Dual-mode index modulation aided OFDM

Index modulation has become a promising technique in the context of orthogonal frequency division multiplexing (OFDM), whereby the specific activation of the frequency domain subcarriers is used for implicitly conveying extra information, hence improving the achievable throughput at a given bit error ratio (BER) performance. In this paper, a dual-mode OFDM technique (DM-OFDM) is proposed, which is combined with index modulation and enhances the attainable throughput of conventional index-modulation-based OFDM. Specifically, the subcarriers are divided into several subblocks, and in each subblock, all the subcarriers are partitioned into two groups, modulated by a pair of distinguishable modem-mode constellations, respectively. Hence the information bits are conveyed not only by the classic constellation symbols, but implicitly also by the specific activated subcarrier indices, representing the subcarriers’ constellation mode. At the receiver, a maximum likelihood (ML) detector and a reduced-complexity near optimal log-likelihood ratio (LLR) based detector are invoked for demodulation. The minimum distance between the different legitimate realizations of the OFDM subblocks is calculated for characterizing the performance of DM-OFDM. Then the associated theoretical analysis based on the pairwise error probability is carried out for estimating the BER of DM-OFDM. Furthermore, the simulation results confirm that at a given throughput DM-OFDM achieves a considerably better BER performance than other OFDM systems using index modulation, while imposing the same or lower computational complexity. The results also demonstrate that the performance of the proposed low-complexity detector is indistinguishable from that of the ML detector, provided that the system’s signal to noise ratio is sufficiently high

Ultrafast observation of critical nematic fluctuations and giant magnetoelastic coupling in iron pnictides

Many of the iron pnictides have strongly anisotropic normal-state characteristics, important for the exotic magnetic and superconducting behavior these materials exhibit. Yet, the origin of the observed anisotropy is unclear. Electronically driven nematicity has been suggested, but distinguishing this as an independent degree of freedom from magnetic and structural orders is difficult, as these couple together to break the same tetragonal symmetry. Here we use time-resolved polarimetry to reveal critical nematic fluctuations in unstrained Ba(Fe_(1-x)Co_x)_2As_2. The femtosecond anisotropic response, which arises from the two-fold in-plane anisotropy of the complex refractive index, displays a characteristic two-step recovery absent in the isotropic response. The fast recovery appears only in the magnetically ordered state, whereas the slow one persists in the paramagnetic phase with a critical divergence approaching the structural transition temperature. The dynamics also reveal a gigantic magnetoelastic coupling that far exceeds electron-spin and electron-phonon couplings, opposite to conventional magnetic metals.Comment: The final, published version in Nature Communications Nat. Commun. 5:3229 doi: 10.1038/ncomms4229 (2014

Revealing intra-urban spatial structure through an exploratory analysis by combining road network abstraction model and taxi trajectory data

The unprecedented urbanization in China has dramatically changed the urban spatial structure of cities. With the proliferation of individual-level geospatial big data, previous studies have widely used the network abstraction model to reveal the underlying urban spatial structure. However, the construction of network abstraction models primarily focuses on the topology of the road network without considering individual travel flows along with the road networks. Individual travel flows reflect the urban dynamics, which can further help understand the underlying spatial structure. This study therefore aims to reveal the intra-urban spatial structure by integrating the road network abstraction model and individual travel flows. To achieve this goal, we 1) quantify the spatial interaction relatedness of road segments based on the Word2Vec model using large volumes of taxi trip data, then 2) characterize the road abstraction network model according to the identified spatial interaction relatedness, and 3) implement a community detection algorithm to reveal sub-regions of a city. Our results reveal three levels of hierarchical spatial structures in the Wuhan metropolitan area. This study provides a data-driven approach to the investigation of urban spatial structure via identifying traffic interaction patterns on the road network, offering insights to urban planning practice and transportation management

Photoinduced femtosecond relaxation of antiferromagnetic orders in the iron pnictides revealed by ultrafast laser ellipsometry

We report ultrafast softening of the antiferromagnetic order, ~150fs after the electron thermalization, which follows a two-step recovery pathway to reveal a distinct interplay of magnetism and the nematic order in iron pnictides

Application and prospect of coal gangue slurry filling technology

In order to realize in-situ, green and large-scale disposal of coal gangue, coal gangue slurry filling technology, as a new filling technology, has been rapidly developed and applied in recent years. This paper systematically reviews and summarizes the landmark achievements and key technologies of coal gangue slurry filling at different stages, such as the proposal of the technical framework, the formation of the theoretical system of slurry filling, the application of engineering demonstration and the innovation of technology iteration, and forms three filling methods, namely, high-level grouting, low-level grouting and adjacent grouting. The “intervention theory” of coal gangue slurry flow in goaf caving zone and the “three degrees and one field” theory of slurry pipeline transportation have been established, and the first demonstration project of coal gangue underground slurry filling and surface slurry preparation + underground adjacent grouting filling has been successfully carried out at home and abroad; This paper expounds the technical system of coal gangue slurry filling, and discusses the key technical core issues of coal gangue high-efficiency grading crushing, slurry precise preparation, slurry pipeline transportation and end filling, focusing on the process flow of coal gangue crushing, water slurrying of finished gangue powder, slurry pumping preparation and underground target area filling. The technical principles and application scenarios of key equipment such as crushing equipment, screening equipment, metering equipment, mixing equipment and pumping equipment are analyzed; Based on the engineering background of small space, multi-equipment and high capacity of coal gangue slurry filling in Zhangjiamao Coal Mine, the layout of different systems such as surface slurry making, pipeline transportation, underground filling and intelligent control of coal gangue slurry filling was innovatively developed and designed, and the annual filling amount of coal gangue could reach 554 000 tons, forming a demonstration of coal gangue slurry filling engineering. In the future, the coal gangue slurry filling technology will be further studied and developed in the direction of small and lightweight equipment, highly integrated system, iterative and innovative technology, which will provide technical support for the construction of green coal mining technology system and the realization of the national carbon peaking and carbon neutrality goal

Improvement of social functioning in patients with first-episode schizophrenia using blonanserin treatment: a prospective, multi-centre, single-arm clinical trial

ObjectivesThis clinical trial primarily aimed to investigate the effects of blonanserin on social functioning in patients with first-episode schizophrenia.MethodsIn this prospective, multi-centre, single-arm clinical trial study, blonanserin (flexible oral dose ranging from 8mg to 24mg per day) was given 26 weeks. Outcome measures included the Personal and Social Performance (PSP) scale for evaluating social functioning, the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB) for measuring neurocognitive performance, and the Positive and Negative Syndrome Scale (PANSS) for assessing symptom severity. The primary endpoint was social function improvement evaluated by PSP scale at the end of blonanserin treatment. And the secondary endpoint was to validate the efficacy and neurocognitive effects of blonanserin. Adverse drug reactions (ADRs) were also recorded and analysed.ResultsA total of 96 patients with first-episode schizophrenia were recruited and proceeded to analysis. Fifty-one participants (53.1%) completed the PSP scale measurements at baseline and week 26. Following 26 weeks of blonanserin treatment, all outcome measurements demonstrated significant improvement during the follow-up period. Notably, PSP scores exhibited a continuous increase up to 68.1% ± 103.7% at the end of the treatment (46.6 ± 14.6 at baseline, 69.4 ± 17.4 at week 26, p<0.001), indicating positive effects on social functioning that were already noticeable by week 8.ConclusionBlonanserin treatment exhibited favourable effects on social functioning in individuals with first-episode schizophrenia. The results suggest that blonanserin was effective treatment options for patients with schizophrenia encountering functional impairments

Flavokawain A alleviates the progression of mouse osteoarthritis: An in vitro and in vivo study

Osteoarthritis (OA) is one of the most prevalent chronic degenerative joint diseases affecting adults in their middle or later years. It is characterized by symptoms such as joint pain, difficulty in movement, disability, and even loss of motion. Moreover, the onset and progression of inflammation are directly associated with OA. In this research, we evaluated the impact of Flavokawain A (FKA) on osteoarthritis. In-vitro effects of FKA on murine chondrocytes have been examined using cell counting kit-8 (CCK-8), safranin o staining, western blot, immunofluorescence staining, senescence β-galactosidase staining, flow cytometry analysis, and mRFP-GFP-LC3 adenovirus infection. An in-vivo model of destabilization of the medial meniscus (DMM) was employed to investigate FKA’s effect on OA mouse. An analysis of bioinformatics was performed on FKA and its potential role in OA. It was observed that FKA blocked interleukin (IL)-1β-induced expression of inflammatory factors, i.e., cyclooxygenase-2 (COX2) and inducible nitric oxide synthase (iNOS) in chondrocytes. In addition, FKA also downregulated the catabolic enzyme expression, i.e., aggrecanase-2 (ADAMTS5) and matrix metalloproteinases (MMPs), and helped in the upregulation of the anabolic protein expression, i.e., type II collagen (Col2), Aggrecan, and sry-box transcription factor 9 (SOX9). Moreover, FKA ameliorated IL-1β-triggered autophagy in chondrocytes, and it was observed that the FKA causes anti-inflammatory effects by the mitogen-activated protein kinase (MAPK) and phosphoinositide-3-kinase/Akt/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathways inhibition. The results of immunohistochemical analysis and microcomputed tomography from the in vivo OA mouse model confirmed the therapeutic effect of FKA. Finally, we assessed the anti-arthritic impacts of FKA by conducting in vivo and in vitro analyses. We concluded that FKA can be employed as a useful therapeutic agent for OA therapy, but the findings require needs further clinical investigation