Backscattering suppression in silicon-on-insulator (SOI) is one of the central issues to reduce energy loss and signal distortion, enabling for capability improvement of modern information processing ...systems. Valley physics provides an intriguing way for robust information transfer and unidirectional coupling in topological nanophotonics. Here we realize topological transport in a SOI valley photonic crystal slab. Localized Berry curvature near zone corners guarantees the existence of valley-dependent edge states below light cone, maintaining in-plane robustness and light confinement simultaneously. Topologically robust transport at telecommunication is observed along two sharp-bend interfaces in subwavelength scale, showing flat-top high transmission of ~10% bandwidth. Topological photonic routing is achieved in a bearded-stack interface, due to unidirectional excitation of valley-chirality-locked edge state from the phase vortex of a nanoscale microdisk. These findings show the prototype of robustly integrated devices, and open a new door towards the observation of non-trivial states even in non-Hermitian systems.
Body size is perhaps the most important trait for organism biologists, as it is associated with a myriad of ecological, evolutionary, behavioral, morphological, physiological and life-history aspects ...(e.g., rates of molecular evolution, metabolic rates, predation, reproduction), and with extinction risk. There are, however, several measures commonly used to quantify organism body size. Within ectothermic tetrapods, the most common measures include snout-vent length (SVL, mostly in lizards), and total length (TL, in most snakes). In endotherms, however, and especially in mammals, body mass is the most common measure of size.
In this article, a fuzzy adaptive nonsingular fixed-time attitude tracking control scheme is proposed for the quadrotor unmanned aerial vehicles (UAVs) subject to inertia uncertainties, actuator ...saturation, and faults. A new nonsingular fixed-time sliding mode surface and an auxiliary function are constructed, such that the singularity problem can be avoided in the controller design without using any piecewise continuous functions. Then, a novel arccot function-based double power reaching law is developed to adjust the control gain and enhance the transient tracking performance. The fixed-time convergence of sliding variables and tracking errors are analyzed by rigorous theoretical proofs, and comparative experiments on a three-degree-of-freedom quadrotor platform are performed to illustrate the effectiveness of the presented scheme.
17 sustainable development goals (SDGs) were committed by 193 countries in 2015. Assessing the spatio-temporal progress of achieving the SDGs can help to track the global sustainable development ...progress and identify critical development issues to eventually accelerate the achievement of SDGs. However, there is a lack of methods for the quantitative assessment of the progress of achieving SDGs at the regional level (above the national level), especially systematic methods that can simultaneously assess regions along the “Belt and Road”. To fill this research gap, after classifying 17 SDGs into four dimensions (society, economy, environment, means of implementation and cooperation), we have developed the Composite SDG Index to represent the comprehensive performance of achieving SDGs. Specifically, the index is constructed by two sub-indices, including the SDG subindex used to assess the overall performance of achieving the four dimensional SDGs and the Coupling Coordinated SDG subindex used for the first time in the SDG assessment to measure the coupling coordination degree between the four SDG dimensions. To implement this methodological framework, we chose 15 countries along the “Belt and Road” as the case study, and used 108 indicators to assess the performance of achieving SDGs for these countries. Eventually, various national development models and related policy recommendations were proposed. The three indices included in the methodological framework developed in this study can effectively enhance the global stakeholders' mutual understanding of the progress of achieving SDGs to support regional coordinated planning and national-level strategic decision-making.
Display omitted
•A composite method for assessing regional progress of achieving SDGs was successfully constructed and testified.•The coupling coordinated index was also constructed and used for the first time in the SDG assessment.•For the sample region, countries belonging to the Central and Eastern Europe had the best progress of achieving SDGs.•Three national development models and related policy recommendations were proposed.
This article proposes an unknown system dynamics estimator (USDE) based sliding mode control for servo mechanisms with unknown dynamics and modeling uncertainties. An invariant manifold is first ...constructed by introducing an auxiliary variable based on a first-order low-pass filter. This is used to design a USDE with only one tuning parameter (i.e., time constant for the filter) and a simpler structure than other estimators. The USDE is used to compensate for the effect of the lumped unknown system dynamics since it can be easily incorporated into control synthesis. Moreover, to avoid the chattering phenomenon in the conventional sliding mode control methods, a novel reaching law is designed based on hyperbolic functions to guarantee that the sliding mode variable infinitely approaches to the equilibrium point instead of crossing it. Consequently, the fast convergence and chattering-free property can be achieved simultaneously. Simulations and experiments are provided to validate the effectiveness and superior performance of the proposed method.
A series of phosphine-sulfonate ligands and the corresponding nickel complexes are prepared and characterized. These ligands are specifically designed to bear systematically varied electron-donating ...and -withdrawing substituents (H, OMe, NMe2, CF3, and Me). More importantly, these substituents are installed at different positions on the ligand framework, namely, the para-position of the phenylphosphino group (position X), and para to the arylsulfonate group of the main ligand (position Y). These nickel complexes are highly active single-component catalysts for the polymerization of ethylene. An electron-donating substituent at position X or an electron-withdrawing substituent at position Y is beneficial to the properties of these nickel catalysts. Specifically, the catalyst bearing the NMe2 substituent at position X exhibits high stability and high activity (3.3 × 106 g mol–1 h–1), and catalyzes the formation of polyethylene of high molecular weight (M n 405 000) and high melting point (T m 138.5 °C). This catalyst also mediates the efficient copolymerizations of ethylene with methyl 10-undecenoate, 6-chloro-1-hexene, and trimethoxyvinylsilane.
The development of high-performance transition metal catalysts has long been a major driving force in academic and industrial polyolefin research. Late transition metal-based olefin polymerization ...catalysts possess many unique properties, such as the ability to generate variously branched polyolefins using only ethylene as the feedstock and the capability of incorporating polar functionalized comonomers without protecting agents. Here we report the synthesis and (co)polymerization studies of a simple but extremely versatile α-imino-ketone nickel system. This type of catalyst is easy to synthesize and modify, and it is thermally stable and highly active during ethylene polymerization without the addition of any cocatalysts. Despite the sterically open nature, these catalysts can generate branched Ultra-High-Molecular-Weight polyethylene and copolymerize ethylene with a series of polar comonomers. The versatility of this platform has been further demonstrated through the synthesis of a dinuclear nickel catalyst and the installation of an anchor for catalyst heterogenization.
Background
A growing number of studies indicate that circular RNAs (circRNAs) play critical roles in human diseases, and show great potential as biomarkers and therapeutic targets. This study aimed ...to investigate the expression and function of circANKS1B in prostate cancer (PC).
Methods
The expression of circANKS1B and miR‐152‐3p was analyzed by real‐time quantitative reverse‐transcription polymerase chain reaction (qRT‐PCR). Cell migration and invasion were measured using a transwell assay. The interaction between circANKS1B and miR‐152‐3p was confirmed by a dual‐luciferase reporter gene assay. Rescue experiments were conducted to determine whether circANKS1B regulated the invasion of PC cells via the circANKS1B‐miR‐152‐3p‐TGF‐α pathway.
Results
The expression of circANKS1B was markedly upregulated in both PC cells and tissues. Moreover, high circANKS1B expression was associated with poor prognosis in PC patients. Dual‐luciferase reporter assay indicated that circANKS1B directly bound to miR‐152‐3p. Furthermore, circANKS1B negatively regulated miR‐152‐3p expression. Knockdown of circANKS1B markedly suppressed cell migration and invasion and TGF‐α expression in PC cells, whereas the effects of circANKS1B silencing were reversed by miR‐152‐3p deficiency. In addition, the impact of miR‐152‐3p silencing on invasion of circANKS1B‐deficient PC cells was also abrogated by TGF‐α deficiency. Overall, circANKS1B acts as a sponge for miR‐152‐3p to promote PC progression by upregulating TGF‐α expression.
Conclusion
Our findings reveal that circANKS1B may be a potential prognostic biomarker and therapeutic target for PC.
Phosphorus (P) is a key indicator of the aquatic organism growth and eutrophication in lakes. The distribution and speciation of P and its release characteristics from sediments were investigated by ...analyzing sediment and water samples collected during high flow and low flow periods. Results showed that the average concentrations (ranges) of total phosphorus (TP) in the surface and deep water were 0.06 mg L(-1) (0.03-0.13 mg L(-1)) and 0.15 mg L(-1) (0.06-0.33 mg L(-1)), respectively, while the average concentration (range) of TP in sediments was 709.17 mg kg(-1) (544.76-932.11 mg kg(-1)). The concentrations of TP and different forms of P varied spatially in the surface sediments, displaying a decreasing trend from south to north. P also varied topographically from estuarine areas to lake areas. The vertical distribution of TP and different forms of P were observed to decrease as depth increased. The P concentrations during the low flow period were higher than those during the high flow period. Inorganic phosphorus (IP) was the dominant form of P, accounting for 61%-82% of TP. The concentration of bioavailable phosphorus in sediments was relatively large, indicating a high risk of release to overlying water. The simulation experiment of P release from sediments showed that the release was relatively fast in the first 0-5 min and then decreased to a plateau after 1 hr. Approximately 84-89% of the maximum amount of P was released during the first hour.
Accurate control of a quantum system is a fundamental requirement in many areas of modern science ranging from quantum information processing to high-precision measurements. A significantly important ...goal in quantum control is preparing a desired state as fast as possible, with sufficiently high fidelity allowed by available resources and experimental constraints. Stimulated Raman adiabatic passage (STIRAP) is a robust way to realize high-fidelity state transfer but it requires a sufficiently long operation time to satisfy the adiabatic criteria. Here we theoretically propose and then experimentally demonstrate a shortcut-to-adiabatic protocol to speed-up the STIRAP. By modifying the shapes of the Raman pulses, we experimentally realize a fast and high-fidelity stimulated Raman shortcut-to-adiabatic passage that is robust against control parameter variations. The all-optical, robust and fast protocol demonstrated here provides an efficient and practical way to control quantum systems.
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