SummaryAlthough hundreds of genetic male sterility (GMS) mutants have been identified in maize, few are commercially used due to a lack of effective methods to produce large quantities of pure male‐sterile seeds. Here, we develop a multicontrol sterility (MCS) system based on the maize male sterility 7 (ms7) mutant and its wild‐type Zea mays Male sterility 7 (ZmMs7) gene via a transgenic strategy, leading to the utilization of GMS in hybrid seed production. ZmMs7 is isolated by a map‐based cloning approach and encodes a PHD‐finger transcription factor orthologous to rice PTC1 and Arabidopsis MS1. The MCS transgenic maintainer lines are developed based on the ms7‐6007 mutant transformed with MCS constructs containing the (i) ZmMs7 gene to restore fertility, (ii) α‐amylase gene ZmAA and/or (iii) DNA adenine methylase gene Dam to devitalize transgenic pollen, (iv) red fluorescence protein gene DsRed2 or mCherry to mark transgenic seeds and (v) herbicide‐resistant gene Bar for transgenic seed selection. Self‐pollination of the MCS transgenic maintainer line produces transgenic red fluorescent seeds and nontransgenic normal colour seeds at a 1:1 ratio. Among them, all the fluorescent seeds are male fertile, but the seeds with a normal colour are male sterile. Cross‐pollination of the transgenic plants to male‐sterile plants propagates male‐sterile seeds with high purity. Moreover, the transgene transmission rate through pollen of transgenic plants harbouring two pollen‐disrupted genes is lower than that containing one pollen‐disrupted gene. The MCS system has great potential to enhance the efficiency of maize male‐sterile line propagation and commercial hybrid seed production.

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Effects of the interstitial carbon atoms on the magnetic properties, especially on the magnetic entropy change, of the LaFe11.5Si1.5 compound, have been studied. X-ray diffraction patterns reveal a monotonous increase of the lattice constant with the concentration of carbon, while the cubic NaZn13-type structure remains unchanged. The Curie temperatures TC of LaFe11.5Si1.5Cy are ∼195, 225, and 241 K for y=0, 0.2, and 0.5, respectively, increasing with the increase of carbon concentration. The maximal magnetic entropy changes |ΔS| of LaFe11.5Si1.5Cy at the respective TC under a magnetic field change of 0–5 T are ∼24.6, ∼22.8, and ∼12.7 J/kg K for y=0, 0.2, and 0.5, respectively, notably exceeding that of Gd (|ΔS| ∼9.8 J/kg K at TC=293 K). The |ΔS| of LaFe11.5Si1.5C0.2 is nearly as giant as that of the parent alloy LaFe11.5Si1.5 due to the first-order field-induced itinerant-electron metamagnetic transition that occurs in both compounds clearly observed for the LaFe11.5Si1.5C0.5 compound. With the increase of carbon concentration, the nature of magnetic transition has been changed from first order to second order, which results in the significant decrease of the magnetic entropy change. The large |ΔS|, convenient adjustment of TC and relatively low cost make the LaFe11.5Si1.5Cy interstitial compounds promising candidates for magnetic refrigerants in the corresponding temperature range.

China, the largest coal producer in the world, is responsible for over 50% of the total global methane (CH) emissions from coal mining. However, the current emission inventory of CH4 from coal mining has large uncertainties because of the lack of localized emission factors (EFs). In this study, province-level CH4 EFs from coal mining in China were developed based on the data analysis of coal production and corresponding discharged CH4 emissions from 787 coal mines distributed in 25 provinces with different geological and operation conditions. Results show that the spatial distribution of CH EFs is highly variable with values as high as 36 m3/t and as low as 0.74 m3/t. Based on newly developed CH EFs and activity data, an inventory of the province-level CH4 emissions was built for 2005-2010. Results reveal that the total CH emissions in China increased from 11.5 Tg in 2005 to 16.0 Tg in 2010. By constructing a gray forecasting model for CH EFs and a regression model for activity, the province-level CH emissions from coal mining in China are forecasted for the years of 2011-2020. The estimates are compared with other published inventories. Our results have a reasonable agreement with USEPA's inventory and are lower by a factor of 1-2 than those estimated using the IPCC default EFs. This study could help guide CH mitigation policies and practices in China.