不锈钢手术器械钝化处理观察及返锈率的研究

目的为了探讨医用钝化剂与除锈剂对手术器械除锈效果及返锈率的研究,降低不锈钢手术器械的返锈率,提高器械的清洗质量,延长不锈钢手术器械的使用寿命,降低医院成本。方法挑选同等锈渍的生锈器械400件,随机分为两组,每组各200件,实验组将器械放在恒温为85 ℃的按1:7比例配置的钝化剂中30 min进行钝化处理;对照组将器械放在80 ℃下按1:7比例配制的除锈剂中浸泡10 min进行除锈处理,然后取出进行刷洗,比较两组器械除锈合格率。除锈合格的两组器械分别浸泡在0.45%Nacl溶液5 h,模拟器械的再次使用及受污染,比较两组器械返锈率。结果实验组器械除锈合格率为99.50%、对照组为98.50%,两组比较差异无统计学意义(P>0.05)。返锈率比较:实验组为8.04%、对照组为27.92%,两组比较差异有统计学意义(P<0.001)。结论钝化剂具有除锈剂同样的除锈效果,但钝化处理可降低器械的返锈率,延长器械的使用周期,降低医院采购器械的成本。

Effects of Tropical Cyclone Activity on the Boundary Moisture Budget over the Eastern China Monsoon Region

In summer, water vapor over the eastern China monsoon region （ECMR） comes mainly from low latitudes and is modu- lated by tropical cyclone （TC） activity in East Asia （EA）. This study examines the variability of water vapor transport over the ECMR, especially of the moisture inflow via the southern and eastern boundaries. The results of composite and correlation analyses, using data from 1979 to 2010, reveal significant differences in moisture budgets along the boundaries between TC days and non-TC days. Almost 80% of the water vapor transport via the eastern boundary occurs during TC days, while at the southern boundary most inflow occurs on non-TC days. The ratio of the total water vapor transport between TC and non-TC days is about 4：6. In addition, the E1 Nifio-Southem Oscillation （ENSO） exhibits a remarkable influence on moisture trans- port over EA and the contributions of moisture inflow on TC days increase （reduce） in E1 Nifio （La Nifia） years. Moreover, different types of TCs, based on their tracks, have different effects on the moisture budgets along the southern and eastern boundaries. When TCs enter EA （but not the ECMR）, they favor the moisture inflow via the eastern boundary and hinder the moisture inflow via the southern boundary. After TCs enter the ECMR, the inhibition of moisture inflow via the southern boundary will be weakened, and more water vapor can be brought into the ECMR. For some recurring TCs with an increase in TC activity in the midlatitudes, the influence is uncertain in different cases. The results herein suggest that TC activity is an important factor that influences the boundary moisture budgets in the ECMR.

Performing optical logic operations by a diffractive neural network

Optical logic operations lie at the heart of optical computing,and they enable many applications such as ultrahighspeed information processing.However,the reported optical logic gates rely heavily on the precise control of input light signals,including their phase difference,polarization,and intensity and the size of the incident beams.Due to the complexity and difficulty in these precise controls,the two output optical logic states may suffer from an inherent instability and a low contrast ratio of intensity.Moreover,the miniaturization of optical logic gates becomes difficult if the extra bulky apparatus for these controls is considered.As such,it is desirable to get rid of these complicated controls and to achieve full logic functionality in a compact photonic system.Such a goal remains challenging.Here,we introduce a simple yet universal design strategy,capable of using plane waves as the incident signal,to perform optical logic operations via a diffractive neural network.Physically,the incident plane wave is first spatially encoded by a specific logic operation at the input layer and further decoded through the hidden layers,namely,a compound Huygens’metasurface.That is,the judiciously designed metasurface scatters the encoded light into one of two small designated areas at the output layer,which provides the information of output logic states.Importantly,after training of the diffractive neural network,all seven basic types of optical logic operations can be realized by the same metasurface.As a conceptual illustration,three logic operations(NOT,OR,and AND)are experimentally demonstrated at microwave frequencies.

Chiral Cobalt(Ⅱ)Complex Catalyzed Asymmetric[2,3]-Sigmatropic Rearrangement of Allylic Selenides withα-Diazo Pyrazoleamides

Organoselenium compounds,due to their high structural diversity,special function,and biological activities,have drawn attention in synthetic chemistry.Herein,a novel example of chiral N,N′-dioxide/cobalt(Ⅱ)complex catalyzed asymmetric[2,3]-sigmatropic rearrangement of allylic selenides withα-diazo pyrazoleamides is disclosed,which represents a highly efficient approach to optically active selenides bearing a quaternary C–Se stereocenter.Most of the reactions proceed with 0.5–2 mol%catalyst loading in an inert-free gas atmosphere,and a wealth of chiral selenides are obtained in up to 99% yield and 97%enantiomeric excess(ee).The control experiments demonstrate the high reactivity of allylic selenides,as well as the conspicuous superiority of chiral N,N′-dioxide ligand andα-diazo pyrazoleamide in[2,3]-sigmatropic rearrangement.The mechanism studies reveal that the key to asymmetric rearrangement of allylic selenium ylides is the transfer of chirality from the stable chiral selenium to the carbon of the product.A feasible catalytic cycle is proposed as well.