Characteristics and Source Apportionment of Volatile Organic Compounds in a Coastal Industrial Area: A Case Study in the Yangtze River Delta of China.

In recent years, the coastal area in East China has experienced elevated volatile organic compounds (VOCs) levels during specific periods. VOCs have become one of the major atmospheric pollutants in these areas. In this study, 64 compounds including alkanes, alkenes, halohydrocarbons, aromatics, and oxygenated VOCs (OVOCs) were obtained by the TO-15 method through a 12-month campaign in industrial, urban and suburban areas in the Yangtze River Delta of China. The overall trends of total VOC (TVOC) concentrations at eight sampling sites were as follows: winter > autumn > spring > summer. The proportion of VOC categories was various at industrial sites, while OVOCs and halohydrocarbons had high proportions at urban sites and suburban sites, respectively. Coating, vehicle emission, petrochemical source, industrial source, and gasoline volatilization were identified as the major VOC emission sources by the positive matrix factorization model. Petrochemical and coating sources were the prime VOC sources at industrial sites. Aromatics contributed the most ozone formation potential at industrial sites, while OVOCs provided the main contributions at both urban and suburban sites during four seasons. According to the health risk assessment, a high probability of non-carcinogenic risk existed at three industrial sites. Special attention should be given to certain VOCs, such as acrolein and 1,2-dibromoethane in industrial areas.

Optimum seeding density and seedling age for the outstanding yield performance of Japonica rice using crop straw boards for seedling cultivation.

Crop straw boards, a novel nursery material, has proven effective for cultivating dense, young rice seedlings suitable for mechanized transplanting, thereby saving labor. However, under high-density nursery conditions, the biomass accumulation and yield formation in rice vary with different seedling ages, necessitating exploration of optimal seeding densities and seedling ages to achieve high yields. This study aims to determine the appropriate seeding densities and seedling ages using crop straw boards to maximize rice yield. Over two years, field studies were conducted using crop straw boards for rice cultivation at seeding densities of 150, 200, 250, 300, and 350 g/tray (labeled as D1, D2, D3, D4, and D5) and seedling ages of 10, 15, 20, and 25 days (labeled as A1, A2, A3, and A4).The results indicated that D4A2 significantly enhanced tiller number, dry matter accumulation, and photosynthetic capacity, resulting in a yield increase of 2.89% compared to the conventional method of D1A3. High-density and short-aged seedlings cultivated with crop straw boards can enhance rice yield by improving photosynthetic capacity and crop quality. This study emphasizes the importance of using crop straw boards for rice nursery practices, as well as selecting the appropriate seeding densities and seedling ages for optimizing rice production.

Optimal seeding rate enhances seedling quality, mechanical transplanting quality, and yield in hybrid rice.

To determine the appropriate seeding rate for machine-transplanted hybrid rice, field experiments were conducted during 2022-2023 using the hybrid rice variety Huazhe You 210 as the material. Four seeding rate treatments were set up: 40 (T1), 60 (T2), 80 (T3) and 100 g tray-1 (T4), to investigate the effects of seeding rate on the seedling quality, transplanting quality, yield formation, and economic benefits of high-quality indica hybrid rice seedlings. The results showed that with increasing seeding rate, the seedling base stem diameter and seedling plumpness of hybrid rice seedlings decreased, but the root entwining force gradually increased, leading to a deterioration in individual seedling quality but an improvement in collective characteristics. As the seeding rate increased, the missing hill rate during mechanical planting of hybrid rice significantly decreased, while the number of seedlings per hill and the damaged seedling rate showed an upward trend. The growth volume of tillers, tillering spikelet rate, and harvest index of hybrid rice in the field showed an overall downward trend with increasing seeding rate, while the accumulation of dry matter initially increased and then decreased. The yield and economic benefits of hybrid rice grains showed an initial increase followed by a decrease with increasing seeding rate, with the highest yield and economic benefits achieved with the T2 treatment. In conclusion, the appropriate seeding rate for machine-transplanted hybrid rice is T2 (60 g tray-1), which can maintain good seedling quality and improve transplanting quality, coordinate larger collective growth and appropriate harvest index, contributing to high yield and good economic benefits.

Hybrid cross-linked sodium carboxymethyl starch/polyacrylamide flexible sensing hydrogels with adhesion, antimicrobial properties and multiple responses.

Ionic hydrogels used as ideal and flexible strain sensor materials should have excellent mechanical, adhesive and antimicrobial properties. However, it is challenging to achieve these multifunctional requirements simultaneously. Herein, we designed and prepared a multifunctional ionic hydrogel with a multi-length tentacle bentonite backbone to initiate the free radical polymerization of acrylic acid bentonite (AABT) and acrylamide (AAm). The interactions of covalent cross-linking, hydrogen bonding cross-linking, charge interactions and physical entanglement between hybrid polyacrylamide-AABT (PAAm-AABT), sodium carboxymethyl starch (SCMS) and PAAm form an multi-in-one hybrid supramolecular network hydrogel (CABZ). This CABZ ion-conductive hydrogel is capable of detecting weak deformation with a detection limit of 1 % strain, high tensile properties of 995 %, excellent strength of 254.5 kPa, fast response (≈0.21 s), high sensitivity of 0.86 and high conductivity of 0.37 S/m. In addition, this CABZ ion-conductive hydrogel has impressive adhesion properties with shear adhesion strength up to 50.78 kPa and broad-spectrum antibacterial properties achieved by AABT-loaded ZnO nanoparticles. Through special AABT hybrid cross-linking, the CABZ ion-conductive hydrogel achieves stable mechanical properties, highly sensitive signal response and antimicrobial properties, which will make it a good choice for flexible wearable sensor materials.