Investigation of the 6H-SiC (0001) surface by AFM

Micropipe and step structures on 6H-SiC （0001） surface were investigated by an atomic force microscopy （AFM）. On the facet,all micropipes examined are the origins of spiral steps,indicating that dislocations intersect the surface at these points. Micropipes are empty-core super-dislocations as originally described by Frank. The micropipe radius increases with the square of the dislocation Burgers vector. From the center to the periphery,step structures change with different surface inclinations. Regular step is observed within the central faceted area. Step bunching and atomically rough surfaces are observed within the peripheral convex area. If the inclination with respect to the （0001） plane is large enough,step bunching of 15R-SiC can be observed.

Approximate Analysis of Power Offset over Spatially Correlated MIMO Channels

Power offset is zero-order term in the capacity versus signal-to-noise ratio curve. In this paper, approximate analysis of power offset is presented to describe MIMO system with uniform linear antenna arrays of fixed length. It is assumed that the number of receive antenna is larger than that of transmit antenna. Spatially Correlated MIMO Channel is approximated by tri-diagonal toeplitz matrix. The determinant of tri-diagonal toeplitz matrix, which is fitted by elementary curve, is one of the key factors related to power offset. Based on the curve fitting, the determinant of tri-diagonal toeplitz matrix is mathematically tractable. Consequently, the expression of local extreme points can be derived to optimize power offset. The simulation results show that approximation above is accurate in local extreme points of power offset. The proposed expression of local extreme points is helpful to approach optimal power offset.

眼带状疱疹性葡萄膜炎合并前房积血1例

患者,男,74岁,因“左眼视物不见伴眼胀、眼痛3 d”于2022年1月6日就诊于济南明水眼科医院,当日上午曾就诊于当地医院眼科,诊断为“左眼新生血管性青光眼”,建议至上级医院就诊。患者于半个月前因“眼带状疱疹”在当地医院行输液治疗,具体不详。患者糖尿病病史2年,血糖控制良好。否认外伤及手术史。眼部检查:右眼最佳矫正视力(BCVA)0.6,左眼光感,光定位准;右眼眼压15 mmHg(1 mmHg=0.133 kPa),左眼35 mmHg。裂隙灯显微镜检查示:右眼晶状体混浊(+),余眼前后节未见明显异常,左眼眼睑肿胀,左侧前额、上眼睑、鼻梁及鼻尖色素沉着.

Study of ciprofloxacin removal by biochar obtained from used tea leaves

In this study, used tea leaves （UTLs） were pyrolyzed to obtain used tea-leaf biochar （UTC）, and then the UTC was used as an adsorbent to remove ciprofioxacin （CIP） from aqueous solutions. Batch experiments were conducted to investigate the CIP adsorption performance and mechanism. The results showed that the CIP-adsorbing ability first increased and then declined as the UTC pyrolysis temperature increased. The UTC obtained at 450℃ presented excellent CIP-absorbing ability at pH 6 and 40℃. The maximum monolayer adsorption capacity was 238.10 mg/g based on the Langrnuir isotherm model. The pseudo-second-order kinetic equation agreed well with the CIP adsorption process, which was controlled by both external boundary layer diffusion and intra-particle diffusion. The characterization analysis revealed that the - OH groups, G=C bonds of aromatic rings, C- H groups in aromatic tings and phenolic C - O bonds play vital roles in the CIP adsorption process, and that the N - C, N - O, O- C-O and C- OH groups of UTC were consumed in large quantities. π-π interactions, hydrogen bonding and electrostatic attraction are inferred as the main adsorption mechanisms. The present work provides not only a feasible and promising approach for UTLs utilization but also a potential adsorbent material for removing high concentrations of CIP from aqueous solutions.

Moderate sewage sludge biochar application on alkaline soil for corn growth:a field study

In view of the risks induced by the inhibitory effects of applying impracticably large amounts of sewage sludge biochar(SSB)to the alkaline soil,this field study investigated the influence of moderate biochar amendments(0,1500,4500,and 9000 kg/hm2)on corn growth,alkaline soil properties,and the uptake of potentially toxic elements(PTEs).The results showed that applying more SSB would decrease the ammonium nitrogen concentration and increase the available phosphorus and potassium concentrations,which inhibited corn plant growth because of high background nutrient levels of the alkaline soil.When the alkaline soil was amended with 1500 kg/hm2 SSB,the dry weight of 100 niblets increased from 32.11 g in the control to 35.07 g.There was no significant variation in the total concentration of PTEs in the soil.The concentrations of Mn,Ni,Cu,and Zn in niblets decreased from 5.54,0.83,2.26,and 27.15 mg/kg in the control to 4.47,0.62,1.30,and 23.45 mg/kg,respectively.Accordingly,the health risk from corn consumption was significantly reduced.Furthermore,the combination of SSB and fertilizer improved corn growth and reduced the risk of consumption of PTEs.Therefore,considering the increase in corn fruit yield and the decrease in consumption risk,applying 1500 kg/hm2 of biochar to alkaline soils is a realistically achievable rate,which can broaden the utilization of SSB for remediation of different types of soil.

中青年视网膜中央动脉阻塞患者的临床观察

目的:观察中青年视网膜中央动脉阻塞(CRAO)患者的临床表现、治疗效果和危险因素。方法:回顾性研究。连续收集2019年11月至2022年1月在济南明水眼科医院眼底病科按就诊时间先后诊治的中青年(≤50岁)单眼发病的CRAO患者17例(17眼)的临床资料,包括一般情况、病史、临床影像学资料、治疗效果及危险因素等。结果:17例患者中男12例,女5例,年龄30~50(43.3±7.0)岁,就诊时血压为(153.24±25.49)/(95.59±15.19)mmHg(1 mmHg=0.133 kPa),发病时间3 h~3 d,其中视力光感1例,手动5例,数指2例,小于0.1者5例,高于0.15者4例。所有患者均行眼底彩色照相和光学相干断层扫描检查,8例患者行眼底荧光素血管造影。结合全身相关检查确诊所有患者为非动脉炎性CRAO,其中完全性CRAO 11例,不完全性CRAO 5例,保留睫状视网膜动脉供应的CRAO 1例。经治疗后(随访5 d~1个月),视力改善者10例,视力不变者6例,视力下降者1例;患者中血压升高者13例(76.5%)。结论:中青年(≤50岁)CRAO患者多数视功能障碍严重,完全性CRAO患者视力预后差,不完全性CRAO患者可恢复较好视力,高血压为最常见全身疾病。