Transforming lignocellulosic biomass into fuels and chemicals has been intensely studied in recent years. A large amount of work has been dedicated to finding suitable solvent systems, which can ...improve the transformation of biomass into value‐added chemicals. These efforts have been undertaken based on numerous research results that have shown that organic solvents can improve both conversion and selectivity of biomass to platform molecules. We present an overview of these organic solvent effects, which are harnessed in biomass conversion processes, including conversion of biomass to sugars, conversion of sugars to furanic compounds, and production of lignin monomers. A special emphasis is placed on comparing the solvent effects on conversion and product selectivity in water with those in organic solvents while discussing the origins of the differences that arise. We have categorized results as benefiting from two major types of effects: solvent effects on solubility of biomass components including cellulose and lignin and solvent effects on chemical thermodynamics including those affecting reactants, intermediates, products, and/or catalysts. Finally, the challenges of using organic solvents in industrial processes are discussed from the perspective of solvent cost, solvent stability, and solvent safety. We suggest that a holistic view of solvent effects, the mechanistic elucidation of these effects, and the careful consideration of the challenges associated with solvent use could assist researchers in choosing and designing improved solvent systems for targeted biomass conversion processes.
Solvents, how art thou interfering? Biomass‐derived molecules are an attractive resource for the production of renewable fuels and chemicals. However, producing intermediates at high yields and rates has been a major challenge to biorefinery development. Organic solvent effects can dramatically improve conversion rates and product selectivities by influencing solubility or thermodynamics of biomass components. Herein, these effects are discussed.
Crop residue retention (RR) is a recommended practice in China and globally. However, comprehensive assessment of changes and mechanisms affecting crop production and soil processes with RR and thus ...identifying systems of sustainable residues management are not widely studied. A national meta‐analysis was conducted to assess changes in 24 indicators (related to soil quality, soil nutrients, crop yield, and environmental impacts) along with their relationships under RR through 4,910 comparisons from 278 publications across China's croplands. Positively, RR significantly increased crop yield (7.8%), soil organic carbon (SOC) pool (12.3% to 36.8%), soil nutrient reserves (1.9% to 15.2%), soil temperature (6.7%), and water contents (5.9%) and improved soil structure when compared with residue removal (P < .05). Negatively, RR may increase soil acidification and significantly increase emissions of greenhouse gases (by 31.7%, 130.9%, and 12.2% for CO2, CH4, and N2O). Nonetheless, the negative effects can be alleviated, and the positive effects can be strengthened by adopting RR in conjunction with appropriate crops, specific farming practices, and avoiding more than 10 years of consecutive use. The results indicated that a higher decomposition of native and newly added organic matters, induced by RR and attendant changes in soil physical properties, could enhance the dynamics of SOC, microbial biomass, soil nutrients, and the final increase in crop yield and greenhouse gases emissions. Thus, the sustainability of RR‐based system could be enhanced by a careful choice and adoption of integrated farming practices. Proper RR management strategies could offer a climate‐smart solution to ensure food security and sustain soil productivity.
An unprecedented cascade dearomative cyclization through hydrogen-bonding-assisted hydride transfer is realized. The aggregate effect of HFIP enables the rapid buildup of polycyclic amines directly ...from phenols and
-aminobenzaldehydes
a cascade dearomatization/rearomatization/dearomatization sequence. This unique transformation addressed the drawbacks of hydride transfer-involved redox-neutral reactions.
This study examined the effects of different levels of linguistic proficiency on the development of pragmatically appropriate requests in L2 Chinese in a study abroad context. The participants were ...31 American learners of Chinese studying in China. Fifteen learners came from intermediate level classes (Intermediate group) and the remaining 16 from advanced level classes (Advanced group). The participants completed a Computerized Oral Discourse Completion Test (CODCT) at the beginning and toward the end of their sojourn. The participants' oral request production was analyzed in terms of appropriateness rating, planning time, and speech rate. The results showed that the Intermediate and Advanced groups made comparable gains in appropriateness rating, that neither group reduced planning time, and that only the Advanced group gained in speech rate. The Intermediate and Advanced groups showed similar patterns of change in their production of alerters, head act forms (i.e., request strategies), internal modification, and external modification.
Carbocation-initiated cascade 1,5-hydride transfer/cyclization and dimerization reactions were developed to synthesize dihydrodibenzob,eazepine and octahydrodipyrroloquinoline derivatives in high ...yields. These redox-neutral C(sp3)–H functionalization-involving cascade reactions feature transition-metal-free, high atom- and step-economy, and environmental friendliness with water as the sole byproduct.
Animal oviducts and human Fallopian tubes are a part of the female reproductive tract that hosts fertilization and pre-implantation development of the embryo. With an increasing understanding of ...roles of the oviduct at the cellular and molecular levels, current research signifies the importance of the oviduct on naturally conceived fertilization and pre-implantation embryo development. This review highlights the physiological conditions within the oviduct during fertilization, environmental regulation, oviductal fluid composition and its role in protecting embryos and supplying nutrients. Finally, the review compares different aspects of naturally occurring fertilization and assisted reproductive technology (ART)-achieved fertilization and embryo development, giving insight into potential areas for improvement in this technology.
Fused deposition modeling (FDM) is utilized in the textile and apparel industry due to its adaptability, low cost, and high productivity. Promoting the efficient, diversified, and sustainable ...development of the textile and apparel industry, and to broaden the scope of application for FDM technology. This paper discusses the fundamental principles, design, and manufacturing processes of FDM printing of textiles and garments, as well as a summary of the commonly used materials for FDM printing of textiles and garments and their associated performance parameters. By examining the forming quality of textiles and garments, we analyze the influencing factors in the four phases of computer aided design (CAD) modeling, model slicing, forming processing, and post-finishing, and propose solutions to potential issues. Finally, case studies are used to summarise the primary applications of FDM in textile and apparel manufacturing, and the challenges and prospects of FDM in textiles and apparel are discussed. The application of FDM in the textiles and apparel industry not only promotes the advancement of manufacturing technology innovation, but also demonstrates a broader range of application value in terms of design development, functional properties, material combinations, and other factors.
The hydride transfer involved redox-neutral cascade cyclization has been developed to construct the spirocyclic bisoxindoles featuring a 3,4-fused oxindole moiety from rationally designed ...C4-amine-substituted isatins, affording the diverse tricyclic 3,4-fused oxindoles with three consecutive chiral centers in good yields and excellent diastereoselectivities (>20:1).
Selective and economic conversion of lignocellulosic biomass components to bio‐based fuels and chemicals is the major goal of biorefineries, but low yields and selectivity for fuel precursors such as ...sugars, furanics, and lignin‐derived monomers pose significant disadvantages in process economics. In this Minireview we summarize the existing protection strategies used in biomass chemocatalytic conversion processes and focus the discussions on the mechanisms, challenges, and opportunities of each strategy. We introduce a concept of using analogous methods to manipulate biomass catalytic conversion pathways during the upgrading of carbohydrates to fuels and chemicals. This Minireview may provide new insights into the development of selective biorefining processes from a different perspective, expanding the options for selective conversion of biomass to fuels and chemicals.
Catalytic conversion of biomass to fuels and chemicals is fraught with low selectivity. This Minireview provides an overview of the physical and chemical protection strategies used to improve selectivity in biomass conversion and describes the potential of using protection chemistry to manipulate catalytic pathways.
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