Reasonable deep application of sheep manure fertilizer to alleviate soil acidification to improve tea yield and quality

Soil acidification in Chinese tea plantations is widespread, and it has significantly affected the growth of tea trees; it was important to explore soil remediation of acidified tea plantations in depth for the sustainable development of tea industry. In this study, the effects of sheep manure fertilizer with different application depths on soil acidification, tea yield and quality, and soil nitrogen transformation in tea plantations were analyzed for five consecutive years from 2018 to 2022. The results showed that long-term use of sheep manure fertilizer significantly reduced soil acidification (P< 0.05) in tea plantations, improved soil pH and soil ammonium nitrogen content, enhanced root activity and root nitrogen uptake capacity of tea trees, and thus improved tea yield and quality. The effect of different application depths of sheep manure fertilizer on tea yield and quality was mainly reflected in the transformation ability of soil ammonium nitrogen and nitrate nitrogen, which showed that high transformation ability of soil ammonium nitrogen and high ammonium nitrogen content were beneficial to high tea yield and vice versa, and the best effect was achieved when sheep manure was applied at a depth of 50 cm and 70 cm. The topsis analysis confirmed that sheep manure fertilization had a greater effect on root activity, ammonium nitrogen, ammonia intensity, and nifH gene. This study provided an important practical basis for the restoration of acidified tea plantation soil through sheep manure fertilizer management

The evolutionary trend and impact of global plastic waste trade network

Marine plastic waste, global warming, and ozone holes have become global environmental problems that need to be resolved urgently. With the promulgation of plastic bans in many countries, the global plastic waste trade will undergo tremendous change. In order to explore the future evolutionary trend of the global plastic waste trade network, this paper focuses on the analysis of the import and export of plastic waste from major trading countries around the world. Based on the bilateral trade volume of plastic waste from 1990 to 2019, a global plastic waste trade network is constructed, and the structure and characteristics of the network are studied. The results show that the global plastic waste trade network has shifted its center of gravity, and the import center has gradually shifted from China to Southeast Asia. The global plastic waste trade network presents a sparse state. Moreover, the dependence of related countries on plastic waste trade decreases, whilst the closeness of trade links also decreases. Sudden factors such as plastic waste import bans have a disruptive impact on plastic waste management.</p

A Crack Propagation Control Study of Directional Hydraulic Fracturing Based on Hydraulic Slotting and a Nonuniform Pore Pressure Field

Hydraulic fracturing techniques for developing deeply buried coal reservoirs face routine problems related to high initial pressures and limited control over the fracture propagation direction. A novel method of directional hydraulic fracturing (DHF) based on hydraulic slotting in a nonuniform pore pressure field is proposed. A mechanical model is used to address crack initiation and propagation in a nonuniform pore pressure field, where cracks tend to rupture and propagate towards zones of high pore pressure for reducing the effective rock stress more. The crack initiation pressure and propagation morphology are analyzed by rock failure process analysis software. The numerical results show that the directional propagation of hydraulic fracturing cracks is possible when the horizontal stress difference coefficient is less than or equal to 0.5 or the slotting deviation angle is less than or equal to 30°. These findings are in good agreement with experimental results, which support the accuracy and reliability of the proposed method and theory

Cellulose Nanocrystals Prepared by Persulfate One-Step Oxidation of Bleached Bagasse Pulp

This article describes a novel one-step method to prepare cellulose nanocrystals (CNCs) from bleached bagasse pulp via ammonium persulfate (APS) oxidation. The obtained persulfate oxidation cellulose nanocrystals (POCNs) were characterized for their microstructure, crystal properties, and chemical composition. The POCNs were successfully prepared with a total yield of 44.6%. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) measurements indicated that the POCNs had an average length of 150 to 300 nm and an average width of 10 to 30 nm, as well as a rod-like morphology. Fourier transform infrared (FTIR) spectroscopy confirmed the introduction of carboxyl groups on the surface of cellulose. The X-ray diffraction (XRD) spectra proved the existence of cellulose type I, with a highly crystalline nature (79.2%), and thermogravimetric analysis (TGA) showed that the thermal stability decreased

Effects of Supercritical CO2 Treatment Temperatures on Mineral Composition, Pore Structure and Functional Groups of Shale: Implications for CO2 Sequestration

Research on the physicochemical reactions between supercritical carbon dioxide (Sc-CO2) and shale at different temperature is essential for geological CO2 sequestration. In this paper, shale from the Longmaxi formation in Sichuan basin of China was collected to study the changes in mineral composition, pore structure, and organic functional groups treated with Sc-CO2 at fixed pressure 8 MPa and temperatures 40 &deg;C to 80 &deg;C. Samples were analyzed with x-ray diffraction, CO2/N2 gas adsorption, and Fourier transform infrared spectroscopy. The results show that the dissolution of clay minerals by Sc-CO2 first declined, but then increased when the temperature increased; dissolution reached a minimum at 60 &deg;C. The specific surface area, total pore volume, predominant pore type (mesopores), and fractal dimension of the shale pore structure first increases and then decreases with increasing temperature. The destruction of hydroxyl structures by Sc-CO2 is related to the destruction of OH&ndash;N and ring hydroxyls. As the temperature increases, the hydroxyl destruction first increases and then decreases. The aromatic hydrocarbons are mainly dominated by 3H and 2H, and their abundances increase significantly as temperature increases, whereas the 4H shows a decreasing trend; the 1H abundance does not change appreciably. The relative abundances of aromatic and aliphatic hydrocarbons decrease linearly as the temperature increases. These research results provide theoretical support for the geological storage of Sc-CO2 in shale at different temperatures

Asymmetric Schottky Barrier in Rubrene Transistor via Monolayer Graphene Insertion toward Self-Powered Imaging

Organic semiconductor materials featuring lightweight, and flexibility may play a significant role in various future applications, such as foldable displays, wearable devices, and artificial skin. For developing high-performance organic devices, organic crystals are highly desired, while a remaining fundamental issue is their contact problem. Here, we have grown a high-quality rubrene single crystal by utilizing a simple in-air sublimation technique. The contact characteristics (barrier height and contact resistance) are detail-studied by resist-free transfer electrodes (Au metal or graphene/Au). The Schottky barrier of the rubrene/graphene interface is lower and can be also modulated by gate bias, which is confirmed by spatial photocurrent mapping. Finally, we demonstrated the zero-bias photocurrent imaging application by constructing the asymmetrical device employing different electrode contacts. Our work would be of significance for studying the contact issue of organic crystals and wireless imaging

Effects of Magnesium on Transcriptome and Physicochemical Index of Tea Leaves

Magnesium (Mg) is one of the essential elements for the growth of tea tree and is extremely important for its development. In this study, we investigated the effect of Mg on the transcriptome and physicochemical indexes of tea leaves, and the results showed that Mg could significantly affect the gene expression of tea leaves. The results of Orthogonal Partial Least-Squares Discriminant Analysis (OPLS-DA) model analysis showed that a total of 300 key genes (Variable Importance for the Projection, VIP > 1) were screened under different concentrations of Mg treatment, among which 140 genes were up-regulated and 160 genes were down-regulated. The bubble map was used to screen the characteristic genes from the above key genes, and a total of 121 representative characteristic genes were obtained, mainly involving 9 metabolic pathways. Among them, gene expression of three metabolic pathways, including porphyrin metabolism, alpha-linolenic acid metabolism and photosynthesis, showed an increasing trend with the increase of Mg concentration, while gene expression of four metabolic pathways, including biosynthesis of secondary metabolites, anthocyanin biosynthesis, ABC transporters, pentose and glucuronate interconversions, showed a decreasing trend. The results of physiological index analysis showed that with the increase of Mg concentration, the photosynthetic physiological index, theanine and soluble sugar content of tea leaves showed an increasing trend, while the content of tea polyphenol, flavone and caffeine showed a decreasing trend. The results of TOPSIS analysis showed that the physiological indexes of tea trees most affected by Mg were chlorophyll, tea polyphenols and flavonoids, while the metabolic pathways most affected by Mg on gene expression were the metabolic pathways and biosynthesis of secondary metabolites. It can be seen that the effects of Mg on tea tree were mainly related to photosynthesis and synthesis of secondary metabolites, and Mg was beneficial for improving the photosynthetic capacity of tea tree, enhancing the accumulation of primary metabolites, and thus increasing tea yield. However, Mg was not conducive to the synthesis of secondary metabolites of tea tree and the accumulation of main quality indexes of tea leaves

Contribution of traditional deep fermentation to volatile metabolites and odor characteristics of Wuyi rock tea

Fermentation is extremely important for the formation of the special flavor of Wuyi rock tea. This study determined volatile metabolite contents using GC-MS technique and futher analyzed their odor characteristics during the traditional deep fermentation technology of Wuyi rock tea. The results showed that 17 characteristic compounds significantly changed during the first stage of the preliminary processing, namely fresh leaves, withering and fermentation. The key to the formation of floral aroma lied in dihydromyrcenol, and the woody aroma derived from six terpenoids, and their synthesis depended on dihydromyrcenol content. The fruity aroma was dominated by six esters, and the fruity aroma mainly came from (Z) -3-hexen-1-yl butyrate, (E) -3-hexen-1-yl butyrate and 5-Hexenyl butyrate. This study provided an important theoretical and practical basis for improving the preliminary processing of Wuyi rock tea