Study on creep deformation and energy development of underground surrounding rock under four‐dimensional support

There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground engineering.The previously proposed four‐dimensional support(hereinafter 4D support),as a new support technology,can set the roadway surrounding rock under three‐dimensional pressure in the new balanced structure,and prevent instability of surrounding rock in underground engineering.However,the influence of roadway depth and creep deformation on the surrounding rock supported by 4D support is still unknown.This study investigated the influence of roadway depth and creep deformation time on the instability of surrounding rock by analyzing the energy development.The elastic strain energy was analyzed using the program redeveloped in FLAC3D.The numerical simulation results indicate that the combined support mode of 4D roof supports and conventional side supports is highly applicable to the stability control of surrounding rock with a roadway depth exceeding 520 m.With the increase of roadway depth,4D support can effectively restrain the area and depth of plastic deformation in the surrounding rock.Further,4D support limits the accumulation range and rate of elastic strain energy as the creep deformation time increases.4D support can effectively reduce the plastic deformation of roadway surrounding rock and maintain the stability for a long deformation period of 6 months.As confirmed by in situ monitoring results,4D support is more effective for the long‐term stability control of surrounding rock than conventional support.

长江经济带人口、经济与环境耦合协调度评价

构建人口-经济-环境系统综合评价指标体系,基于熵值法和耦合协调度模型对2006~2016年长江经济带116个地区进行人口、经济与环境耦合协调度评价.研究结果表明,长江经济带116个地区的人口、经济与环境耦合协调度整体水平不高、梯度差异显著、两极分化明显,耦合协调度较高的地区普遍分布于东、中部地区,耦合协调度较低的地区普遍分布于中、西部地区,整个经济带各地区的主要协调类型为濒临失衡和轻度失衡,主要制约因素为经济因素和环境因素.

Electron promoted ZnO for catalytic synthesis of higher alcohols from syngas

Direct conversion of syngas from those non-petroleum carbon resources to higher alcohols are very attractive due to the process simplicity with low energy consumption.However,the reaction always suffers from low yield as well as low selectivity.Herein,effective increase of higher alcohols proportion in the product is realized by direct conversion of syngas over electronically-modulated ZnO semiconductor via Cu doping.It is considered that the lower Fermi level and narrower band gap of catalysts by embedding Cu^(2+)into ZnO lattice could facilitate donor reaction by boosting the process for the reactants to obtain electrons on the catalyst surface for the formation of CH_(x) species and carbon chain growth,in which the Cu doping on ZnO lattice play important role in the promotion of CO adsorption.As a result,4 mol%Cu doped ZnO exhibits a highest C_(2+) OH/ROH fraction of 48.1%.Selectivity of catalysts from straight chain alcohol is better than from branch chain alcohol,which is different from promoted Cu/ZnO based catalyst.However,over-doping of Cu(7 mol%)on ZnO results in the aggregation Cu species on ZnO surface,leading to a sharp decrease of higher alcohols proportion to 3.2%.The results shed light on the nature that a direct correlation between semiconductor Fermi level and synthesis of higher alcohols,and the semiconductor-based catalysts mainly accelerate the hydrogenation reactions by enhancing thermally excited electron transfer.

Radiomics: Status quo and future challenges

Noninvasive imaging(computed tomography,magnetic resonance imaging,endoscopic ultrasonography,and positron emission tomography)as an important part of the clinical workflow in the clinic,but it still provides limited information for diagnosis,treatment effect evaluation and prognosis prediction.In addition,judgment and diagnoses made by experts are usually based on multiple years of experience and subjective impression which lead to variable results in the same case.With accumulation of medical imaging data,radiomics emerges as a relatively new approach for analysis.Via artificial intelligence techniques,highthroughput quantitative data which is invisible to the naked eyes extracted from original images can be used in the process of patients’management.Several studies have evaluated radiomics combined with clinical factors,pathological,or genetic information would assist in the diagnosis,particularly in the prediction of biological characteristics,risk of recurrence,and survival with encouraging results.In various clinical settings,there are limitations and challenges needing to be overcome before transformation.Therefore,we summarize the concepts and method of radiomics including image acquisition,region of interest segmentation,feature extraction and model development.We also set forth the current applications of radiomics in clinical routine.At last,the limitations and related deficiencies of radiomics are pointed out to direct the future opportunities and development.

Arbuscular mycorrhizal fungi reduce ammonia emissions under different land-use types in agro-pastoral areas

Ammonia(NH3)emissions,the most important nitrogen(N)loss form,always induce a series of environmental problems such as increased frequency of regional haze pollution,accelerated N deposition,and N eutrophication.Arbuscular mycorrhizal(AM)fungi play key roles in N cycling.However,it is still unclear whether AM fungi can alleviate N losses by reducing NH3emissions.The potential mechanisms by which AM fungi reduce NH_(3)emissions in five land-use types(grazed grassland,mowed grassland,fenced grassland,artificial alfalfa grassland,and cropland)were explored in this study.Results showed that AM fungal inoculation significantly reduced NH3emissions,and the mycorrhizal responses of NH3emissions were determined by land-use type.Structural equation modeling(SEM)showed that AM fungi and land-use type directly affected NH_(3)emissions.In addition,the reduction in NH_(3)emissions was largely driven by the decline in soil NH_(4)^(+)-N and pH and the increases in abundances of ammonia-oxidizing archaea(AOA)amoA and bacteria(AOB)amoB genes,urease activity,and plant N uptake induced by AM fungal inoculation and land-use type.The present results highlight that reducing the negative influence of agricultural intensification caused by land-use type changes on AM fungi should be considered to reduce N losses in agriculture and grassland ecosystems.

Single-Exosome Profiling Identifies ITGB3+and ITGAM+Exosome Subpopulations as Promising Early Diagnostic Biomarkers and Therapeutic Targets for Colorectal Cancer

Tumor metastasis is a hallmark of colorectal cancer(CRC),in which exosome plays a crucial role with its function in intercellular communication.Plasma exosomes were collected from healthy control(HC)donors,localized primary CRC and liver-metastatic CRC patients.We performed proximity barcoding assay(PBA)for single-exosome analysis,which enabled us to identify the alteration in exosome subpopulations associated with CRC progression.By in vitro and in vivo experiments,the biological impact of these subpopulations on cancer proliferation,migration,invasion,and metastasis was investigated.The potential application of exosomes as diagnostic biomarkers was evaluated in 2 independent validation cohorts by PBA.Twelve distinct exosome subpopulations were determined.We found 2 distinctly abundant subpopulations:one ITGB3-positive and the other ITGAM-positive.The ITGB3-positive cluster is rich in liver-metastatic CRC,compared to both HC group and primary CRC group.On the contrary,ITGAM-positive exosomes show a large-scale increase in plasma of HC group,compared to both primary CRC and metastatic CRC groups.Notably,both discovery cohort and validation cohort verified ITGB3+exosomes as potential diagnostic biomarker.ITGB3+exosomes promote proliferation,migration,and invasion capability of CRC.In contrast,ITGAM+exosomes suppress CRC development.Moreover,we also provide evidence that one of the sources of ITGAM+exosomes is macrophage.ITGB3+exosomes and ITGAM+exosomes are proven 2 potential diagnostic,prognostic,and therapeutic biomarkers for management of CRC.

通过控制陷阱分布实现高灵敏度窄带近红外响应有机光探测器

近红外(NIR)窄带光电探测在机器视觉、医学检测、智能通信等领域具有重要应用.本文提出了一种基于激子解离窄化机制的改进型层级器件结构,以实现响应峰值为940 nm的近红外窄带有机光电探测器(OPD).系统研究表明,通过调节器件内部的陷阱态密度分布,可以有效地提高窄带探测器的外量子效率(EQE)峰值.最终,基于双激子耗散层结构的器件在940 nm处达到了接近60%的峰值EQE,半峰宽为79 nm,峰值比探测率为2.3×10^(13) Jones.所构筑的可见盲-近红外OPD对940 nm波段的辐射具有选择性响应,可自主屏蔽环境光干扰.此外,基于该优化的器件结构制备了柔性窄带OPD,并在反射模式下利用光容积描记技术成功地实现了无创实时心率监测,证明了这种器件结构对于实现高性能窄带光电探测功能的适用性.

SERK Receptor-like Kinases Control Division Patterns of Vascular Precursors and Ground Tissue Stem Cells during Embryo Development in Arabidopsis

During embryo development, the vascular precursors and ground tissue stem cells divide to renew them-selves and produce the vascular tissue, endodermal cells, and cortical cells. However, the molecular mech-anisms regulating division of these stem cells have remained largely elusive. In this study, we show that loss of function of SOMATIC EMBRYOGENESIS RECEPTOR-UKE KINASE (SERK) genes results in aberrant em-bryo development. Fewer cortical, endodermal, and vascular cells are generated in the embryos of serk1 serk2bak1 triple mutants. WUSCHEL-RELATED HOMBOBOX5 (WOXS) is ectopically expressed in vascular cells of serkl serk2 bak1 embryos. The first transverse division of vascular precursors in mid-globular em-bryos and second asymmetric division of ground tissue stem cells in early-heart embryos are abnormally altered to a longitudinal division. The embryo defects can be partially rescued by constitutively activated mitogen-activated protein kinase (MAPK) kinase kinase YODA (YDA) and MAPK kinase MKK5. Taken together, our results reveal that SERK-mediated signals regulate division patterns of vascular precursors and ground tissue stem cells, likely via the YDA-MKK4/5 cascade, during embryo development.

Stretchable transparent electrodes for conformable wearable organic photovoltaic devices

To achieve adhesive and conformable wearable electronics,improving stretchable transparent electrode(STE)becomes an indispensable bottleneck needed to be addressed.Here,we adopt a nonuniform Young’s modulus structure with silver nanowire(AgNW)and fabricate a STE layer.This layer possesses transparency of>88%over a wide spectrum range of 400–1000 nm,sheet resistance below 20Ωsq^(−1),stretchability of up to 100%,enhanced mechanical robustness,low surface roughness,and good interfacial wettability for solution process.As a result of all these properties,the STE enables the fabrication of a highly efficient ultraflexible wearable device comprising of both organic photovoltaic(OPV)and organic photodetector(OPD)parts with high mechanical durability and conformability,for energy-harvesting and biomedical-sensing applications,respectively.This demonstrates the great potential of the integration of OPVs and OPDs,capable of harvesting energy independently for biomedical applications,paving the way to a future of independent conformable wearable OPV/OPDs for different applications.