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In order to solve the safety problem of deep intelligent mining and prevention and control personnel threatened by rock burst, an intelligent prevention and control method of deep rock burst was put forward. Based on the key role of foundational static load inducing rock burst initiation, theoretical basis of intelligent prevention and control of deep rock burst was proposed, which was to automatically detect the foundational static load of surrounding rock in mining space, and achieve intelligent and precise decrease of its concentration degree, so as to improve threshold of acquiring static load or dynamic load increment in later stage for achieving purpose of rock burst prevention and control. Development paths of researching intelligent prevention and control of deep rock burst in the future were put forward, which included active schedule theory and method of multi-source information of rock burst disaster, expert database of disaster prevention scheme based on multi-source information fusion, rapidly interactive and intelligent robot and informationized equipment, intelligent control of rock burst disaster and compound disaster self-adaption technology and effect self-evaluation technology of major disaster prevention and control.

A novel printed ultra-wideband(UWB) slot antenna with reconfigurable band-notched characteristics for cognitive radio(CR) applications is presented. An improved rectangular monopole antenna is used as the basic model and a tangential rectangular floor is used to realize the ultra-wideband characteristics of 2.9～12 GHz. The band-notched function is achieved by etching one symmetric folded slot which consists of an inverted U-shaped slot and H-shaped slot on the modified rectangular radiation patch. By switching the pin-diodes to change the shape and effective length of the folded slot, the reconfigurable function is achieved. The antenna is compact and easy to process, and has potential application in CR system. Simulated and measured results obtained for the antenna show that it exhibits good radiation behavior and also has three reconfigurable frequency band-notched functions in the range of WiMAX(3.4～3.9 GHz), WLAN(4.6～6.0 GHz) and downlink of X-band satellite communication(6.5～8.2 GHz).

Free radical polymerization was selected to obtain a promising copolymer scale inhibitor IA‐AM‐SAS with good water solubility and temperature and salt resistance, which is suitable for the treatment of surface pipeline water in oil fields, using itaconic acid (IA), acrylamide (AM), and sodium acrylsulfonate (SAS) as the monomers. The structure of the synthesized copolymer was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance hydrogen spectroscopy. Thermogravimetric results showed that the copolymer does not undergo significant thermal degradation at temperatures below 356°C, indicating that the copolymer has good thermal stability. The molecular weights of the polymers at different monomer ratios were measured using gel permeation chromatography and the relationship between the molecular weights and scale inhibition performance was discussed. The results showed that the scale inhibition effect was best when the monomer molar ratio n(IA): n(AM): n(SAS) was 0.5:2:1.5 and the number of average molecular weight of the prepared copolymer was 7712 g/mol, and the inhibition efficiency of CaCO3 was 84.02% when IA‐AM‐SAS was at a concentration of 30 mg L−1, and the inhibition rate was measured by the standard of static scale inhibition test in the oilfield measured. The range of conditions (PH, Ca2+ concentration, water temperature, and time) of the static scale inhibition test was then expanded using a one‐way controlled variable experiment to explore the performance of IA‐AM‐SAS scale inhibitors under different water quality conditions. The scale inhibition mechanism was explored by scanning electron microscopy, x‐ray diffraction, and x‐ray photoelectron spectroscopy. Briefly, the combination of multiple functional groups enables IA‐AM‐SAS to be applied in complex and challenging environments. [ABSTRACT FROM AUTHOR]

Marine primary producers are largely dependent on and shape the Earth's climate, although their relationship with climate varies over space and time. The growth of phytoplankton and associated marine primary productivity in most of the modern global ocean is limited by the supply of nutrients, including the micronutrient iron. The addition of iron via episodic and frequent events drives the biological carbon pump and promotes the sequestration of atmospheric carbon dioxide (CO2) into the ocean. However, the dependence between iron and marine primary producers adaptively changes over different geological periods due to the variation in global climate and environment. In this review, we examined the role and importance of iron in modulating marine primary production during some specific geological periods, that is, the Great Oxidation Event (GOE) during the Huronian glaciation, the Snowball Earth Event during the Cryogenian, the glacial–interglacial cycles during the Pleistocene, and the period from the last glacial maximum to the late Holocene. Only the change trend of iron bioavailability and climate in the glacial–interglacial cycles is consistent with the Iron Hypothesis. During the GOE and the Snowball Earth periods, although the bioavailability of iron in the ocean and the climate changed dramatically, the changing trend of many factors contradicted the Iron Hypothesis. By detangling the relationship among marine primary productivity, iron availability and oceanic environments in different geological periods, this review can offer some new insights for evaluating the impact of ocean iron fertilization on removing CO2 from the atmosphere and regulating the climate. [ABSTRACT FROM AUTHOR]