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Non‐noble Ni−Cu alloys serve as an alternative catalytic material for noble metal‐based catalysts that could be applied in the efficient conversion of levulinic acid (LA) into the high value γ‐valerolactone (GVL). However, maintaining the catalytic stability for Ni−Cu nanoparticles in the LA hydrogenation process remains a substantial challenge, Herein, this problem is solved by constructing carbon‐protected catalytic sites within carbon layer‐coated Ni−Cu nanoalloy composite via pyrolysis of NiCux(OH)/glucose precursor. The optimized NiCu0.68@C catalyst exhibits excellent stability and selectivity to GVL (>99 %) in the hydrogenation of LA reaction. Various characterization indicates that the enhancement in stability originates from the protective effect of the carbon layer, which prevents the metal leaching, oxidation and aggregation of Ni−Cu nanoparticles during the reaction process. This work greatly advances non‐noble metal‐catalyzed conversion of LA to GVL and helps the rational design of bimetallic catalysts. [ABSTRACT FROM AUTHOR]

Catalytic olefin metathesis represents a vital reaction in the chemical industry, as it provides a feasible route for the interconversion of olefins. However, traditional supported catalysts usually suffer from low activity due to sluggish kinetics for the formation of catalytically active metal‐carbene species. This work tackles this issue by taking phosphoric acid as a promoter and constructing a Brønsted acidic site to cooperate with the MoOx sites, thus facilitating the formation of Mo‐carbene. It turns out that the turnover frequency of propene metathesis over the Mo−P/Al2O3 catalyst is 7.1 times higher than that over the unmodified Mo/Al2O3 catalyst. The combined characterization reveals the promotion of phosphorus results from the alignment of olefin toward adjacent MoOx and thus facilitates formation of active Mo‐carbene species. [ABSTRACT FROM AUTHOR]

To meet the lightweight needs of modern machinery equipment, welded structure is widely used in practical engineering. During the service period, the welded structure is often subjected to multilevel variable amplitude loading, and fatigue failure is easy to occur. Due to the complexity and stochasticity of fatigue process, the traditional life prediction models cannot meet the demand of practical engineering. In this work, a novel prediction model based on the whale optimization algorithm (WOA) together with the support vector regression (SVR), namely, a WOA‐SVR model, is established. It combines the advantages of WOA and SVR for global searching optimization and high prediction accuracy dealing with small sample size. By taking into account the sequence of loadings and the interaction effect between loadings, the proposed WOA‐SVR model could overcome the deficiencies and shortcomings in existing models. Experiment results show that WOR‐SVR has better prediction performance than five models. Highlights: The WOA‐SVR model is established to predict the fatigue life under two‐level loading.The proposed model is verified by 190 experimental results.The proposed model has higher accuracy compared with other five models.The proposed model can be effectively applied to both welded joints and metal materials. [ABSTRACT FROM AUTHOR]

Exceedingly strong aeolian dust activity has occurred in inland Asia. Comparisons of the late Cenozoic sedimentation rates between aeolian and fluvial‐lacustrine sequences around the northern Tibetan Plateau suggest that aeolian process has played an important role in the erosion, weathering and deposition of sediment. However, recognizing dust as an important source in fluvial‐lacustrine sequences is a vital but difficult task. Here, clay‐sized mineral and elemental records of regional silicate weathering histories are revisited during the period of Asian dust expansion at ~9–8 Ma. The aeolian dust input from the Tianshan‐Altay Orogens into the Jiuquan Basin is identified using the Th/Sc ratio while that from the Qilian Shan into the Xining Basin is identified based on inconsistent fine‐grained silicate weathering proxies. Our study suggests that the use of appropriate dust provenance tracers and recognition of wind transport‐induced changes in dust grain size and chemistry can provide useful aeolian dust discrimination approaches. [ABSTRACT FROM AUTHOR]

In recent years, convolutional neural networks have achieved great success in streak artifacts reduction. However, there is no special method designed for the artifacts reduction of the prostate. To solve the problem, the artifacts reduction CliqueNet (ARCliqueNet) to reconstruct dense‐view computed tomography images form sparse‐view computed tomography images is proposed. In detail, first, the proposed ARCliqueNet extracts a set of feature maps from the prostate sparse‐view CT image by Clique Block. Second, the feature maps are sent to ASPP with memory to be refined. Thenanother Clique Block is applied to the output of ASPP with memory and reconstruct the dense‐view CT images. Later on, reconstructed dense‐view CT images are used as new input of the original network. This process is repeated recurrently with memory delivering information between these recurrent stages. The final reconstructed dense‐view CT images are the output of the last recurrent stage. Our proposed ARCliqueNet outperforms the SOTA (state‐of‐the‐art) general artifacts reduction methods on the prostate dataset in terms of PSNR (peak signal‐to‐noise ratio) and SSIM (structural similarity). Therefore, we can draw the conclusion that Clique structures, ASPP with memory and recurrent learning are useful for prostate sparse‐view CT Artifacts here. [ABSTRACT FROM AUTHOR]

Fast late Miocene global cooling since ∼7 Ma accompanied by less changeable atmospheric CO2 levels revealed by existing proxy reconstructions has suggested an intriguing tectonic‐climate link that remains controversial. Here, we present late Cenozoic clay mineral records of the silicate weathering intensity from the Chinese Loess Plateau and northeastern Tibetan Plateau to demonstrate a remarkable increase in silicate weathering intensity at ∼9–7 Ma induced by enhanced monsoon. This change caused CO2 consumption ranging from 0.18 to 1.8 × 1011 mol C yr−1 over the East Asian monsoon region, accounting for 0.2%–2% of the modern continental silicate weathering flux, thus providing an additional atmospheric CO2 sink. Moreover, we propose that this additional sink may have contributed to the large atmospheric CO2 consumption and fast global cooling in the late Miocene, which ultimately caused the onset of the Northern Hemisphere glaciation at ∼7 Ma. Key Points: Late Cenozoic clay mineral records of silicate weathering intensity in the northeastern Tibetan Plateau and Chinese Loess PlateauSilicate weathering intensity has been greatly enhanced over the East Asian monsoon region at ∼9–7 MaMonsoon‐forced silicate weathering acting as an emerging CO2 sink may regulate fast global cooling since ∼7 Ma [ABSTRACT FROM AUTHOR]

Rationale: An inductively coupled plasma tandem mass spectrometry (ICP‐MS/MS) instrument can be developed to determine 87Sr/86Sr ratios with an external precision better than 0.05% relative standard deviation (RSD) in "mass shift" mode without prior Sr purification. Previous studies suggested using CH3F, N2O, and SF6 as reaction gases for this method because a better reaction rate can be achieved with Sr+ than with O2 in the reaction cell. However, these gases are not commonly used in general chemistry laboratories, and processes using these gases are difficult to implement quickly due to regulations. We aim to develop a rapid method that can be applied to many samples for the accurate determination of 87Sr/86Sr isotope ratios with precision below 0.1% RSD (or approximately to the fourth decimal place). Methods: We evaluated the accuracy and precision of 87Sr/86Sr ratios in certified reference materials and different rock types determined using ICP‐MS/MS with O2 as the reaction gas in comparison with those determined using the multicollector inductively coupled plasma mass spectrometry (MC‐ICP‐MS) method. Results: This study showed that by using the ICP‐MS/MS method, the 87Sr/86Sr ratios of BCR‐2 and BHVO‐2 do not vary significantly with and without prior Sr purification; when the Sr concentration of the measured solution is within the range of 60–350 ng/mL, there is no significant effect on the measured 87Sr/86Sr ratios. The results also showed that the 87Sr/86Sr ratios of 23 different rock types measured by ICP‐MS/MS and MC‐ICP‐MS methods agree very well. Conclusions: The precision of the 87Sr/86Sr ratio measured using ICP‐MS/MS varies between 0.0001 and 0.0019 (2SD). This precision is less than that of the MC‐ICP‐MS method but is sufficient for certain applications, such as identifying 87Sr/86Sr ratios in different rock types. These results suggest that the developed ICP‐MS/MS method has the potential for future studies involving the identification of Sr sources. [ABSTRACT FROM AUTHOR]

The evolution and driving factors underlying dust activity in central Asia remain controversial, particularly in its effects on downwind regions. We present a Holocene dust storm activity record retrieved from the Tarim Basin (TB) and perform linear and nonlinear analyses on dust records from the TB and the Greenland areas. The results indicate a similar response of dust activities to total solar irradiance in both areas, and an outbreak of dust storms in the TB at ~3.5 kyr BP. We suggest that decreasing temperature in high northern latitudes, aided by solar activity change, reached a critical threshold near ~3.5 kyr BP. The resulting steepening of the meridional temperature gradient would have facilitated strengthening and southward shift of the Northern Hemisphere westerly jet, leading to the outbreak of dust storms through intensification of low level wind intensity and prolonged spring conditions in the Asian interior. Key Points: A possible tipping point of dust activity in central Asia at ~3.5 kyr BP was indicated by intensity and regime changes of dust recordWe identify similar response of dust activities in both central Asia and Greenland areas to solar activity changeInsolation and solar activity change drive dust storm outbreak in Asia by increased wind intensity and prolonged spring conditions [ABSTRACT FROM AUTHOR]

The uplift of the Tibetan Plateau (TP) during the late Cenozoic is thought to be one of crucial factors controlling Asian climate. However, the complex interaction between tectonics and climate change is still unclear. Here we present the first record of clay mineralogy and elemental geochemistry covering ~12.7–4.8 Ma in a fluvial‐lacustrine sequence in the Xining Basin. Geochemical provenance proxies (Th/Sc, Zr/Sc, and Cr/Zr) in the <2‐μm fraction show a significant provenance change at ~8.8 Ma. Silicate‐based weathering indexes (CIA, CIW, and PIA) displayed coeval changes with provenance but discrepant changes with regional climate. Since the clay mineralogy exhibits significant change at ~7.8 Ma uncorrelated with modifications in provenance, it can be employed to reveal regional climate change. The rise in illite and associated decrease in the sum of smectite and illite/smectite mixed layers reflect gradual and slow aridification since ~12.7 Ma with intensified drying since ~7.8 Ma until approaching the modern climate status. Our results, together with other regional climatic and tectonic records, clearly illustrate that accelerated uplift of the northeastern TP since ~8–9 Ma has mainly modulated the regional erosion, weathering, transportation, and sedimentation and amplified the global cooling and drying trend toward the regional climate of modern conditions. Our study suggests that in the tectonically active northeastern TP, a comprehensive mineralogical and geochemical investigation of the fine‐grained fraction of the basin sediments could retrieve the interactions between tectonics and climate behind the complex change in exhumed lithology and sedimentary routing systems. Key Points: A long‐term gradual aridification since 12.7 Ma and an enhanced drying event since ~7.8 Ma occurred in the Xining BasinUplift of the northeastern Tibetan Plateau was the major driver of the evolution of regional climate and landscape since the late MioceneClay minerals are well‐used potential proxies for paleoclimatic reconstructions in complex sedimentary routing systems [ABSTRACT FROM AUTHOR]

Abstract: Palygorskite is a widely used indicator of semiarid to arid environments in paleoclimate studies. In this study, we present detailed mineralogical and geochemical investigations exploring the genesis of palygorskite found in Eocene fluvial sediment in the northern Qaidam Basin on the northeastern Tibetan Plateau. The presence of two types of palygorskite is revealed, based on their crystallinity characteristics and distinctive rare earth element (REE) patterns in the coexisting clay fraction. Well‐crystallized palygorskite samples are characterized by remarkably negative Ce anomalies and obvious middle rare earth element enrichment. Poorly crystallized palygorskite samples generally exhibit positive Ce anomalies and less pronounced middle rare earth element enrichment, which resemble those of nonpalygorskite‐bearing clay samples. Given the presence of an overall oxidized fluvial sedimentary environment, we attribute the well‐crystallized palygorskite (which has textures comprising long, interwoven fibers) to direct precipitation (i.e., neoformation) occurring within a reducing environment during early/postdepositional processes while the poorly crystallized palygorskite (which is characterized by short, club‐shaped single crystals) originates as catchment‐delivered detritus. These poorly crystallized palygorskites occur mostly in 49.5–47.0 Ma and are accompanied by decreasing kaolinite content, increasing chlorite content, and abundant xerophytic spore‐pollen from the Qaidam Basin, and its neighboring Xining Basin. Collectively, these evidences suggest that a less humid climate followed after the Early Eocene Climate Optimum. [ABSTRACT FROM AUTHOR]

The Xining Basin lies in the transitional zone between the arid Asian interior and the East Asian monsoon region. The continuous Cenozoic sediments in the basin provide a unique archive recording the uplift of the Tibetan Plateau and its environmental effects on central Asian aridification and Asian monsoon evolution. However, sediments deposited since the middle Middle Miocene have not been precisely dated, hindering our ability to address these issues. Here we dated a 336 m-thick section containing many Late Miocene fossil mammals from the eastern basin. High-resolution paleomagnetism revealed 16 normal and 16 reversed zones that correlate well with chrons 3n to 5Ar.1r of the Geomagnetic Polarity Time Scale, constraining the section to ∼12.7-4.8 Ma. The changes in lithofacies from floodplain to braided river at ∼8.6 Ma and to thick alluvial fan at ∼6.3 Ma with predominantly southerly paleocurrent directions occur simultaneously with an increase in the sedimentation rates, representing two periods of rapid uplift in the eastern Qilian Shan to the north. Our results provide a robust oldest age constraint (<4.8 Ma) on the ancient Huang Shui and Yellow River terraces on the basin sediments and eolian deposits on the terraces. The presence of well-developed floodplain paleosols, shallow lake marls, and many large mammals in the lower section suggests that the monsoon climate in the late Middle Miocene to Late Miocene was more humid and stronger than that at present. [ABSTRACT FROM AUTHOR]

An abstract of the article "Deep Drilling Campaign in the Western Qaidam Basin, NE Tibetan Plateau and their Revealed Global Temperature Forcing of Salt Formation in the Late Miocene-Quaternary," by Fang Xiaomin and colleagues is presented.