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With intensive and extensive using herbicides, the level of weed resistance was increased, new resistance mechanisms are constantly being discovered. Adcances on the mechanisms of target-site resistance (TSR) and non-target-site resistance (NTSR) in recent ten years were summarized in this paper. The progress of TSR mainly included new resistance mutation in herbicide target enzymes of acetolactate synthase, acetyl-CoA carboxylase and 5-enolpyruvylshikimate-3-phosphatesynthase, as well as various resistance mutations occurring in target enzyme and multiple mutated target isozymes that resisting stronger herbicide selection. In addition, the roles of NTSR in glyphosate resistance of cytochrome P450 (CYP81), aldo-keto reductase and ABC transporter protein (EcABCC8) were also described in detail. This paper is beneficial for understanding the molecular mechanisms and evolutionary laws of weed resistance from more profound and comprehensive perspective, and also provides inspriration for scientifically using herbicides and designing new herbicides with new mode of action. [ABSTRACT FROM AUTHOR]

The electrical contact materials are widely used in various low-volt age switching devices such as electrical switches, relays, contactors and circuit breakers, and their characteristics are of great importance to the switching capacity, reliability, stability and service life of the overall electrical system. The conventional Ag- based contact materials have good performance, but still suffer from defects such as high contact resistance, low interfacial bonding strength, and poor plasticity, and their applications are limited to some extent. Tn recent years, domestic and foreign researchers have reported new group element contact materials such as Ag-Sn()2- Me(), Ag-GNPs, Ag-MAX and Ag-RE on the basis of the traditional Ag-based contact materials. This paper will review the current research status of new Ag-based contact materials in terms of their organization and properties as well as arc erosion performance, and finally summarize the key scientific issues and challenges facing new Ag-based contact materials and look forward to their future development trends. [ABSTRACT FROM AUTHOR]