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The β and γ phases of methylammonium chloride CH3NH3Cl and methylammonium bromide CH3NH3Br are identified to be ferroelectric via pyroelectric current and dielectric constant measurements.

In vendor managed inventory (VMI) operations, it is necessary for both the suppliers and the customers to reach an agreement on the maximal and minimal inventory level. In practice, in VMI, inventory levels are decided manually by planning personnel, based on their experience and past operating records. From a system optimization point of view, the determination of the upper and lower inventory levels in storage areas is complicated, necessitating analysis of many factors. Consequently, it may not be possible to obtain the best planning results, to determine and maintain the optimum levels of inventory. In this study, we utilize network flow techniques to build a replenishment model to deal with the upper-and-lower inventory level control problem, with the objective of minimizing the total cost in short-term operations, subject to inventory level control and other operating constraints. The model is formulated as an integer network flow problem with side constraints and is characterized as NP-hard in terms of optimization. To efficiently and effectively solve the large-scale problems that occur in the real world, a solution algorithm is also developed. Finally, numerical tests are conducted using real data from a major retail company in northern Taiwan. The results demonstrate the usefulness of the proposed model and solution algorithm for replenishment planning in actual practice.

We observe sharp step-down discontinuities in the magnetic susceptibility of NH4H2PO4 and NH4H2PO4-d60 (60% deuterated) along the a- and c-axes occurring exactly at their antiferroelectric transiti...

Most ferroelectric crystals have their own set of unique characteristics, and ammonium sulfate (NH4)2SO4 is no exception. We report on two previously unidentified features in ammonium sulfate: (1) ...

Different types of magnetism arise mainly from how electrons move and interact with each other. In this work, we show how protons (H+) also exhibit magnetic behavior. We measured the magnetic susce...

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We observe sharp step-down discontinuities in the magnetic susceptibility of NH

The associated magnetic moments of the periodic rotational motion of methyl groups in hexamethylbenzene C$_6$(CH$_3$)$_6$ were recently identified to contribute to its overall magnetic susceptibility. Those measurements however, were only performed on hydrogenous polycrystalline samples. We report magnetic susceptibility measurements on single crystalline C$_6$(CH$_3$)$_6$ in the cases where the applied magnetic field is parallel and perpendicular to the molecular basal planes. In the former case, metastable behavior near the onset temperature T$_{C-H}$=118 K is identified while in the latter, no anomalous behavior is observed. Similar anomalies are observed in deuterated hexamethylbenzene C$_6$(CD$_3$)$_6$ (where D is deuterium), however, T$_{C-D}$ occurs 14 K higher at 132 K. In addition, a peak anomaly identified near 42 K is suggested to be due to the onset of coherent quantum tunneling of deuterons. The near cubic ground state is proposed to be the result of a more radical form of the Jahn-Teller effect occurring in a molecular solid where the lattice distorts to remove the orbital degeneracies of the protons to lower its energy. The apparent magnetic anisotropy and isotope effect provide evidence that apart from electrons, not only protons, but also deuterons establish strongly correlated behavior., Comment: 21 pages (double spaced), 4 figures + 2 supplementary figures, Just Accepted Manuscript by the Journal of Physical Chemistry C

The polarity of the magnetic susceptibility χ(T) of ammonium alum NH4Al(SO4)2•12H2O single crystals below its ferroelectric Curie temperature TC is identified to depend only on the cooling rate. To explain this, we consider reorienting distorted NH4+ to carry weak magnetic and electric dipole moments that are linearly coupled. Slow cooling allows the dipole moments to align which enhances χ(T) to become positive. However, due to energy degeneracy of rotational motion and geometric frustration of the NH4+, faster cooling rates render the system to become an orientational glass state causing χ(T) to remain negative. Specific heat measurements also show the presence of excess entropy below a negative anomaly near 53 K. Our findings identify a possible new class of non-equilibrium system with potential applications in non-volatile memory devices.

PurposeTo determine the in vitro accuracy, test-retest repeatability, and interplatform reproducibility of T1 quantification protocols used for dynamic contrast-enhanced MRI at 1.5 and 3 T.MethodsA T1 phantom with 14 samples was imaged at eight centers with a common inversion-recovery spin-echo (IR-SE) protocol and a variable flip angle (VFA) protocol using seven flip angles, as well as site-specific protocols (VFA with different flip angles, variable repetition time, proton density, and Look-Locker inversion recovery). Factors influencing the accuracy (deviation from reference NMR T1 measurements) and repeatability were assessed using general linear mixed models. Interplatform reproducibility was assessed using coefficients of variation.ResultsFor the common IR-SE protocol, accuracy (median error across platforms = 1.4-5.5%) was influenced predominantly by T1 sample (P

The types of magnetism known to date are all mainly based on contributions from electron motion. We show how rotational motion of protons (H+) within the methyl groups in hexamethylbenzene (C6(CH3)6) also contribute significantly to the magnetic susceptibility. Starting from below 118 K, as the rotational motion of the methyl groups set in, an associated magnetic moment positive in nature due to charge of the protons renders the susceptibility to become anomalously dependent on temperature. Starting from 20 K, the susceptibility diverges with decreasing temperature indicative of spin–spin interactions between methyl groups aligned in a previously unclassified type of anti-ferromagnetic configuration. Complementary dielectric constant measurements also show the existence of magneto-dielectric coupling. Our findings allow for the study of strongly correlated systems that are based on a species that possesses much slower dynamics.

A linear induction motor system composed of a high– T c superconducting secondary with close-ended coils made of REBCO coated conductor wire was designed and tested experimentally. The measured thrust, normal force and power loss are presented and explained by combining the flux dynamics inside superconductors with existing linear drive theory. It is found that an inherent capacitive component associated to the flux motion of vortices in the Type-II superconductor reduces the impedance of the coils; from such, the associated Lorentz forces are drastically increased. The resulting breakout thrust of the designed linear motor system was found to be extremely high (up to 4.7 kN/m 2 ) while the associated normal forces only a fraction of the thrust. Compared to its conventional counterparts, high- T c superconducting secondaries appear to be more feasible for use in maglev propulsion and electromagnetic launchers.

Epitaxy and misfit strain imposed by underlying substrates have been intensively used to tailor the microstructure and electronic properties of oxide films, but this approach is largely restricted by commercially limited substrates. In contrast to the conventional epitaxial misfit strains with a positive Poisson’s constant, we show here a tunable Poisson’s ratio with anomalous values from negative, zero, to positive. This permits effective control over the out-of-plane lattice parameters that strongly correlate the magnetic and transport properties in perovskite mixed-valence La1–xSrxMnO3 thin films. Our results provide an unconventional approach to better modulation and understanding of elastic-mediated microstructures and physical properties of oxide films by engineering the Poisson’s ratios.

Stochastic disturbances occurring in real world operations could have a significant influence on the planned routing and scheduling results for inter-school buses. An optimal schedule might therefore lose its optimality when applied in actual operations where stochastic disturbances occur. In this study we employ network flow techniques to construct an inter-school bus routing and scheduling model, considering the characteristics of inter-school buses for class attendance, under stochastic travel times. The model is formulated as a special multiple commodity network flow problem which is characterized as NP-hard. To efficiently solve realistically large problems a problem decomposition and variable fixing method, coupled with the use of CPLEX mathematical programming solver, is employed to develop a solution algorithm. Finally, computational tests are performed using data from an allied university system in Taiwan. The test results show that the model and the solution algorithm are good and therefore could be useful for actual operations.

As a follow-up of our previous work on pressure-induced metallization of the 2H_{c}-MoS_{2} [Chi et al., Phys. Rev. Lett. 113, 036802 (2014)PRLTAO0031-900710.1103/PhysRevLett.113.036802], here we extend pressure beyond the megabar range to seek after superconductivity via electrical transport measurements. We found that superconductivity emerges in the 2H_{a}-MoS_{2} with an onset critical temperature T_{c} of ca. 3 K at ca. 90 GPa. Upon further increasing the pressure, T_{c} is rapidly enhanced beyond 10 K and stabilized at ca. 12 K over a wide pressure range up to 220 GPa. Synchrotron x-ray diffraction measurements evidenced no further structural phase transition, decomposition, and amorphization up to 155 GPa, implying an intrinsic superconductivity in the 2H_{a}-MoS_{2}. DFT calculations suggest that the emergence of pressure-induced superconductivity is intimately linked to the emergence of a new flat Fermi pocket in the electronic structure. Our finding represents an alternative strategy for achieving superconductivity in 2H-MoS_{2} in addition to chemical intercalation and electrostatic gating.

The methyl groups in hexamethylbenzene C$_6$(CH$_3$)$_6$ become magnetically ordered at the molecular level below 118 K. This is also near the temperature at which the system structurally transitions from triclinic to a unique near-cubic phase. High-precision measurements of the near-static dielectric constant reveal that the structural phase transition is actually comprised of four successive transformations upon cooling at T$_1$=110.7 K, T$_2$=109.5 K, T$_3$=109.1 K and T$_4$=107.8 K. In contrast to warming, only two transitions occur at T'$_4$=119.2 K and T'$_1$=120.9 K. The methyl groups in the near-cubic phase become slightly distorted according to existing neutron powder diffraction measurements. Analysis of the 2$^6$=64 possible spin orientation configurations of the methyl groups reveal a 20-fold ground state degeneracy presiding in each molecule rendering the system to become highly unstable. From such, it is interpreted that T$_1$ and T$_2$ are temperatures at which the molecules successively lower their symmetry to remove the energy degeneracy which involve methyl group elongation and further out-of-plane tilting. This triggers the system to phase transition into the near-cubic phase which involves a shearing of the molecular planes and partial rotation of the methyl groups at T$_3$ and T$_4$. We interpret the low temperature near-cubic phase to be a manifestation of Jahn-Teller distortions based on energy degeneracies of the orbital motion of protons in each molecule and suggest that the metastable nature of the phase transition originates from the methyl groups requiring a larger amount of energy to order than to disorder. Our findings help explain why many unusual structural phase transitions occur at low temperatures in other molecular crystals possessing periodic motion of protons., Comment: 14 pages (1.5 spaced, 3 figures + 1 'Table of Contents' graphic; accepted (on Dec. 4th, 2018) by the Journal of Physical Chemistry C

As a follow-up of our previous work on pressure-induced metallization of the 2H_{c}-MoS_{2} [Chi et al., Phys. Rev. Lett. 113, 036802 (2014)PRLTAO0031-900710.1103/PhysRevLett.113.036802], here we extend pressure beyond the megabar range to seek after superconductivity via electrical transport measurements. We found that superconductivity emerges in the 2H_{a}-MoS_{2} with an onset critical temperature T_{c} of ca. 3 K at ca. 90 GPa. Upon further increasing the pressure, T_{c} is rapidly enhanced beyond 10 K and stabilized at ca. 12 K over a wide pressure range up to 220 GPa. Synchrotron x-ray diffraction measurements evidenced no further structural phase transition, decomposition, and amorphization up to 155 GPa, implying an intrinsic superconductivity in the 2H_{a}-MoS_{2}. DFT calculations suggest that the emergence of pressure-induced superconductivity is intimately linked to the emergence of a new flat Fermi pocket in the electronic structure. Our finding represents an alternative strategy for achieving superconductivity in 2H-MoS_{2} in addition to chemical intercalation and electrostatic gating.

PURPOSE: To determine the in-vitro accuracy, test-retest repeatability and interplatform reproducibility of T(1) quantification protocols used for DCE-MRI at 1.5T and 3.0T. METHODS: A T(1) phantom with 14 samples was imaged at 8 centers with a common inversion recovery spin echo (IR-SE) protocol and a variable flip angle (VFA) protocol using 7 flip angles (FA), as well as site-specific protocols [VFA with different FA, variable TR (VTR), proton density (PD) and Look-Locker IR]. Factors influencing accuracy (deviation from reference NMR T(1) measurements) and repeatability were assessed using general linear mixed models. Interplatform reproducibility was assessed using coefficients of variation (CV). RESULTS: For the common IR-SE protocol, accuracy (median error across platforms=1.4%–5.5%) was influenced predominantly by T(1) sample (P

The electrical properties of a close-ended coil made of REBCO-coated conductor wire are studied via the measurement of its induced currents upon exposure to a sinusoidal magnetic field at different frequency. Results show a similarity to the behavior of currents inside an RLC circuit where the peak amplitude is dependent on the contact resistance of the solder joining the two ends of the coil and the resonant frequency, i.e., a function of the inductance of the coil and penetration rate of fluxons into the superconducting layers. Our findings suggest highly feasible applications stemming from such experimental setup in the field of linear and rotating machinery and low-frequency high-quality-factor resonators.

In order to optimize the structure of high temperature superconducting coils for linear motor applications, three separate coils with different shapes made of Re-BCO coated conductor were studied: circular shaped single pancake, circular shaped double-pancake and racetrack shaped single-pancake. The thrust and vertical forces of the three coils above a conventional flat linear three-phases winding were investigated experimentally. With the aid of the experimentally obtained values, it was found that single-pancake coil in the shape of a racetrack was the best selection for a flat single-sided linear motor system. Studies were also made on the frequency characteristics of the vertical force of the racetrack shaped single-pancake coil.

The potential application of bulk high temperature superconductor (HTS) magnets has attracted much attention because of the potential high trapped flux in HTS magnets. This paper focuses on the magnetization method design of bulk multi-seeded HTS magnets for obtaining their better flux-trapping performance. Firstly, three different magnetization methods were carried out based on the current experimental setup to find a better way of magnetizing a bulk melt-texture three-seeded YBaCuO superconductor. The experimental results indicated that when the three domains of this three-seeded YBaCuO bulk were magnetized in order, the maximum trapped flux was higher than that when only one domain was magnetized. However, this method costs about three times of the magnetization time than the other two methods and the increasing ratio was only about 11.11%. It has been found that another method of magnetizing only the middle domain could also get a good result such as the uniformity of trapped flux is good. In order to improve the current experimental magnetization conditions for further improvement, two sheets of iron were designed to attach two poles of the electromagnet (Lakeshore, Model EM4-CV) for increasing the magnetizing area, and that all domains of a bulk multi-seeded HTS can be magnetized in one time. Firstly, the appropriate size and thickness of the iron sheets was simulated and optimized by Comsol Multiphysics. It has been found that the magnetic field between two poles was highest when the thickness of iron was 2 mm and the length was 68 mm. Then, the simulating and optimization results had been verified by the following experiments. According to the comparison experiments, it is proved that to choose the magnetization method that only magnetizing the middle domain with the improved setup is helpful to obtain larger and more homogeneous magnetic flux for the bulk multi-seeded HTS magnet due to the added iron sheets.

In the real world, planned aircraft maintenance schedules are often affected by incidents. Airlines may thus need to adjust their aircraft maintenance schedules following the incidents that occur during routine operations. In tradition, such aircraft maintenance schedule adjustment has been performed manually, a process which is neither effective nor efficient, especially when the problem scale is large. In this study, an aircraft maintenance schedule adjustment model is developed, with the objective of minimizing the total system cost, subject to the related operating constraints. The model is formulated as a zero-one integer program and is solved using a mathematical programing solver. The effectiveness of the model is evaluated by application to a case study using data from an aircraft maintenance center in Taiwan. The test results show the proposed model, as well as the scheduling rules abstracted from the results are useful for the decision maker to adjust good maintenance schedules.

In the practical application of a High-Tc Superconducting (HTS) maglev vehicle, the onboard HTS bulks are inevitably exposed to a varying inhomogeneous magnetic field due to limited magnetic field precision during the processing and assembling of the permanent magnetic guideway (PMG). To explore the levitation force of YBa2Cu3O7-x bulk samples with respect to a PMG in such changing external magnetic fields, we study experimentally the wave detail and general transition of the levitation force at different dynamic operation modes with the aid of a spinning circular PMG. The rotation of the circular PMG simulates translational movement of the superconductor with respect to a PMG and the rotational speed was set under several shift processes for simulating the different running operation speeds of HTS maglev vehicle. The highest linear equivalent experimental speed was 238 km/h. The change in levitation force was almost instantaneous in accordance to the varying of the vertical component of the applied field, and generally attenuated with running time. The saturation behavior after a change in speed was discussed thoroughly. This observed phenomenon is of great importance in the design and application of the HTS maglev system.

This year marks the tenth anniversary of the first man-loading high temperature superconducting (HTS) maglev test vehicle “Century” in the world. This report summarizes development advances of major topics related to the HTS maglev vehicle at the Applied Superconductivity Laboratory (ASCLab) at Southwest Jiaotong University (SWJTU). The HTS Maglev measurement systems are described, including the HTS maglev dynamic test system capable of speeds up to 300 km/h. Through these measurement systems, many problems related to the HTS maglev have been studied such as system optimization, stability control, influence from ramp angles, influence from AC field, and investigation of the system's properties at temperatures lower than 77 K. Apart from experimental studies, the 3-D model of the HTS maglev was constructed via two different methods to simulate the Maglev's behavior.

High temperature superconducting (HTS) bulk sample acts as quasi-permanent magnet when it traps magnetic field, and the superconducting bulk magnet can substitute the traditional permanent magnet in the engineering of the linear motor for the purpose of achieving higher efficiency. The electromagnetic forces between the HTS bulk magnets and the ac magnetic field are the most important parameters to consider for the engineering of a motor. We measured the static vertical and thrust forces of an HTS magnet subject to a sinusoidal traveling magnetic field at different trapped fields and at different current amplitude and frequencies. The force relaxation of the HTS bulk magnet was also compared with that of a traditional permanent magnet. The feasibility of replacing the conventional magnet in the ac application machines by HTS bulk ones was preliminary validated experimentally.

High-Tc superconducting (HTS) bulk samples used for a maglev system can be re-magnetized after being subjected to another applied magnetic field which may influence the levitation performance of a HTS bulk over the permanent magnetic guideway (PMG). In order to clarify the relationship between the HTS bulk’s re-magnetization and its levitation performance, a YBCO bulk was re-magnetized at different values and its levitation performance studied experimentally above a permanent guideway (PMG) system. The results show that the increase of trapped magnetic flux inside the HTS bulk is closely related to the magnitude and direction of the applied field during the re-magnetization process. Furthermore, the levitation force changes on the HTS-PMG system affected by the re-magnetized HTS bulk are discussed allowing for optimization improvements to the maglev system load capabilities.

In this research, we develop a stochastic-demand cargo container loading plan model with the objective of minimizing the total operating cost, subject to the related operating constraints. The model is formulated as a nonlinear mixed integer program that is characterized as NP-hard. We employ a problem linearization technique, coupled with a mathematical programming solver, to develop a solution method. To preliminarily evaluate the model and the solution method, we perform a case study using data from an international air express carrier. The results show that the model and the solution method could be useful for air express carriers.

Temperature and field-dependent magnetization measurements on polycrystalline CeMnCuSi2 reveal that the Mn moments in this compound exhibit ordering with a ferromagnetic (FM) component ordered instead of the previously reported purely antiferromagnetic (AFM) ordering. The FM ordering temperature, Tc, is about 120 K and almost unchanged with external fields up to 50 kOe. Furthermore, an AFM component (such as in a canted spin structure) is observed to be present in this phase, and its orientation is modified rapidly by the external magnetic field. The Ce L3-edge X-ray absorption result shows that the Ce ions in this compound are nearly trivalent, very similar to that in the heavy fermion system CeCu2Si2. Large thermomagnetic irreversibility is observed between the zero-field-cooled (ZFC) and field-cooled (FC) M(T) curves below Tc indicating strong magnetocrystalline anisotropy in the ordered phase. At 5 K, a metamagnetic-type transition is observed to occur at a critical field of about 8 kOe, and this critical field decreases with increasing temperature. The FM ordering of the Mn moments in CeMnCuSi2 is consistent with the value of the intralayer Mn–Mn distance RaMn–Mn=2.890 A, which is greater than the critical value 2.865 A for FM ordering. Finally, a magnetic phase diagram is constructed for CeMnCuSi2.

Ti-sheathed MgB2 wires doped with nanosize crystalline-SiC up to a concentration of 15?wt% SiC have been fabricated, and the effects of the SiC doping on the critical current density (Jc) and other superconducting properties studied. In contrast with the previously reported results that nano-SiC doping with a doping range below 16?wt% usually enhances Jc, particularly at higher fields, our measurements show that SiC doping decreases Jc over almost the whole field range from 0 to 7.3?T at all temperatures. Furthermore, it is found that the degradation of Jc becomes stronger at higher SiC doping levels, which is also in sharp contrast with the reported results that Jc is usually optimized at doping levels near 10?wt% SiC. Our results indicate that these negative effects on Jc could be attributed to the absence of significant effective pinning centres (mainly Mg2Si) due to the high chemical stability of the crystalline-SiC particles.

Ti-sheathed monocore MgB 2 wires with improved magnetic critical current density ( J c ) have been fabricated by in situ powder-in-tube (PIT) method and characterized by magnetization, X-ray diffraction, scanning electron microscopy and electrical resistivity measurements. For the best wire, the magnetic J c values at 5 K and fields of 2 T, 5 T, and 8 T are 4.1 × 10 5 A/cm 2 , 7.8 × 10 4 A/cm 2 , and 1.4 × 10 4 A/cm 2 , respectively. At 20 K and fields of 0.5 T and 3 T, the J c values are about 3.6 × 10 5 A/cm 2 and 3.1 × 10 4 A/cm 2 , respectively, which are much higher than those of the Fe-sheathed mono-core MgB 2 wires fabricated with the same in situ PIT process and under the same fabricating conditions. It appears that the overall J c for the average Ti-sheathed wires is comparable to that of the Fe-sheathed wires. Our X-ray diffraction and scanning electron microscopy analysis indicates that J c in the Ti-sheathed MgB 2 wires can be strongly suppressed by MgO impurities and micro-cracks.

H2O is one of the most important substances needed in sustaining life; but yet not much is known about its ground state. Here, a previously unidentified anomaly is identified in the form of a minimum in the imaginary part of the dielectric constant with respect to temperature near 20 K while the real part remains monotonic. Isothermal dispersion and absorption measurements show coinciding results. For the case of heavy ice (D2O), no anomaly was identified confirming an apparent isotope effect. Concerted quantum tunneling of protons is believed to be the main cause behind the reported anomaly. Our findings identify another system that exhibits macroscopic quantum phenomena of which rarely occur in nature., Comment: 12 pages (single column double spaced), 4 figures

From high precision measurements of the complex dielectric constant of H2O ice, we identify the critical temperatures of the phase transition into and out of ice XI from ice Ih to occur at T_Ih-IX=58.9 K and T_IX-Ih=73.4 K. For D2O, T_Ih-IX=63.7 K and T_IX-Ih=78.2 K. A triple point is identified to exist at 0.07 GPa and 73.4 K for H2O and 0.08 GPa and 78.2 K for D2O where ices Ih, II and XI coexist. A first order phase transition with kinetic broadening associated to proton ordering dynamics is identified at 100 K., 11 pages, 5 figures

Working towards developing lightweight superconducting magnets for future space and other applications, we have successfully fabricated mono-core Ti-sheathed MgB2 wires by the powder-in-tube method. The wires were characterized by magnetization, electrical resistivity, x-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry measurements. The results indicate that the Ti sheath does not react with the magnesium and boron, and the present wire rolling process can produce MgB2 wires with a superconducting volume fraction of at least 64% in the core. Using the Bean model, it was found that at 5 K, the magnetic critical current densities, Jc, measured in magnetic fields of 0, 5, and 8 T are about 4.2 × 105, 3.6 × 104, and 1.4 × 104 A cm−2, respectively. At 20 K and 0 T, the magnetic Jc is about 2.4 × 105 A cm−2. These results show that at zero and low fields, the values of the magnetic Jc for Ti-sheathed MgB2 wires are comparable with the best results available for the Fe-sheathed MgB2 wires. At high fields, however, the Jc for Ti-sheathed MgB2 wires appears higher than that for the Fe-sheathed MgB2 wires.

Growth anisotropies of bulk high temperature superconductors (HTSCs) fabricated by a top-seeded melt texture growth process, that is, different pinning effect in the growth sectors (GSs) and growth sector boundaries (GSBs), possess effect on the macro flux trapping and levitation performance of bulk HTSCs. Previous work (Physics Procedia, 36 (2012) 1043) has found that the bulk HTSC array with aligned GSB pattern (AGSBP) exhibits better capability for levitation and suppression of levitation force decay above a permanent magnet guideway (PMG) compared with misaligned GSB pattern (MGSBP). In this paper, we further examine this growth anisotropy effect on the maglev performance of a double-layer bulk HTSC. In contrast to reported trapped flux cases (Supercond. Sci. Technol. 19 (2006) S466), the two superposed bulk HTSCs with same AGSBP with PMG are found to show better maglev performance. These series of results are helpful and support a new way for the performance optimization of present HTS maglev systems.

The phase diagram of H2O is extremely complex, in particular, it is believed that a second critical point exists deep below the supercooled water (SCW) region where two liquids of different densities coexist. The problem however, is that SCW freezes at temperatures just above this hypothesized liquid-liquid critical point (LLCP) so direct experimental verification of its existence has yet to be realized. Here, we report two anomalies in the complex dielectric constant during warming in the form of a peak anomaly near Tp=203 K and a sharp minimum near Tm=212 K from ice samples prepared from SCW under hydrostatic pressures up to 760 MPa. The same features were observed about 4 K higher in heavy ice. Tp is believed to be associated to the nucleation process of metastable cubic ice Ic and Tm the transitioning of ice Ic to either ices Ih or II depending on pressure. Given that Tp and Tm are nearly isothermal and present up to at least 620 MPa and ending as a critical point near 33-50 MPa, it is deduced that two types of SCW with different density concentrations exists which affects the surface energy of ice Ic nuclei in the "no man's land" region of the phase diagram. Our results are consistent with the LLCP theory and suggest that a metastable critical point exists in the region of 33-50 MPa and Tc > 212 K., 17 pages (single-columned, double-spaced), 4 figures + ToC graphic, The Journal of Physical Chemistry C, Publication Date (Web): August 18, 2015

A method to transport up to 180 A of current into the sample space of a pressure cell without causing thermal instabilities at 77 K was developed in order to study the critical current Ic of samples of first-generation Bi-2223 superconducting wire at different hydrostatic pressures. Ic was found to linearly decrease with increasing application of external pressure and was found to be irreversible upon release of pressure. The n-value of the voltage-current curves at different pressure was also found to systematically decrease. The decrease in Ic and the irreversibility effect is attributed to the deformation of the filamentary walls of the wire.

The distribution of and relationship between F-actin and G-actin were investigated in pollen grains and pollen tubes of Lilium davidii Duch. using a confocal laser scanning microscope after fluorescence and immunofluorescence labeling. Circular F-actin bundles were found to be the main form of microfilament cytoskeleton in pollen grains and pollen tubes. Consistent with cytoplasmic streaming in pollen tubes, there were no obvious F-actin bundles in the 10- to 20-microm tip region of long pollen tubes, only a few short F-actin fragments. Labeling with fluorescein isothiocyanate (FITC)-DNase I at first established the presence of a tip-focused gradient of intracellular G-actin concentration at the extreme apex of the tube, the concentration of G-actin being about twice as high in the 10- to 20-microm region of the tip as in other regions of the pollen tube. We also found that the distribution of G-actin was related negatively to that of the F-actin in pollen tubes of L. davidii. Caffeine treatment caused the G-actin tip-focused gradient to disappear, and F-actin to extend into the pollen tube tip. Based on these results, we speculate that the circular F-actin bundles may be the track for bidirectional cytoplasmic streaming in pollen tubes, and that in the pollen tube tip most of the F-actin is depolymerized into G-actin, leading to the absence of F-actin bundles in this region.

The distribution of integrin-like proteins in the pollen tube was examined by immunofluorescent labeling and western blotting techniques using antibodies against human placenta integrin vitronectin receptor (VnR), and alpha(v), beta3 and beta1 integrin subunits. Pseudocolor-coded confocal images showed intense immunostaining within 10 and 5 microm of the tip of the pollen tube in Lilium davidii and Nicotiana tabacum respectively. In both segments the site near the plasma membrane was labeled. Western blotting analyses revealed cross-reaction of anti-beta3, anti-alpha(v) and anti-VnR with the proteins in the plasma membrane preparation of L. davidii and Hemerocallis citrina pollen tube. These studies provide evidence for the first time that the integrin-like protein is present in pollen tubes, and it may be mainly composed of alpha(v) and beta3 subunits in lily pollen tubes. In a functional assay, neither anti-VnR antibody nor the Arg-Gly-Asp-Ser tetrapeptide inhibited pollen tube growth of N. tabacum in vitro, but both of them depressed tube growth on the stigma and in style under quasi in vivo culture conditions. The integrin-like proteins localized in the tip and periphery of the pollen tube appeared to play roles in growth of the pollen tube tip and interaction with the extracellular matrix of the style.

The reaction of mercaptoacetaldehyde dialkyl acetals 1a-c in the presence of sulfuric acid, polyphosphoric acid and zinc chloride is described. Other than the disulfide reported previously, new compounds 1,2-bis-(mercapto)ethylene, 1,2,3-tris-(mercapto)ethane and 1,2-bis-(mercapto)methane have been isolated for the first time.

MnWO 4 has attracted attention because of its ferroelectric property induced by frustrated helical spin order. Strong spin–lattice interaction is necessary to explain ferroelectricity associated with this type of magnetic order. We have conducted thermal expansion measurements along the a, b, c axes revealing the existence of strong anisotropic lattice anomalies at T 1 = 7.8 K , the temperature of the magnetic lock-in transition into a commensurate low-temperature (reentrant paraelectric) phase. The effect of hydrostatic pressure up to 1.8 GPa on the FE phase is investigated by measuring the dielectric constant and the FE polarization. The low-temperature commensurate and paraelectric phase is stabilized and the stability range of the ferroelectric phase is diminished under pressure.

Polymerization of actin was investigated by a microcalorimetric method at 298.15 K. The calorimetric curves showed that polymerization of actin in the presence of Mg 2+ at the concentration range 1.00–6.00 mM was an exothermic process. There was only one exothermic peak in the thermal curves under each condition. The average molar enthalpy change of actin polymerization was −0.703 kJ mol −1 . It was still exothermic in the presence of K + when the concentration was in the range 25.0–200.0 mM. The average molar enthalpy change of polymerization was −3.03 kJ mol −1 . However, the calorimetric curves contained only one exothermic peak when the K + concentration was lower, in the range 25.0–75.0 mM; there were two peaks, first exothermic and second endothermic, in the calorimetric curves as the K + concentration was higher, in the range 100.0–200.0 mM. The result not only indicated that calorimetric curves of actin polymerization changed with different concentration of K + but also showed that there were some differences between K + - and Mg 2+ -induced polymerization of actin in the presence of 0.1 mM CaCl 2 and 0.2 mM ATP. The ΔG 0 of actin polymerization in each condition was also assayed at 298.15 K and ΔS 0 in the corresponding condition were consequently evaluated from the energy-entropy relation at constant temperature and pressure.

The heat effect produced in the interaction of rabbit muscle F-actin with myosin and its proteolytic fragments (HMM, S 1 ) was measured with an MS-80 Calvet microcalorimeter (Setaram, France). An improved reaction cell of the microcalorimeter was used. There were three thermokinetic peaks in the measured curve of the interaction of myosin with F-actin in the absence of ATP, which were exothermic, endothermic and exothermic in order of appearance. When ATP was added to F-actin before mixing with myosin, the curve remained similar in feature to that in the absence of ATP. But the first peak (exothermic) became smaller and the second and third peaks became larger. There was only one exothermic peak in the measured curve of the interaction between S 1 and F-action. But ATP caused big changes in the curve of their interaction. With addition of ATP to F-action solution before it was mixed with S 1 , there were four thermokinetic peaks in the curve which were endothermic, exothermic, endothermic, and exothermic in order of appearance. The measured curves of interaction between HMM and F-actin in the presence and absence of ATP were quite similar to that of interaction between S 1 and F-action.

The Functional Requirements for Bibliographic Records (hereafter FRBR) has been adopted to address the relationships for bibliographic records and the related aggregate works. However, an approach to transform FRBR-based bibliographic relationships and their patterns into path-based rules for retrieval, navigation, display and data mining in the bibliographic space is still lacking. This study used the FRBR as a basis to analyze bibliographic relationships and their path-based rules. The novel "Harry Potter and the Philosopher's Stone" was used as a case study. Up until now, 87 unique records were retrieved from OCLC's Open WorldCat for analysis. Two specialists in library and information science familiar with FRBR conducted in-depth analysis to achieve inter-reliability agreement. This study generalizes several patterns of path-based rules for associating bibliographic records and outlines related issues for future study.

Multiferroic rare earth manganites attracted recent attention because of the coexistence of different types of magnetic and ferroelectric orders resulting in complex phase diagrams and a wealth of physical phenomena. The coupling and mutual interference of the different orders and the large magnetoelectric effect observed in several compounds are of fundamental interest and bear the potential for future applications in which the dielectric (magnetic) properties can be modified by the onset of a magnetic (dielectric) transition or the application of a magnetic (electric) field. The physical mechanisms of the magnetoelectric effect and the origin of ferroelectric order at magnetic transitions have yet to be explored. We discuss multiferroic phenomena in the hexagonal HoMnO 3 and show that the strong magneto-dielectric coupling is intimately related to the lattice strain induced by unusually large spin-phonon correlations.

An applied magnetic field offers the opportunity to drive new transitions and tune competing interactions in complex materials. Here, we employ magnetoinfrared spectroscopy to probe magnetic ordering-induced local lattice distortions through the series of field-induced transitions in the frustrated Kagom\'e staircase material ${\text{Co}}_{3}{\text{V}}_{2}{\text{O}}_{8}$. These experiments reveal that the most important local lattice distortion involves Co center displacement, mainly along the direction perpendicular to the buckled Kagom\'e planes. This result is important for understanding the microscopic aspects of magnetically driven transitions in functional oxides.

Pollen is an excellent source of actin for biochemical and physiological studies of the actomyosin system in higher plants. We have developed an efficient method to prepare relatively high levels of actin from the pollen of maize (Zea mays L.). The procedures of purification include acetone powder preparation, saturated ammonium sulfate fractionation, diethylaminoethyl-cellulose chromatography, a cycle of polymerization-depolymerization, and Sephacryl S-200 gel filtration. The average yield of actin is 19 milligrams per 100 grams of pollen grains extracted. This is comparable with those of Acanthamoeba castellanii and human platelets. The purified pollen actin is electrophoretically homogeneous and its molecular mass is 42 kilodaltons. The amino acid composition and circular dichroism spectrum of pollen actin are identical to those of muscle actin. The actin purified from pollen is able to polymerize to F-actin. The pollen F-actin activated the activity of the muscle myosin ATPase sevenfold.

The thermodynamic, magnetic, dielectric, and magnetoelectric properties of ${\text{HoFe}}_{3}{({\text{BO}}_{3})}_{4}$ and ${\text{Ho}}_{0.5}{\text{Nd}}_{0.5}{\text{Fe}}_{3}{({\text{BO}}_{3})}_{4}$ are investigated. Both compounds show a second order Ne\'el transition above 30 K and a first-order spin reorientation transition below 10 K. ${\text{HoFe}}_{3}{({\text{BO}}_{3})}_{4}$ develops a spontaneous electrical polarization below the Ne\'el temperature $({T}_{N})$ which is diminished in external magnetic fields. No magnetic-field induced increase of the polarization could be observed in ${\text{HoFe}}_{3}{({\text{BO}}_{3})}_{4}$. In contrast, the solid solution ${\text{Ho}}_{0.5}{\text{Nd}}_{0.5}{\text{Fe}}_{3}{({\text{BO}}_{3})}_{4}$ exhibits both, a spontaneous polarization below ${T}_{N}$ and a positive magnetoelectric effect at higher fields that extends to high temperatures. The superposition of spontaneous polarization, induced by the internal magnetic field in the ordered state, and the magnetoelectric polarizations due to the external field results in a complex behavior of the total polarization measured as a function of temperature and field.