ZnCdS Dotted with Highly Dispersed Pt Supported on SiO2 Nanospheres Promoting Photocatalytic Hydrogen Evolution

[EN] The efficiency of solar hydrogen evolution closely depends on the fast transfer of charge carriers and the effective use of visible light. In this work, a novel photocatalyst SiO2/ZnCdS/Pt was successfully prepared to solve these two problems. An artistic structure of the photocatalyst was constructed and ZnCdS was successfully wrapped on the surface of SiO2 spheres with uniform Pt nanoparticles (NPs) in a size of 4.1 +/- 0.7 nm highly dispersed on the ZnCdS shell through the self-assembly method. Pt NPs can absorb the scattered light in the near field of SiO2 spheres. With the synergistic effect of SiO2 spheres and small highly dispersed Pt NPs, the absorption of visible light was significantly promoted. Meanwhile, the electron-hole recombination was also effectively inhibited, thus improving the photocatalytic activity. The hydrogen production activity of the highly efficient photocatalyst was as high as 8.3 mmol g(-1) h(-1) under visible light (lambda > 420 nm). The photocatalytic activity of SiO2/ZnCdS/Pt was 2.9 times higher than that of the ZnCdS/Pt photocatalyst.This work was supported by the National Natural Science Foundation of China (21976111), Shandong Provincial Natural Science Foundation (ZR2019MB052), and Large Instrument Open Foundation of Shandong Normal University (KFJJ2019004; KFJJ2021006).Liu, K.; Peng, L.; Zhen, P.; Chen, L.; Song, S.; García Gómez, H.; Sun, C. (2021). ZnCdS Dotted with Highly Dispersed Pt Supported on SiO2 Nanospheres Promoting Photocatalytic Hydrogen Evolution. The Journal of Physical Chemistry C. 125(27):14656-14665. https://doi.org/10.1021/acs.jpcc.1c0353514656146651252

Design by Radical Indigenism: Equitable Underwater & Intertidal Technologies of the Global South

This article considers the traditional water systems of indigenous cultures and explores their innovations as unique responses to the impacts of climate change in the global south. Local communities have been living with and developing water-responsive infrastructures for generations that engage and support the complex ecosystems they inhabit. Many of these innovations improve coastal resiliency, yet remain undocumented and unexplored in the evolution of contemporary solutions. Rooted in traditional ecological knowledge, or TEK, these technologies work symbiotically with, rather than against nature, and offer examples of a more comprehensive approach to underwater and intertidal design. These innovations are Lo—TEK, a term coined by designer and author Julia Watson, that is defined as resilient infrastructures developed by indigenous people through Traditional Ecological Knowledge (TEK) (Watson 2019). The movement to bring these innovations to the forefront of the design field counters the idea that Lo—TEK indigenous innovation is low-tech, a term often incorrectly applied to indigenous innovation that means unsophisticated, uncomplicated, and primitive. In actuality, Lo—TEK aligns to today’s sustainable values of low-energy, low-impact and low-cost, while producing complex nature-based innovations that are inherently sustainable. Lo-TEK expands the definition of contemporary technology by rebuilding our understanding of climate resilient design using indigenous knowledge and practices that are sustainable, adaptable, and borne out of necessity. Indigenous people have learned to live symbiotically with their environments, especially water. This essay will explore the Kuttanad Kayalnilam Farming System by the Malayalis in India, the Sangjiyutang Mulberry Dyke and Fish Ponds in China, and the Ramli Lagoon farms in Ghar El Melh, Tunisia. These innovations are inherently resilient to the stresses of the climate and are multi-functional, symbiotic structures themselves. While not directly intended for protection from the new challenge of sea level rise, they can inform how we can build circular water systems that work with the environment, rather than disrupting it

Size effect of CoS2 cocatalyst on photocatalytic hydrogen evolution performance of g-C3N4

The main goal of researchers is to obtain cheap cocatalysts that can promote the photocatalytic activity of catalysts. In this work, a series of CoS2/g-C3N4 (denoted as CoS2/CN) composite photocatalysts were synthesized by photodepositing CoS2 on g-C3N4 surface. The size of CoS2 species could be tuned from single-atom to nanometer scale, which had effect on photocatalysis. The 5CoS2/CN sample with proper nano size of CoS2 cocatalyst had the best photocatalytic performance (1707.19 μmol g−1h−1) in producing H2 under visible light irradiation (λ > 420 nm). Its photocatalytic activity was about 1434.6 times higher than that of pure g-C3N4 and almost equal with that of Pt/CN catalyst (1799.54 μmol g−1h−1). The Density Functional Theory (DFT) calculation results further suggested that the ability of accumulating the electrons of the cocatalyst was based on the size effect of CoS2, and the proper size of the cocatalyst efficiently promoted the separation of photogenerated electron-hole pairs.This work was supported by the National Natural Science Foundation of China (21976111) and Shandong Provincial Natural Science Foundation (ZR2019MB052). TEM studies were performed in the Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza (Spain). R.A. acknowledges funding from the Spanish MICIN (PID2019-104739GB-100/AEI/10.13039/501100011033).Peer reviewe

The discovery and characterization of AeHGO in the branching route from shikonin biosynthesis to shikonofuran in Arnebia euchroma

Shikonin derivatives are natural naphthoquinone compounds and the main bioactive components produced by several boraginaceous plants, such as Lithospermum erythrorhizon and Arnebia euchroma. Phytochemical studies utilizing both L. erythrorhizon and A. euchroma cultured cells indicate the existence of a competing route branching out from the shikonin biosynthetic pathway to shikonofuran. A previous study has shown that the branch point is the transformation from (Z)-3’’-hydroxy-geranylhydroquinone to an aldehyde intermediate (E)-3’’-oxo-geranylhydroquinone. However, the gene encoding the oxidoreductase that catalyzes the branch reaction remains unidentified. In this study, we discovered a candidate gene belonging to the cinnamyl alcohol dehydrogenase family, AeHGO, through coexpression analysis of transcriptome data sets of shikonin-proficient and shikonin-deficient cell lines of A. euchroma. In biochemical assays, purified AeHGO protein reversibly oxidized (Z)-3’’-hydroxy-geranylhydroquinone to produce (E)-3’’-oxo-geranylhydroquinone followed by reversibly reducing (E)-3’’-oxo-geranylhydroquinone to (E)-3’’-hydroxy-geranylhydroquinone, resulting in an equilibrium mixture of the three compounds. Time course analysis and kinetic parameters showed that the reduction of (E)-3’’-oxo-geranylhydroquinone was stereoselective and efficient in presence of NADPH, which determined that the overall reaction proceeded from (Z)-3’’-hydroxy-geranylhydroquinone to (E)-3’’-hydroxy-geranylhydroquinone. Considering that there is a competition between the accumulation of shikonin and shikonofuran derivatives in cultured plant cells, AeHGO is supposed to play an important role in the metabolic regulation of the shikonin biosynthetic pathway. Characterization of AeHGO should help expedite the development of metabolic engineering and synthetic biology toward production of shikonin derivatives

Resilience through aqua-agriculture transformation: Towards a multiscale approach for adaptive landscape development in Pear River Delta

The Pearl River Delta (PRD) is a river dominated floodplain in southeast China. Long known as one of the country’s richest agricultural regions, in recent years it has also become known as one of the world’s most densely urbanized areas. Decreasing space for water through dyke-ring construction, channelization and urbanization has led to increased flood risk from the river, rain, and the sea. To protect residents from flood risk, a more adaptive urbanization strategy is required, one that takes account of ecological agriculture (e.g. the traditional dyke-pond system) as well as historical water-management methods, which uses a multi-scalar approach. The objective of this thesis is to identify landscape architecture principles for multiscale water sensitive design based on traditional agri-aquacultural practice in this region. In Shunde district, a flood prone lowland located between the West and North rivers in the PRD, there is a century-old tradition in working with water via integrated agri-aquaculture systems. By learning from traditional agri-aquacultural practices, new design principles can be developed to mitigate flood risk while allowing for increased but sustainable urbanization, not just for the Shunde district, but also for the Pearl River Delta, so that they can be more resilient to flood risk in the future. Finally, an article called "Learning from Agri-Aquaculture for Multiscale Water-Sensitive Design in the Pearl River Delta" is also written by the author and Steffen Nijhuis and Gregory Bracken about principles and application through study.An article called "Learning from Agri-Aquaculture for Multiscale Water-Sensitive Design in the Pearl River Delta" is also written by Chuanzhi Sun, Steffen Nijhuis and Gregory Bracken about principles and application through study.AUTArchitecture, Urbanism and Building Sciences | Landscape Architectur

Blade Sorting Method for Unbalance Minimization of an Aeroengine Concentric Rotor

This paper proposes a blade sorting method based on the cloud adaptive genetic algorithm (CAGA), which is used to optimize the unbalanced of asymmetric rotor of aero-engine. Firstly, by analyzing the unbalance of the arrangement caused by the deviation of the mass moment of the blade, and considering the concentricity of the disk, an optimization model of the unbalanced amount of the blade assembly was established. Secondly, the selection operator, crossover operator, and mutation operator of the algorithm were designed, and the cloud adaptive genetic algorithm was used to optimize the assembly unbalance. Thirdly, the mass moments of a group of aero-engine blades were weighed using a moment scale (MW0), and the blade mass moment distribution and assembly unbalance under the six blade arrangements were analyzed. Finally, by setting different disk concentricity, the corresponding blade arrangement and the final rotor unbalance were obtained. Through analysis, it was found that the unbalance of GA is at least 57.5% optimized relative to the weight sorted, sorting type 2, sorting type 4, and sorting-1/4 skip method, and the unbalance optimized by the CAGA is 95.7% optimized relative to GA. In the case of different initial concentricity of the disk, the effective algorithm accuracy is still maintained, which proves the effectiveness of the method for the arrangement of asymmetric rotor blades. This method establishes an effective asymmetric rotor blade arrangement model, uses the cloud adaptive genetic algorithm to sort the blade assembly, and effectively reduces the unbalanced amount of the asymmetric rotor

Learning from Agri-Aquaculture for Multiscale Water-Sensitive Design in the Pearl River Delta

The Pearl River Delta (PRD) is a river dominated floodplain in southeast China. Decreasing space for water, through dike-ring construction, channelization, and urbanization, has led to increased flood risk from river, rain, and sea. To protect from flood risk, a more adaptive urbanization strategy is required; one takes into account a multiscale approach while investigating agri-aquaculture, i.e. ecological agriculture, for example, the dike-pond system which makes use of traditional water management methods. The objective of this article is to identify landscape architecture principles for multiscale water-sensitive design based on traditional agri-aquacultural practices in the region. In the Shunde district (a flood prone lowland located between the West and North rivers of the PRD) there is a centuries’ old tradition of working with water via integrated agri-aquaculture systems. By learning from traditional agri-aquacultural practices, new design principles can be developed to mitigate flood risk while allowing for increased but sustainable urbanization, not just for the Shunde district, but also for the PRD, so that these areas can be more resilient to floods in the future.Spatial Planning and StrategyLandscape Architectur

Tensile Test and Numerical Simulation Investigations on the Mechanical Properties of a New Type of Slightly Curved Arc HRB400 Steel Bars in Mass Concrete

Abstract The temperature stress in mass concrete structure is relatively high during construction, which usually leads to temperature cracks. To solve this problem, concrete blocks are usually placed by setting wide slots. Connecting the truncated steel bars at the position of the wide slots by welding or extruding sleeves has many disadvantages. To solve the problem of temperature-induced stress loss, a new type of slightly curved arc HRB400 (SCAHRB400) steel bars was proposed without cutting off the steel bars in this article. Tensile tests and numerical simulations were performed for five types of SCAHRB400 steel bars considering geometric and material nonlinearity. Based on the test results and numerical simulation results, the equivalent stress–strain relationships of SCAHRB400 steel bars were established, and the emergence of the plastic zone of SCAHRB400 steel bars in the tensile process were observed, the tensile properties of SCAHRB400 steel bars were analyzed and discussed. The test results indicate that SCAHRB400 steel bars are prone to local yielding near the crown of large arches and at the connection of horizontal and arc sections. The numerical simulation equivalent stress–strain curves have good regularity. The equivalent stress–strain curves of slightly curved arc HRB400 and HRB335 steel bars have the similar changing law. When the stress is small, the tensile stiffness and compressive axial stiffness of slightly curved arc HRB400 and HRB335 steel bars are similar; when the stress is large, the axial stiffness of SCAHRB400 steel bars is greater than that of slight curved arc HRB335 steel bars. Through test and numerical simulation studies, the theoretical basis can be established for the engineering application of new slightly curved arc steel bars in mass concrete