摘要：Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium （Se） concen- trations. A long-term （over 20 years） experimental field study, started in 1989, was conducted to investigate the changes in soil Se fractions and its uptake by crops, as affected by different fertilizer practices, in the North China Plain with an annual crop rotation of winter wheat and summer maize. The long-term experiment was arranged in a complete randomized block design consisting of 4 replications with 7 fertilizer treatments： 1） organic compost （OC）, 2） half organic compost plus half N-P-K chemical fertilizers （OC ＋ NPK）, 3） N-P-K fertilizers （NPK）, 4） N-P fertilizers （NP）, 5） P-K fertilizers （PK）, 6） N-K fertilizers （NK）, and 7） an un-amended control. soil samples from the surface （20 cm） were collected in 1989, 1994, 1999, 2004 and 2009 to characterize Se and other soil properties. In 2009, the average soil Se concentrations in the treatments （149 ± 8 beg kg-1） were higher than those in the soil samples collected in 1989 at the beginning of the experiment （112 4- 4 beg kg-1）, and decreased in the order of OC 〉 OC ＋ NPK 〉 NPK NP 〉 PK NK 〉 control. Sequential extraction showed the oxidizable fraction （50.06%± 3.94%） was the dominant form of Se in the soil, followed by the residual fraction （24.12% ± 2.89%）, exchangeable fraction （15.09% ± 4.34%） and Fe-Mn oxides fraction （10.73%±4.04%）. With an increase of soil K, the exchangeable Se concentrations in the soil increased. The Se concentrations in the soil tillage layer （0-20 cm） were mainly related to soil organic carbon （SOC）, although different contributions came from atmospheric deposition, irrigation and fertilizers. With the accumulation of SOC, the uptakes of soil Se by two crops were inhibited. For the OC and OC ＋ NPK treatments, Se concentrations in wheat grains were lower than the critical standard of Se in stable food （100 μg kg·1]. Additionallv. Se concentrations in

摘要：为验证土工布用于加速引黄河泥沙充填采煤沉陷地的后期侧向排水及降低排水中泥沙含量的效果,在室内进行了基于土工布的泥沙充填排水模拟试验。该试验在玻璃槽内完成,设计3个试验处理,分别为ZT-250(整个断面开口+铁丝网+ZW-250土工布)、ZT-300(整个断面开口+铁丝网+ZW-300土工布)以及CK(断面中间部分开口+可调节高度的塑料板)。测定了3个处理的排水含沙量及泥沙粒径、玻璃槽内表层泥沙粒径以及充填表层和底层泥沙含水率随时间的变化。结果表明:1)3种处理排水含沙量整体差异较小,但使用土工布处理的排水含沙量随时间的延长逐渐降低,而对照处理排水含沙量随时间的延长逐渐增大;2)排水初期和中期,对照CK的排水中泥沙的黏粒含量均高于使用土工布的2个处理。排水后期CK的黏粒含量介于处理ZT-250和ZT-300之间。随着试验的进行,使用土工布的2个处理排水中泥沙的黏粒含量逐渐升高,粉粒含量逐渐降低,而对照处理呈现相反的变化趋势。使用土工布的2个处理拦沙效果较为稳定。3)3种处理充填表层泥沙粒径级配无明显差异,但使用土工布处理充填的表层泥沙的极细砂粒含量较高。4)3种处理充填泥沙表层和底层含水率变化存在差异,使用土工布可以加速泥沙中过饱和水的排除,其中处理ZT-250排水效果最好。该研究可为中国东部高潜水位平原矿区采煤沉陷地引黄河泥沙充填复垦的快速排水工艺革新提供依据。

摘要：plants are complex systems hierarchically organized and composed of various cell *** understand the molecular underpinnings of complex plant systems,single-cell RNA sequencing(scRNA-seq)has emerged as a powerful tool for revealing high resolution of gene expression patterns at the cellular level and investigating the cell-type ***,scRNA-seq analysis of plant biosystems has great potential for generating new knowledge to inform plant biosystems design and synthetic biology,which aims to modify plants genetically/epigenetically through genome editing,engineering,or re-writing based on rational design for increasing crop yield and quality,promoting the bioeconomy and enhancing environmental *** particular,data from scRNA-seq studies can be utilized to facilitate the development of high-precision Build-Design-Test-Learn capabilities for maximizing the targeted performance of engineered plant biosystems while minimizing unintended side *** date,scRNA-seq has been demonstrated in a limited number of plant species,including model plants(e.g.,Arabidopsis thaliana),agricultural crops(e.g.,Oryza sativa),and bioenergy crops(e.g.,Populus spp.).It is expected that future technical advancements will reduce the cost of scRNA-seq and consequently accelerate the application of this emerging technology in *** this review,we summarize current technical advancements in plant scRNA-seq,including sample preparation,sequencing,and data analysis,to provide guidance on how to choose the appropriate scRNA-seq methods for different types of plant *** then highlight various applications of scRNA-seq in both plant systems biology and plant synthetic biology ***,we discuss the challenges and opportunities for the application of scRNA-seq in plants.

摘要：The long atmospheric residence time of CO2 creates an urgent need to add atmospheric carbon drawdown to CO2 regulatory *** and systems biology(SSB),which enables manipulation of cellular phenotypes,offers a powerful approach to amplifying and adding new possibilities to current land management practices aimed at reducing atmospheric *** participants(in attendance:Christina Agapakis,George Annas,Adam Arkin,George Church,Robert Cook-Deegan,Charles DeLisi,Dan Drell,Sheldon Glashow,Steve Hamburg,Henry Jacoby,Henry Kelly,Mark Kon,Todd Kuiken,Mary Lidstrom,Mike MacCracken,June Medford,Jerry Melillo,Ron Milo,Pilar Ossorio,Ari Patrinos,Keith Paustian,Kristala Jones Prather,Kent Redford,David Resnik,John Reilly,Richard ***,Daniel Segre,Susan Solomon,Elizabeth Strychalski,Chris Voigt,Dominic Woolf,Stan Wullschleger,and Xiaohan Yang)identified a range of possibilities by which SSB might help reduce greenhouse gas concentrations and which might also contribute to environmental sustainability and *** include,among other possibilities,engineering plants to convert CO2 produced by respiration into a stable carbonate,designing plants with an increased root-to-shoot ratio,and creating plants with the ability to self-fertilize.A number of serious ecological and societal challenges must,however,be confronted and resolved before any such application can be fully assessed,realized,and deployed.