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【Objective】 Micro sprinkler irrigation is often mounted on the top of seeding beds to nurture crop seedlings. The purpose of this paper is to study the impact of the mounting height and working water pressure on performance of the irrigation system. 【Method】 We compared three mounting heights: 0.5, 0.6 and 0.7 m, and four working water pressures: 200, 250, 300 and 350 kPa. In each treatment, we measured the spatial distribution of water droplets. Based on the mass balance, we derived a model to calculate the water distribution sprayed from the nozzle, and converted constant water distribution measured from a single sprinkler to dynamic water distribution. We also measured the uniformity coefficient of water in all treatments and linked it to water pressure and the distance between adjacent nozzles. 【Result】 Increasing the installation height from 0.5 to 0.7 m improved uniformity of the water distribution and reduced the maximum irrigation intensity; the average intensity of single sprinkler increased with water pressure. When the working pressure was the same, the uniformity coefficient decreased first and then increased before declining again as the distance between adjacent nozzles increased. When the installation height was the same, the uniformity coefficient of water distribution did not show noticeable change with the working water pressure. For all treatments we compared, the optimal working conditions were as follows: installation height, 0.5 m, working water pressure, 300 kPa, space between adjacent nozzles, 0.5 m. These gave a uniformity coefficient as high as 98.08%. 【Conclusion】 Raising the mounting height of the system increased the uniformity coefficient of water distribution and the area that the water could cover, and reduced the maximum water intensity. Increasing the working water pressure increased water irrigation intensity. For the system we studied, the optimal installation height, working water pressure and nozzle spacing were 0.5 m, 300 kPa and 0.5 m, respectively.

[Objective] This study screened high-yielding and high-quality screw pepper varieties suitable for substrate bag cultivation in Northern Shaanxi to provide basis for the development of soilless cultivation of pepper. [Method] Twenty screw pepper varieties including Silk Road New Star, Silk Road Star, Lou Lan Star, Extra Early One-foot Long, Zhongnong Qingluo Prince, Longxuan 339, Biosow 019, HP29017, HP29037, HP29047, HP29082, Western Long Dragon, Kubota Conch Pepper King, Golden Pepper No.6, Golden Pepper No.8, Golden Pepper No.9, Golden Pepper No.12, Bolon (37 - 94) > Stem Hair 802 and Vols Tenro were chosen for substrate bag cultivation in this study. The weight of single fruit, pericarp thickness, fruit length, contents of vitamin C, soluble protein, free amino acid, reducing sugar, total soluble sugar, nitrate nitrogen as well as yield were measured and compared. The correlations of indexes were analyzed by Pearson analysis. The yield and quality indexes of each variety were evaluated by principal component analysis, technique for order preference by similarity to ideal solution, membership function analysis and grey relational degree analysis. The results of three single comprehensive evaluations by extant consistency test (Kendall-W) were evaluated in combination and the fuzzy Borda evaluation method was used to select varieties suitable for substrate bag culturing in Northern Shaanxi. [Result] The weight of ingle fruit was 25.62 - 52.83 g, with the heaviest in Longxuan 339. The pericarp thickness was 1.58 - 2.17 mm, with Vols Tenro the thickest. The fruit length was 19.42 - 30.55 cm, with the longest in HP29082. The content of vitamin C was 276.37 - 1 058.09 mg/hg, and Golden Pepper No.8 was the highest. The content of soluble protein was 0.97 - 1.61 mg/g, and Golden Pepper No.12 was the highest. The content of free amino acid was 393.78 - 969.69 µg/g, with the highest in Vols Tenro. Contents of reducing ugar and total soluble sugar were 3.82% -6.65% and 9.87% -13.91%, and Biosow 019 had the highest ontents. There was no significant difference in nitrate content among varieties. The yield was 9 625.98 - 84 600.00 kg/hm², and Silk Road New Star had the highest value. The results of single comprehensive evaluation methods were different, and the results of principal component analysis method had weak correlations with those of other methods. The correlations among other single evaluation methods passed the Kendall-W test and they were compatible for combined evaluation. The fuzzy Borda combination evaluation method passed tests with good credibility. The obtained top 5 varieties were Silk Road New Star, HP29047, Silk Road Star, Longxuan 339 and Biosow 01 9. [Conclusion] Silk Road New Star, HP29047, Silk Road Star, Longxuan 339 and Biosow 019 were suitable for substrate cultivation in Northern Shaanxi. [ABSTRACT FROM AUTHOR]

In order to ensure the lateral stability of adaptive cruise control (ACC) vehicles during curve following, this paper proposes a hierarchical multi‐objective coordinated control ACC system structure for in‐wheel motor drive electric vehicles. Different control strategies are designed for the cruise mode and car‐following mode of the ACC system. A proportion integral differential (PID) controller is used to meet the need for speed control in cruise mode. For the car‐following mode, a multi‐objective ACC system distance control strategy is proposed considering the performance of car following, passenger comfort, driving safety and driving economy of ACC vehicles. The weight coefficients in the objective function are updated in real time by using the fuzzy model predictive control (FMPC) strategy to meet the needs of different road conditions and improve the driving economy. Then, the desired front wheel steering angle is obtained by preview control theory. According to the theory of sliding mode control (SMC), a lateral stability controller is designed to track the desired yaw rate and sideslip angle. Simulation results show that the electric vehicle driven by in‐wheel motors based on FMPC and SMC has better car‐following performance and lateral stability performance under variable curvature curved road conditions. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to study the control of differential steering for four-in-wheel-motor electric vehicles. The so-called differential steering means that the front wheel steering is realized through the differential driving torque between the left and right front wheels. With the consideration of tire friction circle, a hierarchical control method is proposed to realize the differential steering and the constant longitudinal speed simultaneously. Firstly, the dynamic models of the front wheel differential steering vehicle, the front wheel differential steering system and the reference vehicle are established. Secondly, the hierarchical controller is designed. The upper controller is to obtain the resultant forces and resultant torque required by the front wheel differential steering vehicle tracking the reference model through the sliding mode controller. In the middle controller, the minimum tire load ratio is selected as the objective function. Combined with the constraints, the resultant forces and resultant torque are decomposed into the longitudinal and lateral forces of four wheels by the quadratic programming method. The lower controller provides the required longitudinal forces and tire sideslip angles for the front wheel differential steering vehicle model through the tire inverse model and the longitudinal force superposition scheme. Simulation results show that the hierarchical controller can guarantee the vehicle to track the reference model well on both of the high and low adhesion coefficient road with all of the tire load ratios smaller than 1. It can be drawn that the control strategy proposed in this paper is effective. [ABSTRACT FROM AUTHOR]

Background: There is increasing evidence on the prognostic significance of D-dimer and fibrinolysis in stroke. However, the systematic analysis of their relationship with adverse outcomes after stroke is lacking. Herein, we comprehensively assessed the correlation of D-dimer and fibrinolysis with stroke outcomes through meta-analysis. Methods: Studies for systematic literature review were retrieved from PubMed, EMBASE, and Cochrane Library databases. The association of D-dimer and fibrinolysis with outcomes of stroke patients was expressed as an odds ratio (OR) with 95% confidence intervals (95% CI). Results: Totally, 52 studies comprising 21,473 stroke patients were included. The results showed that the high D-dimer level was significantly associated with peripheral venous thrombosis after stroke (OR 1.03, 95% CI 1.01–1.05), poor outcome (MRS >2) after stroke (OR 1.731, 95% CI 1.464–2.048), death after stroke (OR 2.367, 95% CI 1.737–3.224), stroke recurrence (OR 1.229, 95% CI 1.113–1.358), and early neurologic deterioration (NIHSS >4) (OR 1.791, 95% CI 1.117–2.870). Moreover, high fibrinogen level was significantly associated with poor outcome (MRS >2) after stroke (OR 1.650, 95% CI 1.314–2.071), death after stroke (OR 1.310, 95% CI 1.128–1.520), stroke recurrence (OR 1.228, 95% CI 1.166–1.422), early neurologic deterioration (NIHSS >4) (OR 2.381, 95% CI 1.156–4.904), and coronary events after stroke (OR 1.427, 95% CI 1.232–1.653). Conclusion: Fibrinogen and D-dimer may be associated with adverse outcomes in patients with stroke, suggesting that they may serve as possible biomarkers for post-stroke adverse outcomes. [ABSTRACT FROM AUTHOR]