A comparison of different cluster mass estimates: consistency or discrepancy ?

Rich and massive clusters of galaxies at intermediate redshift are capable of magnifying and distorting the images of background galaxies. A comparison of different mass estimators among these clusters can provide useful information about the distribution and composition of cluster matter and their dynamical evolution. Using a hitherto largest sample of lensing clusters drawn from literature, we compare the gravitating masses of clusters derived from the strong/weak gravitational lensing phenomena, from the X-ray measurements based on the assumption of hydrostatic equilibrium, and from the conventional isothermal sphere model for the dark matter profile characterized by the velocity dispersion and core radius of galaxy distributions in clusters. While there is an excellent agreement between the weak lensing, X-ray and isothermal sphere model determined cluster masses, these methods are likely to underestimate the gravitating masses enclosed within the central cores of clusters by a factor of 2--4 as compared with the strong lensing results. Such a mass discrepancy has probably arisen from the inappropriate applications of the weak lensing technique and the hydrostatic equilibrium hypothesis to the central regions of clusters as well as an unreasonably large core radius for both luminous and dark matter profiles. Nevertheless, it is pointed out that these cluster mass estimators may be safely applied on scales greater than the core sizes. Namely, the overall clusters of galaxies at intermediate redshift can still be regarded as the dynamically relaxed systems, in which the velocity dispersion of galaxies and the temperature of X-ray emitting gas are good indicators of the underlying gravitational potentials of clusters.Comment: 16 pages with 7 PS figures, MNRAS in pres

Anomalous pressure behavior of tangential modes in single-wall carbon nanotubes

Using the molecular dynamics simulations and the force constant model we have studied the Raman-active tangential modes (TMs) of a (10, 0) single-wall carbon nanotube (SWNT) under hydrostatic pressure. With increasing pressure, the atomic motions in the three TMs present obvious diversities. The pressure derivative of E1g, A1g, and E2g mode frequency shows an increased value (), a constant value (), and a negative value () above 5.3 GPa, respectively. The intrinsic characteristics of TMs consumedly help to understand the essence of the experimental T band of CNT. The anomalous pressure behavior of the TMs frequencies may be originated from the tube symmetry alteration from D10h to D2h then to C2h.Comment: 15 pages, 3 pages, submitted to Phys. Rev.

氯氮平所致体位性低血压的观察及护理

Objective: To observe the effect of clozapine induced hypotension in patients with postural hypotension, and nursing effectively prevent the occurrence of postural hypotension. Methods: 120 patients with schizophrenia who were treated by clozapine in our hospital in January 2015, June 2015, were randomly selected and blood pressure was analyzed by clinical observation. Results: In the 120 cases of the patients with schizophrenia, the incidence of postural hypotension is much associated with the length of time, drug dosage size, the patient's age, lifestyle, diet, sleep quality and so on. Conclusion: On the basis of the observation of patients taking clozapine, the health education can effectively prevent the postural hypotension. 目的  观察氯氮平致体位性低血压的情况，做好预防及护理，有效防止体位性低血压的发生。方法  对2015年1—6月在我病房住院服用氯氮平治疗的精神分裂症患者随机抽取120例，通过临床观察测定患者血压情况进行调查分析。结果  在120例住院的精神分裂症患者中，体位性低血压的发生与用药时间长短，药物剂量大小，患者的年龄、生活习惯、饮食睡眠质量等有关。结论  对服用氯氮平的患者，做好基础护理观察，同时开展健康教育，能有效地防止体位性低血压

Enhanced stability of Zr-doped Ba(CeTb)O3−δ-Ni cermet membrane for hydrogen separation

A mixed protonic and electronic conductor material BaCe0.85Tb0.05Zr0.1O3−δ (BCTZ) is prepared and a Ni-BCTZ cermet membrane is synthesized for hydrogen separation. Stable hydrogen permeation fluxes can be obtained for over 100 h through the Ni-BCTZ membrane in both dry and humid conditions, which exhibits an excellent stability compared with Ni-BaCe0.95Tb0.05O3−δ membrane due to the Zr doping.Sino-German center for Science Promotion/GZ 911National Science Foundation of China/21225625National Science Foundation of China/2117608

Joint Optimization of Active and Passive Beamforming in Multi-IRS Aided mmWave Communications

Intelligent reflecting surface (IRS) has been considered as a promising technology to alleviate the blockage effect and enhance coverage in millimeter wave (mmWave) communication. To explore the impact of IRS on the performance of mmWave communication, we investigate a multi-IRS assisted mmWave communication network and formulate a sum rate maximization problem by jointly optimizing the active and passive beamforming and the set of IRSs for assistance. The optimization problem is intractable due to the lack of convexity of the objective function and the binary nature of the IRS selection variables. To tackle the complex non-convex problem, an alternating iterative approach is proposed. In particular, utilizing the fractional programming method to optimize the active and passive beamforming and the optimization of IRS selection is solved by enumerating. Simulation results demonstrate the performance gain of our proposed approach.Comment: 6 pages, 4 figures, accepted by IEEE GLOBECOM 202

Role of microRNAs in Stroke and Poststroke Depression

. microRNAs (miRNA), a sort of noncoding RNAs widely distributed in eukaryotic cells, could regulate gene expression by inhibiting transcription or translation. They were involved in important physiological and pathological processes including growth, development, and occurrence and progression of diseases. miRNAs are crucial for the development of the nervous system. Recent studies have demonstrated that some miRNAs play important roles in the occurrence and development of ischemic cerebrovascular diseases such as stroke and were also involved in the occurrence and development of poststroke depression (PSD). Herein, studies on the role of miRNAs in the cerebral ischemia and PSD were reviewed, and results may be helpful for the diagnosis and prognosis of cerebral ischemia and PSD with miRNAs in clinical practice