An approach for preventing the indexing of hijacked journal articles in scientific databases

Hijacked journals are cloned websites that resemble the homepages of legitimate journals, whose aim is to collect processing and publication fees from unwary authors. There is a growing recognition that the recent proliferation of these scam sites poses a threat to the integrity of the scientific process. This study presents an approach intended to prevent the indexing of papers published by hijacked journals in scientific databases by using classification algorithms. We will provide an overview of the problem, define key features of hijacked journals, and present a decision tree that can be used to detect hijacked publications.     

Engineering of Magnetically Intercalated Silicene Compound: An Overlooked Polymorph of EuSi2

Silicene, a Si analogue of graphene, is suggested to become a versatile material for nanoelectronics. Being coupled with magnetism, it is predicted to be particularly suitable for spintronic applications. However, experimental realization of free‐standing silicene and its magnetic derivatives is lacking. Fortunately, magnetism can be induced into silicene layers, in particular, by intercalation. Here, a successful synthesis of multilayer silicene intercalated by inherently magnetic Eu ions – a compound expected to exhibit both massless Dirac‐cone states, as its Ca analogue, and a nontrivial magnetic structure – is reported. This new polymorph with EuSi₂ stoichiometry is epitaxially stabilized by continual replication of silicene layers employing Sr‐intercalated multilayer silicene as a template. The atomic structure of the new compound and its sharp interface with the template are confirmed using electron diffraction, X‐ray diffraction, and electron microscopy techniques. Below 80 K, the material demonstrates anisotropic antiferromagnetism coexisting with weak ferromagnetism. The magnetic state is accompanied by an anomalous behavior of magnetoresistivity.     

Approximating functions for computation of resonant wavelengths of the reentrant cavity resonator with extended capacitance gap

New configuration of cylindrical reentrant cavity with modified shape of the metal post is considered. The eigen wavelengths of two lowest modes obtained numerically are compared with analogous parameters of conventional reentrant cavity. Approximate analytical expressions for calculation of resonant wavelengths are derived with the help of statistical package TableCurve3D. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

Initial stage growth of GexSi1?x layers and Ge quantum dot formation on GexSi1?x surface by MBE

Critical thicknesses of two-dimensional to three-dimensional growth in Ge_xSi_1−x layers were measured as a function of composition for different growth temperatures. In addition to the (2 × 1) superstructure for a Ge film grown on Si(100), the Ge_xSi_1−x layers are characterized by the formation of (2 × n) reconstruction. We measured n for all layers of Ge/Ge_xSi_1−x/Ge heterosystem using our software with respect to the video recording of reflection high-energy electron diffraction (RHEED) pattern during growth. The n reaches a minimum value of about 8 for clear Ge layer, whereas for Ge_xSi_1−x films, n is increased from 8 to 14. The presence of a thin strained film of the Ge_xSi_1−x caused not only the changes in critical thicknesses of the transitions, but also affected the properties of the germanium nanocluster array for the top Ge layer. Based on the RHEED data, the hut-like island form, which has not been previously observed by us between the hut and dome islands, has been detected. Data on the growth of Ge/Ge_xSi_1−x/Ge heterostructures with the uniform array of islands in the second layer of the Ge film have been received.     

Session "Interval and Computer-Algebraic Methods in Science and Engineering" at the 6th International Association for Mathematics and Computers in Simulation (IMACS) Conference on Applications of Computer Algebra (ACA'2000) Saint Petersburg,Russia, June 25–28, 2000

Reliable Computing -     

Chemical precipitation of copper from copper–zinc solutions onto selective sorbents

The selective sorption and multiple concentration of copper in the form of an ultradisperse precipitate from a diluted Cu²⁺–Zn²⁺-solution has been investigated. The selective sorption is accomplished by means of weakly basic anion exchangers in their free base forms. Regeneration of the sorbent and conversion of Cu²⁺ to Cu⁰ is carried out by means of a chemical reduction in the resin phase. Thus the resins can be reused for sorption of further copper ions. The process has been investigated in both, batch and packed bed experiments. After multiple saturation–reduction cycles an accumulation of metallic copper on the surface and in the pores of the sorbent is observed. The presence of finely dispersed metallic copper leads to the additional sorption of the Cu²⁺ ions due to a synproportional reduction–oxidation reaction. The total uptake of copper after several cycles amounts to more than 300 % of the anion exchange capacity.     

Evolutionary Origins of the Photosynthetic Water Oxidation Cluster: Bicarbonate Permits Mn2+ Photo‐oxidation by Anoxygenic Bacterial Reaction Centers

The enzyme that catalyzes water oxidation in oxygenic photosynthesis contains an inorganic cluster (Mn₄CaO₅) that is universally conserved in all photosystem II (PSII) protein complexes. Its hypothesized precursor is an anoxygenic photobacterium containing a type 2 reaction center as photo‐oxidant (bRC2, iron–quinone type). Here we provide the first experimental evidence that a native bRC2 complex can catalyze the photo‐oxidation of Mn²⁺ to Mn³⁺, but only in the presence of bicarbonate concentrations that allows the formation of (bRC2)Mn²⁺(bicarbonate)_1–2 complexes. Parallel‐mode EPR spectroscopy was used to characterize the photoproduct, (bRC2)Mn³⁺(CO₃^2?), based on the g tensor and ⁵⁵Mn hyperfine splitting. (Bi)carbonate coordination extends the lifetime of the Mn³⁺ photoproduct by slowing charge recombination. Prior electrochemical measurements show that carbonate complexation thermodynamically stabilizes the Mn³⁺ product by 0.9–1 V relative to water ligands. A model for the origin of the water oxidation catalyst is presented that proposes chemically feasible steps in the evolution of oxygenic PSIIs, and is supported by literature results on the photoassembly of contemporary PSIIs.     

Ti3SiC2-Cu composites by mechanical milling and spark plasma sintering: Possible microstructure formation scenarios

We present several possible microstructure development scenarios in Ti₃SiC₂-Cu composites during mechanical milling and Spark Plasma Sintering (SPS). We have studied the effect of in situ consolidation during milling of Ti₃SiC₂ and Cu powders and melting of the Cu matrix during the SPS on the hardness and electrical conductivity of the sintered materials. Under low-energy milling, (3–5) vol.%Ti₃SiC₂-Cu composite particles of platelet morphology formed, which could be easily SPS-ed to 92–95% relative density. Under high-energy milling, millimeter-scale (3–5) vol.%Ti₃SiC₂-Cu granules formed as a result of in situ consolidation and presented a challenge to be sintered into a bulk fully dense sample; the corresponding SPS-ed compacts demonstrated a finer-grained Cu matrix and more significant levels of hardening compared to composites of the same composition processed by low-energy milling. The 3 vol.% Ti₃SiC₂-Cu in situ consolidated and Spark Plasma Sintered granules showed an extremely high hardness of 227 HV. High electrical conductivity of the Ti₃SiC₂-Cu composites sintered from the granules was an indication of efficient sintering of the granules to each other. Partial melting of the Cu matrix, if induced during the SPS, compromised the phase stability and uniformity of the microstructure of the Ti₃SiC₂-Cu composites and thus it is not to be suggested as a pathway to enhanced densification in this system.     

Novel Approach for the Synthesis of Chlorophosphazene Cycles with a Defined Size via Controlled Cyclization of Linear Oligodichlorophosphazenes [Cl(PCl2=N)n–PCl3]+[PCl6]−

Despite a significant number of investigations in the field of phosphazene chemistry, the formation mechanism of this class of cyclic compounds is still poorly studied. At the same time, a thorough understanding of this process is necessary, both for the direct production of phosphazene rings of a given size and for the controlled cyclization reaction when it is secondary and undesirable. We synthesized a series of short linear phosphazene oligomers with the general formula Cl[PCl2=N]n–PCl₃⁺PCl₆^– and studied their tendency to form cyclic structures under the influence of elevated temperatures or in the presence of nitrogen-containing agents, such as hexamethyldisilazane (HMDS) or ammonium chloride. It was established that linear oligophosphazenes are inert when heated in the absence of the mentioned cyclization agents, and the formation of cyclic products occurs only when these agents are involved in the process. The ability to obtain the desired size phosphazene cycle from corresponding linear chains is shown for the first time. Known obstacles, such as side interaction with the PCl₆^– counterion and a tendency of longer chains to undergo crosslinking elongation instead of cyclization are still relevant, and ways to overcome them are being discussed.