A brief review: effects of resonant magnetic perturbation on classical and neoclassical tearing modes in tokamaks

This paper reviews the effects of resonant magnetic perturbation (RMP) on classical tearing modes (TMs) and neoclassical tearing modes (NTMs) from the theory, experimental discovery and numerical results with a focus on four major aspects: (i) mode mitigation, where the TM/NTM is totally suppressed or partly mitigated by the use of RMP; (ii) mode penetration, which means a linearly stable TM/NTM triggered by the externally applied RMP; (iii) mode locking, namely an existing rotating magnetic island braked and finally stopped by the RMP; (iv) mode unlocking, as the name suggests, it is the reverse of the mode locking process. The key mechanism and physical picture of above phenomena are revealed and summarized.

Superconductivity above 200K Observed in Superhydrides of Calcium

Searching for superconductivity with Tc near room temperature is of great interest both for fundamental science & potential applications. Here we report the experimental discovery of superconductivity with maximum critical temperature(Tc) above 210 K in calcium superhydrides, the third type hydride experimentally showing superconductivity above 200K in addition to sulfur hydride & rare earth hydride system. The materials are synthesized at the synergetic conditions of 160~190 GPa and ~2000K using diamond anvil cell combined with in-situ laser heating technique. The superconductivity was studied through in situ high pressure resistance measurements in applied magnetic field for the sample quenched from high temperature while maintained at the synthesized pressure. The upper critical field was estimated to be ~268T while the GL coherent length is ~11 Å. The in situ x ray diffractions with synchrotron suggest that the synthesized calcium hydrides are primarily composed of CaH6 while there also exist other calcium hydrids with different hydrogen.

Remarks on Parabolicity in a One-Dimensional Interdiffusion Model with the Vegard Rule

Until 1948 the interdiffusion theory was based on the Onsager phenomenology, namely thermodynamics of irreversible processes, and a drift was not included. Its main limitation is practical impossibility of the experimental as well as theoretical determination of mobilities (diffusivities) in multicomponent systems ($$r > 2$$ r > 2 ). After experimental discovery of the drift by Smigelskas and Kirkendall (Trans AIME 171:130–142, 1947), Darken (Trans AIME 175:184–201, 1948) formulated his famous model for the binary system. Consequently, the bi-velocity approach dominates interdiffusion studies (e.g. in more than 500 papers in 2020). In this paper, we consider the diffusional transport in a one-dimensional r-component solid solution. The model is expressed by the nonlinear system of strongly coupled evolution differential equations with initial and nonlinear coupled boundary conditions. We present a non-trivial proof of a theorem called the criterion of parabolicity, which implies the generalized parabolicity condition formulated without a proof in our previous works. This condition is a key in the proofs of our previous theorems on existence, uniqueness and properties of global weak solutions of the differential problem studied. The criterion of parabolicity works if diffusion coefficients are not too dispersed, and it is true in many physical systems. The numerical simulations consistent with real experiments for which our criterion works are given.

The Discovery of Black Light

|This article is the beginning of a reexpresson, and partial revision, of my book Black Light. The questions that I discuss in this article are listed in the below list of sections. In Sections 7, 8, 27, and 28, I discuss my discovery of black light. |The theoretical discovery of black light (that is, the thought experimental discovery of black light): The black spatial field in, for example, a “dark” room is actually, I argue, black light; and it is emitted from everything in the spatial field of the room (that is, the relatively empty space, and all objects). If, hypothetically, the black light in the above room was removed, we, when we would look into the spatial field of the room, would be blind, despite that we have the capacity to see. |The observational discovery of black light: There is no such thing as a “colorless” visual field for observers: A “colorless” visual field would be a visual field of blindness for observers, despite that they have vision, and that their eyes would be open. The black visual field is not, as is commonly stated, “the absence of photons”, “the absence of visible light”, and the, as such, absence of color: If it were, then it would be “colorless” (that is, not black), and, as such, a visual field of blindness for observers. |The experimental confirmation of black light via neurophysics: In Section 28, I demonstrate that particular EEG experimentation that was done on test-subjects in various conditions provides evidence or proof that the black of the black visual field that strikes our retinas is black light.

Brief Review of the Results Regarding the Possible Underlying Mechanisms Driving the Neutrinoless Double Beta Decay

Since the experimental discovery of neutrino oscillations, the search for the neutrinoless double beta (0νββ) decay has intensified greatly, as this particular decay mode, if experimentally discovered, could offer a testing ground for Beyond Standard Model (BSM) theories related to the yet hidden fundamental properties of neutrinos and the possibility of violating of some fundamental symmetries. In this work we make a brief review of the nuclear matrix elements and phase space factors calculations performed mainly by our group. Next, using these calculations and the most recent experimental half-life limits, we revise the constraints on the BSM parameters violating the lepton number corresponding to four mechanisms that could contribute to 0νββ decay. Finally, using the values obtained for the BSM parameters from one of the most sensitive double-beta decay experiments, we provide a comparison with the sensitivities of other experiments.

The microbiome and human cancer

Microbial roles in cancer formation, diagnosis, prognosis, and treatment have been disputed for centuries. Recent studies have provocatively claimed that bacteria, viruses, and/or fungi are pervasive among cancers, key actors in cancer immunotherapy, and engineerable to treat metastases. Despite these findings, the number of microbes known to directly cause carcinogenesis remains small. Critically evaluating and building frameworks for such evidence in light of modern cancer biology is an important task. In this Review, we delineate between causal and complicit roles of microbes in cancer and trace common themes of their influence through the host’s immune system, herein defined as the immuno-oncology-microbiome axis. We further review evidence for intratumoral microbes and approaches that manipulate the host’s gut or tumor microbiome while projecting the next phase of experimental discovery.

Statistical Techniques for Detecting Cyberattacks on Computer Networks Based on an Analysis of Abnormal Traffic Behavior

Represented paper is currently topical, because of year on year increasing quantity and diversity of attacks on computer networks that causes significant losses for companies. This work provides abilities of such problems solving as: existing methods of location of anomalies and current hazards at networks, statistical methods consideration, as effective methods of anomaly detection and experimental discovery of choosed method effectiveness. The method of network traffic capture and analysis during the network segment passive monitoring is considered in this work. Also, the processing way of numerous network traffic indexes for further network information safety level evaluation is proposed. Represented methods and concepts usage allows increasing of network segment reliability at the expense of operative network anomalies capturing, that could testify about possible hazards and such information is very useful for the network administrator. To get a proof of the method effectiveness, several network attacks, whose data is storing in specialised DARPA dataset, were chosen. Relevant parameters for every attack type were calculated. In such a way, start and termination time of the attack could be obtained by this method with insignificant error for some methods.

Metallization of diamond

Experimental discovery of ultralarge elastic deformation in nanoscale diamond and machine learning of its electronic and phonon structures have created opportunities to address new scientific questions. Can diamond, with an ultrawide bandgap of 5.6 eV, be completely metallized, solely under mechanical strain without phonon instability, so that its electronic bandgap fully vanishes? Through first-principles calculations, finite-element simulations validated by experiments, and neural network learning, we show here that metallization/demetallization as well as indirect-to-direct bandgap transitions can be achieved reversibly in diamond below threshold strain levels for phonon instability. We identify the pathway to metallization within six-dimensional strain space for different sample geometries. We also explore phonon-instability conditions that promote phase transition to graphite. These findings offer opportunities for tailoring properties of diamond via strain engineering for electronic, photonic, and quantum applications.