Dynamic spin-lattice coupling and nematic fluctuations in NaFeAs

We use inelastic neutron scattering to study acoustic phonons and spin excitations in single crystals of NaFeAs, a parent compound of iron pnictide superconductors. NaFeAs exhibits a tetragonal-to-orthorhombic structural transition at $T_s\approx 58$ K and a collinear antiferromagnetic (AF) order at $T_N\approx 45$ K. While longitudinal and out-of-plane transverse acoustic phonons behave as expected, the in-plane transverse acoustic phonons reveal considerable softening on cooling to $T_s$, and then harden on approaching $T_N$ before saturating below $T_N$. In addition, we find that spin-spin correlation lengths of low-energy magnetic excitations within the FeAs layer and along the $c$-axis increase dramatically below $T_s$, and show weak anomaly across $T_N$. These results suggest that the electronic nematic phase present in the paramagnetic tetragonal phase is closely associated with dynamic spin-lattice coupling, possibly arising from the one-phonon-two-magnon mechanism

Bone Metastases in Patients with Prostate Cancer: A Literature Review

Prostate cancer is a major threat to men's health around the world. Bone is the most common metastasis site in patients with prostate cancer, which may lead to bone pain, pathological fracture and spinal cord compression, and it is related to various physiological or pathological factors such as age, physical condition, and previous treatment. The occurrence of bone-related events will seriously affect the quality of life of patients. In recent years, more and more people are concerned about bone metastasis of prostate cancer. Some important international cancer organizations have issued guidelines for the diagnosis and treatment of prostate cancer with bone metastasis. However, Clinicians still have some misunderstandings about bone metastasis of prostate cancer, especially selection of therapeutic strategies and the screening of appropriate drugs. Nowadays, the therapeutic strategies of prostate cancer with bone metastases mainly include primary lesions and bone metastases lesions. The former include surgery, radiotherapy, endocrine therapy, chemotherapy, immunotherapy, radiofrequency ablation and so on. And the later is made up of bone modification drug, radiopharmaceutical, lifestyle adjustment, and symptomatic analgesic treatment. The purpose of this review is to summarize the status and progression of bone metastasis in prostate cancer and to explore the best diagnosis and therapeutic strategies

An attitude determination method based on convected Euler angle error model for SINS/CNS integrated system

The attitude determination method plays an important role in SINS/CNS integrated system for spacecraft. Since the misalignment angels are indirect measurements, the misalignment angle model used in the existing attitude determination method can cause transformation errors. To solve the problem, an attitude determination method based on convected Euler angle error model for SINS/CNS integrated system is proposed. The attitude error propagation is analyzed, and the convected Euler angle error model is derived. Furthermore, the state equation of SINS/CNS integrated system is established. The Kalman filter estimates and compensates the Euler angle errors. Finally, simulation results verified that the proposed method can improve the attitude accuracy compared to the conventional misalignment angle method

Axial behaviour of prestressed high strength steel tubular members

The axial behaviour of high strength steel tubular elements with internal prestress-ing cables, representing the chord members in prestressed trusses, is investigated herein. Ex-periments on tensile and compressive members were carried out, with the key variables exam-ined being the steel grade (S460 and S690), the initial prestress level and the presence of grout. FE models were developed to replicate the experiments and generate parametric results. The presence of cables was shown to enhance the tensile load-carrying capacity of the mem-bers while the application of prestress extended the elastic range. In compression, prestressing was detrimental, and a modified Perry-Robertson design approach was examined

Restoring the buyer–seller relationship through online return shipping: The role of return shipping method and return shipping fee

Relationships with consumers are critical to the success of online sellers. Online returns can detrimentally influence buyer–seller relationships and, thus, online sellers should carefully approach online returns to restore their relationship with consumers. Returns due to consumer satisfaction-related reasons are a significant and inevitable part of e-commerce. This article focuses on how online sellers deal with the method and the fee aspects of their return shipping policy to improve buyer–seller relationships. We also studied the effects of return shipping policies on several pivotal consumer perceptions and repurchase intentions. A two-factor (integrated return shipping vs. separated return shipping; free return shipping vs. fee return shipping), between-subject experiment was conducted. This research revealed that both using an integrated return shipping method and offering free return shipping can lead to a better buyer–seller relationship and improve other consumer responses. No interaction effect was found between the two factors

Generation of subcycle isolated attosecond pulses by pumping ionizing gating

We present a novel approach named as pumping ionizing gating (PIG) for the generation of isolated attosecond pulses (IAPs). In this regime, a short laser is used to ionize a pre-existing gas grating, creating a fast-extending plasma grating(FEPG) having an ionization front propagating with the velocity of light. A low-intensity long counterpropagating pump pulse is then reflected by a very narrow region of the ionization front, only where the Bragg conditions for resonant reflection is satisfied. Consequently, the pump reflection is confined within a sub-cycle region called PIG, and forms a wide-band coherent IAP in combination with the frequency up-conversion effect due to the plasma gradient. This approach results in a new scheme to generate IAPs fromlong picosecond pump pulses. Three-dimensional (3D) simulations show that a 1.6-ps, 1-{\mu}m pump pulse can be used to generate a 330 as laser pulse with a peak intensity approximately 33 times that of the pump and a conversion efficiency of around 0.1%.These results highlight the potential of the PIG method for generating IAPs with high conversion efficiency and peak intensity.Comment: It provides a new way to generate isolated attosecond pulse(IAP) by a picosecond pump, which has a protential to boost the IAP energy to joule leve

Evaluation of Fermentation Dynamics and Structural Carbohydrate Degradation of Napiergrass Ensiled with Additives of Urea and Molasses

This study examined the effects of urea and molasses on fermentation dynamics and structural carbohydrate degradation of Napiergrass (Pennisetum purpureum Schumach), which was ensiled in laboratory silos for 3, 7, 14, and 30 days at the ambient temperature. The treatments were additions (fresh weight basis) of: no molasses or urea (control), no molasses and 0.4% urea (U), 4% molasses and 0% urea (M), 4% molasses and 0.4% urea (MU). The results showed that the control group produced an unstable fermentation. U silage always had smallest amount of lactic acid and highest levels of pH, acetic acid, butyric acid and ammonia nitrogen. Compared with control, both M and MU increased water soluble carbohydrate contents which promoted lactic acid fermentation domination, but MU did not restrain clostridial fermentation. After 30 days of ensiling, compared with the control, both M and MU lowered structural carbohydrate contents, and U lowered crude protein content but MU increased this parameter. It was concluded that the combination of 4% molasses with 0.4% urea could improve the fermentation and nutritive qualities of Napiergrass but was not sufficient to inhibit clostridial fermentation

The variation changes of the precipitation – runoff relationship

The variation of the rainfall-runoff relationship t will lead to the disappearance of the consistency assumption of engineering hydrology, which will influence the planning, design, operation management and development and utilization of water resources. Therefore, the variation diagnosis of the rainfall -runoff relationship has become one of the hot topics and key issues in this area. In this study, the variation points of the precipitation-runoff relationship are defined, the difference between the variation point and the mutation point is distinguished, and the method of variation classification is proposed based on the the dimensionless mean and variation coefficients. Then, a comprehensive diagnosis system of the rainfall-runoff relationship variation is constructed on the basis of systematically summarying and analyzing of the diagnosis method of rainfall - runoff relationship variation at home and abroad. Taking the Weihe River Basin as a case study, the comprehensive diagnosis system is verified by applying it to test the change point the annual runoff time series at the Huaxian hydrological station. And the results show that the comprehensive diagnosis method proposed in this paper is scientific and reasonable