Cu-Zr,Cu-Ti非晶态合金原子近邻结构的EXAFS研究

本工作用EXAFS技术测定了非晶态合金Cu_XZr_1-X（X=33,50）和Cu₈₀Ti₂₀中Cu原子K吸收EXAFS谱,得出了原子间距和配位数等结构参数。本文通过对上述非晶态合金EXAFS数据的分析,给出了Cu_XZr_1-X和Cu_XTi_1-X体系中化学短程有序的研究结果。当Cu原子含量为50%时,体系中不显示化学短程有序,Cu原子的含量增加,此类非晶态合金中异类原子趋子互相结合;Cu原子的含量低于50%时,同类原子倾向于互相结合。     

Smart fabric strain sensor comprising reduced graphene oxide with structure-based negative piezoresistivity

Journal of Materials Science - Fabric strain sensors have attracted significantly increased interest as wearable electronics for their flexibility, softness, and wearing comfort in recent years....     

煤矿雷管专用黑索金中的消焰剂含量测定

生产煤矿许用雷管的高分子胶造粒黑索金中含有消焰剂,为准确分析出黑索金中的消焰剂含量,本文采取离心分离法和灼烧法进行了试验对比,认为离心分离法更适合企业使用,并对影响离心分离法测定结果准确度的主要因素进行了探讨。     

非周期随机共振信号处理中的码元恢复新方法

分析了利用非周期随机共振进行基带信号检测的物理机制,提出了一种基于统计的信号恢复新方法.该方法利用系统达到稳定状态后的所有样本的平均值,而不是码元持续时间的最后一个样本或者所有样本的平均值作为测度来恢复输入端的二进制信号.仿真实验结果表明该方法有效地提高了系统性能.同时本文对将该方法应用于实际信号处理时碰到的同步问题进行了讨论,给出了相应的解决方案.     

Bridging gaps between environmental flows theory and practices in China

In recent decades,a series of policies and practices for environmental flows(e-flows) have been implemented in China,with the sustainable development goal of balancing the utilization and protection of water resources among social,economic,and ecological needs.The aims of this study were to determine the main challenges and issues in e-flows implementation at different scales by analyzing policies and practices for eflows in China,and to propose some recommendations for bridging the gaps between the science and implementation of e-flows.The gaps between the science and implementation of e-flows were found after review of literature,policies,and practices,and it was found that ecological flow was a more widely used term by the government,rather than e-flows,in implementation.The plans and effects of e-flows implementation are discussed in this paper and challenges of e-flows implementation are recognized:(1) limited water resources and uneven spatial and temporal distribution,(2) a weak scientific basis for e-flows implementation,(3) poor operability of e-flows science,and(4) ineffective supervision and guarantee measures.The recommendations are(1) to strengthen the scientific foundation of e-flows,(2) to improve effectiveness in application of e-flows science,and(3) to propose operable and effective supervision and guarantee measures.This paper elaborates the current understanding of e-flows science and provides practical recommendations for implementing e-flows and for improving the effectiveness in e-flows implementation.To bridge the gaps between science and implementation of e-flows and improve the operability of policies in future practices,more scientific research on practices is recommended through adaptive management.     

Substrate-induced Selective α-C(sp3)−H Activation of N-alkyl Amines: Synthesis of Coumarin-fused Quinolinones under Air

A substrate-induced synthesis of coumarin-fused quinolinones is achieved from 4-(phenylamino)-2H-chromen-2-ones using N-alkyl amines as the solvent and a carbon source under air conditions without any catalysts in one pot. This protocol highlights the special roles of 4-(phenylamino)-2H-chromen-2-ones which were not only used as reactants but also as an internal oxidant selectively activated N-α-C(sp³)−H bond. This reaction features catalyst-free, broad substrate scopes (N-alkyl amines 27 examples and quinolinones 24 examples), operationally simple for the one-step synthesis, and recovery and recycling of the solvent.     

Molecular Mechanisms of Parthanatos and Its Role in Diverse Diseases

Differential evolution of apoptosis, programmed necrosis, and autophagy, parthanatos is a form of cell death mediated by poly(ADP-ribose) polymerase 1 (PARP1), which is caused by DNA damage. PARP1 hyper-activation stimulates apoptosis-inducing factor (AIF) nucleus translocation, and accelerates nicotinamide adenine dinucleotide (NAD⁺) and adenosine triphosphate (ATP) depletion, leading to DNA fragmentation. The mechanisms of parthanatos mainly include DNA damage, PARP1 hyper-activation, PAR accumulation, NAD⁺ and ATP depletion, and AIF nucleus translocation. Now, it is reported that parthanatos widely exists in different diseases (tumors, retinal diseases, neurological diseases, diabetes, renal diseases, cardiovascular diseases, ischemia-reperfusion injury...). Excessive or defective parthanatos contributes to pathological cell damage; therefore, parthanatos is critical in the therapy and prevention of many diseases. In this work, the hallmarks and molecular mechanisms of parthanatos and its related disorders are summarized. The questions raised by the recent findings are also presented. Further understanding of parthanatos will provide a new treatment option for associated conditions.     

Microstructure and mechanical properties of TiAl/Ni-based superalloy joints vacuum brazed with Ti-Zr-Fe-Cu-Ni-Co-Mo filler metal

For the purpose of elevated temperature service and weight reduction in aerospace vehicle applications,a novel Ti-Zr-Fe-Cu-Ni-Co-Mo filler metal was employed to...     

Synthesis of barium mercaptides and application of antimony/barium mercaptides

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Cytokinin Confers Brown Planthopper Resistance by Elevating Jasmonic Acid Pathway in Rice

Plants have evolved a sophisticated defense system that employs various hormone pathways to defend against attacks by insect pests. Cytokinin (CK) plays an important role in plant growth and stress tolerance, but the role of CKs in plant–insect interaction remains largely unclear. Here, we report that CKs act as a positive regulator in rice resistance against brown planthopper (BPH), a devastating insect pest of rice. We found that BPH feeding promotes CK biosynthesis and signaling in rice. Exogenous application of CKs significantly increased the rice resistance to BPH. Increasing endogenous CKs by knocking out cytokinin oxidase/dehydrogenase (OsCKXs) led to enhanced resistance to BPH. Moreover, the levels of the plant hormone jasmonic acid (JA) and the expression of JA-responsive genes were elevated by CK treatment and in OsCKXs knockout plants. Furthermore, JA-deficient mutant og1 was more susceptible to BPH, and CK-induced BPH resistance was suppressed in og1. These results indicate that CK-mediated BPH resistance is JA-dependent. Our findings provide the direct evidence for the novel role of CK in promoting insect resistance, and demonstrate that CK-induced insect resistance is JA-dependent. These results provide important guidance for effective pest management strategies in the future.