The characteristics and heterogeneity of coal pores are crucial for understanding the production mechanism of coalbed methane (CBM). In this study, coal samples with varying degrees of metamorphism (0.58% ≤ R, ≤ 3.
View Article and Find Full Text PDFTraditional semiconductors are known to exhibit excellent electrical properties but oversized lattice thermal conductivities, thus limiting their thermoelectric performance. Herein, we have discovered a low-energy allotrope of those traditional semiconductors. Compared with the wurtzite structure, the lattice thermal conductivity is reduced by more than five times in the haeckelite structure.
View Article and Find Full Text PDFThis research examines internet collective behavior in mainland China during the COVID-19 pandemic, focusing on the factors and characteristics that drive such behavior. The Chinese government initially implemented a conservative and biased policy to contain the spread of the virus, but the sudden lifting of lockdown measures in late 2022 resulted in a surge in infections and scarcity of medical resources. This policy shift led many Chinese internet users to perceive the government's actions as hasty and harsh, prompting them to engage in collective online behavior.
View Article and Find Full Text PDFHampered by their susceptibility to nucleophilic attack and chemical bleaching, electron-deficient squaraine dyes have long been considered unsuitable for biological imaging. This study unveils a surprising twist: in aqueous environments, bleaching is not irreversible but rather a reversible spontaneous quenching process. Leveraging this new discovery, we introduce a novel deep-red squaraine probe tailored for live-cell super-resolution imaging.
View Article and Find Full Text PDFThe 6-Degree-of-Freedom (6-DoF) robotic grasping is a fundamental task in robot manipulation, aimed at detecting graspable points and corresponding parameters in a 3D space, i.e affordance learning, and then a robot executes grasp actions with the detected affordances. Existing research works on affordance learning predominantly focus on learning local features directly for each grid in a voxel scene or each point in a point cloud scene, subsequently filtering the most promising candidate for execution.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2024
Fluorescent probes are essential for single-molecule imaging. However, their application in biological systems is often limited by the short photobleaching lifetime. To overcome this, we developed a novel thiolation strategy for squaraine dyes.
View Article and Find Full Text PDFDye-sensitization can enhance lanthanide-based upconversion luminescence, but is hindered by interfacial energy transfer from organic dye to lanthanide ion Yb . To overcome these limitations, modifying coordination sites on dye conjugated structures and minimizing the distance between fluorescence cores and Yb in upconversion nanoparticles (UCNPs) are proposed. The specially designed near-infrared (NIR) dye, disulfo-indocyanine green (disulfo-ICG), acts as the antenna molecule and exhibits a 2413-fold increase in luminescence under 808 nm excitation compared to UCNPs alone using 980 nm irradiation.
View Article and Find Full Text PDFThe ocean, covering 71% of the Earth's surface, is integral to human life [...
View Article and Find Full Text PDFUpconversion nanoparticles (UCNPs) doped with lanthanides have limited brightness due to their small absorption cross section to light. However, using organic sensitizers can significantly enhance their light absorption ability. Unfortunately, the practical application of organic sensitizers has been hindered by poor stability and aggregation-caused quenching (ACQ).
View Article and Find Full Text PDFAtmospheric solids analysis probe-mass spectrometry (ASAP-MS), an ambient mass spectrometry technique, was used to differentiate spring and autumn Tieguanyin teas. Two configurations were used to obtain their chemical fingerprints - ASAP attached to a high-resolution quadrupole time-of-flight mass spectrometer (i.e.
View Article and Find Full Text PDFThe influence mechanism of different geological parameters on the activation of small faults under mining in the deep coal face was investigated by numerical simulation. The study shows that (1) the degree of influence of six parameters including the fault lateral pressure coefficient λ, elastic modulus , Poisson's ratio μ, cohesion , internal friction angle φ, and fault inclination angle θ on the activation of small faults was ranked in order as θ > λ > φ > μ > > . (2) The lateral pressure coefficient λ of the fault zone rock mass, the internal friction angle φ, and the fault inclination angle θ had a great influence on the fault activation.
View Article and Find Full Text PDFAcidizing technology is an important means to increase production in oil-gas reservoirs. In recent years, acidizing technology has been widely used to increase the permeability of coal seams to enhance gas extraction, where acidizing fluid is the key factor to determine the permeability improvement effect by acidizing technology. In order to clarify the influence of mixed acid fluid on the pore structure of high rank coal and seek the optimal mixed acid fluid suitable for acidizing and permeability improvement of high rank coal in the Jiaozuo coal mine area.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2022
Single molecule localization microscopy based on photoactivation is a powerful tool for investigating the ultrastructure of cells. We developed a general strategy for photoactivatable fluorophores, using 2,3-dihydro-1,4-oxathiine group (SO) as a tag to attach to various skeletal structures, including coumarin, BODIPY, rhodamine, and cyanine. The conjugation of SO resulted in a significant loss of fluorescence due to photoinduced electron transfer (PeT).
View Article and Find Full Text PDFGas explosion is one of the main causes of casualties in coal mines. Studying the propagation law of shock wave of mine gas explosion can reduce the economic loss and personnel injury caused by mine gas explosion. To solve the difficulty in the research of shock wave propagation of gas explosion in the mine scale, the segmented relay simulation method of shock wave propagation of gas explosion in a coal mine was put forward, the related key problems were studied, and the results were successfully applied in Yangchangwan No.
View Article and Find Full Text PDFoolong tea (TOT), a semi-oxidized tea originating from Anxi county in China, is categorized into jade TOT, medium-baked TOT, and deep-baked TOT, based on different baking processes. To study the effects of baking, chemical analysis, sensory evaluation, and bioactivity assessments of the three TOTs were conducted. The results indicated that the baking process promoted the formation of colored macromolecules (e.
View Article and Find Full Text PDFTieguanyin is one of the most consumed oolong teas because of its distinctive flavor. The brewing process is crucial for the flavor performance of traditional teas, thus the effects of brewing conditions, including water/tea ratio (R), brewing temperature (T), and time (S) on the sensory traits, chemical composition, and antioxidant activity of Tieguanyin tea infusion were investigated using quadratic orthogonal regression design. Results showed that R affected all the quality variables most, its reduction could lead to the promotion of tea infusion concentration, antioxidant activity, and taste intensity, which was favored by the tea consumers drinking tea almost daily (DTD) but unacceptable for those drinking tea hardly (DTH).
View Article and Find Full Text PDFA new boric agent with bridged structure, boric acid D, was first synthesized and used as an excellent chiral derivative agent for highly efficient enantiodiscrimination of various diols. The derivatization reaction is fast and complete, easy to operate and has high accuracy in measurement of ee values. The characteristic split NMR signals are well-distinguishable with a large chemical shift nonequivalence (up to 0.
View Article and Find Full Text PDFThis paper presents a feature classification method based on vision sensor in dynamic environment. Aiming at the detected targets, a double-projection error based on orb and surf is proposed, which combines texture constraints and region constraints to achieve accurate feature classification in four different environments. For dynamic targets with different velocities, the proposed classification framework can effectively reduce the impact of large-area moving targets.
View Article and Find Full Text PDFA simple chiral binuclear titanium complex (()-TiLNa) was first prepared and served as an excellent chiral sensor for discriminating a variety of chiral ammoniums by H NMR. In the presence of trifluoroacetic acid, the in-situ-generated ammoniums of varied amines can be effectively resolved by ()-TiLNa. The different binding forces between ()-TiLNa and two enantiomers of analytes generate different shielding effects on two enantiomers, resulting in a split in the distinguishable chemical shift.
View Article and Find Full Text PDFBMC Musculoskelet Disord
December 2019
Background: Despite potential for improving patient outcomes, studies using three-dimensional measurements to quantify proximal tibial sclerotic bone and its effects on prosthesis stability after total knee arthroplasty (TKA) are lacking. Therefore, this study aimed to determine: (1) the distribution range of tibial sclerotic bone in patients with severe genu varum using three-dimensional measurements, (2) the effect of the proximal tibial sclerotic bone thickness on prosthesis stability according to finite-element modelling of TKA with kinematic alignment (KA), mechanical alignment (MA), and 3° valgus alignment, and (3) the effect of short extension stem augment utilization on prosthesis stability.
Methods: The sclerotic bone in the medial tibial plateau of 116 patients with severe genu varum was measured and classified according to its position and thickness.
In this paper, we introduce a novel sub-bottom profiler, making good use of the Mills cross configuration of multibeam sonar and synthetic aperture techniques of the synthetic aperture sonar system. The receiver array is mounted along the ship keel, while the transmitter array is mounted perpendicular to the receiver array. With the synthetic aperture technique, the along-track resolution can be greatly improved.
View Article and Find Full Text PDFAn axially chiral binuclear μ-hydroxo Pd complex (BPHP) first served as an excellent chiral sensor for discriminating a variety of analytes including amino alcohol, amino amide, amino acid, mandelic acid, diol, diamine, and monoamine by P{H} NMR. A detailed recognition mechanism was proposed based on the single crystal and mass spectrum of Pd-complexes. In general, BPHP sensor, through extracting the acidic hydrogen of an analyte by its Pd-OH group, forms stable diastereomeric complexes with two enantiomers of the analyte giving well distinguishable split P{H} NMR signals for chiral discrimination.
View Article and Find Full Text PDFJ Assoc Res Otolaryngol
February 2019
This paper proposes a novel monocular visual servoing strategy, which can drive a wheeled mobile robot to the desired pose without a prerecorded desired image. Compared with existing methods that adopt the teaching pattern for visual regulation, this scheme can still work well in the situation that the desired image has not been previously acquired. Thus, with the aid of this method, it is more convenient for mobile robots to execute visual servoing tasks.
View Article and Find Full Text PDFUnlike mammalian hair cells, which are essentially unable to regenerate after damage, avian hair cells have a robust capacity for regeneration. The prerequisite for understanding the above difference is knowing the genetic programming of avian hair cell regeneration. Although the major processes have been known, the precise molecular signaling that induces regeneration remains unclear.
View Article and Find Full Text PDF