Raw Material Mass Research Articles

Recovery and partial isolation of ⍺-mangostin from mangosteen pericarpsvia sequential extraction and precipitation.

This study introduced an innovative sequential extraction methodology designed for the efficient recovery of alpha-mangostin (⍺-M) from mangosteen pericarps. Alpha-mangostin, renowned for its pharmacological properties including anti-inflammatory, anti-cancer, and anti-bacterial effects, has garnered significant attention across diverse industries. The proposed method of sequential extraction achieved 73% recovery and a yield of 46.75 mg/g based on the weight/weight percentage of the mass of ⍺-M extracted from the sequence and the mass of raw material. Furthermore, the purity of the dried product was 67.9%. The sequence solvent extraction system, comprising water, hexane, and acetonitrile, plays a pivotal role in enhancing the efficacy of the extraction process. Notably, this methodology offers a cost-effective alternative to conventional extraction methods. It reduces the need for complex equipment and processes, positioning it as a resource-efficient extraction technique in comparison to existing methodologies. This novel sequential extraction method presents a promising avenue for the economical and sustainable recovery of alpha-mangostin (⍺-M) from pericarps.

CHEMICAL COMPOSITION OF THE ESSENTIAL OIL OF WORMWOOD (ARTEMISIA ABSINTHIUM L.), GROWING IN THE WESTERN REGION OF AZERBAIJAN

Wormwood (Artemisia absinthium L.) is a widespread plant species in the Western region of Azerbaijan. The dependence of the composition, quantity and growth of various biologically active substances contained in the above-ground parts of wormwood on the vegetation period and climatic conditions was studied. The results of the study of the essential oil obtained by the steam distillation method from wet and dry samples of the aerial parts of bitter wormwood are presented. The yield of essential oil is determined in % in terms of the weight of air-dried raw materials. The study of the yield of essential oil was different months of the year showed that its amount varies depending on the vegetation period (yield of 0.56-0.66% by mass of fresh raw materials; yield of 0.58-0.77% by mass of dry raw materials). The composition of volatile distillates was studied by the chromatography method. In all samples, the amount of camphor component, which belongs to oxygenated terpenoid hydrocarbons, prevailed with a percentage above 35%. 25.44-34.24% phase budding in June for fresh and dry plant material; 25.14-35.21% phase mass flowering in August; it was determined between 25.67-35.20% phase the seed ripening in September.

Influence of raw material temperature on the properties of silicate-modified polyurethane grouting materials

Silicate-modified polyurethane (PU/WG) is an effective organic–inorganic hybrid-grouting material that blocks water and reinforces weak formations. In deep high-temperature formations, owing to environmental impacts, PU/WG raw materials are heated before grouting. To elucidate the basic characteristics of PU/WG grouting materials in deep, high-temperature environments, we investigated the effects of raw material temperature on the curing time and strength of PU/WG by considering different mass ratios during the curing time test. Furthermore, the influence of raw material temperature on the micro-structure of PU/WG was analysed from a microscopic perspective using scanning electron microscopy. Energy-dispersive X-ray spectroscopy revealed the composition and curing mechanism of PU/WG. The results indicated that as the raw material temperature increased from 24 to 60°C, the peak strength decreased from 41.65 to 14.51 MPa, and the peak strain decreased from 27.03 % to 8.83 %. Based on the experimental results of the curing time testing and strength test, we established a PU/WG curing time-variation model considering the coupling of raw material temperature and mass ratio and provided an optimisation scheme for the PU/WG strength, which provides effective guidance for grouting time design in high-temperature environments.

Microstructure and properties of high-strength lightweight ceramsites customised with ultra-fine copper tailings

The accumulation of copper tailings not only consumes a significant amount of land resources but also incurs substantial treatment expenses and causes environmental pollution. This article presents an investigation on the feasibility of utilizing ultra-fine copper tailings (CTs), polishing slag (PS), and fly ash (FA) to produce customised high-strength ceramsites for treating and reusing copper tailings.Additionally, the effects of raw material mass ratio and sintering temperature on the physical properties, thermal properties, chemical structure, and expansion mechanism of the high-strength ceramsites were investigated. The experimental results revealed that the well-formed ceramsites exhibited an apparent density of 486–2304 kg/m3, a bulk density of 288–1659 kg/m3, a 1-h water absorption rate of 0.13–3.9 %, and a particle compressive strength of 0.87–22.4 MPa with copper tailings content of 50∼100 % under preheating temperature 950 ℃ for 40 min and sintering temperature 1195–1225 ℃ for 40 min. The XRD analysis of crystal phases indicated that the mineral compositions of ceramsites contained quartz, anorthite, albite, and mullite. Moreover, the FTIR spectra displayed that [AlO4] and [SiO4] were interconnected into a complementary network which enhanced the strength of ceramsites. Additionally, the microstructure analysis revealed that more evenly distributed and smaller pore structures and rougher matrix were associated with higher compressive strength. The temperature difference between the interior and exterior led to the preferential formation of a slag phase which exerted a bonding effect on the composite feldspar phase. These findings suggest that ultra-finecopper tailings could be recycled in artificial aggregate technology in concrete engineering, and provide theoretical support for the large-scale utilization of tailings.

Study on radon release behaviors of the tubular flow-through radon source with natural radium-bearing materials

To obtain a radon source that is easy to access natural radium-bearing raw material and does not require the approval of relevant departments, the tubular flow-through radon source using radium-bearing ore as the radon-generating material was designed. Based on the theories of radon diffusion-convection migration in porous media, the simplified calculation formula and numerical calculation models of radon activity concentration at the outlet of the tubular flow-through radon source were established, and the radon release rules of the tubular flow-through radon source were studied using a combination of simplified calculation formulas, numerical simulations, and experiments, respectively. The results show that (1) the radon activity concentration at the outlet of the tubular flow-through radon source was dominated by mass (or the volume) of the natural radium-bearing raw material, free radon production rate, and gas flow rate. (2) When the range of radon activity concentration at the outlet is 260–1308 Bq m-3, the relative deviation of the three methods is less than 2.62%. (3) The simplified calculation formula and numerical simulation method proposed in this paper can provide a reference for the design and control of the radon activity concentration of a tubular flow-through radon source.

Comparative phytochemical analysis of papaya leaves

One of the promising and developing areas of modern medicine and pharmacy is turning to food plants as a source of biologically active compounds. Plant biologically active substances are well absorbed by the body,being involved in many vital processes, have broad pharmacological activity, low toxicity, and are milder than synthetic drugs. Such food plants that are promising for scientifically based use as raw materials and application in scientific pharmacy include papaya (Carica papaya L.). According to electronic databases including Scopus, Google Scholar, Web of Science, and PubMed, there are many in vivo and in vitro studies, the main results of which show that papaya leaf extract has antibacterial, immunomodulatory, antioxidant, antitumor, hypoglycemic, and anti-inflammatory properties [1, 2]. The pharmaceutical industry of foreign countries produces more than 100 papaya-based medicines, widely used in various fields of medicine. In our country, it remains little studied, since there is no raw material base. However, this tropical plant is perfectly cultivated in warm greenhouses, grows quickly, and has a large mass of raw materials. Papaya leaves and fruits are a source of biologically active compounds and a promising type of medicinal plant raw material for medicine and pharmacy. In addition, the introduction of plants that are analogues of imported plant raw materials valuable for practical use, including Carica papaya L., is currently relevant [2].

Transesterifikasi In situ Produksi Biodiesel Dengan Variasi Massa Bahan Baku Terhadap Karakteristik Biodiesel

Biodiesel is one of the promising alternative fuels, environmentally friendly, and has no adverse effects on health. In this study, biodiesel production was carried out using the in situ transesterification method. The raw material used was mahogany seeds with variations in raw material mass of 10 grams and 20 grams. The catalyst used was KOH with methanol as the solvent and n-hexane as the co-solvent. In situ transesterification was performed at a reaction temperature of 65°C, stirring speed of 400 rpm, and a reaction time of 40 minutes. The research results show that the mass of the raw material affects the biodiesel yield. At a raw material mass of 10 grams, a yield of 70.09% was obtained, while for a raw material mass of 20 grams, the yield was 82.00%. The biodiesel analysis results show that the density values for the 10-gram raw material mass variation are 0.8512, and for the 20-gram raw material mass variation, it is 0.8556. The water content is 1.46%, and the free fatty acid (FFA) content is 0.76 mg KOH/gram for the 10-gram raw material mass variation and 0.675 mg KOH/gram for the 20-gram raw material mass variation. The results of the biodiesel characteristic tests meet the SNI 7182:2015 standard.

Circularity of new composites from recycled high density polyethylene and leather waste for automotive bumpers. Testing performance and environmental impact

New composite materials (suitable for automotive bumpers), composed of recycled high-density polyethylene (rHDPE) and leather buffing dust waste (BF) ranging from 20 to 50 wt%, were produced and investigated for mechanical properties. Optimal mechanical performance was achieved with composites containing 30 % wt BF. The environmental performance of automotive bumper production from both virgin and recycled HDPE reinforced with 30 % wt BF (HDPE-BF, rHDPE-BF) composites was compared to that of conventional polypropylene (PP) by performing a cradle to gate life cycle assessment.A component-based approach, instead of a comprehensive LCA assessment for the entire car was adopted using various functional units (FU) such as mass (FU1), volume (FU2), and volume of raw material fulfilling a specific impact strength requirement (FU3), thus enriching the paper with methodological discussions.The rHDPE-BF system provided better environmental performance compared to the virgin PP system, when considering both mass and volume-related functional units, mainly due to the avoidance of virgin polymer production. Even with the inclusion of the use phase in FU2 and a slightly higher density (+1.7 %) of composites than PP-based bumpers, the rHDPE system still provides better environmental performance (10 % less impact). The sensitivity analysis highlighted the significance of car type and final density of the bumper on the impact results. Finally, when using FU3, due to its higher impact strength, HDPE-BF system is clearly the best environmental alternative (50 % less impact) followed by rHDPE-BF system. In all cases, rising the content of recycled materials in the bumpers increases its circularity.The paper illustrates the importance of selecting a suitable functional unit, based on a specific application (i.e., automotive bumpers), to evaluate the environmental impact of new composite materials in comparison to traditional options. Expanding the assessment to encompass multiple functions provides a more accurate portrayal of reality but also introduces greater result uncertainty.

CHEMICAL COMPOSITION OF EXTRACTS AND ESSENTIAL OILS OBTAINED FROM COMMON JUNIPER (JUNIPERUS COMMUNIS L.) IN AZERBAIJAN

Juniperus communis L. (common juniper) is a widespread plant species in the Western region of Azerbaijan. The dependence of the composition and content of various biologically active substances in juniper on natural climatic conditions was studied. The results of the study of the substances obtained from the extraction of leaves and branches in ethanol were presented. The composition of volatile compounds was studied by the gas chromatography technique. In all samples, monoterpene hydrocarbons always predominated with percentages higher than 70% (from 71.12% for the plant material collected in August to 74.38% for those in September), followed in similar quantities by oxygenated monoterpenes or sesquiterpene hydrocarbons with values between 10.45% and 12.77% and between 10.50% and 12.72%, respectively. Ascorbic acid content varying from 33.1 to 123.2 mg/100 g was also determined. The investigation of the yield of essential oils in different months of the year showed that its amount varies depending on the season (3.5-4.4% of the mass of dry raw materials).

Analysis of Targeted Components in the Combination Extract of Hovenia dulcis and Phyllanthus emblica by UPLC-MS/MS

This study aimed to establish a UPLC-MS/MS method for rapid analysis and identification of target components in the combination extract of Hovenia dulcis and Phyllanthus emblica. The gradient elution was carried out with methanol (A) −0.2% formic acid solution (A) with low rate of 1.0 mL · min−1, column temperature of 30 °C, detection wavelength of 285 nm. The ESI ion source was used to collect data under the negative ion mode. Through analysis and identification, five target components were inferred, namely gallic acid, dihydromyricetin, corilagine, taxifolin, and ellagic acid in the combination extract. Quantitative analysis was conducted on the combination extract. By utilizing the theory of modern supramolecular technology in traditional Chinese medicine, the functional composite product was obtained by selecting the compound extraction of Hovenia dulcis and Phyllanthus emblica as raw materials, and quantitative analysis was conducted on on the combination extract. The results showed that the flavonoid extraction rate and the content of target components were both higher when the mass ratio of Hovenia dulcis to Phyllanthus emblica was 1:1 and 1:2. This indicates that the co-extraction of Hovenia dulcis and Phyllanthus emblica not only simplified the extraction process but also enhances the extraction rate of the flavonoids in Hovenia dulcis. The developed UPLC-MS/MS method is rapid, sensitive, which provides a technical basis for the selection of raw material mass ratios and product development of Hovenia dulcis and Phyllanthus emblica combination.

Study of the process of the frozen raw beef defrosting with its simultaneous massaging in industrial conditions

Many meat processing enterprises use the frozen raw meat. Its defrosting and thawing is a crucial technological operation that fundamentally affects the quality of food products. The experience and knowledge obtained directly in the workshop in the process of thawing the raw materials and their using to obtain a specific finished product are of great importance. Defrosting and thawing of the frozen beef meat, as one of the stages of raw meat processing, still remains a challenging process in industrial food production. The importance of this process is constantly increasing due to the growing volumes of frozen raw materials processed in food enterprises. Scientific research shows that one of the most efficient methods of defrosting and thawing is the process of meat thawing with saturated water steam under vacuum. When applying the steam the raw materials is heated at its least and minimal losses are observed, while the duration of the process is significantly reduced. This work examines the process of beef meat defrosting and thawing with simultaneous shaking and crumpling the frozen mass, which can be called as massaging of raw materials. As studies have shown, this method of thawing makes it possible to reduce losses down to almost zero and obtain raw materials with good structural characteristics for the production of a finished product with a wide range of consumer properties. The obtained experimental curves of changes in the mass and temperature of raw materials make it possible to analyze the kinetics of heat transfer and mass transfer processes at the macro- and micro levels of the food system, which serve as the basis for modeling and controlling the technological process. This study presents the results of conventional defrosting and thawing of the raw meat but combined with massaging. Studies of the parameters of processing modes have shown that the proposed program makes it possible to use efficiently the design and technological features of the defroster-massager in order to obtain the raw beef for the production of high-quality food products. The results of experimental studies and their analysis allow making conclusion about the prospects of applying this process for the other types of raw meat materials before the main technological processing of raw materials.

Heat and shear stability of particle stabilised foams for application in gluten-free bread

Bread forms an integral part of the daily diet in many cultures worldwide. At the same time, a significant number of people try to avoid wheat-based products for either health reasons or due to personal preferences. The absence of a protein network in gluten free bread affects its structure, taste, texture and shelf-life. This paper suggests a technological solution to this issue that uses a pre-foamed mass of gluten free raw materials which is mixed with the bread’s ingredients, then kneaded and baked to form a high quality gluten free bread. To survive the high shear stresses during kneading and temperature increase during baking, the foam requires exceptional stability. This stability was achieved through particle stabilisation of the bubble interfaces. Both of the tested foams (with and without particles) exhibited thermal stability up to 80 °C. However, resistance to shear stresses was higher in the particle stabilised foams. Of all the tested particles, linseed press cake and banana powder led to the best results. In conclusion, particle stabilised foams seem very well suited to applications in gluten free baked goods. Further application potential is seen for vegan foamed desserts.

Содержание биологически активных веществ в вегетативной массе очитков (Sedoideae)

Abstract. The aim of the study was to determine the content of the main groups of biologically active substances in the vegetative mass of 10 stonecrops in different phases of seasonal development. Methods. The freshly collected raw materials – vegetative shoots of the following species: Aizopsis aizoon (L.) Grulich, A. hybrida (L.) Grulich, A. kurilensis (Vorosch.) S. Gontch., Hylotelephium ewersii (Ledeb.) H. Ohba, Sedum acre L., S. album L., S. hispanicum L., S. reflexum L., S. rupestre L. and S. spurium M. Bieb. were analyzed. Generally accepted methods of phytochemical analysis were used. The dry matter content was determined by drying 1 g of raw materials to a constant weight. The amount of phenolic compounds, pectin substances and total sugars was determined in ethanol extracts spectrophotometrically, the amount of saponins – by the weight method, and their indicators were calculated for the mass of absolute dry raw materials. The concentration of ascorbic acid was determined by the titrimetric method for wet weight. Scientific novelty. The quantitative content of dry substances, catechins, flavonols, and pectic polysaccharides was studied in stonecrops for the first time. The dynamics of the content of the main groups of secondary metabolites from the flowering phase to the end of the growing season has been established. Results. It was found that the vegetative mass of stonecrops contains: dry matter – up to 19,74 %, flavonols – up to 2,38 %, tannins – up to 19,35 %, pectic polysaccharides – up to 9,9 %, total sugars – up to 41,55 %, and ascorbic acid – up to 112,8 mg%; the amount of catechins does not exceed 3,15 mg%. The tendency to the accumulation of flavonols, saponins and pectic substances during flowering phase in summer, but sugars, tannins and dry substances to the end of the growing season in autumn was revealed. Aizopsis species, S. spurium, S. hispanicum have the highest content of the main groups of biologically active substances. The findings testify to the prospects of stonecrops as a source of various bioactive substances.

EVALUATION OF LOSSES AT THE PRIMARY PRODUCTION STAGE OF EDIBLE CARROTS

The aim of the article is to present the magnitude of losses at the stage of primary edible carrot production and to indicate directions for redistributing production waste. The study included producers of edible carrots located in the Kuyavian-Pomeranian Voivodeship, whose average yield size in the years 2019-2021 corresponded to 15% of the total yield collected in the voivodeship and approximately 2.4% in the country. Based on expert interviews and commercial documentation analysis, it was found that, due to high customer demands regarding the appearance of carrots (cosmetic standards), on average, only about 44% of the weight of calibrated carrots intended for sale constituted the mass of the harvested raw material. Approximately 7% was allocated to processing plants, and around 26% of the raw material mass was used for animal feed. The remaining portion of the harvest represented production losses (19%) and fuel for biogas plants (4%). In order to reduce production losses, primarily resulting from the depreciation of items solely based on their appearance, recipients (e.g., retail chains) should enable producers to deliver less visually appealing raw materials with corresponding price discounts. It is also crucial to raise awareness among customers through educational and promotional efforts, emphasizing the equal nutritional value of raw materials regardless of their appearance (straight, curved, thicker, thinner). This will increase both the product’s availability to the public and production efficiency for the producer.

Efficient enrichment of platinum group metals from spent automotive catalysts by alkaline hydrothermal treatment and the subsequent acid leaching method

Spent automotive catalysts (SAC) is the most important secondary resource for the recovery of platinum group metals (PGMs). This paper demonstrates that the acid-resistant and alkali-resistant cordierite carrier can be transformed into hydroxysodalite by a alkaline hydrothermal treatment (AHT), which can then be dissolved by subsequent acid leaching (AL) to enrich PGMs. Experiments were conducted to assess the influencing factors and the optimal conditions were determined as follows: holding temperature of 150 °C; NaOH to raw material mass ratio 10:10; holding time of 60 min; liquid to solid ratio of 3:1, and stirring speed of 400 rpm. The residue ratio in the AHT process was 132.57% under optimized conditions. The total residue ratio was 18.68% under fixed acid leaching experimental conditions of holding temperature of 60 °C, liquid to solid ratio of 15:1, holding time of 60 min, stirring speed of 400 rpm, and hydrochloric acid concentration of 2.5 mol·L-1. The contents of Pt, Pd, and Rh in the enriched residue reached 650.50, 2131.54, and 405.28 g·t−1, respectively, and the corresponding enrichment times were 7.13, 7.25, and 7.07. The additions of sodium formate before the AHT and aluminum powder during the AL were found to effectively inhibit PGMs leaching. The losses of Pt, Pd, and Rh throughout the entire process were only 2.77%, 1.89%, and 4.28%, respectively.

Features of winter pea seeds germination under the action of growth regulators

Physiological features of pea seed germination under treatment with exogenous growth regulators based on biologically active substances were studied. Purpose. To investigate the influence of complex growth and development stimulators containing phytohormones and their analogs, Biosil and Gulliver Stimul, on the peculiarities of the seed germination processes and formation of the winter pea seedlings of the Moroz NS variety. Methods. Laboratory, measuring, weighing, quantitative, statistical. Results. The influence of aqueous solutions of growth regulators Biosil and Gulliver Stimul on the germination processes of winter pea seeds was analyzed. During research, it was established that the use of growth regulators contributes to the faster exit of seeds from the state of rest, which is illustrated by the active dynamics of germination. Treatment of winter pea seeds with growth regulators leads to an increase in germination energy by 10-12% and laboratory germination by 6-8% compared to the control. It was noted that the indicators of seed germination were sufficiently high in all samples, including control. The soaking in growth regulators solutions contributes to the 10-16 mg bigger swelling of seeds than in the control; better utilization of reserve compounds, and 38- 50 mg seed weight loss during germination. Phytohormones which are part of the preparations induced an increase in the development of the vegetative organs of pea seedlings, which was expressed in a rapid increase in the length of the shoot and root in experimental variants. The growth of the linear dimensions of the aboveground and underground parts of the seedlings was accompanied by the increase in the mass of raw material. Conclusions. Application of the Biosil and Gulliver Stimul composite plant growth regulators affects the processes of germination and the initial stages of growth of winter pea plants. Treatment of winter pea seeds with these preparations helps to improve seed germination and increase germination energy. The linear dimensions and mass of the raw matter of the roots and shoots of pea seedlings enlarged due to the influence of growth regulators. The maximum length of the root and shoot was observed under the use of Gulliver Stimul preparation

Green growth for whom, how and why? The REPowerEU Plan and the inconsistencies of European Union energy policy

The REPowerEU plan redefines the European Union (EU) energy transition agenda in response to the Russia-Ukraine war. Formally, it aims to boost green growth, defend liberal democracy, and increase Europe's energy sovereignty. Yet, the new course of EU energy policy may be paradoxically yoking the continent into raw materials dependency and lock-in investments in fossil fuel infrastructures, while partnering with other warmonger and dictatorial states. I argue that even a much-needed switch to low-carbon energy sources is not immune from the calamitous consequences of an energy transition based on the growth imperative. Building on the System of Provision approach and integrating it with insights from ecological economics and political ecology, this paper asks how, for what purpose, and on whose terms is the remarkable expansion of solar photovoltaics outlined in the REPowerEU taking place. I find that the mass of raw materials required to meet solar energy targets will increase 3-fold by 2030. This could provide 4.4–6.7 % of EU energy while occupying 5.5–8 % of urbanised spaces. It will also strengthen the dependency on Chinese refining and manufacturing, besides intensifying mining and extractive activities around the globe. The findings in this paper show that the EU economy is not de-materialising, but rather harnessing discontent around rosy narratives like “green growth”. To conclude, I argue that a truly transformative energy policy requires questioning the material foundations of ecological modernisation approaches, abandoning the growth imperative, and reorganising energy systems around sufficiency and decentralised provisioning beyond, rather than within, global capitalism.

Segregating Amazonia logging wastes from sustainable forest management improves carbonization in brick kilns

Carbonizing Amazon wood waste with similar physical, chemical, and energy properties improves the quality of the derived charcoals. However, the effect of a quality-based grouping of wood on the productivity of a charcoal production unit remains an unfulfilled gap. This research compares the carbonization indexes of segregated and non-segregated wastes performed in brick kilns of an industrial facility in the Brazilian Amazonia. The wastes came from the Reduced Impact Exploration of twenty-three Amazonia species. Wood's physical properties (moisture, basic and apparent densities, and maximum moisture content) were determined by species. Segregating the wastes into four quality groups provided alternative carbonization, while the randomly mixed wastes underwent carbonization as the usual methodology. Overall productivity and productivity per kiln were explored for the five carbonization models. The research revealed that segregating the logging wastes raised the filled mass and volume of raw material, productivity, and carbonization yield per kiln. It promoted gains ranging from 6.81 (group 3) to 30.23% (group 1) for the charcoal volume and 17.65 (group 4) to 70.59% (group 1) for the charcoal mass per kiln. This study revealed a practical and straightforward solution to improve the sustainability and effectiveness of the wood production chain in the Amazonia region.

Synthesis of Nanocellulose‐Based Nitrogen‐Doped Carbon Quantum Dots with High Fluorescence Quantum Yields for Multifunctional Applications

AbstractCarbon quantum dots (CQDs) are one of the most promising luminescent nanomaterials for anti‐counterfeiting due to their excellent optical properties, low toxicity, and environmental friendliness. With the development of green chemistry, biomass carbon sources have attracted attention. Herein, nitrogen‐doped carbon quantum dots (N‐CQDs) are synthesized using waste corn bract nanocellulose as the carbon source and L‐histidine as the nitrogen source in a simple and quick one‐step microwave method. It is found that a raw material mass ratio of 1:4, a temperature of 100 °C, and a preparation time of 5 min are the optimum preparation conditions. The fluorescence quantum yield of N‐CQDs obtained under these conditions is 32.64%. Under the excitation of light at a wavelength of 365 nm, the emission peak of N‐CQDs is located at 430 nm and emits blue light. This study also provides a method to prepare fluorescent anti‐counterfeiting films with excellent performance and fluorescent detection probes solely from waste biomass corn bract leaves and L‐histidine.

Highly Stable Potassium Metal Anodes with Controllable Thickness and Area Capacity.

K metal battery is a kind of high-energy-density storage device with economic advantages. However, due to the dendrite growth and difficult processing characteristics, it is difficult to prepare stable K metal anode with thin thickness and fixed area capacity, which severely limits its development. In this work, a multi-functional 3D skeleton (rGCA) is synthesized by simple vacuum filtration and thermal reduction, and K metal anodes with controllable thickness and area capacity (K content) can be fabricated by changing the raw material mass and graphene layer spacing of rGCA. Moreover, the graphene sheet layer of rGCA can relax stress and relieve volume expansion; carbon nanotubes can serve as the fast transport channel of electrons, reducing internal impedance and local current density; Ag nanoparticles can induce the uniform nucleation and deposition of K+ . The K metal composite anodes (rGCA-K) based on the conductive skeleton can effectively suppress dendrites and exhibit excellent electrochemical performance in symmetric and full cells. The controllable fabrication process of stable K metal anode is expected to help K metal batteries move toward the stage of commercial production.