22 research outputs found
Photocatalytic Activity Enhancement of Anatase TiO 2
We employed high-energy ball-milling technique to fabricate TiO/TiO2 heterogeneous nanostructures. XRD proved the existence of TiO/TiO2 heterogeneous structures. SEM and HRTEM investigation evidenced that the mean particle size and mean grain size of the as-prepared samples are 23 nm and 13 nm, respectively. UV-Vis spectra exhibited that TiO has enhanced the visible light absorption of TiO2 and has changed the Eg of TiO2. UPS examination indicated that the electron work function (EWF) of TiO is higher than that of TiO2. Photocatalytic degradation experiments revealed that an appropriate TiO content can enhance the photocatalytic activity of pure anatase TiO2. The best photocatalytic activity of TiO/TiO2 heterogeneous nanostructures is even better than that of Au-deposited TiO2 by keeping high degradation efficiency of 93%. The internal electrical field producing in TiO/TiO2 heterogeneous nanostructures was considered to be dominantly responsible for the enhanced photocatalytic activity. Therefore, the substitution of TiO with noble metal in TiO2 will be widely used in the future due to its low cost. This study also provides a clear direction of enhancing photocatalytic activity of TiO2: incorporating a guest compound into TiO2 with an appropriate content if the compound has much higher electron work function than that of TiO2
Genome-wide association and genomic prediction for resistance to southern corn rust in DH and testcross populations
Southern corn rust (SCR), caused by Puccinia polysora Underw, is a destructive disease that can severely reduce grain yield in maize (Zea mays L.). Owing to P. polysora being multi-racial, it is very important to explore more resistance genes and develop more efficient selection approaches in maize breeding programs. Here, four Doubled Haploid (DH) populations with 384 accessions originated from selected parents and their 903 testcross hybrids were used to perform genome-wide association (GWAS). Three GWAS processes included the additive model in the DH panel, additive and dominant models in the hybrid panel. As a result, five loci were detected on chromosomes 1, 7, 8, 8, and 10, with P-values ranging from 4.83×10-7 to 2.46×10-41. In all association analyses, a highly significant locus on chromosome 10 was detected, which was tight chained with the known SCR resistance gene RPPC and RPPK. Genomic prediction (GP), has been proven to be effective in plant breeding. In our study, several models were performed to explore predictive ability in hybrid populations for SCR resistance, including extended GBLUP with different genetic matrices, maker based prediction models, and mixed models with QTL as fixed factors. For GBLUP models, the prediction accuracies ranged from 0.56-0.60. Compared with traditional prediction only with additive effect, prediction ability was significantly improved by adding additive-by-additive effect (P-value< 0.05). For maker based models, the accuracy of BayesA and BayesB was 0.65, 8% higher than other models (i.e., RRBLUP, BRR, BL, BayesC). Finally, by adding QTL into the mixed linear prediction model, the accuracy can be further improved to 0.67, especially for the G_A model, the prediction performance can be increased by 11.67%. The prediction accuracy of the BayesB model can be further improved significantly by adding QTL information (P-value< 0.05). This study will provide important valuable information for understanding the genetic architecture and the application of GP for SCR in maize breeding
Multisatellite Task Allocation and Orbit Planning for Asteroid Terminal Defence
Near-Earth asteroids are a great threat to the Earth, especially potential rendezvous and collision asteroids. To protect the Earth from an asteroid collision, it is necessary to investigate the asteroid defence problem. An asteroid terminal defence method based on multisatellite interception was designed in this study. For an asteroid intruding in the sphere of the gravitational influence of the Earth, multiple interceptor satellites are used to apply a kinetic energy impulse to deflect the orbit of the asteroid. First, the effects of planned interception time and planned interception position on the required impulse velocity increment applied to the asteroid are assessed for interception opportunity selection. Second, multiple interceptor satellites are selected to perform the defence task from the on-orbit available interceptor satellite formation. An improved contract net protocol algorithm considering the Lambert orbital manoeuvre is designed to fulfil the task allocation and satellite orbit planning. Finally, simulation experiments demonstrate the rationale and effectiveness of the proposed method, which provides support for asteroid terminal defence technology
Collaborative Attention Memory Network for Video Object Segmentation
Semi-supervised video object segmentation is a fundamental yet Challenging
task in computer vision. Embedding matching based CFBI series networks have
achieved promising results by foreground-background integration approach.
Despite its superior performance, these works exhibit distinct shortcomings,
especially the false predictions caused by little appearance instances in first
frame, even they could easily be recognized by previous frame. Moreover, they
suffer from object's occlusion and error drifts. In order to overcome the
shortcomings , we propose Collaborative Attention Memory Network with an
enhanced segmentation head. We introduce a object context scheme that
explicitly enhances the object information, which aims at only gathering the
pixels that belong to the same category as a given pixel as its context.
Additionally, a segmentation head with Feature Pyramid Attention(FPA) module is
adopted to perform spatial pyramid attention structure on high-level output.
Furthermore, we propose an ensemble network to combine STM network with all
these new refined CFBI network. Finally, we evaluated our approach on the 2021
Youtube-VOS challenge where we obtain 6th place with an overall score of
83.5\%.Comment: Technical Report. Proposed systems attain 6th in YouTube-VOS
challenge 202
B7-H3 Overexpression Predicts Poor Survival of Cancer Patients: A Meta-Analysis
Background: B7-H3 exhibits altered expression in various cancers. However, the correlation between B7-H3 expression and prognosis of cancer patients remains controversial. Therefore, we elicit a meta-analysis to investigate the potential value of B7-H3 in the prognostic prediction in human cancers. Materials and Methods: We searched PubMed (last update by June 15th, 2016) to identify studies assessing the effect of B7-H3 on survival of cancer patients. Hazard ratios (HRs) for overall survival (OS), recurrence free survival (RFS) and progression-free survival (PFS) from individual studies were calculated and pooled by using a random-effect or fix-effect model, and heterogeneity and publication bias analyses were also performed. Results: Data from 24 observational studies consisting of 4141 patients were summarized. An elevated baseline B7-H3 was significantly correlated with poor OS (pooled HR = 2.09; 95% CI =1.60-2.74; P P = 0.324), year of publication (P = 0.431), ethnicity (P = 0.940), source of HR (P = 0.145), analysis type (P = 0.178) and sample size (P = 0.909) were not significant. Furthermore, high B7-H3 expression also predicted a significantly poor RFS (pooled HR = 1.39; 95% CI = 1.11-1.75; P = 0.004) but not PFS. Conclusions: This meta-analysis clarifies that elevated B7-H3 expression is significantly associated with poor survival in cancer patients
Synergetic Design of Transparent Topcoats on ITO-Coated Plastic Substrate to Boost Surface Erosion Performance
Transparent conductive films (TCFs) have received much research attention in the area of aeronautical canopies. However, bad wear, corrosion resistance and weak erosion performance of TCFs dramatically limit their scalable application in the next-generation aeronautical and optoelectronic devices. To address these drawbacks, three types of optically transparent coatings, including acrylic, silicone and polyurethane (PU) coatings were developed and comparatively investigated ex situ in terms of Taber abrasion, nanoindentation and sand erosion tests to improve the wear-resistance and sand erosion abilities of ITO-coated PMMA substrates. To elucidate the sand erosion failure of the coatings, the nanoindentation technique was employed for quantitative assessment of the shape recovery abilities under probe indentation. Results show that the PU topcoats can greatly enhance the sand erosion properties, which were superior to those of acrylic and silicone topcoats. This result can be attributed to the good toughness and self-healing properties of PU topcoats. Additionally, high hardness and good Taber abrasion properties of the ITO films and silicone topcoats did not have an obvious or affirmatory effect on the sand erosion abilities, based on their brittleness and irreparable properties under sand erosion
Trivalent Nickel-Catalyzing Electroconversion of Alcohols to Carboxylic Acids
The comprehension of activity and selectivity origins
of the electrooxidation
of organics is a crucial knot for the development of a highly efficient
energy conversion system that can produce value-added chemicals on
both the anode and cathode. Here, we find that the potential-retaining
trivalent nickel in NiOOH (Fermi level, −7.4 eV) is capable
of selectively oxidizing various primary alcohols to carboxylic acids
through a nucleophilic attack and nonredox electron transfer process.
This nonredox trivalent nickel is highly efficient in oxidizing primary
alcohols (methanol, ethanol, propanol, butanol, and benzyl alcohol)
that are equipped with the appropriate highest occupied molecular
orbital (HOMO) levels (−7.1 to −6.5 eV vs vacuum level)
and the negative dual local softness values (Δsk, −0.50 to −0.19) of nucleophilic atoms
in nucleophilic hydroxyl functional groups. However, the carboxylic
acid products exhibit a deeper HOMO level (<−7.4 eV) or
a positive Δsk, suggesting that
they are highly stable and weakly nucleophilic on NiOOH. The combination
(HOMO, Δsk) is useful in explaining
the activity and selectivity origins of electrochemically oxidizing
alcohols to carboxylic acid. Our findings are valuable in creating
efficient energy conversions to generate value-added chemicals on
dual electrodes
Climate‐induced increase in terrestrial carbon storage in the Yangtze River Economic Belt
Abstract Predicting the change in carbon storage in regions of high carbon uptake and those under highly intensive human disturbance is crucial for regional ecosystem management to promote sustainable development of the economy and ecology in the future. We use a process‐based model to estimate the terrestrial carbon storage in Yangtze River Economic Belt (YREB) and to predict the change of carbon storage over the next 100 years. The results show that the vegetation carbon (VC) and soil organic carbon (SOC) storage were 8.97 and 28.85 Pg C in the YREB from 1981 to 2005, respectively. The highest VC density is distributed in the southern region of the YREB, and the highest SOC density distributes in subalpine and alpine area of the western region of the YREB. Carbon storage in the YREB continued to increase from 1981 to 2005 and in future projections, under both the representative concentration pathway 4.5 (RCP4.5) and the RCP8.5 scenarios. The increased rate of carbon storage in the YREB under the RCP8.5 scenario is higher than that under the RCP4.5 scenario. Under the RCP4.5 scenario, the increasing trend of VC storage tends to be reduced after the 2060s; conversely, the increase of both VC and SOC is accelerated after the 2050s under the RCP8.5 scenario. The SOC density in Western Sichuan will decrease in the future, especially under the RCP8.5 scenario. Western Sichuan has the highest SOC density in the YREB; therefore, it is important to manage the ecosystems there in order to cope with significant warming. The positive impact of warming and the CO2 fertilization effect on vegetation growth and carbon uptake will be predominantly attributed to the increase of terrestrial carbon storage in the YREB. However, warming will stimulate the decomposition of soil organic carbon, contributing directly to reducing SOC storage in high‐altitude regions (e.g., alpine and subalpine regions of Western Sichuan)
Elasto-Aerodynamics-Driven Triboelectric Nanogenerator for Scavenging Air-Flow Energy
Efficient scavenging the kinetic energy from air-flow represents a promising approach for obtaining clean, sustainable electricity. Here, we report an elasto-aerodynamics-driven triboelectric nanogenerator (TENG) based on contact electrification. The reported TENG consists of a Kapton film with two Cu electrodes at each side, fixed on two ends in an acrylic fluid channel. The relationship between the TENG output power density and its fluid channel dimensions is systematically studied. TENG with a fluid channel size of 125 × 10 × 1.6 mm<sup>3</sup> delivers the maximum output power density of about 9 kW/m<sup>3</sup> under a loading resistance of 2.3 MΩ. Aero-elastic flutter effect explains the air-flow induced vibration of Kapton film well. The output power scales nearly linearly with parallel wiring of multiple TENGs. Connecting 10 TENGs in parallel gives an output power of 25 mW, which allows direct powering of a globe light. The TENG is also utilized to scavenge human breath induced air-flow energy to sustainably power a human body temperature sensor