiment, designed: Treatment II (intermittent irrigation), Treatment WI (wet irrigation), Treatment IID (II plus DCD), and Treatment WID (WI plus DCD), was conducted in Jurong, Jiangsu Province, China, from 2011 to 2012. Relative to Treatment II, Treatment WI decreased CH4 emission significantly by 49-71 % while increasing N2O emission by 33-72 %. By integrating CH4 and N2O emissions and grain yield, Treatment WI was 20-28 and 11-15 % lower than Treatment II in GWP and GHGI, respectively. The use of DCD under wet irrigation reduced N2O emission significantly by 25-38 % (p

Winter flooded paddy fields emit considerable amounts of CH4 and N2O that add to global warming potential (GWP). However, mitigating the GWP and water use without compromising crop yield in the fields is poorly documented. A 3 year-round field experiment was conducted with the use of PM (plastic film mulching cultivation with water-saving irrigation in rice season while drainage in winter season) in comparison of two traditional paddies that were flooded in the winter season but either rain-fed (TC1) or continuously flooded (TC2) in the rice season. Shifting TC1 into PM significantly promoted rice tiller and increased grain yields by 23 %, showing a significant increase in effective number of panicles per m2 (40 %), total filled grains per m2 (55 %) and filled grains percentage (4.2 %). Changing TC2 into PM, however, had little effect on these variables. Compared with TC1 and TC2, the PM reduced annual water use by 20–69 %. Meanwhile, it decreased annual cumulative CH4 emissions by 23–64 % and increased N2O emissions by 56–4.2 %. This change was probably related to the significant decreases in both dissolved organic carbon content (DOC) and CH4 production potential (MPP) for CH4, and much higher NH4+-N concentration at the beginning of the rice season and a more favorable soil water content (SWC) for N2O. Because mean CH4 emission was positively correlated with mean DOC and MPP, and mean N2O emission was negatively related to mean SWC, respectively. Overall, the PM reduced annual GWP by 18–60 % and yield-scaled GWP by 34–60 % relative to TC1 and TC2. The findings suggest that the application of PM in the winter flooded paddy fields substantially mitigates GWP and has a great potential to reduce water use while maintaining high yields.

A water-soluble sulphonato-(salen)manganese(III) complex with excellent catalytic properties was synthesized and demonstrated to greatly enhance the chemiluminescence signal of the hydrogen peroxide − luminol reaction. Coupled with flow-injection technique, a simple and sensitive chemiluminescence method was first developed to detect hydroquinone based on the chemiluminescence system of the hydrogen peroxide–luminol–sulphonato-(salen)manganese(III) complex. Under optimal conditions, the assay exhibited a wide linear range from 0.1 to 10 ng mL–1 with a detection limit of 0.05 ng mL–1 for hydroquinone. The method was applied successfully to detect hydroquinone in tap-water and mineral-water, with a sampling frequency of 120 times per hour. The relative standard deviation for determination of hydroquinone was less than 5.6%, and the recoveries ranged from 96.8 to 103.0%. The ultraviolet spectra, chemiluminescence spectra, and the reaction kinetics for the peroxide–luminol–sulphonato-(salen)manganese(III) complex system were employed to study the possible chemiluminescence mechanism. The proposed chemiluminescence analysis technique is rapid and sensitive, with low cost, and could be easily extended and applied to other compounds. Copyright © 2015 John Wiley & Sons, Ltd.

Large-volume Sample Stacking (LVSS) is commonly used as an effective on-line preconcentration method in capillary zone electrophoresis (CZE). In this paper, the method LVSS combined with CZE has been proposed to analysis the camptothecin alkaloids. Optimum separation can be achieved in conditions as following: pH 9.0, 25 mM borate buffer containing 20 mM Sulfobutylether-β-Cyclod- extrin (SBE-β-CD) and 20 mM ionic liquid [EMIM] [L-Lac] (IL), the applied voltage was 20 kV and the capillary temperature was 25°C. The LVSS was optimized as hydrodynamic injection 4 s at 5.0 psi and the polarity switching time was 0.17 min. Under the above conditions, the analytes could be separated completely in less than 20 min and the detector response had been increased compared with conventional hydrodynamic injection. The limit of detection were between 0.20 and 0.78 μg/L. A good linearity could be obtained with correlation coefficients from 0.9991 to 0.9997. The recoveries ranged from 97.72 to 103.2% and the results demonstrated excellent accuracy. In terms of the migration time and peak area, the experiment was reproducible. And the experimental results indicated that baseline separation can be obtained and this method is suitable for the quantitative determination of camptothecin alkaloids in real samples.

This work presents a theoretical model to calculate the acoustic radiation force of a fluid cylindrical particle immersed in water near a boundary. A solution of the acoustic radiation force function, which is the radiation force per unit energy density and unit cross-sectional surface area, is derived for a cylinder near a boundary in normal incident plane wave by applying the translation addition theorem of cylindrical function. The effects of impedance boundary on acoustic radiation force of a fluid oleic acid cylinder and a mixture fluid cylinder immersed in water are analyzed with particular emphasis on the radius of fluid cylinder and the distance from its center to the impedance boundary. The results reveal that the existence of particle trapping behavior depends on the choice of the nondimensional frequency ka as well as the offset distance from the impedance boundary. This study provides a theoretical basis for acoustic manipulation, which may be of benefit to the improvement and development of the acoustic control technology.

To depress the fluctuation of the transmitting voltage response (TVR) for a double excitation broadband transducer, an electrical method is proposed in this paper by connecting resistances in series with the upper and lower piezoelectric ceramic stacks of the transducer. The equivalent circuit and the finite element method are used to analyze the effect of the resistances on TVR, and the optimizing values of the resistances connected in series with the piezoelectric ceramic stacks are obtained. The results obtained by equivalent circuit model and finite element simulation show that the fluctuation of the TVR for the double excitation transducer is obviously depressed when resistances are connected in series with the piezoelectric ceramic stacks. Based on the computational results, a double excitation broadband transducer with a working frequency range from 14 kHz to 36 kHz is made, and the TVR of the transducer is measured to validate the proposed method. The experimental results imply that the fluctuation of the TVR within the working frequency band for a double excitation piezoelectric transducer decreased from 12 dB to 7.3 dB.

The purpose of this study was to develop a simple, quick and precise capillary zone electrophoresis method (CZE) for the separation and determination of uncaria alkaloids using dual cyclodextrins as additives for the separation. The four analytes were baseline separated within 15min at the applied voltage of 15kV with a running buffer (pH 5.7) consisting of 40.0mM phosphate buffer, 161.7mM 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and 2.21mM mono-(6-ethylenediamine-6-deoxy)-β-cyclodextrin (ED-β-CD). Under the optimum conditions, a good linearity was achieved with correlation coefficients from 0.9989 to 0.9992. The detection limits and the quantitation limits ranged from 0.63 to 0.98μg/mL and from 2.08 to 3.28μg/mL, respectively. Excellent accuracy and precision were obtained. Recoveries of the analytes varied from 97.1 to 103.2%. This method was suitable for the quantitative determination of these alkaloids in the stem with hook of Uncaria rhynchophylla and the formulations of Uncaria rhynchophylla.

The aim of this study was to develop a novel, sensitive, precise, simple, and rapid capillary zone electrophoresis method for the quality control of spironolactone in three different formulation types and a rapid simultaneous determination of the content of spironolactone and canrenone in urine samples using fluocinonide as an internal standard. After optimization of separation conditions, the electrolyte solution was the pH 5.5, 20 mM phosphate buffer containing 4.5 g/L sulfated-β-cyclodextrin, 15 kV of electric filed across the capillary applied at 25°C. A diode array detector was used, and the detection wavelength was 260 nm. Under optimum conditions, good linearity was achieved with correlation coefficients from 0.9976 to 0.9997. Detection limits were 0.56 and 0.20 μg/mL, and the quantitation limits were 1.87 and 0.67 μg/mL, respectively. Excellent accuracy and precision were obtained. Recoveries of the analytes varied from 100.8 to 103.1%. The results indicated that baseline separation of analytes was obtained and this method was suitable for quantitative determination of spironolactone in pharmaceutical preparations and rapid simultaneous determination of the content of spironolactone and its major metabolite canrenone in urine samples.