Multi-functional anodes boost the transient power and durability of proton exchange membrane fuel cells.

Proton exchange membrane fuel cells have been regarded as the most promising candidate for fuel cell vehicles and tools. Their broader adaption, however, has been impeded by cost and lifetime. By integrating a thin layer of tungsten oxide within the anode, which serves as a rapid-response hydrogen reservoir, oxygen scavenger, sensor for power demand, and regulator for hydrogen-disassociation reaction, we herein report proton exchange membrane fuel cells with significantly enhanced power performance for transient operation and low humidified conditions, as well as improved durability against adverse operating conditions. Meanwhile, the enhanced power performance minimizes the use of auxiliary energy-storage systems and reduces costs. Scale fabrication of such devices can be readily achieved based on the current fabrication techniques with negligible extra expense. This work provides proton exchange membrane fuel cells with enhanced power performance, improved durability, prolonged lifetime, and reduced cost for automotive and other applications

Local vibration characteristics of rotating blades induced by moving rub-impact loads

Considering spin softening and centrifugal stiffening effect of blades, the parameterized finite element model of rotating blades with moving rub-impact loads is established. Time domain response and frequency domain response are analyzed along with the change of speed and local vibration characteristic of the blade is studied under the different harmonic components. With investigation of the rotating blades, some conclusions have been found: The displacement caused by centrifugal effect has a maximum amplitude at blade tip and appears a smaller amplitude at blade root. And the stress change is just the opposite, which is basically a linear relation with location, and stress value caused by the centrifugal effect is basically in direct proportion to square of rotation speed within a certain range. Rub-impact can induced a variety of frequency multiplication components of the rotating blades, which cause different levels vibration response of the blade. The corresponding high-frequency components of the local stress mostly appear at angular position and root position of blade, which is easy to cause local fatigue damage of blade. Therefore, it need pay more attention to avoid frequency multiplication omponents caused by rub-impact approaching the natural frequency of the blade in order to prevent from local vibration. The results of the study in this paper will provide theoretical reference for the characteristic analysis and fault diagnosis of similar rotating blades

Local vibration characteristics of rotating blades induced by moving rub-impact loads

Considering spin softening and centrifugal stiffening effect of blades, the parameterized finite element model of rotating blades with moving rub-impact loads is established. Time domain response and frequency domain response are analyzed along with the change of speed and local vibration characteristic of the blade is studied under the different harmonic components. With investigation of the rotating blades, some conclusions have been found: The displacement caused by centrifugal effect has a maximum amplitude at blade tip and appears a smaller amplitude at blade root. And the stress change is just the opposite, which is basically a linear relation with location, and stress value caused by the centrifugal effect is basically in direct proportion to square of rotation speed within a certain range. Rub-impact can induced a variety of frequency multiplication components of the rotating blades, which cause different levels vibration response of the blade. The corresponding high-frequency components of the local stress mostly appear at angular position and root position of blade, which is easy to cause local fatigue damage of blade. Therefore, it need pay more attention to avoid frequency multiplication omponents caused by rub-impact approaching the natural frequency of the blade in order to prevent from local vibration. The results of the study in this paper will provide theoretical reference for the characteristic analysis and fault diagnosis of similar rotating blades

Local vibration characteristics of rotating blades induced by moving rub-impact loads

Considering spin softening and centrifugal stiffening effect of blades, the parameterized finite element model of rotating blades with moving rub-impact loads is established. Time domain response and frequency domain response are analyzed along with the change of speed and local vibration characteristic of the blade is studied under the different harmonic components. With investigation of the rotating blades, some conclusions have been found: The displacement caused by centrifugal effect has a maximum amplitude at blade tip and appears a smaller amplitude at blade root. And the stress change is just the opposite, which is basically a linear relation with location, and stress value caused by the centrifugal effect is basically in direct proportion to square of rotation speed within a certain range. Rub-impact can induced a variety of frequency multiplication components of the rotating blades, which cause different levels vibration response of the blade. The corresponding high-frequency components of the local stress mostly appear at angular position and root position of blade, which is easy to cause local fatigue damage of blade. Therefore, it need pay more attention to avoid frequency multiplication omponents caused by rub-impact approaching the natural frequency of the blade in order to prevent from local vibration. The results of the study in this paper will provide theoretical reference for the characteristic analysis and fault diagnosis of similar rotating blades

Local vibration characteristics of rotating blades induced by moving rub-impact loads

Considering spin softening and centrifugal stiffening effect of blades, the parameterized finite element model of rotating blades with moving rub-impact loads is established. Time domain response and frequency domain response are analyzed along with the change of speed and local vibration characteristic of the blade is studied under the different harmonic components. With investigation of the rotating blades, some conclusions have been found: The displacement caused by centrifugal effect has a maximum amplitude at blade tip and appears a smaller amplitude at blade root. And the stress change is just the opposite, which is basically a linear relation with location, and stress value caused by the centrifugal effect is basically in direct proportion to square of rotation speed within a certain range. Rub-impact can induced a variety of frequency multiplication components of the rotating blades, which cause different levels vibration response of the blade. The corresponding high-frequency components of the local stress mostly appear at angular position and root position of blade, which is easy to cause local fatigue damage of blade. Therefore, it need pay more attention to avoid frequency multiplication omponents caused by rub-impact approaching the natural frequency of the blade in order to prevent from local vibration. The results of the study in this paper will provide theoretical reference for the characteristic analysis and fault diagnosis of similar rotating blades

Effect of Infrared Pretreatment on Quality and Storage Stability of Cold-Pressed Pecan Oil

After infrared (IR) pretreatment for 22, 41, 68, 104 and 148 s, the internal temperature of pecan kernels reached 70, 90, 110, 130 and 150 ℃, respectively. To investigate the effect of IR pretreatment on the quality and storage stability of cold-pressed pecan oil, oil yield, fatty acid composition, lipid concomitants, physicochemical indicators, microstructure, and antioxidant capacity and storage stability were analyzed. The results showed that IR pretreatment increased the oil yield of pecan kernels by 11.10%–58.42% compared with the control group, but had no significant effect on the fatty acid composition of cold-pressed pecan oil. Moreover, IR pretreatment significantly the activities of lipase and polyphenol oxidase in pecan oil (P 0.05), and a 23.52% and 13.16% increase in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and ferric reducing antioxidant power (FRAP), respectively, thereby significantly enhancing the storage stability. To summarize, IR pretreatment for 148 s is the best pretreatment method to obtain cold-pressed pecan oil. The results of this study provide a theoretical basis for the application of IR pretreatment in the preparation of cold-pressed pecan oil

Genome-wide identification of the nuclear redox protein gene family revealed its potential role in drought stress tolerance in rice

IntroductionThioredoxins (TRX) are redox-active proteins critical for plant stress adaptation. As a TRX family member, nucleoredoxin (NRX) maintains drought-induced redox homeostasis, yet its genome-wide characterization in rice remains uninvestigated.MethodsUsing HMMER3.0 (E-value <1e-5) and TBtools, we identified OsNRX genes across three rice varieties (Minghui63, Nipponbare, 9311). Conserved domains were verified by SMART/CDD, while promoter cis-elements were systematically predicted with PlantCARE. Tissue-specific expression patterns were analyzed using RiceXPro data, and drought responses were quantified via qRT-PCR in drought-tolerant (Jiangnong Zao 1B) versus sensitive (TAISEN GLUTINOUS YU 1157) varieties under PEG6000 stress.ResultsTen OsNRX genes were classified into three subfamilies (NRX1/NRX2/NRX3) exhibiting conserved domain architectures. Promoter analysis identified abundant stress-responsive elements (ABRE, MBS) and phytohormone signals (ABA/JA/SA). Tissue-specific expression profiles revealed NRX1a dominance in roots/hulls, versus NRX1b/NRX2 enrichment in endosperm. Drought stress triggered rapid OsNRX upregulation (20-53-fold within 3-6h), with tolerant varieties showing earlier NRX2 activation than sensitive counterparts.DiscussionOsNRX genes exhibit dynamic drought-responsive regulation, while their spatiotemporal expression in glumes, embryos, and endosperm suggests potential dual roles in stress adaptation and grain development. These results provide molecular targets for improving drought resilience in rice breeding

Experimental studies on the complex oscillatory behaviour in gallic acid – BrO₃^{-  }Mn²⁺- H₂SO₄

823-828The title system has been studied in the batch reactor and its state followed by the bromide electrode potentials and UV spectroscopy. The system exhibits complex oscillatory behaviour including sequential oscillations. aperiodic oscillations and even the more complex oscillating states. On the basis of the analysis of the reaction products. the oscillations involving the following systems have been distinguished: (a) uncatalvzcd oscillations in gallic acid (GA)-BrO3 –H2SO4, system. (b) Mn2+ -catalyzcd oscillations in gallic acid (GA)-BrO3 –H2SO4 system. (c) Mn2+-catalyzed oscillations in monobromogallic acid(BrGA)-BrO3 –H2SO4 system. The inhibition and combination between these oscillations result in the complex oscillatory pattern observedm the present system. The oscillating mechanism has been discussed on the basis of FKN mechanism and OKN mechanism