查找使用阿拉丁产品的科研文献

Mapping the Space Charge at Nanoscale in Dielectric Polymer Nanocomposites

Simin Peng,Zhen Luo,Shaojie Wang,Jiajie Liang,Chao Yuan,Zhikang Yuan,Jun Hu,Jinliang He,Qi Li

Heterogeneous dielectric materials such as dielectric polymer nanocomposites have attracted extensive attention because of their exceptional insulating and dielectric performance, which originates from the unique space charge dynamics associated with the various interfacial regions. However, the space charge distribution and transport in polymer nanocomposites remain elusive due to the lack of analytical methods that can precisely probe the charge profile at the nanoscale resolution. Although a few studies have explored the possibility of using scanning probe techniques for characterizing the local charge distribution, the interference from induced electrical polarization of the material has been unfortunately ignored, leading to inaccurate results. In this contribution, we report an open-loop Kelvin probe force microscopy (KPFM) method with nanoscale resolution for the direct detection of the space charge profile in dielectric polymer nanocomposites. Unlike the conventional studies where a vertical direct current (DC) voltage is applied on the sample through the probe to evoke the charge injection and transport in dielectric polymer nanocomposites, the present method is established based on a delicate electrode configuration where a lateral electric field is allowed to be applied on the sample during the KPFM test. This special testing configuration enables real-time charge injection and transport without inducing the electrical polarization of material along the vertical direction, which gives rise to clean mapping of space charges and reveals the interfacial charge trapping in polymer nanocomposites. This work provides a robust and reliable method for studying the sophisticated charge transport properties associated with the various interfacial regions in heterogeneous dielectric materials.

3D structural-engineering evaporator integrating light-space-heat omnibearing regulation

Xuemin Geng,Peng Yang,Yanfen Wan

Interfacial solar evaporators designed with sophisticated 3D structure hold the potentiality for ameliorating the evaporation rate through expanding the surface area for evaporation, facilitating water movement and bolstering air convection. However, the most current 3D evaporators are stalemated of constrained light absorption, circumscribed evaporative surface or thermal dissipation which collectively result in the curtailment of evaporation rate escalation. In this work, an omnibearing convergence of new cup-like 3D solar steam generator (C-3D SSG) based on MoS 2 /C and PVA materials with integrated coordination of light-space-heat is constructed. The innovative cup-like structural design of C-3D SSG successfully embodies the convergence of light, space and heat management through the strategic integration of photothermal materials (PTM), substrate materials and evaporative elements across multiple scales, demonstrating a compelling advancement in light absorption, copious heat diffusion space and prodigious energy-harvesting zone and water evaporation rate enhancement. The omnibearing regulation attains a premium evaporation rate of 3.89 kg m -2 h −1 under 1 Sun illumination with recycle energy of 1.71 W. By incorporating the C-3D SSG for practical application, it can function as an evaporator within a cup, thereby enhancing its practical utility. And C-3D SSG with panoramic convergence provides a broad range of research avenues and methodologies for addressing the water crisis and the development of ISSG technology.

How the space environment influences organisms: an astrobiological perspective and review

Binod Prasad,Peter Richter,Nithya Vadakedath,Ferdinand W. M. Haag,Sebastian M. Strauch,Rocco Mancinelli,Achim Schwarzwälder,Emmanuel Etcheparre,Nicolas Gaume,Michael Lebert

The unique environment of space is characterized by several stress factors, including intense radiation, microgravity, high vacuum and extreme temperatures, among others. These stress conditions individually or in-combination influence genetics and gene regulation and bring potential evolutionary changes in organisms that would not occur under the Earth's gravity regime (1 × g). Thus, space can be explored to support the emergence of new varieties of microbes and plants, that when selected for, can exhibit increased growth and yield, improved resistance to pathogens, enhanced tolerance to drought, low nutrient and disease, produce new metabolites and others. These properties may be more difficult to achieve using other approaches under 1 × g. This review provides an overview of the space microgravity and ionizing radiation conditions that significantly influence organisms. Changes in the genomics, physiology, phenotype, growth and metabolites of organisms in real and simulated microgravity and radiation conditions are illustrated. Results of space biological experiments show that the space environment has significant scientific, technological and commercial potential. Combined these potentials can help address the future of life on Earth, part of goal e of astrobiology.

Gas Purification Technology Suitable for Space Mice Cultured in Sealed Box

Ru Yuan,Haoyuan Sun,Qian Zhang,Le Zhang,Shidong Yuan,Fangwu Liu,Tao Zhang

A stable atmosphere is very important for long-term life science experiments with small mammals in sealed habitats. In this study, we constructed a multi-stage, solid-state purification system to regulate and control the supply of oxygen and remove carbon dioxide, humidity, and trace contaminants in a sealed metal box. Lithium hydroxide was used as the material to absorb CO2; molecular sieves and humidity-indicating silica gel were used as dehumidification material; and activated carbon-based sorbent was used to remove ammonia and hydrogen sulfide. We evaluated the performance of the system by implementing a sealed culture test with mice for 7 days. The pressure, relative humidity, oxygen concentration, carbon dioxide concentration, and ammonia/hydrogen sulfide concentration in the sealed box were maintained at 101–103 kPa, 30–36%, 19–21%, <1000 ppm, and the main goal of this study was to test for single gas absorption. In the future, we will investigate the competitive effect of multi-gas mixtures.

Through-Space Electron Coupling in Nonaromatic Architectures Drives Solar Hydrogen Production

Yu Pei,Yu Zhang,Hu Shi,Dan Zhang,Yanbing Lv,Pengju Yang,Wentao Song,Hengquan Yang

The rational design of next-generation photocatalytic materials capable of simultaneously addressing sustainability challenges and performance demands represents a critical frontier in photocatalysis research. Herein, these finding are reported that nonaromatic biomass-derived architectures have exceptional visible-to-near-infraredphotocatalytic activity for hydrogen evolution via a novel 3D through-space conjugation (TSC) mechanism, which leads to a transformative strategy for sustainable hydrogen production. It is identified that the oxygen-mediated 2p orbital hybridization in these biomass-derived materials constitutes semiconductor-like band structures with exceptionally broad band light absorption capabilities. Moreover, the inherent electronegativity gradient among carbon, hydrogen, and oxygen atoms creates an asymmetric charge distribution, generating substantial molecular dipole moments (>10 Debye) that leads to enhanced charge separation. The optimized materials achieve record-high apparent quantum yields of 44.63% (420 nm) and 1.58% (800 nm) for hydrogen production, rivaling state-of-the-art photocatalysts. This revealed TSC mechanism fundamentally redefines the design paradigm for organic photocatalysts, creating a sustainable materials platform that concurrently enables biomass valorization and efficient solar fuel generation. These findings represent a conceptual breakthrough in the photocatalyst design, offering a vast opportunity for advancing next-generation solar fuel technologies.

Varying heterojunction thickness within space charge region for photocatalytic water splitting

Fengzai Lv,Wencai Huang

Photocatalytic overall water splitting for converting solar energy into hydrogen is a potential means of pursuing a renewable, scalable, and eco-friendly energy source. It is challenging to achieve the 5%–10% solar-to-hydrogen (STH) efficiency needed to be economically viable for renewable solar hydrogen production. Here, we report a heterojunction in which the thickness within the space charge region can be precisely adjusted to enhance the redox capacity, increase light absorption, and reduce carrier transport distance. The fully stacked two catalysts and aqueous-solution-exposed surfaces exhibit advantages of an enhanced built-in-electric field and a highly effective surface area. Based on that, an Ag 3 PO 4 /CdS/Pt photocatalyst exhibits overall water splitting with an STH efficiency, dramatically improving from zero to 0.75% under visible light at ambient pressure by tuning CdS/Ag 3 PO 4 thickness from 200 nm/120 nm to 60 nm/30 nm. The STH efficiency can be further enhanced to 2% under visible light in 0.01 mol L −1 Na 2 S solution.

Supratough and stretchable hydrogels with time-space controllability for athletic rehabilitation

Tian-Cai Sun,Xu-Chao Ning,Seeram Ramakrishna,Yun-Ze Long,Jun Zhang

There is a higher risk of injury for athletes when the intensive competition occurs. Minimally invasive surgery is still the first choice for athletes because of its small wound surface and fast recovery. In addition, knowing whether athletes recover in real time at the first time is beneficial for the athletes to return to the competition as soon as possible and maintain their peak performance. We developed a medical hydrogel to meet the dual needs of minimally invasive therapy and wearable testing. A novel ε-PL/PVP/MXene (εPM) hydrogel with spatio-temporal control and in situ enhancement was prepared by the concept of microchemical reaction cavity. MXene was introduced as the microchemical reaction center, and the dual effects of heat transport and microcatalysis were utilized to make the gel network uniform and moldability after injection in vivo, so as to realize the filling and treatment of irregular wounds. The hydrogel tissue is not only adhesive, self-healing and soft, but also super tough, keeping its shape stable under repeated stretches, intense hammering, continuous trampling, and even the extremely catastrophic impact of being run over 50 times by a car. At the same time, the hydrogel has excellent ionic conductivity (4.12 S/m) and sensing ability, which can record athletes' movement characteristics in real time and transmit them to doctors through wireless Bluetooth, so as to make accurate judgment on the recovery of health. This is the first exploration of the combination of hydrogel in the field of minimally invasive therapy and wearable devices, which opens up a new avenue for efficient minimally invasive therapy and accurate rehabilitation monitoring.

Insight Into Space Charge Suppression by Interfacial Deep Traps in Polymer Nanocomposites

Yao Zhou,Yujie Zhu,Chao Yuan,Qi Li,Xiangdong Xu,Yuriy Serdyuk,Qing Wang,Jinliang He

Tuning Guest Cations to Liberate Pore Space for Efficient C4 Hydrocarbon Separation

Xue Zhang,Tao Zhang,Miao Zeng,Puxu Liu,Suhang Wang,Yu Wang,Kaijie Chen

Although C4 hydrocarbons are important raw materials for synthetic rubber and fine chemicals, their similar physicochemical properties limit the effectiveness of traditional high-energy separation processes. Herein, we report a post-synthetic modification strategy that tunes the pore space of an anionic Cu-MOF ([Me2NH2][Cu3(μ3-OH)(pyc)3], 1) via simple cation exchange. Replacing the bulky dimethylammonium (Me2NH2+) cations with smaller potassium (K+) ions ([K][Cu3(μ3-OH)(pyc)3], 1·K) liberates additional pore volume, which significantly enhances the adsorption capacity for C4 olefins. At 298 K and 95 kPa, 1·K showed higher iso-C4H8 (74.9 cm3 g-1 vs 42.7 cm3 g-1) and C4H6 (77.9 cm3 g-1 vs 49.0 cm3 g-1) adsorption capacities than 1. The expanded pore space, rather than strong specific interactions with K+, is identified as the key factor driving the superior separation selectivity for both the isobutene/isobutane binary and the n-butene/isobutene/1,3-butadiene ternary mixtures, as confirmed by adsorption and breakthrough experiments and theoretical simulations.

Structural and functional benefits of Ganoderma lucidum polysaccharides due to space mutagenesis

Bingqian Nie,Jianle Chen,Wenkang Wang,Tong Cao,Xingqian Ye,Shiguo Chen,Zhiqiang Hou

Ganoderma lucidum samples from space-mutated strains transported by China's “Shenzhou” recoverable satellites, along with traditionally cultivated counterparts, were selected for this study. Polysaccharides from Ganoderma lucidum were extracted using a two-step sequential method integrating hot water and alkaline extractions. Liquid chromatography-mass spectrometry (LC-MS) was employed to characterize polysaccharide structures (monosaccharide composition and glycosidic linkages) and profile terpenoids, assessing the impact of space mutation. Results showed a significant increase ( p  < 0.05) in polysaccharide and terpenoid contents, with polysaccharide yield rising from 178.59 % to 265.38 %. Space-mutated polysaccharides exhibited higher glucose content, altered monosaccharide composition, lower molecular weight, and an enriched β-1,3-glucan structure. They also demonstrated enhanced anti-inflammatory activity, underscoring the functional benefits of space-induced modifications. This study presents the first comprehensive analysis of structural alterations in Ganoderma lucidum polysaccharides induced by space mutation. It provides valuable scientific insights into the space breeding of medicinal plants and suggests that space mutation technology could serve as a promising strategy for developing functional foods from Ganoderma lucidum .

Data-driven discovery of active phosphine ligand space for cross-coupling reactions

Sicong Ma,Yanwei Cao,Yun-Fei Shi,Cheng Shang,Lin He,Zhi-Pan Liu

The design of highly active catalysts is a main theme in organic chemistry, but it still relies heavily on expert experience. Herein, powered by machine-learning global structure exploration, we forge a Metal–Phosphine Catalyst Database (MPCD) with a meticulously designed ligand replacement energy metric, a key descriptor to describe the metal–ligand interactions. It pushes the rational design of organometallic catalysts to a quantitative era, where a ±10 kJ mol−1 window of relative ligand binding strength, a so-called active ligand space (ALS), is identified for highly effective catalyst screening. We highlight the chemistry interpretability and effectiveness of ALS for various C–N, C–C and C–S cross-coupling reactions via a Sabatier-principle-based volcano plot and demonstrate its predictive power in discovering low-cost ligands in catalyzing Suzuki cross-coupling involving aryl chloride. The advent of the MPCD provides a data-driven new route for speeding up organometallic catalysis and other applications.

Space exposure enhanced pectin-degrading enzymes expression and activity in Aspergillus costaricaensis

Song Xiaohui,Li Tang,Gu Hui,Yin Heng

Aspergillus is a well-studied fungal genus that is widely used in the processing of plant biomass in industries. This study investigated the effects of space exposure on the ability of Aspergillus costaricaensis , a filamentous fungus isolated from rotten orange peel, to degrade pectin. These fungal spores were carried into space by the Long March 5B carrier rocket and exposed to cosmic radiation for 79 h. After the flight, these spores were resuscitated, and then the growing strains were screened with pectin as the sole carbon source, and the pectinase activity was evaluated. A mutant with increased biomass accumulation ability and pectin-degrading activity compared to the ground control strain was obtained. Comparative transcriptome analysis revealed that several CAZymes genes were significantly upregulated in the mutant, especially those related to pectin degradation. Among the 44 pectinases identified from the annotated genome, 42 were up-regulated. The activities of these pectinases are able to synergistically break down the structure of pectin. In addition, the expression of some genes involved in metabolism, sugar transport, and stress response was altered. These results imply that space exposure might serve as a potential mutagenesis breeding technique, offering the opportunity to acquire biomass-degrading microbial strains with potential for industrial application.