不同贮存方式对顺阿曲库铵起效时间和作用时间的影响

目的观察不同贮存方式下顺阿曲库铵对其肌肉松弛起效时间和作用时间的影响。方法随机将拟行妇科腹腔镜手术的90例患者分为6组,每组15例,任选3组为A组(3×ED95,顺阿曲库铵诱导剂量为0.15 mg/kg)和B组(4×ED95,顺阿曲库铵诱导剂量为0.2 mg/kg),并依据使用不同贮存方式下顺阿曲库铵将其标记为AI(低温组)、AII(交替温度组)、AIII(室温组)、BI(低温组)、BII(交替温度组)、BIII(室温组)。观察和比较不同贮存方式下顺阿曲库铵的肌肉松弛起效时间和作用时间情况。结果AII(BII)、AIII(BIII)组患者使用顺阿曲库铵的起效时间、作用时间均慢于和短于AI(BI);而AII(BII)、AIII(BIII)组间患者使用顺阿曲库铵的起效时间、作用时间无统计学差异(P>0.05)。结论交替温度下的顺阿曲库铵,即使是仅8 h的室温,仍然对其肌肉松弛起效时间和作用时间有一定的影响。

Environmentally Friendly and Multifunctional Shaddock Peel-Based Carbon Aerogel for Thermal-Insulation and Microwave Absorption

Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property,heat-insulating ability and compression resistance are highly attractive in practical applications.Meeting the aforesaid requirements simultaneously is a formidable challenge.Herein,ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process,forming porous network architecture.With the heating platform temperature of 70℃,the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend.The color of the sample surface in thermal infrared images is similar to that of the surroundings.With the maximum compressive stress of 2.435 kPa,the carbon aerogels can provide favorable endurance.The shaddock peel-based carbon aerogels possess the minimum reflection loss value(RLmin)of−29.50 dB in X band.Meanwhile,the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm.With the detection theta of 0°,the maximum radar cross-sectional(RCS)reduction values of 16.28 dB m^(2) can be achieved.Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature.This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.

Environment-Stable CoxNiy Encapsulation in Stacked Porous Carbon Nanosheets for Enhanced Microwave Absorption

Magnetic/dielectric@porous carbon composites,derived from metal–organic frameworks(MOFs)with adjustable composition ratio,have attracted wide attention due to their unique magnetoelectric properties.In addition,MOFs-derived porous carbon-based materials can meet the needs of lightweight feature.This paper reports a simple process for synthesizing stacked CoxNiy@C nanosheets derived from CoxNiy-MOFs nanosheets with multiple interfaces,which is good to the microwave response.The CoxNiy@C with controllable composition can be obtained by adjusting the ratio of Co^2+ and Ni^2+.It is supposed that the increased Co content is benefit to the dielectric and magnetic loss.Additionally,the bandwidth of CoNi@C nanosheets can take up almost the whole Ku band.Moreover,this composite has better environmental stability in air,which characteristic provides a sustainable potential for the practical application.

From intrinsic dielectric loss to geometry patterns: Dual-principles strategy for ultrabroad band microwave absorption

As electromagnetic absorbers with wide absorption bandwidth are highly pursued in the cutting-edge electronic and telecommunication industries, the traditional dielectric or magnetic bulky absorbers remain concerns of extending the effective absorption bandwidth. In this work, a dual-principle strategy has been proposed to make a better understanding of the impact of utilizing conductive absorption fillers coupled with implementing artificial structures design on the absorption performance. In the comparison based on the microscopic studies, the carbon nanotubes (CNTs)-based absorbers are confined to narrow operating bandwidth and relatively fixed response frequency range, which can not fulfill the ever-growing demands in the application. With subsequent macroscopic structure design based on the CNTs-based dielectric fillers, the artificial patterns show much more broadened absorption bandwidth, covering the majority of C-band, the whole X-band, and Ku-band, due to the tailored electromagnetic parameters and more reflections and scatterings. The results suggest that the combination of developing microscopic powder/bulky absorbers and macroscopic configuration design will fundamentally extend the effective operating bandwidth of microwave.

The point defect and electronic structure of K doped LaCo_(0.9)Fe_(0.1)O_(3)perovskite with enhanced microwave absorbing ability

ABO_(3)perovskites,owning unique properties,have great research prospect in electromagnetic wave absorption field.Normally,doping can significantly regulate the dielectric loss,whereas the magnetic loss can be ignored.In this work,the crystal structure and electromagnetic properties can be regulated systematically by the K,Fe co-doping for LaCoO_(3)perovskites(LKCFO)under the condition of fixed F content.In addition,the obtained samples show the obvious interfacial polarization effect on accounting to the small size effect,which is conducive to the effective microwave absorption.By analyzing the evolution of the positron annihilation lifetime and the first-principles calculation of the oxygen density of states for the series of LKCFO perovskites,it is found that the charge transport characteristics will be controlled by the point defect generated by allelic doping.The point defect content decreases and then increases as the doping level rises.The prepared perovskite exhibits the lowest defect density and the largest dielectric loss capability,which indicates that the lower point defects promote electron migration and thus enhance the dielectric loss;thus,the electromagnetic wave absorption bandwidth up to 6.2 GHz is reached.In contrast,both insufficient and excessive K doping are detrimental to the enhancement of microwave absorption.Especially,the practical application value was investigated using Computer Simulation Technology(CST)simulations.The LKCFO-2 exhibits the smallest RCS value(below-10 dBm^(2))at almost-90°-90°with a thickness of 2 mm,providing an effective method for study excellent microwave absorption and scattering property.

Improved electromagnetic dissipation of Fe doping LaCoO_(3)toward broadband microwave absorption

Perovskite LaCoO_(3)is of great potential in electromagnetic wave absorption considering its outstanding dielectric loss as well as the existing magnetic response with the magnetic doping.However,the dissipation mechanism of the magnetic doping on the microwave absorption is lack of sufficient investigated.In this paper,LaCo_(1-x)Fe_(x)O_(3)(x=0,0.05,0.1,0.15,0.2,0.25,0.3,LCFOs)perovskites with different Fe doping amounts were prepared successfully by the sol-gel method and subsequent heat treatment in the air atmosphere.The structure characterization carried out by the frst-principles calculations shows the effect of Fe doping on the dielectric and magnetic properties of LCFOs and the strong hybridization of Co/Fe-3d with O-2p in the LCFOs system was successfully demonstrated.Particularly,when x=0.1 and the thickness is only 1.95 mm,the LaCo_(0.9)Fe_(0.1)O_(3)exhibits the best microwave absorption performance with the minimum reflection loss(RL)value of about-41 dB.The typical samples achieve a broad effective absorption bandwidth(EAB)of 5.16 GHz(7.92-13.08 GHz),which covers the total X band(8-12 GHz).Considering that,the especial Fe doping perovskite is promising to be a candidate as efficient microwave absorbers.

Lightweight,flexible and freestanding PVA/PEDOT:PSS/Ag NWs film for high-performance electromagnetic interference shielding

In order to fulfill the ever-growing requirements for electromagnetic interference(EMI)shielding materials,achieving a high efficiency with great flexibility is still a big challenge.Herein,high-performance EMI shielding composite films with excellent mechanical properties were fabricated via a convenient evaporation method using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)and silver nanowires(Ag NWs)as conductive fillers.By adding 1.38 wt% Ag NWs into the original polyvinyl alcohol/PEDOT:PSS(PVA/PEDOT:PSS)composite,the obtained film with a thickness of about 20μm shows a remarkable EMI shielding performance(~33 dB)and a special EMI shielding efficiency of 16,800 dB cm^(-1) at 10 GHz.Furthermore,PVA/PEDOT:PSS/Ag NWs films present excellent tensile strength(~62.39 MPa)and elongation at break(~29.3%).The good mechanism allows the films to apply in actual harsh environments.Overall,this study will draw attention to the new films for electromagnetic shielding application.

Heterostructure design of Fe^(3)N alloy/porous carbon nanosheet composites for efficient microwave attenuation

The self-dissipation and attenuation capacity of materials play an important role in realizing efficient electromagnetic absorption,in this case,the roles of macroscopic composition and micro-structure should be emphasized simultaneously in the reasonable design of microwave absorbent.Given that,Fe_(3)N alloy embedded in two-dimensional porous carbon composites were fabricated via facile sol-gel and sacrificial template methods.Satisfactorily,the magnetic/dielectric materials combination and porous structure introduction are conductive to the optimization of impedance matching property,as result of the enhancement of microwave absorption capacity.In addition,sufficient magnetic loss capacity,strong conductivity as well as polarization attenuation bring about the outstanding microwave absorbing performance with an effective absorption bandwidth of 6.76 GHz and a minimum reflection loss value of-65.6 d B.It is believed that this work not only lay a foundation to achieve microwave response materials in a wide frequency range,but also emphasize the significant role of the component selection and structural design.

Indoor air particles in research vessel from Shanghai to Antarctic: Characteristics, influencing factors, and potential controlling pathway

Despite millions of seafarers and passengers staying on ships each year, few studies have been conducted on the indoor air quality inside ship hulls. In this study, we investigated the levels and size distribution of indoor particulate matter during two cruises of the research vessel “Xuelong” from Shanghai to Antarctica. The results showed that the particle size less than 2.5 μm(PM_(2.5)), and particle size less than 10 μm(PM_(10)) concentrations in different rooms of the ship widely varied. We observed high particulate matter(PM) levels in some of the rooms. The mass concentration distribution was dominated by 1–4 μm particles, which may have been caused by the hygroscopic growth of fine particles. The dominant factors influencing PM concentrations were indoor temperature, relative humidity, and human activity. We quantified contributions of these factors to the levels of indoor particles using a generalized additive model. In clean rooms, the levels of indoor particles were controlled by temperature and relative humidity, whereas in polluted rooms, the levels of indoor particles were mainly influenced by temperature and human activity, which implied that controlling temperature and human activity would efficiently reduce the levels of indoor particles.