Chemical ordering suppresses large-scale electronic phase separation in doped manganites

For strongly correlated oxides, it has been a long-standing issue regarding the role of the chemical ordering of the dopants on the physical properties. Here, using unit cell by unit cell superlattice growth technique, we determine the role of chemical ordering of the Pr dopant in a colossal magnetoresistant (La1-yPry)1-xCaxMnO3 (LPCMO) system, which has been well known for its large length-scale electronic phase separation phenomena. Our experimental results show that the chemical ordering of Pr leads to marked reduction of the length scale of electronic phase separations. Moreover, compared with the conventional Pr-disordered LPCMO system, the Pr-ordered LPCMO system has a metal–insulator transition that is ~100 K higher because the ferromagnetic metallic phase is more dominant at all temperatures below the Curie temperature

Forests Growth Monitoring Based on Tree Canopy 3D Reconstruction Using UAV Aerial Photogrammetry

Land cover monitoring is a major task for remote sensing. Compared to traditional methods of forests monitoring which mostly use orthophotography from satellites or aircraft, there is very little research on the use of 3D canopy structure to monitor forest growth. Unmanned aerial vehicle (UAV) aerial could be a novel and feasible platform to generate more timely and high resolution forest 3D canopy images. In spring, the forest is supposed to experience rapid growth. In this research, we used a small UAV to monitor campus forest growth in spring at 2-day intervals. Each time, 140 images were acquired and the ground surface dense point cloud was reconstructed at high precision. Excess Green indexes (ExG) was used to extract the green canopy points. The segmented point cloud was triangulated using the greedy projection triangulation method into a mesh and its area was calculated. Forest canopy growth was analyzed at three levels: forest level, selected group level and individual tree level. A logistic curve was used to fit the time series canopy growth. Strong correlation was found R2 = 0.8517 at forest level, R2 = 0.9652 at selected group level and R2 = 0.9606 at individual tree level. Moreover, high correlation was found between canopies. By observing these results, we can conclude that the ground 3D model can act as a useful data type to monitor forest growth. Moreover UAV aerial remote sensing has advantages when monitoring forests in periods when the ground vegetation is growing and changing fast

Smog Pollution, Environmental Uncertainty, and Operating Investment

Smog pollution in China has drawn worldwide attention. Using companies’ data from Chinese Securities Markets and Accounting Research database (CSMAR) and air quality monitoring data from China National Environmental Monitoring Centre(CNEMC), we employ the PM2.5 concentration as a proxy for smog pollution and examine the effect of smog pollution on company environmental uncertainty and operating investment in 74 key cities in China. The empirical results show that smog pollution causes an increase in company environmental uncertainty and a decrease in operating investment for Chinese listed companies, with environmental uncertainty as a mediating variable. Smog pollution can positively influence companies’ environmental uncertainty through their employees and high pressure from the public and government. According to the real-options-based investment approach, companies choose to “wait and see” and, correspondingly, reduce operating investment under high environmental uncertainty such as that caused by smog pollution. Additionally, we find that state-owned enterprises are more significantly influenced by smog pollution in terms of environmental uncertainty and operating investment because of their close relationships with the government and their responsibility to set an example among Chinese companies in the fight against smog pollution

Recent advances and trends in visual tracking: A review

The goal of this paper is to review the state-of-the-art progress on visual tracking methods, classify them into different categories, as well as identify future trends. Visual tracking is a fundamental task in many computer vision applications and has been well studied in the last decades. Although numerous approaches have been proposed, robust visual tracking remains a huge challenge. Difficulties in visual tracking can arise due to abrupt object motion, appearance pattern change, non-rigid object structures, occlusion and camera motion. In this paper, we first analyze the state-of-the-art feature descriptors which are used to represent the appearance of tracked objects. Then, we categorize the tracking progresses into three groups, provide detailed descriptions of representative methods in each group, and examine their positive and negative aspects. At last, we outline the future trends for visual tracking research

An electron-hole rich dual-site nickel catalyst for efficient photocatalytic overall water splitting

Vast majority of photocatalysts for hydrogen production relies on additional sacrificial agents and noble metal cocatalysts. It is of great importance yet challenging to achieve photocatalytic overall water splitting with decent performance. Here, the authors report Ni2P based photocatalyst assisted by H2O2-craking reaction for overall water splitting with H2 and O2 production of 1507 μmol h−1 g−1 H2 and 702 μmol h−1 g−1

Application of mapping and dating techniques in the study of ancient carbonate reservoirs: a\ua0case study of Sinian Qigebrak Formation in northwestern Tarim Basin, NW China

Ancient marine carbonates experienced complex modifications, making it difficult to identify reservoir genesis and effective porosity before hydrocarbon migration. To solve these issues, we used element mapping and carbonate mineral laser U-Pb radiometric dating techniques to study the diagenetic environments based on geochemistry and diagenesis-porosity evolution based on geochronology of the dolomite reservoir of the Sinian Qigebrak Formation, northwest Tarim Basin. Two major understandings were obtained as follows: (1) Supported by petrographic observations, the element mapping, stable isotopes, strontium isotope, and cathodoluminescence tests were performed on different phases of dolomite cements precipitated in vugs and dissolved fissures. The results show that the dolomite reservoirs of the Qigebrak Formation went through freshwater, marine, extremely shallow burial, burial and hydrothermal diagenetic environments after synsedimentary dolomitization; the reservoir spaces were mainly formed in the synsedimentary period (primary pores) and freshwater environment (supergene dissolution pores) before burial; whereas the marine, burial and hydrothermal environments caused the gradual filling of reservoir space by dolomite cements. (2) Based on the above understandings, each phase of dolomite cement precipitated in the reservoir space was dated by the U-Pb radiometric dating technique, and the diagenesis-porosity evolution curves constrained by geochronology were established. The loss of reservoir porosity mainly occurred in the early Caledonian, and during the peak period of hydrocarbon generation of Yuertusi Formation source rock, the reservoirs still maintained at a porosity of 6%–10%. The above understandings provide a certain basis for the evaluation of accumulation effectiveness of the Sinian Qigebrak Formation, northwestern Tarim Basin, and provide a case for the application of mapping and dating techniques in the study of ancient carbonate reservoirs

Whole genome sequencing and the lignocellulose degradation potential of Bacillus subtilis RLI2019 isolated from the intestine of termites

Abstract Background Lignocellulosic biomass is the most abundant and renewable terrestrial raw material for conversion into bioproducts and biofuels. However, the low utilization efficiency of lignocellulose causes environmental pollution and resource waste, which limits the large-scale application of bioconversion. The degradation of lignocellulose by microorganisms is an efficient and cost-effective way to overcome the challenge of utilizing plant biomass resources. This work aimed to screen valuable cellulolytic bacteria, explore its molecular mechanism from genomic insights, and investigate the ability of the strain to biodegrade wheat straw. Results Bacillus subtilis (B. subtilis) RLI2019 was isolated from the intestine of Reticulitermes labralis. The strain showed comprehensive enzyme activities related to lignocellulose degradation, which were estimated as 4.06, 1.97, 4.12, 0.74, and 17.61 U/mL for endoglucanase, β-glucosidase, PASC enzyme, filter paper enzyme, and xylanase, respectively. Whole genome sequencing was performed to better understand the genetic mechanism of cellulose degradation. The genome size of B. subtilis RLI2019 was 4,195,306 bp with an average GC content of 43.54%, and the sequence characteristics illustrated an extremely high probability (99.41%) as a probiotic. The genome contained 4,381 protein coding genes with an average GC content of 44.20%, of which 145 genes were classified into six carbohydrate-active enzyme (CAZyme) families and 57 subfamilies. Eight cellulose metabolism enzyme-related genes and nine hemicellulose metabolism enzyme-related genes were annotated by the CAZyme database. The starch and sucrose metabolic pathway (ko00500) was the most enriched with 46 genes in carbohydrate metabolism. B. subtilis RLI2019 was co-cultured with wheat straw for 7 days of fermentation, the contents of neutral detergent fiber, acid detergent fiber, hemicellulose, and lignin were significantly reduced by 5.8%, 10.3%, 1.0%, and 4.7%, respectively. Moreover, the wheat straw substrate exhibited 664.9 μg/mL of reducing sugars, 1.22 U/mL and 6.68 U/mL of endoglucanase and xylanase activities, respectively. Furthermore, the fiber structures were effectively disrupted, and the cellulose crystallinity was significantly reduced from 40.2% to 36.9%. Conclusions The complex diversity of CAZyme composition mainly contributed to the strong cellulolytic attribute of B. subtilis RLI2019. These findings suggest that B. subtilis RLI2019 has favorable potential for biodegradation applications, thus it can be regarded as a promising candidate bacterium for lignocellulosic biomass degradation

Additional file 5 of Whole genome sequencing and the lignocellulose degradation potential of Bacillus subtilis RLI2019 isolated from the intestine of termites

Additional file 5: Table S7. CAZyme annotation of the genome sequence

Additional file 3 of Whole genome sequencing and the lignocellulose degradation potential of Bacillus subtilis RLI2019 isolated from the intestine of termites

Additional file 3: Table S5. COG annotation of carbohydrate metabolism genes