Pupose/Significance The library community can contribute greatly to scientific culture construction. This paper aims tosystematically analyze the connotation of scientific culture construction and ...explore the potential space where libraries can participate inscientific culture construction. give some enlightenment to libraries in our country.MethodProcess This research adopts the methodsof literature research, network research and systematic literature review.First,this study extracts Chinese keywords based on the Chineseliterature about "scientific culture" and analyzes its connotations. Ssecond it builds a list of English and Chinese keywords containing thesub concepts of "scientific culture". After retrieving, classifying and reading the literature about practice of libraries' participation inscientific culture construction carefully,this study compares the practice of Euro-American libraries and Chinese libraries, and putsforward countermeasures and suggestions for Chinese libraries to bridge the gap.
Sensory experience is critical to development and plasticity of neural circuits. Here we report a new form of plasticity in neonatal mice, where early sensory experience cross-modally regulates ...development of all sensory cortices via oxytocin signaling. Unimodal sensory deprivation from birth through whisker deprivation or dark rearing reduced excitatory synaptic transmission in the correspondent sensory cortex and cross-modally in other sensory cortices. Sensory experience regulated synthesis and secretion of the neuropeptide oxytocin as well as its level in the cortex. Both in vivo oxytocin injection and increased sensory experience elevated excitatory synaptic transmission in multiple sensory cortices and significantly rescued the effects of sensory deprivation. Together, these results identify a new function for oxytocin in promoting cross-modal, experience-dependent cortical development. This link between sensory experience and oxytocin is particularly relevant to autism, where hypersensitivity or hyposensitivity to sensory inputs is prevalent and oxytocin is a hotly debated potential therapy.
Hybrid perovskite materials are famous for their great application potential in photovoltaics and optoelectronics. Among them, lead‐iodide‐based perovskites receive great attention because of their ...good optical absorption ability and excellent electrical transport properties. Although many believe the ferroelectric photovoltaic effect (FEPV) plays a crucial role for the high conversion efficiency, the ferroelectricity in CH3NH3PbI3 is still under debate, and obtaining ferroelectric lead iodide perovskites is still challenging. In order to avoid the randomness and blindness in the conventional method of searching for perovskite ferroelectrics, a design strategy of fluorine modification is developed. As a demonstration, a nonpolar lead iodide perovskite is modified and a new 2D fluorinated layered hybrid perovskite material of (4,4‐difluorocyclohexylammonium)2PbI4, 1, is obtained, which possesses clear ferroelectricity with controllable spontaneous polarization. The direct bandgap of 2.38 eV with strong photoluminescence also guarantees the direct observation of polarization‐induced FEPV. More importantly, the 2D structure and fluorination are also expected to achieve both good stability and charge transport properties. 1 is not only a 2D fluorinated lead iodide perovskite with confirmed ferroelectricity, but also a great platform for studying the effect of ferroelectricity and FEPV in the context of lead halide perovskite solar cells and other optoelectronic applications.
Through a design strategy of fluorine modification, a nonpolar lead iodide perovskite is modified and a new 2D fluorinated layered hybrid perovskite material of (4,4‐difluorocyclohexylammonium)2PbI4 is obtained, which possesses clear ferroelectricity with controllable spontaneous polarization and ferroelectric photovoltaic effect. The discovery of such a material provides a great platform for the fundamental study of lead halide perovskite solar cells and other optoelectronic applications.
Conspectus A micro/nanomotor (MNM), as miniaturized machinery, can potentially bridge the application gap between the traditional macroscale motor and the molecular motor to manipulate materials at ...the cellular scale. The fascinating biomedical potential application for these tiny robots has been long envisioned by science fiction, such as “Fantastic Voyage”, where complicated surgery can be performed at single cell precision without any surgical incision. However, to enter the highly conservative biomedical and healthcare industry in practice, the MNM must provide unique advantages over existing technology without introducing additional health risk, which has not been fully materialized. As an emerging approach, light-driven micro/nanomotors (LMNMs) have demonstrated several unique advantages over other MNMs, which will be addressed in this Account. As a control signal, light promises additional degrees of freedom to manipulate MNMs by modulating the light intensity, frequency, polarization, and propagation direction with spatial and temporal precision, which enables excellent controllability and programmability of LMNMs. Additionally, the fruitful knowledge and catalysts from the well-studied photocatalysis can be readily transferred to LMNMs for photoelectrochemical reactions, which provides a rich materials inventory for the development of advanced LMNM systems. A model LMNM in general can be regarded as a miniaturized solar cell combined with electrokinetic propulsion parts, where electric current is provided by the photovoltaic effect and then converted to propulsion thrust through a variety of electrokinetic mechanisms. It can be envisioned that the electric current may be further regulated with the onboard electronic circuit for advanced logic-controlled nanorobots. Finally, because incident photons instead of active chemicals provide the energy for LMNM propulsion, the highly active but toxic chemical fuels can be avoided, which suggested their better biocompatibility. It is essential to emphasize that all of these promises rely on the in-depth understanding of the photoelectrochemical reaction as well as the physics of electrokinetic phenomena, which requires further investigations. As a persistent endeavor, the biomedical application is the most attractive but challenging target for MNMs. Currently, most of the MNMs are demonstrated with in vitro conditions largely deviating from the biological environment, and nontrivial in vivo studies and cytotoxicity experiments are rarely reported. As merits of MNMs, the efficiency, biocompatibility, ion tolerance, and controllability critically determine the future success of MNMs. In this Account, existing and prospective solutions in these aspects are systemically discussed for light-propelled MNMs. We believe that, with a better understanding of the fundamental photoelectrochemical and electrokinetic processes, the development of motor design strategies, and improved fabrication methods, the promised practical biomedical application, such as early disease diagnosis, interventional therapy, targeted therapy, and microsurgery, could be realized in the near future.
The charge redistribution strategy driven by heteroatom doping or defect engineering has been developed as an efficient method to endow inert carbon with significant oxygen reduction reaction (ORR) ...activity. The synergetic effect between the two approaches is thus expected to be more effective for manipulating the charge distribution of carbon materials for exceptional ORR performance. Herein we report a novel molecular design strategy to achieve a 2D porous turbostratic carbon nanomesh with abundant N‐doped carbon defects (NDC). The molecular level integration of aromatic rings as the carbon source and urea units as the N source and sacrificial template into the novel precursor of polyurea (PU) promises the formation of abundant carbon edge defects and N doping sites. A special active site—a carbon edge defect doped with a graphitic valley N atom—was revealed to be responsible for the exceptional ORR performance of NDC material.
Defects on purpose: A two‐dimensional porous turbostratic carbon nanomesh with abundant carbon defects coupled with N doping sites was developed by a novel molecular design strategy. This material displays exceptional oxygen reduction reaction electrocatalytic activity, which is attributed to the formation of highly exposed carbon edge defects doped with graphitic valley N atoms.
A wide area quantum key distribution (QKD) network deployed on communication infrastructures provided by China Mobile Ltd. is demonstrated. Three cities and two metropolitan area QKD networks were ...linked up to form the Hefei-Chaohu-Wuhu wide area QKD network with over 150 kilometers coverage area, in which Hefei metropolitan area QKD network was a typical full-mesh core network to offer all-to-all interconnections, and Wuhu metropolitan area QKD network was a representative quantum access network with point-to-multipoint configuration. The whole wide area QKD network ran for more than 5000 hours, from 21 December 2011 to 19 July 2012, and part of the network stopped until last December. To adapt to the complex and volatile field environment, the Faraday-Michelson QKD system with several stability measures was adopted when we designed QKD devices. Through standardized design of QKD devices, resolution of symmetry problem of QKD devices, and seamless switching in dynamic QKD network, we realized the effective integration between point-to-point QKD techniques and networking schemes.
Multi-omics data are good resources for prognosis and survival prediction; however, these are difficult to integrate computationally. We introduce DeepProg, a novel ensemble framework of ...deep-learning and machine-learning approaches that robustly predicts patient survival subtypes using multi-omics data. It identifies two optimal survival subtypes in most cancers and yields significantly better risk-stratification than other multi-omics integration methods. DeepProg is highly predictive, exemplified by two liver cancer (C-index 0.73-0.80) and five breast cancer datasets (C-index 0.68-0.73). Pan-cancer analysis associates common genomic signatures in poor survival subtypes with extracellular matrix modeling, immune deregulation, and mitosis processes. DeepProg is freely available at https://github.com/lanagarmire/DeepProg.
We report herein a new strategy of the Rh(III)-catalyzed C–H activation/cyclization of indoles and pyrroles, for the divergent synthesis of privileged heterocycles. A simple derivation of indoles and ...pyrroles to N-carboxamides with oxidative bidentate directing group could enable rhodacycle formation and late-stage redox-neutral cyclization with alkynes, alkenes and diazo compounds, for access to five- and six-membered fused heterocycles, such as pyrimido1,6-aindol-1(2H)-one, 3,4-dihydropyrimido1,6-aindol-1(2H)-one, and 1H-imidazo1,5-aindol-3(2H)-ones. Kinetic isotope effect study was conducted, and a plausible mechanism was proposed. Furthermore, this protocol was applied to concise synthesis of 5-HT3 receptor antagonist in gram-scale.
•Temperatures increased, but relative humidity, wind speed and sunshine hour decreased.•More generally decreasing trends than increasing trends in annual ET0 were found.•Abrupt changes were detected ...in 1990s in the MPZ, while in 1980s in the other zones.•Relative humidity was the most sensitive climatic variable except for the MPZ.•Increasing ET0 after 1985 increases crop water demand and aggravates water shortage.
Global climate change has been an increasing challenge to agricultural ecosystems, which will significantly affect the reference crop evapotranspiration (ET0) and subsequently crop water requirements. In this study, the temporal trends and magnitudes of key climatic variables and the accompanying effects on ET0 during 1956–2015 were evaluated at 200 meteorological stations across the temperate continental zone (TCZ), temperate monsoon zone (TMZ), mountain plateau zone (MPZ), and subtropical monsoon zone (SMZ) of China. Results show that maximum and minimum temperatures have increased significantly over the past 60 years, whilst relative humidity, wind speed and sunshine hour exhibited significant decreasing trends across all climatic zones. The overall decreasing trends in annual ET0 were more pronounced than the increasing trends, whereas more increasing trends were found in spring and winter. Abrupt changes for climatic variables and ET0 series were detected in 1990s in the MPZ, while in 1980s in the other climatic zones mainly due to the aggregated emission of greenhouse gases and air pollution from energy consumption in recent decades. Relative humidity was the most sensitive climatic variable in all climatic zones except for the MPZ where ET0 was most sensitive to sunshine hour. However, ET0 had different responses to changing climatic variables in different regions and climatic conditions. The negative contribution of wind speed to the decrease in ET0 was greater than the other climatic variables in the TCZ and the TMZ, whilst the significant increase in minimum temperature and the decrease in sunshine hour contributed most to increasing ET0 in the MPZ and to decreasing ET0 in the SMZ, respectively. Although ET0 displayed a generally decreasing trend during 1956–2015, there was a significantly increasing trend from 1985 to 2015 across China except for the SMZ, especially in the arid and semi-arid zones of China during dry seasons (spring and winter). This may lead to the increase in crop water requirements and aggravate the water shortage in these areas in view of the increase in ET0 in response to ongoing climate change.
TA15 (Ti–6Al–2Zr–1Mo–1V) is a near-α titanium alloy and has wide applications in the aerospace industry because of its high strength to mass ratio, good weldability, and superior creep resistance at ...high temperatures up to 550 °C, compared to other titanium alloys. This study investigates the flow behavior and microstructural evolution as functions of temperatures and strain rates during deformations under the superplastic conditions at 880 °C/0.01s−1, 900 °C/0.01s−1, 880 °C/0.001s−1, and 920 °C/0.0005s−1. Results showed that this alloy exhibit excellent superplastic behavior for all selected temperatures and strain rates. The maximum tensile elongation of 1450% is achieved at 880 °C with a strain rate of 0.001s−1. Flow softening is observed under deformation conditions of 880 °C/0.01s−1 and 900 °C/0.01s−1, while strain hardening is observed at deformation conditions of 880 °C/0.001s−1 and 920 °C/0.0005s−1. These complex flow behaviors are rationalized by characterizing the underlying microstructures on the interrupted tensile samples using electron backscatter diffraction (EBSD) and backscattered electrons (BSE). The geometrically necessary dislocations (GNDs) density, which is caused by lattice rotation and misorientations and plays a vital role in the plastic constitutive behaviors, was for the first time, systematically revealed. Together with other key microstructures, i.e. grain sizes, texture, phase fractions, the results show that the dominant deformation mode changes at initial, intermediate, and final stages of the deformation. The probable deformation mechanisms, such as grain boundary sliding (GBS) under different deformation conditions, are discussed in terms of grain morphology, GNDs, and texture evolution. Also, it is observed that the β-phase transformation is accelerated during deformation and contributes to the enhancement of superplasticity.
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