The environmental pollution has become a serious issue because the pollutants can cause permanent damage to the DNA, nervous system, and circulating system, resulting in various incurable diseases, ...such as organ failure, malformation, angiocardiopathy, and cancer. The effective detection of environmental pollutants is urgently needed to keep them far away from daily life. Among the reported pollutant sensors, luminescent metal–organic frameworks (LMOFs) with tunable structures have attracted remarkable attention to detect the pollutants because of their excellent selectivity, sensitivity, and recyclability. Although lots of metal–organic framework (MOF)‐based luminescent sensors have been summarized and discussed in previous reviews, the detection of environmental pollutants, especially radioactive ions and heavy metal ions, still have not been systematically presented. Here, the sensing mechanisms and construction principles of luminescent MOFs are discussed, and the state‐of‐the‐art MOF‐based luminescent sensors of environmental pollutants, including pesticides, antibiotics, explosives, VOCs, toxic gas, toxic small molecules, radioactive ions, and heavy metal ions are highlighted. This comprehensive review may further guide the development of luminescent MOFs and promote their practical applications for sensing environmental pollutants.
Luminescent MOFs have attracted remarkable attention to detect environmental pollutants because of their excellent selectivity, sensitivity, and recyclability. In this review, the sensing mechanisms and construction principles of luminescent MOFs are discussed, and the state‐of‐the‐art luminescent MOF‐based sensors of environmental pollutants, including pesticides, antibiotics, explosives, VOCs, toxic gas, toxic small molecules, radioactive ions, and heavy metal ions are highlighted.
In recent years there has been an exponential growth in the number of publications related to theory and applications of Data Envelopment Analysis (DEA). Charnes, Cooper, and Rhodes (1978) introduced ...DEA as a tool for measuring efficiency and productivity of decision making units. DEA has immediately been recognized as a modern tool for performance measurement. Since then, a large and considerable amount of articles has been appeared, including significant breakthroughs in theory and a great portion of works on DEA applications, both public and private sectors, to assess the efficiency and productivity of their activities. Although there have been several bibliographic collections reported, a comprehensive analysis and listing of DEA-related articles covering its first four decades of history is still missing. This paper, thus, aims to report an extensive listing of DEA-related articles including theory and methodology developments and "real" applications in diversified scenarios from 1978 to end of 2016. Some summary statistics of the publications' growth, the most utilized academic journals, authorship analysis, as well as keywords analysis are also provided.
This paper introduces Jittor, a fully just-in-time (JIT) compiled deep learning framework. With JIT compilation, we can achieve higher performance while making systems highly customizable. Jittor ...provides classes of Numpy-like operators, which we call meta-operators. A deep learning model built upon these meta-operators is compiled into high-performance CPU or GPU code in real-time. To manage metaoperators, Jittor uses a highly optimized way of executing computation graphs, which we call unified graph execution. This approach is as easy to use as dynamic graph execution yet has the efficiency of static graph execution. It also provides other improvements, including operator fusion, cross iteration fusion, and unified memory.
The increasing building energy consumption in China has been acknowledged as a key concern in future climate mitigation and sustainable development. Though reliable accounting of energy consumption ...is the prerequisite, estimates of China's building energy consumption remain subject to large discrepancies. One of the primary causes of these disparities is an inaccurate estimation of building energy intensities due to flaws in estimation methods and data. Here, we present a bottom-up approach and use large-scale nationwide building energy survey data (covering 30 provinces, four different types of buildings, and district heating from 2009 to 2016) to correct the existing, widely used assumption of normal distribution for building energy intensity and provide a more accurate estimate of building energy consumption in China. Our improved estimate of China's building energy consumption differs by −10% to 36% from existing mainstream estimates, indicating a significant bias in existing research and applications.
•The non-normal probability distribution of building energy intensity is identified.•A bottom-up approach for the accurate estimate of building energy use is developed.•The re-quantified building energy use differs by −10% ~ 36% from the main estimates.•The features of building energy consumption in China were explored.
Coronal mass ejections（CMEs） and solar flares are the large-scale and most energetic eruptive phenomena in our solar system and able to release a large quantity of plasma and magnetic flux from the ...solar atmosphere into the solar wind. When these high-speed magnetized plasmas along with the energetic particles arrive at the Earth, they may interact with the magnetosphere and ionosphere, and seriously affect the safety of human high-tech activities in outer space. The travel time of a CME to 1 AU is about 1–3 days, while energetic particles from the eruptions arrive even earlier. An efficient forecast of these phenomena therefore requires a clear detection of CMEs/flares at the stage as early as possible. To estimate the possibility of an eruption leading to a CME/flare, we need to elucidate some fundamental but elusive processes including in particular the origin and structures of CMEs/flares. Understanding these processes can not only improve the prediction of the occurrence of CMEs/flares and their effects on geospace and the heliosphere but also help understand the mass ejections and flares on other solar-type stars. The main purpose of this review is to address the origin and early structures of CMEs/flares, from multi-wavelength observational perspective. First of all, we start with the ongoing debate of whether the pre-eruptive configuration, i.e., a helical magnetic flux rope（MFR）, of CMEs/flares exists before the eruption and then emphatically introduce observational manifestations of the MFR. Secondly, we elaborate on the possible formation mechanisms of the MFR through distinct ways. Thirdly, we discuss the initiation of the MFR and associated dynamics during its evolution toward the CME/flare. Finally, we come to some conclusions and put forward some prospects in the future.
Heteroaromatic‐conjugated aromatic molecules have inspired numerous interests in rechargeable batteries like Li‐ion batteries, but were limited by low conductivity and easy dissolution in ...electrolytes. Herein, we immobilize a nitrogen‐rich aromatic molecule tricycloquinazoline (TQ) and CuO4 unit into a two‐dimensional (2D) conductive metal–organic framework (MOF) to unlock their potential for Li+ storage. TQ was identified redox activity with Li+ for the first time. With a synergistic effect of TQ and CuO4 unit, the 2D conductive MOF, named Cu‐HHTQ (HHTQ=2,3,7,8,12,13‐hexahydroxytricycloquinazoline), can facilitate the Li+/e− transport and ensure a resilient electrode, resulting in a high capacity of 657.6 mAh g−1 at 600 mA g−1 with extraordinary high‐rate capability and impressive cyclability. Our findings highlight an efficient strategy of constructing electrode materials for energy storage with combining multiple redox‐active moieties into conductive MOFs.
The 2D conductive metal–organic framework Cu‐HHTQ with multiple redox‐active sites originating from a nitrogen‐rich aromatic molecule tricycloquinazoline (TQ) and a CuO4 unit was designed for Li‐ion batteries with high capacity, extraordinary high‐rate capability and impressive cyclability. TQ was identified as redox‐active with Li+ for the first time.
Microglia are brain resident macrophages originated from primitive progenitor cells in the yolk sac. Microglia can be activated within hours and recruited to the lesion site. Traditionally, microglia ...activation is considered to play a deleterious role in ischemic stroke, as inhibition of microglia activation attenuates ischemia induced brain injury. However, increasing evidence show that microglia activation is critical for attenuating neuronal apoptosis, enhancing neurogenesis, and promoting functional recovery after cerebral ischemia. Differential polarization of microglia could likely explain the biphasic role of microglia in ischemia. We comprehensively reviewed the mechanisms involved in regulating microglia activation and polarization. The latest discoveries of microRNAs in modulating microglia function are discussed. In addition, the interaction between microglia and other cells including neurons, astrocytes, oligodendrocytes, and stem cells were also reviewed. Future therapies targeting microglia may not exclusively aim at suppressing microglia activation, but also at modulating microglia polarization at different stages of ischemic stroke. More work is needed to elucidate the cellular and molecular mechanisms of microglia polarization under ischemic environment. The roles of microRNAs and transplanted stem cells in mediating microglia activation and polarization during brain ischemia also need to be further studied.
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•Recent bipyridinium-based coordination polymers (CPs) are reviewed.•The advantages of bipyridinium ligands for CPs synthesized are discussed.•The bipyridinium-based CPs for materials ...applications are highlighted.
The past decade has witnessed the rapid development of functional coordination polymers (CPs) for various potential applications. Generally speaking, functionalization of coordination framework to enhance materials performance could be achieved either during the framework formation or by post-synthesis modification. In spite of great progress over the past few years, there is still growing demand in expanding the research by introducing new structure motifs, among which the incorporation of stimuli-responsive ligand into the coordination skeleton is an option. In particular, the fusion of typically charged units, e.g. bipyridinium derivatives with metal ions to fabricate CPs has attracted tremendous attention. The electrostatic interaction, electron-deficient characteristic and photoelectrochemical activity make this family of materials show a wide variety of intriguing applications including smart chromic response, switching, sensing, adsorption and separation, and molecular magnets, etc. This review aims to highlight the recent progress in this area, and seek to uncover promising ideas that will stimulate future advancements at both the basic and applied levels.
Temporal stability of net primary productivity (NPP) is important for predicting the reliable provisioning of ecosystem services under global changes. Although nitrogen (N) addition is known to ...affect the temporal stability of aboveground net primary productivity (ANPP), it is unclear how it impacts that of belowground net primary productivity (BNPP) and NPP, and whether such effects are scale dependent. Here, using experimental N addition in a grassland, we found different responses of ANPP and BNPP stability to N addition at the local scale and that these responses propagated to the larger spatial scale. That is, N addition significantly decreased the stability of ANPP but did not affect the stability of BNPP and NPP at the two scales investigated. Additionally, spatial asynchrony of both ANPP and BNPP among communities provided greater stability at the larger scale and was not affected by N addition. Our findings challenge the traditional view that N addition would reduce ecosystem stability based on results from aboveground dynamics, thus highlighting the importance of viewing ecosystem stability from a whole system perspective.
It remains unknown how would nitrogen (N) enrichment affect the stability of belowground productivity. Using a field experiment with six N addition rates in a temperate steppe, we found that N addition decreased the stability of ANPP, but did not affect the stability of BNPP and total NPP at both local and larger scales. Spatial asynchrony of both ANPP and BNPP provided greater stability at larger scale and was not affected by N addition, highlighting the importance of understanding stability from a whole system perspective.
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