•The concept of mechanical modulation energy harvesting is classified.•The methods and principles of mechanical modulation energy harvesting are summarized.•The applications of mechanical modulations ...to energy harvesting systems are reviewed.•The prospects of the research on mechanical modulation energy harvesting are presented.
Mechanical kinetic energy harvesting, which converts the mechanical motions and vibrations that are commonly available in the surrounding environment to electrical energy, can realize self-power sensing, control and actuation, with the advantages of convenience, energy saving, ecofriendliness and sustainability. It has broad application prospects in the fields of aerospace, biomedical engineering, environmental monitoring and military engineering. The forms of mechanical energy in the ambient are various and may be time-varying, and its direct conversion to electrical energy may result in low output power, low conversion efficiency, and even damage to the device. In order to improve the performance of energy harvester, the mechanical energy can be mechanically modulated and then be converted to electrical energy. In this paper, the key roles of mechanical modulations for energy harvesting are emphasized. The methods and principles of mechanical modulations and their applications to energy harvesting systems are reviewed and classified into three categories: excitation type conversions, frequency up-conversions, force/motion amplifications. The prospects of the research on mechanical modulation based energy harvesting are also presented.
This study aims at constructing an efficient bacterial consortium to biodegrade crude oil spilled in China's Bohai Sea. In this study, TCOB-1 (Ochrobactrum), TCOB-2 (Brevundimonas), TCOB-3 ...(Brevundimonas), TCOB-4 (Bacillus) and TCOB-5 (Castellaniella) were isolated from Bohai Bay. Through the analysis of hydrocarbon biodegradation, TCOB-4 was found to biodegrade more middle-chain n-alkanes (from C17 to C23) and long-chain n-alkanes (C31–C36). TCOB-5 capable to degrade more n-alkanes including C24–C30 and aromatics. On the basis of complementary advantages, TCOB-4 and TCOB-5 were chosen to construct a consortium which was capable of degrading about 51.87% of crude oil (2% w/v) after 1week of incubation in saline MSM (3% NaCl). It is more efficient compared with single strain. In order to biodegrade crude oil, the construction of bacterial consortia is essential and the principle of complementary advantages could reduce competition between microbes.
•Oil-degrading bacterial consortia are more efficient than one kind of bacterium.•The biodegradation efficiency of TPH by indigenous bacterial consortium reaches 51.87%.•Bacterial consortium consisting of inefficient bacteria exhibited low degradation efficiency.•Inappropriate adding of inefficient bacteria may reduce the dosage of efficient ones and reduce the degradation efficiency.•The utilization of complementary advantages is recommendable.
SnS2 has been widely studied as an anode material for sodium‐ion batteries (SIBs) based on the high theoretical capacity and layered structure. Unfortunately, rapid capacity decay associated with ...volume variation during cycling limits practical application. Herein, SnS2/Co3S4 hollow nanocubes anchored on S‐doped graphene are synthesized for the first time via coprecipitation and hydrothermal methods. When applied as the anode for SIBs, the sample delivers a distinguished charge specific capacity of 1141.8 mAh g−1 and there is no significant capacity decay (0.1 A g−1 for 50 cycles). When the rate is increased to 0.5 A g−1, it presents 845.7 mAh g−1 after cycling 100 times. Furthermore, the composite also exhibits an ultrafast sodium storage capability where 392.9 mAh g−1 can be obtained at 10 A g−1 and the charging time is less than 3 min. The outstanding electrochemical properties can be ascribed to the enhancement of conductivity for the addition of S‐doped graphene and the existence of p–n junctions in the SnS2/Co3S4 heterostructure. Moreover, the presence of mesopores between nanosheets can alleviate volume expansion during cycling as well as being beneficial for the migration of Na+.
Nanocube‐shaped SnS2/Co3S4‐rGO composites are synthesized for the first time via coprecipitation of Sn4+, Co2+, and OH− followed by alkaline etching and hydrothermal methods. The SnS2/Co3S4‐rGO electrode exhibits a high reversible capacity (1141.8 mAh g−1 at 0.1 A g−1 after 50 cycles) and excellent rate performance (392.9 mAh g−1 at 10 A g−1) when used as an anode for sodium‐ion batteries.
Autophagy modulates the degradation and recycling of intracellular materials and contributes to male gametophyte development and male fertility in plants. However, whether autophagy participates in ...seed development remains largely unknown. Here, we demonstrate that autophagy is crucial for timely programmed cell death (PCD) in the integumentary tapetum, the counterpart of anther tapetum, influencing embryo pattern formation and seed viability. Inhibition of autophagy resulted in delayed PCD of the integumentary tapetum and defects in embryo patterning. Cell-type-specific restoration of autophagic activities revealed that the integumentary tapetum plays a non-autonomous role in embryo patterning. Furthermore, high-throughput, comprehensive lipidomic analyzes uncovered an unexpected seed-developmental-stage-dependent role of autophagy in seed lipid metabolism: it contributes to triacylglycerol degradation before fertilization and to triacylglycerol biosynthesis after fertilization. This study highlights the critical role of autophagy in regulating timely integumentary tapetum PCD and reveals its significance in seed lipid metabolism and viability.
Chronic pain is a major clinical problem with limited treatment options. Previous studies have demonstrated that activation of adenosine monophosphate-activated protein kinase (AMPK) can attenuate ...neuropathic pain. Inflammation/immune response at the site of complete Freund's adjuvant (CFA) injection is known to be a critical trigger of the pathological changes that produce inflammatory pain. However, whether activation of AMPK produces an analgesic effect through inhibiting the proinflammatory cytokines, including interleukin-1β (IL-1β), in inflammatory pain remains unknown.
Inflammatory pain was induced in mice injected with CFA. The effects of AICAR (5-aminoimidazole-4-carboxyamide ribonucleoside, an AMPK activator), Compound C (an AMPK inhibitor), and IL-1ra (an IL-1 receptor antagonist) were tested at day 4 after CFA injection. Inflammatory pain was assessed with von Frey filaments and hot plate. Immunoblotting, hematoxylin and eosin (H&E) staining, and immunofluorescence were used to assess inflammation-induced biochemical changes.
The AMPK activator AICAR produced an analgesic effect and inhibited the level of proinflammatory cytokine IL-1β in the inflamed skin in mice. Moreover, activation of AMPK suppressed CFA-induced NF-κB p65 translocation from the cytosol to the nucleus in activated macrophages (CD68
and CX3CR1
) of inflamed skin tissues. Subcutaneous injection of IL-1ra attenuated CFA-induced inflammatory pain. The AMPK inhibitor Compound C and AMPKα shRNA reversed the analgesic effect of AICAR and the effects of AICAR on IL-1β and NF-κB activation in inflamed skin tissues.
Our study provides new information that AMPK activation produces the analgesic effect by inhibiting NF-κB activation and reducing the expression of IL-1β in inflammatory pain.
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•EP particles as a novel bacteria carrier on crack-healing in concrete was studied.•EP particles exert more positive effects on the healing capacity over EC particles.•Microstructures ...of the mineral precipitations on the crack surface were analyzed.•Completely healed crack widths were maximized in EP-B specimens.
Immobilization has been reported to be an efficient approach for bacteria-based self-healing concrete to maintain the high-efficiency mineral-forming capacity of incorporated bacteria over a period of time. However, the relatively high-cost, local unavailability, and low adsorption capacity of the current bacteria carriers make them impractical for potential implementation in large-scale concrete structures. In this study, the feasibility of expanded perlite (EP) as a novel bacteria carrier on quantifying cracks-healing in concrete via immobilization of Bacillus cohnii was demonstrated. The effects of two other self-healing techniques, i.e., direct introduction of bacteria and expanded clay (EC) immobilized bacteria, on the efficiency of crack-healing were also investigated. Experimental results showed that specimens incorporated with EP-immobilized bacteria exhibited the most efficient crack-healing after each healing time. The values of completely healed crack widths were up to 0.79mm after 28days of healing, which is larger than the value of 0.45mm for specimens incorporated with EC-immobilized bacteria. Field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) analysis confirmed that mineral precipitations on their crack surfaces are calcite crystals. The findings obtained in this study may provide a scientific basis for the potential implementation of expanded perlite, as a new microorganism carrier, in bacteria-based self-healing concrete.
Abstract
A cross‐1,3‐dipolar cycloaddition reaction of
α
‐halohydroxamates (in situ generated azaoxyallyl cations) with
N,N′
‐cyclic azomethine imines was developed. The synthetic protocol provided ...facile and rapid access to pyrazolo1,2‐
a
1,2,4triazine derivatives in good yields and excellent diastereoselectivities under mild metal‐free conditions.
Mesoporous Zn4O(−COO)6-based metal–organic frameworks (MOFs), including UMCM-1, MOF-205, MUF-7a, and the newly synthesized MOFs, termed ST-1, ST-2, ST-3, and ST-4 (ST = ShanghaiTech University), ...have been systematically investigated for ultrahigh capacity methane storage. Exceptionally, ST-2 was found to have the highest deliverable capacity of 289 cm3 STP/cm3 (567 mg/g) at 298 K and 5–200 bar, which surpasses all previously reported records held by porous materials. We illustrate that the fine-tuned mesoporosity is critical in further improving the deliverable capacities at ultrahigh pressure.
Recent advances in thermally localized solar evaporation hold significant promise for vapor generation, seawater desalination, wastewater treatment, and medical sterilization. However, salt ...accumulation is one of the key bottlenecks for reliable adoption. Here, we demonstrate highly efficient (>80% solar-to-vapor conversion efficiency) and salt rejecting (20 weight % salinity) solar evaporation by engineering the fluidic flow in a wick-free confined water layer. With mechanistic modeling and experimental characterization of salt transport, we show that natural convection can be triggered in the confined water. More notably, there exists a regime enabling simultaneous thermal localization and salt rejection, i.e., natural convection significantly accelerates salt rejection while inducing negligible additional heat loss. Furthermore, we show the broad applicability by integrating this confined water layer with a recently developed contactless solar evaporator and report an improved efficiency. This work elucidates the fundamentals of salt transport and offers a low-cost strategy for high-performance solar evaporation.
Accurate information on the distribution of permafrost and its thermal and hydrological properties is critical for environmental management and engineering development. This study modeled the current ...state of permafrost on the Qinghai‐Tibet Plateau (QTP), including the spatial distribution of permafrost, active‐layer thickness (ALT), mean annual ground temperature (MAGT), depth of zero annual amplitude (DZAA) and ground‐ice content using an improved Noah land surface model (LSM). The improved model was examined at a typical permafrost site and then applied to the entire QTP using existing gridded meteorological data and newly developed soil data. The simulated permafrost distribution and properties were validated against existing permafrost maps in three representative survey areas and with measurements from 54 boreholes. The results indicate that the Noah LSM with augmented physics and proper soil data support can model permafrost over the QTP. Permafrost was simulated to underlie an area of 1.113 × 106 km2 in 2010, accounting for 43.8% of the entire area of the QTP. The modeled regional average ALT and MAGT were 3.23 m and −1.56°C, respectively. Spatially, MAGT increases and DZAA becomes shallower from north to south. Thermally unstable permafrost (MAGT above −0.5°C) is predominant, accounting for 38.75% of the whole permafrost area on the QTP. Ice‐rich permafrost was mainly simulated around lakes across the north‐central QTP.
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