With the rapid popularization of the Internet plus China and China’s rapid economic development, machine learning is playing an increasingly important role in model research. This paper presents a ...cold start method based on a hybrid Dirichlet process model and isolated forest. As we all know, the soil rock mixed slope is between the slope of soil and rock, most of its structure is loose and has large porosity, high permeability, and poor slope stability. Compared with soil slope and rock slope, the research on soil rock mixed slope is not comprehensive enough. Based on the study of geological environment conditions of highway slope, the mechanical properties of soil rock mixed slope are tested by traditional boundary equilibrium method and numerical simulation method. The stability of the three-dimensional slope is systematically studied in this paper. Nowadays, the mental health of left-behind children is still the focus of social attention. In this paper, a special school for left-behind children in a city is selected as the research object. The school is located between urban and rural areas. Since the children who stay in the school are from urban and rural areas, they will be selected as the research objects. Compared with ordinary children, left-behind children are more likely to have concerns, and their psychological changes are difficult to predict. What is more worrying is the long-term mental health problems. This paper aims to find the correlation between sports games and left-behind children’s mental health by introducing sports games in order to provide some methods and theoretical reference materials for solving the mental health problems of left-behind children.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Lineament is a unique geological structure. The study of Lunar lineament structure has great significance on understanding its history and evolution of Lunar surface. However, the existing geographic ...feature extraction methods are not suitable for the extraction of Lunar lineament structure. In this paper, a new lineament extraction method is proposed based on improved-UNet++ and YOLOv5. Firstly, new lineament dataset is created containing lineaments structure based on CCD data from LROC. At same time the residual blocks are replaced with the VGG blocks in the down sample part of the UNet++ with adding the attention block between each layer. Secondly, the improved-UNet++ and YOLO networks are trained to execute the object detection and semantic segmentation of lineament structure respectively. Finally, a polygon-match strategy is proposed to combine the results of object detection and semantic segmentation. The experiment result indicate that this new method has relatively better and more stable performance compared with current mainstream networks and the original UNet++ network in the instance segmentation of lineament structure. Additionally, the polygon-match strategy is able to perform preciser edge detail in the instance segmentation of lineament structure result.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
As a broad-spectrum antibiotic, tetracycline (TC) is widely used in agricultural purposes and human therapy. More attention is paid to TC as a serious threat to human health, including the fast ...spreading of antibiotic resistance gene and the serious toxicity to aquatic organisms. Therefore, the timely and accurate determination of TC residues is an urgent task to protect the safety of human. Herein, an effective and facile photoelectrochemical sensor platform based on carbon nitride/bismuth oxyhalide (CN/BiOBr) composites can be constructed for monitoring TC. The flower-like CN/BiOBr composites are prepared via a simple one-pot ethylene glycol-assisted solvothermal process with the addition of ionic liquid 1-hexadecyl-3-methylimidazolium bromide (C16mimBr). In view of matched energy band positions of CN and BiOBr, the addition of CN can reduce the recombination of photogenerated electron-hole pairs and improve the efficiency of visible light utilization, leading to enhancing photoelectrochemical response of BiOBr. Under light excitation, the photocurrent of CN/BiOBr composites is drastically improved, which is 6 times as much as that of pure BiOBr. Considering the superior photoelectrochemical performance, a photoelectrochemical sensor for monitoring TC has been developed, displaying linearly enhanced photocurrent with increasing the TC concentration. Two linear relationships received are from 8.0 to 4.0 × 102 ng mL−1, and 4.0 × 102 to 5.2 × 103 ng mL−1, respectively. The detection limit is 3.8 ng mL−1. The photoelectrochemical sensor exhibits a series of benefits including excellent stability, a wide linear range, a low detection limit and good anti-interference ability. Therefore, this work may offer great promises in providing a universal and efficient photoelectrochemical sensor for the tetracycline detection, and pave the way of constructing more materials used in photoelectrochemical detection field.
Display omitted
•A photoelectrochemical sensing platform is fabricated for tetracycline detection.•The photoelectrochemical sensor is based on the flower-like CN/BiOBr composites.•The CN/BiOBr has been prepared by ionic liquid-associated solvothermal method.•The photoelectrochemical sensor shows wide detectable range and low detection limit.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
As more and more genomes are sequenced, genome annotation becomes increasingly important in bridging the gap between sequence and biology. Gene prediction, which is at the center of genome ...annotation, usually integrates various resources to compute consensus gene structures. However, many newly sequenced genomes have limited resources for gene predictions. In an effort to create high-quality gene models of the cucumber genome (Cucumis sativus var. sativus), based on the EVidenceModeler gene prediction pipeline, we incorporated the massively parallel complementary DNA sequencing (RNA-Seq) reads of 10 cucumber tissues into EVidenceModeler. We applied the new pipeline to the reassembled cucumber genome and included a comparison between our predicted protein-coding gene sets and a published set.
The reassembled cucumber genome, annotated with RNA-Seq reads from 10 tissues, has 23, 248 identified protein-coding genes. Compared with the published prediction in 2009, approximately 8, 700 genes reveal structural modifications and 5, 285 genes only appear in the reassembled cucumber genome. All the related results, including genome sequence and annotations, are available at http://cmb.bnu.edu.cn/Cucumis_sativus_v20/.
We conclude that RNA-Seq greatly improves the accuracy of prediction of protein-coding genes in the reassembled cucumber genome. The comparison between the two gene sets also suggests that it is feasible to use RNA-Seq reads to annotate newly sequenced or less-studied genomes.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ciprofloxacin (CIP) has been a serious threat to the ecological environment and human health due to extensive application and persistence. Low concentrations of CIP can cause toxic effects on the ...surface and ground waters. It is critical to fabricate accurate and sensitive detection platform of CIP. Herein, a photoelectrochemical detecting platform of CIP has been constructed using metallic Bi self-doping BiOBr (Bi/BiOBr) composites. The Bi/BiOBr composites can be synthesized by a facile ethylene glycol (EG)-assisted solvothermal method. The metallic Bi nanoparticles can evenly distribute on the surface of BiOBr microspheres. In order to the incorporation of metallic Bi nanoparticles, the Bi/BiOBr composites exhibit excellent photoabsorption property and photoelectric conversion efficiency in visible region. Consequently, the result of photoelectrochemical measurements shows that the photocurrent density of Bi/BiOBr composites is superior to pure BiOBr. The increased photoelectrochemical properties of Bi/BiOBr composites are attributed to the efficient separation of electron-hole pairs and rapid electrons transfer. In addition, the photoelectrochemical sensor based on Bi/BiOBr composites has been constructed for sensitively detecting CIP. The photoelectrochemical sensor exhibits a good linear relationship, a low detect limitation and relatively stability for monitoring CIP.
Display omitted
•A ciprofloxacin PEC sensor based on Bi/BiOBr composites was fabricated.•Bi/BiOBr composites were prepared by reducing partial Bi3+ on the surface of BiOBr.•The introduction of Bi contributed to the excellent PEC performance.•The PEC sensor exhibited outstanding performances for ciprofloxacin detection.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
An hour precipitation dataset of 42 automatic weather stations is developed and applied to analyze the temporal and spatial characteristics of light precipitation in urban areas of Beijing City ...during 2007–2017. The stations are classified into three groups, including 18 sites in central urban area (4th Ring-Road, RR), 10 sites in peri-urban area (4th–5th RR), and 14 sites in suburban area (5th–6th RR). Light precipitation is defined as hourly rainfall of 0.1–0.3 mm. Analysis shows that light precipitation occurred in urban area the whole day, with the peak value in 0600 LST and minimum value in 1600 LST; monthly variation of light precipitation frequency (LPF) was characterized by the highest value in summer and the lowest value in winter; remarkable differences are found for the various urbanized areas, with the annual and seasonal mean LPF being generally small in central urban area and gradually increasing toward suburban area; the hourly mean LPFs during morning and nighttime are higher in summer than those in other seasons in each of the urban areas; relative humidity, aerosol, and wind speed might have been the major influential factors for the observed temporal and spatial pattern of light precipitation.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Nitroxides can absorb both ultraviolet (UV) and visible light, and their electron can be excited from the π-bonding orbital to the antibonding π* orbital or the n-bonding orbital to the antibonding ...π* orbital, respectively. Despite the reported UV-induced hydrogen atom transfer (HAT) process, the potential of nitroxides for visible light-excited photosynthesis is underexplored. Here we demonstrate that nitroxide can convert indole to its radical through a visible light-induced HAT process. A chiral phosphoric acid-catalyzed cyclization of the in situ-formed imine radical, followed by trapping by another molecule of nitroxide, provides the product in high yield and enantioselectivity. To highlight the novelty and efficiency of this strategy, an asymmetric total synthesis of natural product (−)-verrupyrroloindoline was accomplished in 5 steps.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
As a broad-spectrum tetracycline antibiotic, the overuse of oxytetracycline (OTC) causes antibiotics residues in the environment and seriously threats to human health owing to effective antibacterial ...properties. Thus, it is particularly important to design a photoelectrochemical (PEC) aptasensor to detect OTC with excellent performance. Herein, we developed a selective and stable PEC aptasensor of OTC on the basis of Co3O4 nanoparticles (Co3O4 NPs)/graphitic carbon nitride (g-CN) heterojunction, used as PEC active materials. The Co3O4 NPs were successfully grown on the g-CN via grinding and calcining mixture of Co3O4 precursors and bulk g-CN. The Co3O4/g-CN heterojunction with improved light utilization and promoted electrons/holes separation capability can exhibit higher PEC signal than that of g-CN. In order to implement the purpose of specific recognition, OTC-aptamer was introduced into modified electrode to construct highly selective PEC aptasensor for OTC determination, which can possess wide linear range (0.01–500 nM) with low detection limit (3.5 pM, S/N = 3). This PEC aptasensor platform with excellent selectivity and high stability can provide a practical application in the field of water monitoring.
Display omitted
•Co3O4-based photoactive materials was reported for detecting OTC.•The PEC aptasensor for OTC detection possessed low detection limit of 3.5 pM and excellent selectivity.•The PEC aptasensor has been applied in real water samples for OTC detection.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A photoelectrochemical (PEC) aptasensor was designed and constructed by Bi
24
O
31
Cl
10
/BiOCl heterojunction as a photoelectric active material for realizing the determination of trace ...ciprofloxacin (CIP) in water. Compared with Bi
24
O
31
Cl
10
, Bi
24
O
31
Cl
10
/BiOCl heterojunction possessed the improvement of light harvesting and the enhancement of photocurrent signal. The formation of heterojunction between Bi
24
O
31
Cl
10
and BiOCl can accelerate the transportation efficiency and inhibit the recombination rate of photoinduced carriers. Based on the excellent PEC performance, CIP aptamer was introduced on the modified Bi
24
O
31
Cl
10
/BiOCl/indium tin oxide (ITO) electrode for fabricating a PEC aptasensor. Owing to the combination between aptamer and CIP, CIP-aptamer complex can block the transfer of charge, leading to the reduction of photocurrent response. The PEC aptasensor possessed high sensitivity with a wide detection range (5.0~1.0 × 10
4
ng L
−1
) and a low detection limit (1.67 ng L
−1
, S/
N
= 3). The PEC aptasensor with good selectivity and reproducibility has been applied to the determination of CIP in water.
Graphical abstract
PDF
