Phonon chirality manipulation mechanism in TMD interlayer-sliding ferroelectrics

As an ideal platform, both the theoretical prediction and first experimental verification of chiral phonons are based on transition-metal dichalcogenide materials. The manipulation of phonon chirality in these materials will have a profound impact on the study of chiral phonons. In this work, we utilize the sliding ferroelectric mechanism to study the phonon chirality manipulation mechanism in transition-metal dichalcogenide materials. Based on first-principles calculations, we study the different effects of interlayer sliding on the phonon properties in bilayer and four-layer MoS$_2$ sliding ferroelectrics. We find that sliding can regulate phonon chirality and Berry curvature, which further affects the phonon angular momentum and magnetization under a temperature gradient and the phonon Hall effect under a magnetic field. Our work connects two emerging fields and opens up a new route to manipulate phonon chirality in transition-metal dichalcogenide materials through the sliding ferroelectric mechanism.Comment: 15 pages, 4 figure

A Feasibility Study of the Integration of Enhanced Oil Recovery (CO2 Flooding) with CO2 Storage in the Mature Oil Fields of the Ordos Basin, China

AbstractRich in energy resources, China's Ordos Basin Shares many similarities with Wyoming's Powder River Basin. As a result, the experience and expertise pertaining to energy development in the Powder River Basin should prove helpful in the Ordos Basin. The b reserves are ranked fourth. The coal deposits in the Ordos Basin account for 39 percent of total Chinese coal reserves (3.98 trillion tonnes), and six of the thirteen largest coal mines in China are located in the basin. The overlapping development of relatively new coal conversion industries with existing oil and gas industries in northern Shaanxi Province is creating an opportunity to apply the systematic approach developed in Wyoming: the integration of geological CO2 storage and CO2-EOR. The coal conversion industry (i.e., coal-to-methanol, coal-to-olefins, etc.) provides affordable, capture-ready CO2 sources for developing large-scale integrated CO2-EOR and carbon storage projects in the Ordos Basin, China. Compared with other CCUS projects, the ability to use CO2 from the coal- conversion industry for CO2-EOR and subsequent geological CO2 storage will make integrated projects in the Ordos Basin more cost-effective and technologically efficient.The low porosity, low permeability, low oil saturation, anomalously low reservoir pressure, and high reservoir heterogeneity of the target storage formations in the Ordos Basin make using CO2 for enhanced oil recovery much more challenging here than in the US. These reservoir characteristics together constitute a major reason that CO2- EOR is not widely employed in the Ordos Basin, even though sources of highly concentrated CO2 (coal conversion plants) have been available for years. Comparisons of reservoir and crude oil properties in the Ordos Basin with the current US CO2-EOR screening guidelines reveal that gravity, viscosity, crude oil composition, and formation type of the Ordos reservoirs all are favorable for CO2 miscible flooding. The major challenges in deploying EOR result from anomalously low reservoir pressure, low porosity, and higher reservoir heterogeneity

Chiral Phonons in Chiral Materials

The concept of chirality makes ubiquitous appearance in nature. Particularly, both a structure and its collective excitations may acquire well defined chiralities. In this work, we reveal an intrinsic connection between the chiralities of a crystal structure and its phonon excitations. We show that the phonon chirality and its propagation direction are strongly coupled with the lattice chirality, which will be reversed when a chiral lattice is switched to its enantiomorph. In addition, distinct from achiral lattices, propagating chiral phonons exist for chiral crystals also on the principal axis through the $\Gamma$ point, which strengthens its relevance to various physical processes. We demonstrate our theory with a 1D helix-chain model and with a concrete and important 3D material, the $\alpha$-quartz. We predict a chirality diode effect in these systems, namely, at certain frequency window, a chiral signal can only pass the system in one way but not the other, specified by the system chirality. Experimental setups to test our theory are proposed. Our work discovers fundamental physics of chirality coupling between different levels of a system, and the predicted effects will provide a new way to control thermal transport and design information devices.Comment: 5 pages, 5 figure

Comparison of characteristics of cervical cancer screening history between cervical adenocarcinoma and cervical squamous cell carcinoma

Objective To comparatively analyze the characteristics of cervical cancer screening history between patients with cervical adenocarcinoma and cervical squamous cell carcinoma， and to preliminarily evaluate the efficacy of cervical cancer screening for precancerous lesions of cervical adenocarcinoma. Methods Clinical data of 117 patients with cervical adenocarcinoma and 712 patients with cervical squamous cell carcinoma were retrospectively analyzed， and the differences in cervical cancer screening history were statistically analyzed between two groups. Results The proportion of cervical adenocarcinoma patients receiving cervical cancer screening was 24.5%， significantly higher than 6.8% of those with cervical squamous cell carcinoma （P < 0.001）. The proportion of cervical adenocarcinoma patients receiving regular screening or above was 18.4%， significantly higher than 2.8% of those with cervical squamous cell carcinoma （P < 0.001）. The proportion of symptom-detected cervical squamous cell carcinoma was 91.6%， significantly higher than 79.1% of their counterparts with cervical adenocarcinoma cell carcinoma （P < 0.001）. The proportion of screening-detected stageⅠ-ⅡA cervical adenocarcinoma was 24.6%， significantly higher than 11.1% of those with screening-detected stage Ⅰ-ⅡA cervical squamous cell carcinoma （P = 0.004）. The proportion of screening-detected stageⅠ-ⅡA cervical adenocarcinoma was 24.6%， significantly higher than 4.0% of those with screening-detected stageⅡB-Ⅳ cervical adenocarcinoma （P = 0.022）. Conclusions Current cervical cancer screening regimen yields higher efficacy for precancerous lesions of cervical squamous cell carcinoma compared with cervical adenocarcinoma. However， it still contributes to the diagnosis of early cervical adenocarcinoma. Therefore， extensive attention should be paid to cervical cancer screening. Cervical cancer screening regimen remains to be further optimized

Phononic real Chern insulator with protected corner modes in graphynes

Higher-order topological insulators have attracted great research interest recently. Different from conventional topological insulators, higher-order topological insulators do not necessarily require spin-orbit coupling, which makes it possible to realize them in spinless systems. Here, we study phonons in 2D graphyne family materials. By using first-principle calculations and topology/symmetry analysis, we find that phonons in both graphdiyne and $\gamma$-graphyne exhibit a second-order topology, which belongs to the specific case known as real Chern insulator. We identify the nontrivial phononic band gaps, which are characterized by nontrivial real Chern numbers enabled by the spacetime inversion symmetry. The protected phonon corner modes are verified by the calculation on a finite-size nanodisk. Our study extends the scope of higher-order topology to phonons in real materials. The spatially localized phonon modes could be useful for novel phononic applications.Comment: 6 pages, 5figure

Preparation and Characteristic of PC/PLA/TPU Blends by Reactive Extrusion

To overcome the poor toughness of PC/PLA blends due to the intrinsic properties of materials and poor compatibility, thermoplastic urethane (TPU) was added to PC/PLA blends as a toughener; meantime, catalyst di-n-butyltin oxide (DBTO) was also added for catalyzing transesterification of components in order to modify the compatibility of blends. The mechanical, thermal, and rheological properties of blends were investigated systematically. The results showed that the addition of TPU improves the toughness of PC/PLA blends significantly, with the increase of TPU, the elongation at break increases considerably, and the impact strength increases firstly and then falls, while the tensile strength decreases significantly and the blends exhibit a typical plastic fracture behavior. Meantime, TPU is conducive to the crystallinity of PLA in blends which is inhibited seriously by PC and damages the thermal stability of blends slightly. Moreover, the increased TPU makes the apparent viscosity of blends melt decrease due to the well melt fluidity of TPU; the melt is closer to the pseudoplasticity melt. Remarkably, the transesterification between the components improves the compatibility of blends significantly, and more uniform structure results in a higher crystallinity and better mechanical properties

Entanglement of single-photons and chiral phonons in atomically thin WSe2_2

Quantum entanglement is a fundamental phenomenon which, on the one hand, reveals deep connections between quantum mechanics, gravity and the space-time; on the other hand, has practical applications as a key resource in quantum information processing. While it is routinely achieved in photon-atom ensembles, entanglement involving the solid-state or macroscopic objects remains challenging albeit promising for both fundamental physics and technological applications. Here, we report entanglement between collective, chiral vibrations in two-dimensional (2D) WSe$_2$ host --- chiral phonons (CPs) --- and single-photons emitted from quantum dots (QDs) present in it. CPs which carry angular momentum were recently observed in WSe$_2$ and are a distinguishing feature of the underlying honeycomb lattice. The entanglement results from a "which-way" scattering process, involving an optical excitation in a QD and doubly-degenerate CPs, which takes place via two indistinguishable paths. Our unveiling of entanglement involving a macroscopic, collective excitation together with strong interaction between CPs and QDs in 2D materials opens up ways for phonon-driven entanglement of QDs and engineering chiral or non-reciprocal interactions at the single-photon level

Complexes Formed in Solution Between Vanadium(IV)/(V) and the Cyclic Dihydroxamic Acid Putrebactin or Linear Suberodihydroxamic Acid

The ability of microbial siderophores to coordinate metal ions, particularly Fe(III), continues to generate interest in the poten-tial applications of these bioligands in the environment and medicine.13 Siderophores produced by terrestrial and marin

IoT intrusion detection method for unbalanced samples

In recent years, network traffic increases exponentially with the iteration of devices, while more and more attacks are launched against various applications.It is significant to identify and classify attacks at the traffic level.At the same time, with the explosion of Internet of Things (IoT) devices in recent years, attacks on IoT devices are also increasing, causing more and more damages.IoT intrusion detection is able to distinguish attack traffic from such a large volume of traffic, secure IoT devices at the traffic level, and stop the attack activity.In view of low detection accuracy of various attacks and sample imbalance at present, a random forest based intrusion detection method (Resample-RF) was proposed, which consisted of three specific methods: optimal sample selection algorithm, feature merging algorithm based on information entropy, and multi-classification greedy transformation algorithm.Aiming at the problem of unbalanced samples in the IoT environment, an optimal sample selection algorithm was proposed to increase the weight of small samples.Aiming at the low efficiency problem of random forest feature splitting, a feature merging method based on information entropy was proposed to improve the running efficiency.Aiming at the low accuracy problem of random forest multi-classification, a multi-classification greedy transformation method was proposed to further improve the accuracy.The method was evaluated on two public datasets.F1 reaches 0.99 on IoT-23 dataset and 1.0 on Kaggle dataset, both of which have good performance.The experimental results show that the proposed model can effectively identify the attack traffic from the massive traffic, better prevent the attack of hackers on the application, protect the IoT devices, and thus protect the related users

Design and fabrication of gelatin-based hydrogel loaded with modified amniotic extracellular matrix for enhanced wound healing

Trauma can damage the structural integrity of skin leading to its function being affected. There is an urgent clinical need for innovative therapeutic wound dressings. However, several challenges persist despite the current demands. The development and application of functional dressings offer a novel approach to address skin and subcutaneous soft tissue defects. Amniotic membrane as an ideal biological multifunctional material covering wound surface has been reported in clinic. However, current clinical applications of amniotic membrane still have limitations, such as thinness and mechanically weak. In this paper, we employed decellularized human amniotic membrane (dHAM) as a bioactive extracellular matrix (ECM) and modified it through methacrylate (MA) grafting for engineering purposes, resulting in the photosensitive dECMMA. Subsequently, we utilized a photosensitizer to achieve photopolymerization of dECMMA with GelMA hydrogel, successfully creating a novel composite hydrogel termed dECMMA/GelMA. This composite hydrogel not only inherits the favorable physicochemical properties of hydrogels but also maintains comparable levels of bioactivity to dHAM itself, supporting cell proliferation, migration, angiogenesis, and retaining significant anti-inflammatory capacity.Additionally, we evaluated the reparative effect of the designed dECMMA/GelMA composite hydrogel on rabbit wound defects. We demonstrated that the dECMMA/GelMA promoted wound healing and re-epithelization. These findings highlight the substantial benefits and therapeutic potential of the dECMMA/GelMA composite hydrogel as a practical solution for clinical applications in the treatment of soft tissue damage. Furthermore, this research provides a new strategy for designing and manufacturing bioactive dressings with exceptional clinical efficacy in the future