摘要：Twenty-one 1-(1H-1,2,4-triazolyl)-2-(2,4-diflurophenyl)-3-(4-substituted-1-piperazinyl) -2-propanol derivatives were designed and synthesized, on the basis of the active site of lanosterol 14α-demethylase. In vitro antifungal activities showed that some of the target compounds had higher antifungal activity and broader antifungal spectrum than fluconazole.

摘要：KONUS beam dynamics design of uranium whose current is 5.0 emA, is accelerated from injection DTL with LORASR code is presented. The 238U34＋ beam, energy of 0.35 MeV/u to output energy of 1.30 MeV/u by IH-DTL operated at 81.25 MHz in HIAF project at IMP of CAS. It achieves a transmission efficiency of 94.95% with a cavity length of 267.8 cm. The optimization aims are the reduction of emittance growth, beam loss and project costs. Because of the requirements of CW mode operation, the designed average acceleration gradient is about 2.48 MV/m. The maximum axial field is 10.2 MV/m, meanwhile the Kilpatrick breakdown field is 10.56 MV/m at 81.25 MHz.

摘要：Beam dynamics and RF design have been performed of a new type trapezoidal IH-RFQ operating at 104 MHz for acceleration of 14C+ in the framework of RFQ based 14C AMS facility at Peking University. Low energy spread RFQ beam dynamics design was approached by the method of internal discrete bunching. 14C+ will be accelerated from 40 keV to 500 keV with the length of about 1.1 m. The designed transmission efficiency is better than 95% and the energy spread is as low as 0.6%. Combining the beam dynamics design, a trapezoidal IH-RFQ structure was proposed, which can be cooled more easily and has better mechanical performance than traditional RFQ. Electromagnetic field distribution was simulated by using CST Microwave Studio (MWS). The specific shunt impedance and the quality factor were optimized primarily.

摘要：What is the most favorite and original chemistry developed in your research group? Developing PIP amine for regio-and enantioselective methylene C-H activation. How do you get into this specific field? Could you please share some experiences with our readers?

摘要：Positronium time of flight spectroscopy（Ps-TOF）is an effective technique for porous material *** has advantages over other techniques for analyzing the porosity and pore tortuosity of *** paper describes a design for Ps-TOF apparatus based on the Beijing intense slow positron beam,supplying a new material characterization *** order to improve the time resolution and increase the count rate of the apparatus,the detector system is *** 3 eV o-Ps,the time broadening is 7.66 ns and the count rate is 3 cps after correction.

摘要：Evapotranspiration(ET)is of great significance for the ecological environment and water resource utilization in arid and semi-arid *** Mongolian Plateau,owing to drought,low rainfall,and extremely uneven distribution of water resources,has a typical temperate continental climate.A refined understanding of the spatiotemporal distribution of ET in this region will help in establishing regulatory strategies for climate change responses,regional livestock regulation,and grassland degradation *** this study,meteorological station data,precipitation data,and the Penman-Monteith model were used to study the temporal and spatial distribution characteristics of actual ET over the Mongolian Plateau from 2011 to *** found that:(1)The spatial distribution of ET in the Mongolian Plateau showed a high trend in the north and east and a low trend in the middle and *** was a significant difference in the regional annual ET,with the highest ET reaching over 500 mm and the lowest being only approximately 70 mm.(2)The annual ET values in 2013,2018,and 2019 were relatively large,varying between 80 and 500 mm,and the overall ET of the Mongolian Plateau first decreased,then increased,and then decreased.(3)The temporal distribution exhibits a unimodal trend of increasing and then decreasing,with July being the turning ***-September was a period of high ET,with the highest ET exceeding 100 *** vegetation coverage was high,precipitation was abundant,and the vegetation ET effect was *** was a period of low ET,with a maximum ET of approximately 10 mm in January and December;the ET for the month with the lowest value was approximately *** quantitative inversion method proposed in this study can provide method and data support for north and central Asia,and other large arid and semi-arid areas.

摘要：为解决钻井泥浆资源化问题,基于“以废治废”的理念,以普通硅酸盐水泥、粉煤灰等原料作为固化剂对水基钻井泥浆进行固化处理,制备成路基材料。研究了钻井泥浆路基材料不同液固比下重金属的溶出特性,并对路基材料应用的环境安全性进行风险评估。结果表明:经固化处理后,钻井泥浆中As和Pb的浸出量降低,而Hg的浸出量升高;钻井泥浆路基材料中4种重金属累积浸出量均随液固比的增大而增加;风险评估计算得到的Cr(Ⅵ)、As和Hg经口摄入、皮肤接触、呼吸吸入3种暴露途径的累积致癌风险和累积危害商,均处于环境风险可接受水平;路基材料中Pb的有效浸出量为0.022 mg/kg,远小于经ALM(成人血铅)模型计算得到的土壤环境铅基准值689.47 mg/kg,处于环境风险可接受水平。研究可为钻井泥浆资源化利用的环境安全性提供科学依据。

摘要：An updated main coupler has been designed for the superconducting accelerator of Free Electron Laser （FEL） project under construction in Peking University. A capacitive structure is chosen for the main coupler. Numerical investigation using CST Microwave Studio demonstrates the cold window part. The other nonstandard structures such as holding rods and antenna are also optimized. The coupler uses a 95% purity Al2O3 ceramic cold window. The VSWR （Vottage Standing Wave Ratio） is 1.02 at 1.3 GHz and the frequency bandwidth is 45 MHz with VSWR〈I.1. The electric field intensity is 8.5× 10-2 kV/mm around the window with 20 kW Continuous Wave （CW） transmitted power. The Qext is designed variable from 5× 10^8 to 1×10^7.

摘要：The virtual laminated element method (VLEM) can resolve structural shap e optimization problems with a new method. According to the characteristics of V LEM , only some characterized layer thickness values need be defined as design v ariables instead of boundary node coordinates or some other parameters determini ng the system boundary. One of the important features of this method is that it is not necessary to regenerate the FE(finite element) grid during the optimizati on process so as to avoid optimization failures resulting from some distortion grid elements. Th e thickness distribution in thin plate optimization problems in other studies be fore is of stepped shape. However, in this paper, a continuous thickness distrib ution can be obtained after optimization using VLEM, and is more reasonable. Fur thermore, an approximate reanalysis method named ″behavior model technique″ ca n be used to reduce the amount of structural reanalysis. Some typical examples are offered to prove the effectiveness and practicality of the proposed method.

摘要：The aim of the electron microscopy image classification is to categorize the projection images into different classes according to their similarities. Distinguishing images usually requires that these images are Migned first. However, alignment of images is a difficult task for a highly noisy data set. In this paper, we propose a translation and rotation invariant based on the Fourier transform for avoiding alignment. A novel classification method is therefore established. To accelerate the classification speed, secondary-classes are introduced in the classification process. The test results also show that our method is very efficient and effective. Classification results using our invariant are also compared with the results using other existing invariants, showing that our invariant leads to much better results.