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Maize seeding is greatly affected by improper seed placement and poor planter performance under a no-tillage mechanisation system. To overcome the issue, we explored the impact of separating board and anti-blocking mechanism (0, 1/4, 1/2, 2/3, 3/4, and 1 type) on maize seeding under different forward speeds (3, 5, 7 km/h) and rotational speeds (260, 400, 530, 740 rpm), where the performance metrics included the mass of straw coiled, seeding height, emergence rate, soil mound depth, straw movement, and straw clearance. The study results show that separating board helps to increase forward and side displacements of the straw, which avoids localized accumulation of straw around the antiblocking mechanism. The straw clearance rate of the anti-blocking mechanism with a separating board is greater than that without the separating board. Therefore, the 2/3 type anti-blocking mechanism with a separating board is recommended for maize seeding at a forward speed of 5 km/h and a rotational speed of 400 rpm.

A readily accessible conjugate‐base‐stabilized carboxylic acid (CBSCA) catalyst facilitates highly enantioselective [4+2] cycloaddition reactions of salicylaldehyde‐derived acetals and cyclic enol ethers, resulting in the formation of polycyclic chromanes with oxygenation in the 2‐ and 4‐positions. Stereochemically more complex products can be obtained from racemic enol ethers. Spirocyclic products are also accessible. [ABSTRACT FROM AUTHOR]

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Prior to dispatch from manufacturing facilities, seeders require rigorous performance evaluations for their seeding capabilities. Conventional manual inspection methods are notably less efficient. This study introduces a wheat seeding detection approach anchored in an enhanced YOLOv5s image-processing technique. Building upon the YOLOv5s framework, we integrated four CBAM attention mechanism modules into its model. Furthermore, the traditional upsampling technique in the neck layer was superseded by the CARAFE upsampling method. The augmented model achieved an mAP of 97.14%, illustrating its ability to elevate both the recognition precision and processing speed for wheat seeds while ensuring that the model remains lightweight. Leveraging this advanced model, we can effectively count and locate seed images, enabling the precise calculation and assessment of sowing uniformity, accuracy, and dispersion. We established a sowing test bench and conducted experiments to validate our model. The results showed that after the model was improved, the average accuracy of wheat recognition was above 97.55% under different sowing rates and travel speeds. This indicates that this method has high precision for the total number of seed particles. The sowing rate and sowing travel speed were consistent with manual measurements and did not significantly affect uniformity, accuracy, or dispersion. [ABSTRACT FROM AUTHOR]

Direct functionalization of alkynes under oxidative conditions is challenging, as alkynes are usually recalcitrant towards typical oxidants. Herein, we communicate a strategy for the divergent functionalization of alkynes with photoexcited acridinium organic dyes, presumably via the formation of vinyl cation radicals as key intermediates. Based on the nature of the nucleophiles, different types of difunctionalized products were obtained in moderate to good yields. Addition of lithium Lewis acids resulted in a surprising reversal of diastereocontrol. [ABSTRACT FROM AUTHOR]

The technology of the divider and lifter mechanisms of a garlic harvester using the depth limit, straw divide, and straw lift modes was studied in Lanling County, Shandong Province, China, according to the characteristics of high hardness, good uprightness and narrow row spacing of garlic planting. A test prototype of the divider and lifter mechanisms of the garlic harvester was designed and manufactured. Single-factor experiments and orthogonal regression experiments were carried out using the experimental factors of working speed, the angle of the divider, the height of the tip of the divider's tooth from the ground, the ratio of the lifter's speed to working speed and the length of the lifter's tooth. The index was the success rate of feed. The results showed that the working speed, the angle of the divider and the length of the lifter's tooth had a significant influence on the success rate of feed (p < 0.05), but the experimental factors of the height of the tip of the divider's tooth from the ground and the ratio of the lifter's speed to working speed did not have a significant influence on the success rate of feed (p > 0.05). The effects of the angle of the divider, the working speed, and the length of the divider's tooth on the success rate of feed decreased in significance. When the working speed was 0.72 km·h−1, the length of the lifter's tooth was 343.5 mm and the angle of the divider was 20°, the success rate of feed was the highest (98.18%). The research results are conducive to promoting high-quality and efficient combined harvesting of garlic in Lanling County, Shandong Province, China. [ABSTRACT FROM AUTHOR]

Banana mechanical crown cutting tool which is a critical component of banana crown cutting machine is designed and studied in this paper. Experiments were designed to optimize parameters of the cutting tool. Indexes are cut surface quality grade of banana crown, maximum cutting force and useful power consumption. For banana preservation, get high grade of cut surface quality is more significant than consume less energy. Results of experiments show that the optimum parameters are as follows: cutting speed is about 50–60 mm/s, number of cut sets are about 4–6, angle between thick cutter and axis of banana rachis is about 5°, width of thick cutter is about 8–14 mm, thickness of thick cutter is about 2–3 mm, edge angle of thick cutter is between 20° and 30°, width of thin cutter is about 10–14 mm and thickness of thin cutter is about 0.2–0.4mm. This study helps to make the completely mechanical postharvest treatments for banana postharvest treatments. [ABSTRACT FROM AUTHOR]

China is planning to construct a new space-borne gravitational-wave (GW) observatory, the TianQin project, in which the spaceborne telescope is an important component in laser interferometry. The telescope is aimed to transmit laser beams between the spacecrafts for the measurement of the displacements between proof-masses in long arms. The telescope should have ultra-small wavefront deviation to minimize noise caused by pointing error, ultra-stable structure to minimize optical path noise caused by temperature jitter, ultra-high stray light suppression ability to eliminate background noise. In this paper, we realize a telescope system design with ultra-stable structure as well as ultra-low wavefront distortion for the space-based GW detection mission. The design requirements demand extreme control of high image quality and extraordinary stray light suppression ability. Based on the primary aberration theory, the initial structure design of the mentioned four-mirror optical system is explored. After optimization, the maximum RMS wavefront error is less than λ /300 over the full field of view, which meets the noise budget on the telescope design. The stray light noise caused by the back reflection of the telescope is also analyzed. The noise at the position of optical bench is less than 10âˆ'10 of the transmitted power, satisfying the requirements of space GW detection. We believe that our design can be a good candidate for TianQin project, and can also be a good guide for the space telescope design in any other similar science project. [ABSTRACT FROM AUTHOR]

In this paper, a garlic combine harvester machine was designed and some influential parameters of the machine were optimized. The working parts of the machine mainly consisted of a reel, a reciprocating cutter, a seedling conveyor, a profiling depth-stop device, a digging shovel and a lifting chain. Each part had unique structural parameters and motion parameters, as different parameters would deeply affect the performance of the machine. A logistical regression algorithm was utilized to analyze the working speed of the reel, the digging depth of the reciprocating cutter and the lifting speed of the lifting chain. This paper also discussed the influence of these three functions on the damage rate based on the collected data when harvesting garlic. Specifically, each function was tested 60 times for collecting data. The experimental results showed that the order of influence of the three functions on the damage rate was the digging depth, working speed and lifting speed. Moreover, the lowest damage rate was 0.18% when the digging depth was 100 mm, the working speed was 1.05 km·h−1 and the lifting speed was 0.69 m·s−1. A validation test was taken out based on the three functions of the analysis results, and the damage rate was 0.83%, which was close to the analysis results, and proved that the analysis results were accurate and meaningful. The research results are beneficial to the development and application of the garlic combine harvester. [ABSTRACT FROM AUTHOR]

Overcoming the light scattering for imaging under natural light conditions is a tough question to solve. One major issue is the absence of an efficient model to characterize the spectral features of incoherent light scattering. Here, we put forward the incoherent light transmission matrix (TM) approach in thin scattering layers. The proposed model is a unique form of TM that characterizes the spectral transmission feature of a system with multiple spatial transmission modes. With this method, we recover hyperspectral information from a single-shot monochromatic light spot without any additional dispersion or imaging elements. The proposed TM method can also be extended to recover other information from the light field, such as the polarization information without the use of a traditional polarizer. Our method also outperforms traditional optimization algorithms in terms of time and memory cost. The results demonstrate the feasibility of our method for retrieving the abundant information from natural light scattering with the help of simple optical setups. [ABSTRACT FROM AUTHOR]

Acyclic ketone‐derived oxocarbenium ions are involved as intermediates in numerous reactions that provide valuable products, however, they have thus far eluded efforts aimed at asymmetric catalysis. We report that a readily accessible chiral carboxylic acid catalyst exerts control over asymmetric cyclizations of acyclic ketone‐derived trisubstituted oxocarbenium ions, thereby providing access to highly enantioenriched dihydropyran products containing a tetrasubstituted stereogenic center. The high acidity of the carboxylic acid catalyst, which exceeds that of the well‐known chiral phosphoric acid catalyst TRIP, is largely derived from stabilization of the carboxylate conjugate base through intramolecular anion‐binding to a thiourea site. [ABSTRACT FROM AUTHOR]

This paper presents a global optimization algorithm specifically tailored for ultra-compact aspherical lens design problems for extended LED sources. The main purpose is to obtain prescribed illumination patterns, particularly the uniform illuminance distribution. This method begins by calculating the initial aspherical lens with two surfaces based on point source approximation. Then a system of polynomials is employed to fit the meridian curves of the two surfaces. In the optimization process, we use the particle swarm optimization (PSO) algorithm to automatically find the optimal polynomial coefficients when the ray tracing simulation is being performed. A series of ultra-compact aspherical lenses with dimension ratio of h/d ranging from 0.95 to 1.25 are presented, where h denotes the center height of the lens and d represents the diameter of the extended source. The results show the high efficiency and versatility of the proposed method in prescribed illumination design for extended LED sources in three-dimensional rotational symmetry geometry. Additionally, an aspherical lens is fabricated and tested, and its practical performance approaches the design. [ABSTRACT FROM AUTHOR]

Abstract Hemin (ferroprotoporphyrin IX), a compound derivative of heme, has been shown to exert numerous beneficial physiological functions in the resistance of plant to various abiotic stresses. This work investigated the effects of hemin on ameliorating Cd toxicity in Chinese cabbage (Brassica chinensis L.). Our results showed that leaf chlorosis, growth inhibition, root morphology and photosynthetic activity were significantly improved by the addition of hemin in Cd-stressed plants. Meanwhile, Cd-induced oxidative damage was also alleviated by hemin, which was supported by the decreased level of malondialdehyde (MDA) in roots of the seedlings treated with hemin. In the same time, the activities of antioxidative enzymes, including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), as well as the concentrations of ascorbic acid (AsA) and glutathione (GSH) were elevated by hemin, which contributed to the scavenging of Cd-elicited H 2 O 2 and O 2 •－ within the roots of Chinese cabbage seedlings. Furthermore, compared with Cd stressed plants, Cd concentrations in both shoots and roots were markedly decreased by exogenous hemin. Hence, it can be speculated that hemin-mediated tolerance to Cd stress may be associated with the inhibition of Cd uptake in Chinese cabbage. This hypothesis was supported by the down-regulated expressions of transporter genes, including BcIRT1 , BcIRT2 , BcNramp1 and BcZIP2 caused by hemin addition in Chinese cabbage seedlings under Cd treatment. Taken together, these results suggested that hemin alleviated Cd toxicity probably through increasing antioxidative capacities and inhibiting Cd uptake of Chinese cabbage. Highlights • Hemin improved growth and photosynthetic activity in the Cd-stressed Chinese cabbage seedlings. • Hemin addition enhanced antioxidative capacity in Chinese cabbage seedlings under Cd stress. • Hemin addition reduced Cd uptake in Chinese cabbage seedlings. [ABSTRACT FROM AUTHOR]

Hydrogen gas (H 2) has been shown as an important factor in plant tolerance to abiotic stresses, but the underlying mechanisms remain unclear. In the present study, the effects of H 2 and its interaction with nitric oxide (NO) on alleviating cadmium (Cd) stress in Brassica campestris seedlings were investigated. NO donor (SNP) or hydrogen-rich water (HRW) treatment showed a significant improvement in growth of Cd-stressed seedlings. Cd treatment upregulated both endogenous NO and H 2 (36% and 66%, respectively), and the increase of H 2 was prior to NO increase. When treated with NO scavenger (PTIO) or NO biosynthesis enzyme inhibitors (L-NAME and Gln), HRW-induced alleviation under Cd stress was prevented. Under Cd stress, HRW pretreatment significantly enhanced the NO accumulation, and together up-regulated the activity of NR (nitrate reductase) and expression of NR. HRW induced lower reactive oxygen species (ROS), higher AsA content, enhanced activity of POD (peroxidase) and SOD (superoxide dismutase) in seedling roots were inhibited by PTIO, L-NAME and Gln. Through proteomic analysis, the level of 29 proteins were changed in response to H 2 and NO-induced amelioration of Cd stress. Nearly half of them were involved in oxidation-reduction processes (about 20%) or antioxidant enzymes (approximately 20%). These results strongly indicate that in Cd-stressed seedlings, pretreatment with HRW induces the accumulation of H 2 (biosynthesized or permeated), which further stimulates the biosynthesis of NO through the NR pathway. Finally, H 2 and NO together enhance the antioxidant capabilities of seedlings in response to Cd toxicity. Image 1 • SNP and HRW treatments both improve Cd tolerance of cabbage seedlings. • Cd increases the endogenous level of both H 2 and NO. • NO biosynthesis inhibitors and scavenger reverse HRW-induced improvement of Cd tolerance. • HRW enhances the accumulation of NO and the activity of NR under Cd stress. • Antioxidant enzymes are the response factors during the improvement of Cd tolerance induced by HRW and SNP. Nitric oxide was involved in the alleviation of cadmium stress mediated by hydrogen gas in Brassica campestris seedlings. [ABSTRACT FROM AUTHOR]

• The system matrix was used to derive the axial displacement equation of the studied zoom system. • The merit functions constructed accurately reflected the design requirements of the zoom system. • Particle swarm optimization was used to optimize the mathematical model globally. • Numerical and Optical design software simulation and were employed to verify the design method. • A simple and effective tool was provided for the trajectory optimization of multi-component zoom system. In this paper, we propose a systematic approach to design a four-component zoom system with fixed spacing between focal points based on matrix optics to achieve a relatively high zoom ratio. In the method, the zoom trajectory under each chosen paraxial design is determined through matrix method, which is challenging but meaningful to achieve a globally optimized design for the complex zoom system. The elements of the system matrix imply the working state of the optical system, and axial displacement equation for the desired zoom system are derived by restricting specific matrix elements. Properly selected trajectory of the particular component described by means of a parametric function can make the model become solvable explicitly. Then the paraxial design problem is transformed into the optimization of these parameters with regard to the merit functions encompassing the primary aberration terms, compactness, smoothness of the trajectories. We adopt Particle Swarm Optimization (PSO) algorithm to globally optimize the parameters to retrieve the optimum zoom trajectory in specific design criteria. The proposed method is demonstrated through two specific examples under different configurations, both of which have acquired a final zoom ratio of 8X. The simulation results demonstrate that our proposed method can be a practical and powerful tool for paraxial design of complex multi-group zoom optical systems. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a major pollutant in farmland, which not only greatly restricts crop production, but also brings a serious threat to human health through entering the food chain. Our previous study showed that hemin treatment could reduce the accumulation of Cd in pak choi seedlings. However, the underlying mechanism remains unclear. In this study, we used non-invasive micro-test technology (NMT) to detect the real-time Cd2+ flux from pak choi roots and demonstrated that hemin treatment decreased Cd uptake rather than its translocation within plants. Moreover, through comparing the responses of different chemical treatments in pak choi seedlings and Arabidopsis wild-type and heme oxygenase-1 (HO-1) mutant, we provided evidence that hemin-decreased Cd uptake was HO-1 dependent. Furthermore, analyses of hemin degradation products suggested that the hemin-derived suppression of Cd uptake suppression was probably relying on its degradation by-products, ferrous iron (Fe2+) and carbon monoxide (CO), via repressing the expression of a Fe2+/Cd2+ transporter BcIRT1 in pak choi roots. Image 1 • Hemin treatment decreased Cd2+ uptake and Cd accumulation in pak choi seedlings. • Hemin-reduced Cd2+ uptake and Cd content were reversed by HO-1 inhibitor (ZnPP). • By-products of hemin reduced Cd2+ uptake, Cd content and the expression of BcIRT1. Capsule: Exogenous hemin reduced Cd uptake in a HO-1 dependent manner, probably relying on its degradation by-products, Fe2+ and CO, via repressing BcIRT1 transcription. [ABSTRACT FROM AUTHOR]

The article presents information on Ugi reaction containing Redox of Neutral Amine bases of Carbon-Hydrogen bonds functionalization method. The article also presents chemical formulas and molecular structures of the components from the reaction including refluxes of toluene, argon and water molecules.