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BackgroundCompared to urban children, children living in rural areas of most countries, including China, are at higher risk of suffering unintentional injuries. Most proven injury prevention interventions, however, are rarely implemented in rural China due to lack of resources. Mobile health interventions are low-cost and easy-to-implement, facilitating implementing injury prevention in resource-limited areas (e.g., rural areas). This study is designed to examine the effectiveness of an app-based intervention for unintentional injury prevention among rural preschoolers in China. MethodsA single-blind, 18-month, parallel-group cluster randomized controlled trial with 1:1 allocation ratio will be implemented in 2 rural areas of China (Yang County, Shaanxi Province, and Shicheng County, Jiangxi Province). In total, at least 3508 rural caregivers of preschoolers aged 3-6 years old who own a smartphone will be recruited from 24 preschools. Clusters will be randomized at the preschool level and allocated to the control group (receiving routine school-based education plus app-based parenting education excluding unintentional injury prevention) or the intervention group (receiving routine school-based education plus app-based parenting education including unintentional injury prevention). External support strategies will be adopted by local partners to minimize user fatigue, non-compliance, and attrition. Data collection will be conducted at baseline and then every 3 months during the 18-month follow-up time period. Intention-to-treat (ITT) data analysis will be implemented. Missing values will be imputed by using the Expectation Maximization algorithm (EM). Generalized estimation equations (GEE) will test the overall effectiveness of the app-based intervention. A per-protocol (PP) sensitivity analysis will be conducted to test the robustness of results. Subgroup analyses will follow the strategies for primary analyses.ResultsThe primary outcome measure is the incidence rate of unintentional injury among preschoolers during the study period. Secondary outcome measures comprise longitudinal changes in caregiver’s attitudes, caregiver-reported supervision behaviors, and caregiver-assessed home environment safety surrounding child unintentional injury prevention in the last week using a standardized audit instrument.ConclusionThe app-based intervention is expected to be feasible and effective over the 18-month intervention period. If the app is demonstrated effective as hypothesized, we will initiate processes to generalize and popularize it broadly to rural child caregivers across China. Trial registrationChiCTR2000037606, registered on August 29, 2020.

Background Media reports may influence criminal behavior that leads to violence against doctors. Little is known about the characteristics of media reports on patient violence against their doctors. Methods Based on the international and domestic guidelines for media reports, we developed a checklist to assess adherence of Chinese media reports to recommended principles. We adopted a seed approach to search influential violence stories. Reports were assessed using the unified coding scheme by different coders; the conflicts between raters were resolved through discussion. Results In total, 17,222 media reports were captured; 788 met inclusion criteria. 49.5% and 52.7% of 788 included reports mentioned real and complete names of writer and editor, respectively. of 329 reports including quotes or opinions from doctors, patients, and hospital administrative personnel, only 15.79%, 11.25% and 18.62% respectively specified they had obtained the consent of the interviewees. 21.6% of reports including all specifically-coded details of the violent acts against doctors (time, place, methods and perpetrators), and 43.5% of reports included some details. Only 18.7% of media reports offered suggestions for seeking professional help in case doctors are threatened by violence and 11.3% offered contact information for third parties who mediate doctor-patient conflicts. Conclusion Most internet-based media reports did not strictly follow media recommendations from authoritative bodies. Strong efforts are needed to require journalists to increase adherence so risk of violence against doctors is reduced in China. Learning Outcomes Most Chinese internet-based media sources did not appropriately report stories concerning violence against doctors.

Improper, unprofessional, or misleading media reports about violence against medical care providers (typically doctors and nurses) may provoke copycat incidents. To examine whether media reports about violence against medical care providers in China follow professional journalism recommendations, we identified 10 influential incidents of violence against medical care providers in China through a systematic strategy and used standardized internet-based search techniques to retrieve media reports about these events from 2007–2017. Reports were evaluated independently by trained coders to assess adherence to professional journalism recommendations using a 14-item checklist. In total, 788 eligible media reports were considered. Of those, 50.5% and 47.3%, respectively, failed to mention the real and complete names of the writer and editor. Reports improperly mentioned specific details about the time, place, methods, and perpetrators of violence in 42.1%, 36.4%, 45.4%, and 54.6% of cases, respectively. Over 80% of reports excluded a suggestion to seek help from professional agencies or mediation by a third party and only 3.8% of reports mentioned the perspectives of all three key informants about an event: medical care providers, patients, and hospital administrators. Of those that mentioned medical care providers, patient, and/or hospital administrator perspectives, less than 20% indicated they had obtained the interviewee’s consent to include their perspective. We concluded that most reports about violence against medical care providers in the Chinese media failed to strictly follow reporting recommendations from authoritative media bodies. Efforts are recommended to improve adherence to professional guidelines in media reports about violence against medical care providers in China, as adherence to those guidelines is likely to reduce future violent events against medical care providers like doctors and nurses.

HVAC is a part of building equipment. The quality of HVAC engineering in buildings is directly related to whether buildings can be directly put into operation. Based on the importance of HVAC construction, we must master the relevant construction technology and analyze the difficulties in the construction, and ensure the overall level of the HVAC construction as far as possible. This article analyzes the difficult points of construction HVAC construction, focuses on the key countermeasures to deal with these problems, and provides a quality assurance for the construction of HVAC projects in China's construction projects.

In this article, the Bargmann system related to the spectral problem (∂2+q∂+∂q+r)φ=λφ+λφxis discussed. By the Euler–Lagrange equations and the Legendre transformations, a suitable Jacobi–Ostrogradsky coordinate system is obtained. So the Lax pairs of the aforementioned spectral problem are nonlinearised. A new kind of finite-dimensional Hamilton system is generated. Moreover, the involutive solutions of the evolution equations for the infinite-dimensional soliton system are derived.

We report an unusual magnetic ground state in single-crystal, double-perovskite $\mathrm{B}{\mathrm{a}}_{2}\mathrm{YIr}{\mathrm{O}}_{6}$ and Sr-doped $\mathrm{B}{\mathrm{a}}_{2}\mathrm{YIr}{\mathrm{O}}_{6}$ with $\mathrm{I}{\mathrm{r}}^{5+}(5{d}^{4})$ ions. Long-range magnetic order below 1.7 K is confirmed by dc magnetization, ac magnetic susceptibility, and heat-capacity measurements. The observed magnetic order is extraordinarily delicate and cannot be explained in terms of either a low-spin $S=1$ state, or a singlet ${J}_{\mathrm{eff}}=0$ state imposed by the spin-orbit interactions (SOI). Alternatively, the magnetic ground state appears consistent with a SOI that competes with comparable Hund's rule coupling and inherently large electron hopping, which cannot stabilize the singlet ${J}_{\mathrm{eff}}=0$ ground state. However, this picture is controversial, and conflicting magnetic behavior for these materials is reported in both experimental and theoretical studies, which highlights the intricate interplay of interactions that determine the ground state of materials with strong SOI.

The perovskite manganite EuMnO3 is known to be a compound with a narrow e g-band width due to small ionic radius of Eu3+ compared to La3+. The Eu1 −x Sr x MnO3 compounds show complex magnetic properties, depending on the Sr concentration x. We have carried out 55Mn spin-echo nuclear magnetic resonance (NMR) measurements on polycrystalline Eu1−x Sr x MnO3 (0 ≤ x≤ 0.5) compounds at 4.2 or 1.4 K in order to clarify the microscopic local magnetic state of the Mn ions. NMR spectra have been observed in the frequency range from ∼250 MHz to ∼400 MHz. For the A-type antiferromagnetic EuMnO3, the resonance frequency is about 260 MHz, which is much lower than that observed for Mn3+ in La1−x Sr x MnO3. For 0.1 ≤ x ≤ 0.4, the resonance lines corresponding to Mn4+ and Mn3+ have been observed at about 315 MHz and 390 MHz, respectively. Furthermore, the spectra originating from Mn2+ have been observed around 590 MHz for 0.1 ≤ x ≤ 0.4. For Eu0.5Sr0.5MnO3, the NMR spectrum spreads widely with several distinct peaks in the frequency range from 250 MHz to 410 MHz, which shows that the compound is in an inhomogeneous state due to competition between the antiferromagnetic and the ferromagnetic states.

The orthorhombic perovskite SrIrO3 is a semimetal, an intriguing exception in iridates where the strong spin-orbit interaction coupled with electron correlations tends to impose a novel insulating state. We report results of our investigation of bulk single-crystal Sr0.94Ir0.78O2.68 or Ir-deficient, orthorhombic perovskite SrIrO3. It retains the same crystal structure as stoichiometric SrIrO3 but exhibits a sharp, simultaneous antiferromagnetic (AFM) and metal-insulator (MI) transition at 185 K. Above it, the basal-plane resistivity features an extended regime of almost linear-temperature dependence up to 800 K but the strong electronic anisotropy renders an insulating behavior in the out-of-plane resistivity. The Hall resistivity undergoes an abrupt sign change and grows below 40 K, which along with the Sommerfeld constant of 20 mJ/mole K2 suggests a multiband effect. All results including our first-principles calculations underscore a delicacy of the metallic state in SrIrO3 that is in close proximity to an AFM insulating state. The contrasting ground states in isostructural Sr0.94Ir0.78O2.68 and SrIrO3 illustrate a critical role of even slight lattice distortions in rebalancing the ground state in the iridates. Finally, the observed simultaneous AFM and MI transitions reveal a direct correlation between the magnetic transition and formation of a charge gap in the iridate, which is conspicuously absent in Sr2IrO4.

Hexagonal $\mathrm{BaIr}{\mathrm{O}}_{3}$ is a magnetic insulator driven by the spin-orbit interaction (SOI), whereas $\mathrm{BaRu}{\mathrm{O}}_{3}$ is an enhanced paramagnetic metal. Our investigation of structural, magnetic, transport, and thermal properties reveals that substitution of $\mathrm{R}{\mathrm{u}}^{4+} (4{d}^{4})$ ions for $\mathrm{I}{\mathrm{r}}^{4+} (5{d}^{5})$ ions in $\mathrm{BaIr}{\mathrm{O}}_{3}$ reduces the magnitudes of the SOI and a monoclinic structural distortion and rebalances the competition between the SOI and the lattice degrees of freedom to render an evolution from a magnetic insulting state to a robust metallic state. The central findings of this paper are as follows: (1) light Ru doping $(0lx\ensuremath{\le}0.15)$ prompts simultaneous, precipitous drops in both the magnetic ordering temperature ${T}_{\mathrm{N}}$ and the electrical resistivity, and (2) heavier Ru doping $(0.41\ensuremath{\le}x\ensuremath{\le}0.9)$ induces a robust metallic state without any long-range magnetic order. All results suggest a critical role of the lattice degrees of freedom in determining the ground state in the heavy transition-metal oxides.

YFeO $_{\boldsymbol 3}$ and other rare earth substituted crystals with distorted orthorhombic pervoskite-like structure (space group, Pbnm) have attracted much attention due to their remarkable magnetic properties of primary significance for technological applications. In the present work, the floating zone growth of YFeO $_{\boldsymbol 3}$ crystals has been systematically investigated and high quality YFeO $_{\boldsymbol 3}$ crystal was obtained by optimized process. The magnetic properties of YFeO $_{\boldsymbol 3}$ crystal were investigated, and it indicated the high magneto-optical property in YFeO $_{\boldsymbol 3}$ crystals with specific orientation due to its anisotropy. YFeO $_{\boldsymbol 3}$ crystals display superior performance in the application magneto-optical current sensors and fast latching optical switches.

The rare-earth orthoferrites RFeO3 (R, rare-earth element) crystallize in an orthorhombic distorted perovskite structure. RFeO3 compounds exhibit interesting physical and chemical properties because of their ionic and electronic defects. Polycrystalline nano-sized RFeO3 powders were synthesized by the sol–gel combustion method. X-ray powder diffraction indicated that nanocrystalline powders were single ReFeO3 phase, which are agglomerated with average crystallite size of 60–90 nm estimated with the Scherrer’s equation. Magnetic measurements were carried out using a superconducting quantum interference device magnetometer. The influence on hysteresis curve of electronic structure of rare-earth element was investigated for R = Y, La and Nd. Varied magnetic behaviors were observed in these compounds, which are believed to be associated with the different interactions of Fe and rare earths.

The properties of light rare earth Nd substitution for heavy rare earth Dy in Dy3Fe5O12 (DyIG) garnet ferrite have been studied. The NdxDy3–xFe5O12 (x = 0, 0.25, 0.5, 0.75 and 1) (Nd:DyIG) garnet powders were prepared by sol–gel autocombustion followed by heat treatment. The structure and the magnetic properties of the annealed powders were measured with X-ray diffraction (XRD), the Fourier Transform Infrared (FT-IR) and the Physical Properties Measurement System (PPMS) techniques. The experimental results indicate that a single Nd:DyIG garnet phase structure can be obtained after the samples annealed above 800 °C. With the Nd substitution content increasing, the average lattice constants of the sample, the a−d super-exchange interaction strengthens and the magnetization of unit cell increase. The maximum saturation magnetization is 13.86 emu/g for x = 1, and coercive force is about 136 Oe, for x = 0.75. The reason of increasing in magnetization with Nd substitution is also discussed.

$\mathrm{S}{\mathrm{r}}_{2}\mathrm{Ir}{\mathrm{O}}_{4}$ is a magnetic insulator assisted by strong spin-orbit coupling (SOC) whereas $\mathrm{S}{\mathrm{r}}_{2}\mathrm{Ru}{\mathrm{O}}_{4}$ is a $p$-wave superconductor. The contrasting ground states have been shown to result from the critical role of the strong SOC in the iridate. Our investigation of structural, transport, and magnetic properties reveals that substituting $4d\phantom{\rule{0.16em}{0ex}}\mathrm{R}{\mathrm{u}}^{4+}(4{d}^{4})$ ions for $5d\mathrm{I}{\mathrm{r}}^{4+}(5{d}^{5})$ ions in $\mathrm{S}{\mathrm{r}}_{2}\mathrm{Ir}{\mathrm{O}}_{4}$ directly adds holes to the ${t}_{2g}$ bands, reduces the SOC, and thus rebalances the competing energies in single-crystal $\mathrm{S}{\mathrm{r}}_{2}\mathrm{I}{\mathrm{r}}_{1\ensuremath{-}x}\mathrm{R}{\mathrm{u}}_{x}{\mathrm{O}}_{4}$. A profound effect of Ru doping driving a rich phase diagram is a structural phase transition from a distorted $I{4}_{1}/acd$ to a more ideal $I4/mmm$ tetragonal structure near $x=0.50$ that accompanies a phase transition from an antiferromagnetic-insulating state to a paramagnetic-metal state. We also make a comparison with Rh-doped $\mathrm{S}{\mathrm{r}}_{2}\mathrm{Ir}{\mathrm{O}}_{4}$, highlighting important similarities and differences.

In this paper, we report structural, magnetic, transport, and thermal properties of single-crystal Ca2Ru1-xIrxO4(0≤x≤0.65). Ca2RuO4 is a structurally driven Mott insulator with a metal-insulator transition at TMI=357K, which is well separated from antiferromagnetic order at TN=110K. Substitution of a 5d element, Ir, for Ru enhances spin-orbit coupling and locking between the structural distortions and magnetic moment canting. Ir doping intensifies the distortion or rotation of Ru/IrO6 octahedra and induces weak ferromagnetic behavior along the c axis. In particular, Ir doping suppresses TN but concurrently causes an additional magnetic ordering TN2 at a higher temperature up to 210 K for x=0.65. The effect of Ir doping sharply contrasts with that of 3d-element doping such as Cr, Mn, and Fe, which suppresses TN and induces unusual negative volume thermal expansion. Finally, the stark difference between 3d- and 5d-element doping underlines a strong magnetoelastic coupling inherent in the Ir-rich oxides.

We have synthesized and studied single-crystal $\mathrm{B}{\mathrm{a}}_{5}\mathrm{AlI}{\mathrm{r}}_{2}{\mathrm{O}}_{11}$ that features dimer chains of two inequivalent octahedra occupied by tetravalent $\mathrm{I}{\mathrm{r}}^{4+}(5{d}^{5})$ and pentavalent $\mathrm{I}{\mathrm{r}}^{5+}(5{d}^{4})$ ions, respectively. $\mathrm{B}{\mathrm{a}}_{5}\mathrm{AlI}{\mathrm{r}}_{2}{\mathrm{O}}_{11}$ is a Mott insulator that undergoes a subtle structural phase transition near ${T}_{S}\phantom{\rule{0.16em}{0ex}}=210\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ and a magnetic transition at ${T}_{M}\phantom{\rule{0.16em}{0ex}}=4.5\phantom{\rule{0.16em}{0ex}}\mathrm{K}$; the latter transition is surprisingly resistant to applied magnetic fields ${\ensuremath{\mu}}_{o}H\ensuremath{\le}12\phantom{\rule{0.16em}{0ex}}\mathrm{T}$ but more sensitive to modest applied pressure $(d{T}_{M}/dp\ensuremath{\approx}+0\phantom{\rule{0.16em}{0ex}}.61\phantom{\rule{0.16em}{0ex}}\mathrm{K}/\mathrm{GPa})$. All results indicate that the phase transition at ${T}_{S}$ signals an enhanced charge order that induces electrical dipoles and strong dielectric response near ${T}_{S}$. It is clear that the strong covalency and spin-orbit interaction (SOI) suppress double exchange in Ir dimers and stabilize a novel magnetic state that is neither $S=3/2$ nor $J=1/2$, but rather lies in an ``intermediate'' regime between these two states. The novel behavior of $\mathrm{B}{\mathrm{a}}_{5}\mathrm{AlI}{\mathrm{r}}_{2}{\mathrm{O}}_{11}$ therefore provides unique insights into the physics of SOI along with strong covalency in competition with double-exchange interactions of comparable strength.

We synthesize and study single crystals of the layered honeycomb lattice Mott insulators ${\mathrm{Na}}_{2}{\mathrm{RuO}}_{3}$ and ${\mathrm{Li}}_{2}{\mathrm{RuO}}_{3}$ with magnetic ${\mathrm{Ru}}^{4+}(4{d}^{4})$ ions. The newly found ${\mathrm{Na}}_{2}{\mathrm{RuO}}_{3}$ features a nearly ideal honeycomb lattice and orders antiferromagnetically at 30 K. Single crystals of ${\mathrm{Li}}_{2}{\mathrm{RuO}}_{3}$ adopt a honeycomb lattice with either $C2/m$ or more distorted $P{2}_{1}/m$ below 300 K, depending on detailed synthesis conditions. We find that ${\mathrm{Li}}_{2}{\mathrm{RuO}}_{3}$ in both structures hosts a well-defined magnetic state, in contrast to the singlet ground state found in polycrystalline ${\mathrm{Li}}_{2}{\mathrm{RuO}}_{3}$. A phase diagram generated based on our results uncovers a new, direct correlation between the magnetic ground state and basal-plane distortions in the honeycomb ruthenates.

We employ a combination of pulsed- and continuous-wave polarized terahertz spectroscopy techniques to probe temperature-dependent spin waves in the antiferromagnet $\mathrm{Nd}\mathrm{Fe}{\mathrm{O}}_{3}$. Our optical data span 1.6--467 K and reveal a conspicuous spin reorientation between 110 and 170 K, during which the lower-energy mode softens completely. Complementary inelastic neutron scattering reveals that the frequencies of the optically excited spin waves are consistent with a temperature-variable spin gap in the low-energy spin-wave dispersion of $\mathrm{Nd}\mathrm{Fe}{\mathrm{O}}_{3}$. The result links the temperature dependence of the spin waves to a dynamic in-plane anisotropy. The magnetic anisotropy is calculated based on the results of the optical measurements. The change observed in the anisotropy energy along the $a$ and $c$ crystal axes suggests that the spin reorientation evident in $\mathrm{Nd}\mathrm{Fe}{\mathrm{O}}_{3}$ is driven by temperature-dependent in-plane anisotropy.

We synthesize and study single crystals of a new double-perovskite Sr2YIrO6. Despite two strongly unfavorable conditions for magnetic order, namely, pentavalent Ir5+(5d4) ions which are anticipated to have Jeff=0 singlet ground states in the strong spin-orbit coupling (SOC) limit and geometric frustration in a face-centered cubic structure formed by the Ir5+ ions, we observe this iridate to undergo a novel magnetic transition at temperatures below 1.3 K. We provide compelling experimental and theoretical evidence that the origin of magnetism is in an unusual interplay between strong noncubic crystal fields, local exchange interactions, and "intermediate-strength" SOC. Sr2YIrO6 provides a rare example of the failed dominance of SOC in the iridates.

We report the successful synthesis of single crystals of the layered iridate (Na${}_{1\ensuremath{-}x}$Li${}_{x}$)${}_{2}$IrO${}_{3}$, $0\ensuremath{\le}x\ensuremath{\le}0.9$, and a thorough study of its structural, magnetic, thermal, and transport properties. This compound allows a controlled interpolation between Na${}_{2}$IrO${}_{3}$ and Li${}_{2}$IrO${}_{3}$, while maintaining the quantum magnetism of the honeycomb Ir${}^{4+}$ planes. The measured phase diagram demonstrates a suppression of the N\'eel temperature ${T}_{N}$ at an intermediate $x$, indicating that the magnetic orders in Na${}_{2}$IrO${}_{3}$ and Li${}_{2}$IrO${}_{3}$ are distinct. X-ray data show that for $x\ensuremath{\approx}0.7$, when ${T}_{N}$ is suppressed the most, the honeycomb structure is least distorted, leading to the speculation that at this intermediate doping of the material is closest to the spin liquid that has been sought after in Na${}_{2}$IrO${}_{3}$ and Li${}_{2}$IrO${}_{3}$. By analyzing our magnetic data with a single-ion theoretical model we also show that the trigonal splitting on the Ir${}^{4+}$ ions changes sign from Na${}_{2}$IrO${}_{3}$ to Li${}_{2}$IrO${}_{3}$.

We present a study of exchange bias generated at the interface between a polycrystalline Co film sputtered on a cleavage plane of single-crystal Ca${}_{2}$Ru${}_{0.98}$Fe${}_{0.02}$FeO${}_{4}$. The exchange bias is accompanied by an extremely large vertical magnetization shift that is characterized by 60$%$ of the saturation magnetization in a 70-kOe cooling field. This phenomenon is seldom observed in other heterostructures. The effects of cooling-field amplitude and temperature on the exchange bias indicate that the magnetization shift results from a ferromagnetic contribution of canted moments in Ca${}_{2}$Ru${}_{0.98}$Fe${}_{0.02}$O${}_{4}$. A Type-I training effect is also observed, in which the hysteresis loop shrinks from both sides with cycling of the applied field.

Sr${}_{3}$Ir${}_{2}$O${}_{7}$ exhibits a novel ${J}_{\mathrm{eff}}=\frac{1}{2}$ insulating state that features a splitting between ${J}_{\mathrm{eff}}=\frac{1}{2}$ and $\frac{3}{2}$ bands due to spin-orbit interaction. We report a metal-insulator transition in Sr${}_{3}$Ir${}_{2}$O${}_{7}$ via either dilute electron doping (La${}^{3+}$ for Sr${}^{2+}$) or application of high pressure up to 35 GPa. Our study of single-crystal Sr${}_{3}$Ir${}_{2}$O${}_{7}$ and (Sr${}_{1\ensuremath{-}x}$La${}_{x}$)${}_{3}$Ir${}_{2}$O${}_{7}$ reveals that application of high hydrostatic pressure $P$ leads to a drastic reduction in the electrical resistivity by as much as six orders of magnitude at a critical pressure ${P}_{C}$ $=$ 13.2 GPa, manifesting a closing of the gap; but further increasing $P$ up to 35 GPa produces no fully metallic state at low temperatures, possibly as a consequence of localization due to a narrow distribution of bonding angles \ensuremath{\theta}. In contrast, slight doping of La${}^{3+}$ ions for Sr${}^{2+}$ ions in Sr${}_{3}$Ir${}_{2}$O${}_{7}$ readily induces a robust metallic state in the resistivity at low temperatures; the magnetic ordering temperature is significantly suppressed but remains finite for (Sr${}_{0.95}$La${}_{0.05}$)${}_{3}$Ir${}_{2}$O${}_{7}$ where the metallic state occurs. The results are discussed along with comparisons drawn with Sr${}_{2}$IrO${}_{4}$, a prototype of the ${J}_{\mathrm{eff}}=\frac{1}{2}$ insulator.

We observe an unusual combination of normal and superconducting state properties without any signature of strong spin fluctuations in single-crystal Ir3Te8. The electrical resistivity does not saturate by 700 K but exhibits a low-resistivity ratio, and it exhibits two extended linear regimes (approximately 20-330 and 370-700 K) with the same slope, separated by a small hysteretic interval marking a strong first-order phase transition from cubic to rhombohedral lattice symmetry at T-S = 350 K. The electronic heat-capacity coefficient (11 mJ mol(-1) K-2) is consistent with a net diamagnetic, rather than a Pauli paramagnetic, normal state that yields to superconductivity below a critical temperature T-C = 1.8 K. The size of the heat-capacity jump near T-C indicates bulk superconductivity.

We report an experimental and computational study of single-crystal NdFeO${}_{3}$, which features two inequivalent magnetic sublattices, namely, Fe and Nd sublattices that are coupled in an antiparallel fashion. This paper reveals that a strong interaction between 3$d$ and 4$f$ electrons of the two sublattices along with a spin-lattice coupling drives an extremely interesting magnetic state that is highly sensitive to the orientation and history of weak magnetic field. The following phenomena are particularly remarkable: (1) sharply contrasting magnetization $M$($T$) along the $a$ and $c$ axes; (2) a first-order spin switching along the $a$ axis below 29 K when the system is zero-field-cooled; and (3) a progressive magnetization reversal when the system is field-cooled. The intriguing magnetic behavior is captured in our first-principles density functional theory calculations.

To predict the time series, a model combining the wavelet transform and support vector machine is set up. First, wavelet transform is applied to decompose the series into sub series with different time scales. Then, the SVM is applied to the sub series to simulate and predict future behavior. And then by the inverse wavelet transform, the series are reconstructed, which is the prediction for the time series. The prediction precision of the new model is higher than that of the SVM model and the artificial neural network model for many processes, such as runoff, precipitation, temperature. And the new Wavelet-SVM model is applied to analyze the month temperature time series of city Tangshan for example. The universal applicability of the new Wavelet-SVM model and the improvement direction are discussed in the end.

The spin reorientation of ErFeO3 that spontaneously occurs at low temperature has been previously determined to be a process involving the continuous rotation of Fe3+ spins. In this work, the dynamic process of spin reorientation in ErFeO3 single crystal has been investigated by AC susceptibility measurements at various frequencies and static magnetic fields. Interestingly, two completely discontinuous steps are induced by a relatively large static magnetic field due to the variation in the magnetic anisotropy during this process. It provides deeper insights into the intriguing magnetic exchange interactions which dominate the sophisticated magnetic phase transitions in the orthoferrite systems.

Polycrystalline sample FeSe was synthesized by a self-flux solution method which shows a zero resistance temperature up to 10.9 K and a Tconset (90% \rhon, \rhon: normal state resistivity) up to 13.3 K. The decrease of superconducting transition temperature by heat treatment indicates that internal crystallographic strain which plays the same effect as external pressure is the origin of its high Tc. The fluctuation conductivity was studied which could be well described by 3D Aslamazov-Larkin (AL) power law. The estimated value of coherence length \xic=9.2 \AA is larger than the distance between conducting layers (~6.0 \AA), indicating the three-dimensional nature of superconductivity in this compound. 5 figures ispartof: Journal of Applied Physics vol:108 issue:5 status: published

The exchange bias phenomena associated with the magnetic glass state at low temperatures in Gd5Ge4 are studied. The exchange bias effect originates from the exchange coupling between the ferromagnetic islands and antiferromagnetic matrix in the magnetic glass state. It is found that the exchange bias in Gd5Ge4 is strongly dependent on the measuring field and the cooling field, which indicates that the antiferromagnetic matrix can be easily transformed into ferromagnetic phase under the applied field. The temperature dependence of the exchange bias field shows that the fluctuation of the temperature has less effect on the exchange bias in the low temperature range.

Systematic AC and DC magnetic measurements were carried out to investigate the magnetic properties of La1-xCaxMn0.90Cu0.10O3 (x=0.05–0.30) system. A striking paramagnetism (PM) to ferromagnetism (FM) transition is observed at the FM ordering temperature TC. Below TC, the samples with x≤.0.20 show a visible unexpected drop in zero-field cooled (ZFC) DC magnetization curves near 100 K, which is believed to be associated with the domain wall pinning effects. As for the sample with x=0.30, there is no anomalous behavior near 100 K, while another different magnetic phase transition is shown up below 50 K in both FC and ZFC curves. Detailed experimental results show that the phenomenon is resulted from the phase competition rather than solely magnetic interactions.

Exchange bias phenomena and the glassy behavior were investigated in low doped La1-xSrxCoO3 cobaltites. Both vertical and horizontal shifts were observed in the hysteresis loops, and the former one vanishes at a critical magnetic field about 40 kOe, the latter one persists to the end. Combining with R – H loop measurement, which shows asymmetric both in resistivity maximum and its corresponding fields, we ascribe the horizontal shifts to the exchange coupling between the surface spin disorder region and ferromagnetic clusters; and the vertical one to the incompletely reversal of ferromagnetic spins. The dc magnetization at low fields and high fields were systematically investigated, and the spin glass region was approved to exist robustly.