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【Objective】 Spring wheat and alfalfa and two crops widely grown by farmers in Northwestern China. A knowledge of their planting areas is important for agricultural management but challenging at regional scale. This paper investigates the feasibility of using air-born technologies to identify their areas at different growing stages. 【Method】 The studies were based on Sentinel-2 imagery acquired from the Qingtongxia Irrigation District, with which we developed a decision tree classification algorithm to identify spring wheat and alfalfa. Accuracy of the method was tested against ground-truth data. 【Result】 The accuracy of the model for identifying spring wheat and alfalfa in early April was 69% and 75%, respectively, due to the similarities of the canopies of the two plants. With the growth of the plants and increase in available data, the accuracy of the model improved gradually, with its accuracy for identifying the spring wheat and alfalfa exceeding 90% on 14th May. Using all five satellite imageries available by 13th May, the accuracy of the model for identifying spring wheat and alfalfa reached 94% and 97%, with their associated Kappa coefficient being 0.75 and 0.86, respectively. The estimated planting areas of the spring wheat and alfalfa in Qingtongxia Irrigation District was 24,000 hm2 and 2,000 hm2, respectively. The spatial distribution of spring wheat was complex, characterized by a large number of fragmented planting zones. 【Conclusion】 The decision tree classification method combined with the Sentinel-2 images can preliminarily identify spring wheat and alfalfa in early April. Its accuracy improves steadily as more data become available, with the accuracy exceeding 90% after the middle of May.

A novel deoxygenative alkynylation of amides promoted by a synergistic action of a divalent rare-earth element and a transition metal has been developed. In this method, α-alkynyl substituted amines are synthesized from unactivated amides and alkynes in a single transformation. Broad substrate scope and excellent selectivity for C＝O cleavage has been demonstrated. This approach represents a general method for the construction of versatile α-alkynyl substituted amines from unactivated amide bonds. [ABSTRACT FROM AUTHOR]

Eye‐tracking is vital in AR/VR/MR systems for display correction, rendering, accommodation, and more. However, existing eye‐tracking solutions fall short in accuracy, efficiency, form factor, and population coverage. Using Liquid crystal polarization hologram (LCPH) for eye‐tracking purposes offers a compact form‐factor with excellent performance. [ABSTRACT FROM AUTHOR]

Strigolactones (SLs) are plant hormones that regulate several key agronomic traits, including shoot branching, leaf senescence, and stress tolerance. The artificial regulation of SL biosynthesis and signaling has been considered as a potent strategy in regulating plant architecture and combatting the infection of parasitic weeds to help improve crop yield. DL1b is a previously reported SL receptor inhibitor molecule that significantly promotes shoot branching. Here, we synthesized 18 novel compounds based on the structure of DL1b. We performed rice tillering activity assay and selected a novel small molecule, C6, as a candidate SL receptor inhibitor. In vitro bioassays demonstrated that C6 possesses various regulatory functions as an SL inhibitor, including inhibiting germination of the root parasitic seeds Phelipanche aegyptiaca, delaying leaf senescence and promoting hypocotyl elongation of Arabidopsis. ITC analysis and molecular docking experiments further confirmed that C6 can interact with SL receptor proteins, thereby interfering with the binding of SL to its receptor. Therefore, C6 is considered a novel SL receptor inhibitor with potential applications in plant architecture control and prevention of root parasitic weed infestation. [ABSTRACT FROM AUTHOR]

The synchronicity of rain and heat in the summer of China's monsoon region provides sufficient water and heat resources for maize growth. However, the intra-annual distribution of precipitation and the probability of extreme precipitation have been inevitably altered by the ongoing climate change, thus affecting the matching degree between precipitation and crop water requirements (MDPCWR). Evaluating the extent to which the MDPCWR will change in the future is of great importance for food security and the sustainable management of water resources. In this study, considering that different growth stages of crops have different sensitivities to water stress, the AquaCrop model was used to calculate the MDPCWR more accurately. In addition, a cumulative distribution function-transform (CDF-t) method was used to remove the bias of 11 global climate models (GCMs) under two typical emission scenarios (SSP2-4.5 and SSP5-8.5) from phase six of the Coupled Model Intercomparison Project (CMIP6). A comprehensive investigation was conducted on how maize growth, water consumption, and the MDPCWR will respond to future climate change with CO2 concentration enrichment in the Huang–Huai–Hai (3H) region in China by driving a well-tested AquaCrop model with the bias-corrected GCMs outputs. The results indicate the following: (1) The CDF-t method can effectively remove seasonal bias, and it also performs well in eliminating the bias of extreme climate events. (2) Under the SSP2-4.5 scenario, the average maximum temperature will increase by 1.31 °C and 2.44 °C in 2021–2050 and 2051–2080, respectively. The average annual precipitation will increase up to 96.8 mm/year, but it will mainly occur in the form of heavy rain. (3) The increased maize evapotranspiration rate does not compensate for the decreased crop water requirement (up to −32 mm/year), due to a shorter growth cycle. (4) The farmland cultivation layer is not able to hold a significant amount of precipitation, due to the increased frequency of heavy rains, resulting in increased irrigation water requirements for maize over the next two periods, with the maximum value of 12 mm/year. (5) Under different scenarios, the projected future MDPCWR will decrease by 9.3–11.6% due to changes in precipitation patterns and crop water requirements, indicating that it will be more difficult for precipitation to meet the water demand of maize growing in the 3H region. The results can provide comprehensive information to understand the impact of climate change on the agricultural water balance and improve the regional strategy for water resource utilization in the 3H region. [ABSTRACT FROM AUTHOR]

Hydrothermal‐based direct regeneration of spent Li‐ion battery (LIB) cathodes has garnered tremendous attention for its simplicity and scalability. However, it is heavily reliant on manual disassembly to ensure the high purity of degraded cathode powders, and the quality of regenerated materials. In reality, degraded cathodes often contain residual components of the battery, such as binders, current collectors, and graphite particles. Thorough investigation is thus required to understand the effects of these impurities on hydrothermal‐based direct regeneration. In this study, we focus on isolating the effects of aluminum (Al) scraps on the direct regeneration process. We found that Al metal can be dissolved during the hydrothermal relithiation process. Even when the cathode material contains up to 15 wt.% Al scraps, no detrimental effects were observed on the recovered structure, chemical composition, and electrochemical performance of the regenerated cathode material. The regenerated NCM cathode can achieve a capacity of 163.68 mAh/g at 0.1 C and exhibited a high‐capacity retention of 85.58 % after cycling for 200 cycles at 0.5 C. Therefore, the hydrothermal‐based regeneration method is effective in revitalizing degraded cathode materials, even in the presence of notable Al impurity content, showing great potential for industrial applications. [ABSTRACT FROM AUTHOR]

Bulk III-nitride materials MN (M = Al, Ga and In) and their alloys have been widely used in high-power electronic and optoelectronic devices, but stable two-dimensional (2D) III-nitride materials, except h-BN, have not been realized yet. A new kind of 2D III-nitride material M 2 Si 2 N 4 (M = Al, Ga and In) is predicted by choosing Si as the appropriate passivation element. The stability, electronic and optical properties of 2D M 2 Si 2 N 4 materials are studied systematically based on first-principles calculations. The results show that Al 2 Si 2 N 4 and Ga 2 Si 2 N 4 are found to be indirect bandgap semiconductors, while In 2 Si 2 N 4 is a direct bandgap semiconductor. Moreover, Al 2 Si 2 N 4 and In 2 Si 2 N 4 have good absorption ability in the visible light region, while Ga 2 Si 2 N 4 is an ultraviolet-light-absorbing material. Furthermore, the carrier lifetimes of Ga 2 Si 2 N 4 and In 2 Si 2 N 4 are as large as 157.89 and 103.99 ns, respectively. All these desirable properties of M 2 Si 2 N 4 materials make them attractive for applications in electronics and photoelectronics. [ABSTRACT FROM AUTHOR]

Renewable electricity-powered CO evolution from CO2 emissions is a promising first step in the sustainable production of commodity chemicals, but performing electrochemical CO2 reduction economically at scale is challenging since only noble metals, for example, gold and silver, have shown high performance for CO2-to-CO. Cu is a potential catalyst to achieve CO2 reduction to CO at the industrial scale, but the C-C coupling process on Cu significantly depletes CO* intermediates, thus limiting the CO evolution rate and producing many hydrocarbon and oxygenate mixtures. Herein, we tune the CO selectivity of Cu by alloying a second metal Sb into Cu, and report an antimony-copper single-atom alloy catalyst (Sb1Cu) of isolated Sb-Cu interfaces that catalyzes the efficient conversion of CO2-to-CO with a Faradaic efficiency over 95%. The partial current density reaches 452 mA cm−2 with approximately 91% CO Faradaic efficiency, and negligible C2+ products are observed. In situ spectroscopic measurements and theoretical simulations reason that the atomic Sb-Cu interface in Cu promotes CO2 adsorption/activation and weakens the binding strength of CO*, which ends up with enhanced CO selectivity and production rates. Engineering Cu to achieve high catalytic selectivity towards carbon monoxide at high current density is challenging. Here, the authors report an Cu-Sb single-atom alloy catalyst that catalyzes CO2 reduction at a current density of 500 mA cm−2 with CO FE of ca. 91%. [ABSTRACT FROM AUTHOR]

A direct numerical method is introduced herein to investigate time-dependent Poisson's ratio of solid propellant based on a representative volume element (RVE) model. Time-dependent longitudinal and transverse strains are considered in the calculation of time-dependent Poisson's ratio under the relaxation test. The molecular dynamics (MD) packing algorithm is used to generate the high area fraction RVE model of solid propellants consisting of ammonium perchlorate (AP) particles whose radius follows lognormal distribution. In order to simulate the dewetting response of the interface between particles and matrix, the PPR model is modified and utilized during the analysis. Time-dependent Poisson's ratio is measured under different cohesive parameters, loading conditions (loading temperature, loading rate, and fixed strain), and area fraction. Numerical results reveal that time-dependent Poisson's ratio can be nonmonotonic or monotonic according to the different cohesive parameters. A concept of critical cohesive parameters is proposed to judge whether the monotonic property of time-dependent Poisson's ratio appears or not. According to the numerical analysis, the cohesive contact and the shrinkage of the bulk element are two main factors which will control the change of monotonic property. All time-dependent Poisson's ratios will increase at the beginning of the relaxation stage because the effects of cohesive contact can be ignored compared with the large shrinkage of the bulk element. However, with the increased shrinkage of the bulk element, the increased cohesive contact will defend further shrinkage at the same time. Although the shrink of the bulk element never changes its direction, the ratio of the transverse strain to longitudinal strain may decrease or keep increasing in this stage. When transverse and longitudinal strains stop to change, all time-dependent Poisson's ratios will achieve their equilibrium values. [ABSTRACT FROM AUTHOR]

Reference evapotranspiration (ET0), which is an indicator of atmospheric evaporation demand over a hypothetical reference surface, is expected to alter along with global climate change. In this study, the changes and driving forces of historical ET0 and its future projections in Xinjiang, China, were comprehensively conducted. The trend analysis revealed that regional ET0 decreased significantly at a rate of −4.1 mm/year2 during 1961–1993 and increased at a rate of 3.4 mm/year2 during 1994–2010. To explore the possible causes, the contributions of major climatic variables to the ET0 trends were derived based on the differential equation method. During 1961–1993, the decreasing trend of ET0 was primarily ascribed to the wind speed. The integrated negative effect from the decrease in wind speed (U) and increase in relative humidity (RH) was more significant than the positive effect from the increase in air temperature (T), resulting in the decrease in ET0. During 1994–2010, combined with increasing T and decreasing RH, the increase in U offset the effect of the net radiation (Rn) decrease and led to an increase in ET0. Future ET0 projections over three periods (2010–2039, 2040–2069, and 2070–2099, which are named as 2020s, 2050s, and 2080s, respectively) were conducted based on the general circulation models under two representative concentration pathways scenarios (RCP4.5 and RCP8.5). A continuous increasing trend in ET0 was demonstrated in the 21st century. The increase in ET0 will increase the irrigated water resource consumption and bring new challenge to water resource management in this area. [ABSTRACT FROM AUTHOR]

Controlled encapsulation of atomically precise nanoclusters (APNCs) into metal–organic frameworks (MOFs) has been an efficient way to create new types of multifunctional crystalline porous materials. Such hybrids (APNCs@MOFs) provide ideal candidates for studying inherent structure–catalysis relationships owing to the well-defined compositions of both components. Moreover, modeling of APNCs@MOFs with precise structures would be more reliable. Herein, we have established an “Electrostatic Attraction Strategy” to synthesize APNCs@MOF catalysts and studied their performance as catalysts for the conversion of CO2. The synthetic strategy presented here has been proved to be general, as evidenced by the syntheses of various APNCs@MOF catalysts including all the combinations of [Au12Ag32(SR)30]4−, [Ag44(SR)30]4−, and [Ag12Cu28(SR)30]4− nanoclusters with ZIF-8, ZIF-67, and MHCF frameworks. In particular, the as-obtained Au12Ag32(SR)30@ZIF-8 composite shows excellent performance in capturing CO2 and converting phenylacetylene into phenylpropiolate under mild conditions (50 °C and ambient CO2 pressure) with a TON as high as 18 164, far exceeding those of most known catalysts. What's more, the catalyst is very stable and reused 5 times without loss of catalytic activity. We anticipate that this general synthetic approach may open up a new frontier in the development of promising APNCs@MOF catalysts, which can be applied in a broad range of heterogeneous catalyses in the future. [ABSTRACT FROM AUTHOR]

Accounting for over 70% of global water withdrawals, irrigation plays a crucial role in the development of agriculture. Irrigation water requirement ( WIRR ) will be influenced by climate change due to the alteration in soil water balances, evapotranspiration, physiology and phenology under global warming. This is particularly true for rice, a high water-consuming crop. Therefore, exploring the impact of climate change on rice WIRR is of great significance for the sustainable utilization of water resources and food security. This paper aims to investigate spatially and temporally the responses of rice WIRR to climate change in the middle and lower reaches of the Yangtze River (MLRYR), which is one of the most important rice farming districts in China. With the help of the specially developed rice growing period calculation method and water balance model coupled with rice irrigation scheduling, the impacts of climate change on WIRR for early rice, late rice and single cropping rice during the historical (1961–2012) and future (2011–2100) periods were evaluated. Meanwhile, to consider the uncertainty from climate models in future projection, four GCMs under RCP2.6, RCP4.5 and RCP8.5 emission scenarios from the 5th Coupled Model Intercomparison Project (CMIP5) were employed as the input of the water balance model. The results indicate the following: (1) The days of growing period ( DGP ) for all three types of rice display shortened trends in historical and most future periods. However, in the middle region of the MLRYR, the DGP for early rice and late rice would increase by up to10 days in 2080s under RCP8.5 scenario. (2) Over the past 50 years, the WIRR significantly decreased by 1.58 and 2.10 mm yr −1 for late rice and single cropping rice, respectively. While for early rice, the WIRR only slightly decreased by 0.13 mm yr −1 . (3) Projected future WIRR would increase for all three types of rice in the whole region under RCP4.5 and RCP8.5 scenarios (up to 100 mm), but decrease for single cropping and late rice in the southeast region (up to 40 mm). The results can provide beneficial reference and comprehensive information to understand the impact of climate change on the agricultural water balance and improve the regional strategy for water resource utilization and agricultural management in the middle and lower reaches of the Yangtze River. [ABSTRACT FROM AUTHOR]

Future changes in reference evapotranspiration (ET0) are of increasing importance in assessing the potential impacts on hydrology and water resources systems of more pronounced climate change. This study assesses the applicability of the Statistical Downscaling Model (SDSM) in projecting ET0, and investigates the seasonal and spatial patterns of future ET0 based on general circulation models (GCMs) across the Haihe River Basin. The results indicate that SDSM can downscale ET0 well in term of different basin-averaged measures for the HadCM3 and CGCM3 GCMs. HadCM3 has a much superior capability in capturing inter-annual variability compared to CGCM3 and thus is chosen as the sole model to assess the changes in future ET0. There are three homogeneous sub-regions of the Haihe River Basin: Northwest, Northeast and Southeast. Change points are detected at around 2050 and 2080 under the A2 and B2 scenarios, respectively. The Northwest is revealed to have a slight to strong increase in ET0, while the Northeast and the Southeast tend to experience a pattern change from decrease to increase in ET0. EDITOR M.C. Acreman ASSOCIATE EDITOR J. Thompson [ABSTRACT FROM AUTHOR]

An ethynylene-linked benzo[1,2-b:4,5-b′]dithiophene-alt-diketopyrrolopyrrole alternating copolymer, EDPP, was designed and synthesized to improve the open-circuit voltage of organic solar cells. The influence of the ethynylene on optoelectronic properties, energy levels, crystallinity, film morphology, and photovoltaic performance was investigated. Optical and electrochemical tests showed that introduction of ethynylene into the polymer backbone resulted in a larger bandgap, deeper HOMO energy level, and enhanced crystallinity due to the planar conformation and electron-withdrawing properties. Grazing incidence wide-angle X-ray scattering (GIWAXS) showed that the pure EDPP film preferentially adopted a face-on orientation with a π–π stacking distance of 3.65 Å. After thermal annealing the face-on and edge-on orientations coexisted and the overall degree of crystallinity increased. Blending with PC71BM did not disrupt the crystallinity of the EDPP. Resonant soft X-ray scattering (RSoXS) showed that the EDPP:PC71BM blend films contained large domains, a few hundred nanometers in size. As a result, EDPP:PC71BM photovoltaic devices exhibited a high open-circuit voltage of 0.88 V, but a low short-circuit current, with a moderate power conversion efficiency of 1.98%. [ABSTRACT FROM AUTHOR]

In this paper, we present the empirical investigation results on the urban public transport networks (PTNs) and propose a model to understand the results obtained. We investigate some urban public traffic networks in China, which are the urban public traffic networks of Beijing, Guangzhou, Wuhan and etc. The empirical results on the big cities show that the accumulative act-degree distributions of PTNs take neither power function forms, nor exponential function forms, but they are described by a shifted power function, and the accumulative act-degree distributions of PTNs in medium-sized or small cities follow the same law. In the end, we propose a model to show a possible evolutionary mechanism for the emergence of such network. The analytic results obtained from this model are in good agreement with the empirical results. [ABSTRACT FROM AUTHOR]

• Yield and irrigation changes in different regions are related to different reasons. • Adequate irrigation and suitable sowing dates can offset average yield losses. • Major rice cultivation regions will have narrow sowing windows at the end of this century. Warming and increasing extreme climate events are expected to reduce crop yields including rice production in China, threatening the Chinese food security. Shifting sowing date has been considered as a key adaptation strategy to sustain rice production in China. However, the extent to which it can mitigate the adverse climate change impact on yield and whether more irrigation is required remains unclear. Here, by driving ORYZA v3 with four climate models (GCMs), we analyzed the impacts of climate change on China rice yield and net irrigation water requirement (NIR) at 21 sites under a wide range of sowing date. We found that without altering sowing date, weighted average rice yield for all sites will decline 5.1, 7.3 and 15.1% in periods 2011–2040, 2041–2070 and 2071–2100, respectively. Yields losses in temperate zones are linked to increased crop development rates with higher temperatures, but in subtropical regions, the reduction is more related to the damage of heat stress during rice heading or flowering periods. NIR increases notably in all regions (up to 71%) except northeastern China, where the shortened growth duration resulted in less time to consume water. When the optimized sowing date is applied, average yield losses will be effectively compensated. To achieve these, rice-sowing date will be shifted by up to 54 days and on average 17.8–23.4 % more fresh water in future periods are needed to meet the water requirement of rice growth. We also found that, due to increasing the frequency of heat events, farmers in Chinese rice production regions (e.g., Yangtze River Basin) will have narrow sowing windows at the end of this century. This study suggests that adequate irrigation and adjusting sowing dates could mitigate the negative climate impacts on rice production in China. [ABSTRACT FROM AUTHOR]

Focuses on the Beijing Genomics Institute, a genome center in China. Reaction of the scientists to Yang Huanming, a chinese geneticist; Facilities in the institute provided by Dawning computers; Project on human genome sequencing.

The efficiency of the alkaline hydrogen evolution reaction (HER) has remained limited. Herein, a bimetallic Ni–W catalyst fabricated by the rapid dehydration of W‐doped Ni(OH)2 is reported. The Ni–W surface exhibits the following merits for an enhanced alkaline HER: a greater number of vacant outer d‐orbitals, better discharge characteristics, and a more significant difference in H adsorption between W and Ni atoms. The free water molecules are adsorbed onto W sites, then dissociated into *OH and *H. While *OH is released into the solution, *H is re‐adsorbed by nearby Ni sites. The synergistic effect of the Ni–W surface sites imparts this catalyst with the highest activity and the best stability at high current density. Specifically, at a current density of 500 mA cm‐2, the Ni–W catalyst reduces the overpotential to 303 mV, compared with 409 mV for the state‐of‐the‐art Pt/C catalyst. Additionally, the Ni–W catalyst exhibits better long‐term stability than the state‐of‐the‐art Pt/C. Whereas the Pt activity decreases by 181 mA cm‐2 after 31 h of testing at 500 mA cm‐2, the Ni–W loses only 55 mA cm‐2 under the same conditions. Density functional theory (DFT) calculations confirm the synergistic mechanism, which can be useful for general alkaline HER processes. [ABSTRACT FROM AUTHOR]

Focuses on the appointment of Xu Guanhua as head of China's Ministry of Science and Technology. Achievements and awards; Job responsibilities; Plan to promote venture capital market.

Reports the reduction of scientist workforce in the Chinese Academy of Sciences in Beijing, China. Elimination of unproductive research programs; Use of financial incentives to spur productivity; Recruitment of young scientists in addition to selecting for quality.