摘要：Considering the essential and influential role of centrifugal compressors in a wide range of industries makes most of engineers research and study on design and optimization of centrifugal compressors. Centrifugal compressors are the key to part ofoil, gas and petrochemical industries as well as gas pipeline transports. Since complete 3D design of the compressor consumes a considerable amount of time, most of active companies in the field, are profoundly interested in obtaining a design outline before taking any further steps in designing the entire machine. In this paper, a numerical algorithm, named ACDA （adapted compressor design algorithm） for fast and accurate preliminary design of centrifugal compressor is presented. The design procedure is obtained under real gas behavior, using an appropriate equation of state. Starting from impeller inlet, the procedure is continued on by resulting in numerical calculation for other sections including impeller exit, volute and exit diffuser. Clearly, in any step suitable correction factors are employed in order to conclude in precise numerical results. Finally, the achieved design result is compared with available reference data.

摘要：The most important aim of nanotechnology development is to construct atomic-scale devices, and those atomic-scale devices are required to use some measurements that have ability to control and build in the range of these dimensions. A method based on super- heterodyne interferometers can be used to access the measurements in nano-scale. One of the most important limitations to increase the resolution of the displacement measurement is nonlinearity error. According to the base and measurement signals received by optical section of super-heterodyne interferometer, it is necessary for circuits to reconstruct and detect corresponding phase with target displacement. In this paper, we designed, simulated, and implemented the circuits required for electronic part of interferometer by complementary metal-oxide-semicon- ductor （CMOS） 0.5 ~tm technology. These circuits included cascade low-noise amplifiers （LNA） with 19.1 dB gain and 2.5dB noise figure （NF） at 500MHz frequency, band-pass filters with 500MHz central fre- quency and 400 kHz bandwidth, double-balanced mixers with 233/0.6pm ratio for metal-oxide-semiconductor field-effect transistors （MOSFETs）, and low-pass filters with 300 kHz cutoff frequency. The experimental results show that the amplifiers have 19.41 dB gain and 2.7 dB noise factor, mixers have the ratio of radio frequency to local oscillator （RF/LO） range between 80 and 2500 MHz with intermediate frequency （IF） range between DC to 1000 MHz, and the digital phase measurement circuit based on the time-to-digital converter （TDC） has a nanosecond resolution.

摘要：Conventional 2D intestinal models cannot precisely recapitulate biomimetic features in vitro and thus are unsuitable for various pharmacokinetic applications,development of disease models,and understanding the host-microbiome ***,recently,efforts have been directed toward recreating in vitro models with intestine-associated unique 3D crypt-villus(for small intestine)or crypt-lumen(for large intestine)*** review comprehensively delineates the current advancements in this research area in terms of the different microfabrication technologies(photolithography,laser ablation,and 3D bioprinting)employed and the physiological relevance of the obtained models in mimicking the features of native intestinal tissue.A major thrust of the manuscript is also on highlighting the dynamic interplay between intestinal cells(both the stem cells and differentiated ones)and different biophysical,biochemical,and mechanobiological cues along with interaction with other cell types and intestinal microbiome,providing goals for the future developments in this *** article also manifests an outlook toward the application of induced pluripotent stem cells in the context of intestinal tissue *** a concluding note,challenges and prospects for clinical translation of 3D patterned intestinal tissue models have been discussed.

摘要：自清洗网式过滤器是一种新型过滤器,为提高其排污系统的排污效率,建立了自清洗网式过滤器排污系统旋喷动力和吸附吸力理论表达式,确定旋喷动力和吸附吸力影响因素;利用CFD方法对自清洗网式过滤器排污过程进行数值模拟,分别得到速度云图和压强云图,结果表明,排污系统吸嘴1~4最大流速差为2.96 m/s,最大压强差为3.65 kPa,排污系统泥沙吸附不均匀,降低了过滤器排污效率;结合理论分析和数值模拟结果设计6组优化方案,对比可知吸沙组件吸嘴1~4开口宽度分别为0.2、0.4、0.6、2 cm,旋喷管开口直径为2 cm的方案,各吸嘴流速分布更加均匀,流速得到明显提高,过滤器进出口压强差增大,有利于提高排污效率。

摘要：Objective Considering the importance of out-of-hospital services,the emergence of home care nursing,and the need for an ethical framework in nursing practice,the present study aimed to explore the nurses’experience of ethical values of home care *** The data of the study was collected using face-to-face individual *** purposive sampling,20 nurses who worked in the home care centers in four cities of Iran in 2020 were *** shared their experiences of the ethical values of home care ***,the interviews were analyzed based on the content analysis approach and using Graneheim and Lundman *** In the present study,416 codes were *** these codes based on the similarity,seven main themes,and 16 sub-themes were *** themes included perception of the professional identity,respect for the client’s autonomy,respecting privacy,establishing human interaction,maintaining mutual safety,observance of justice,and cultural-religious *** sub-themes included responsibility,development of professional and inter-professional interactions,maintaining the professional status at home,providing the holistic artistic care,patient’s privacy,nurse’s privacy,and maintaining the confidentiality of information,respect for the client’s choice,honestly informing,empathetic interaction,adjusting the power positions,client's safety,nurse’s safety,establishing justice,respect for the religious beliefs at home and cultural *** The participants stated that due to entering the patient’s privacy in the home care cases,the ethical values such as perception of the professional identity,privacy,family interactions’management,mutual security,and cultural-religious competence became doubly important compared to the hospital caring.

摘要：目的确定早年(3岁以内)导致英国儿童肥胖的危险因素。设计前瞻性队列研究。方法Avon英国父母及儿童纵向调查研究。参与者参与队列研究的8234名年龄为7岁的儿童以及亚组的909名重点儿童,后者需额外提供与早期发育有关并涉及可能导致肥胖的各种资料。诊断标准7岁儿童体重指数≥95百分位确定为肥胖,参考1990年英国人口调查的诊断标准。结果经过最终验证,在假设的25项危险因素中有8项与肥胖有关:父母肥胖(父母双方校正后的相对危险度10.44,95%可信区间5.11～21.32);最早期(43个月内)的体重指数或体重反弹升高(校正后的相对危险度15.00,95%可信区间5.32～42.30);3岁时每周看电视的时间超过8小时(校正后的相对危险度1.55,95%可信区间1.13～2.12);追赶性生长(校正后的相对危险度2.60,95%可信区间1.09～6.16);8个月(校正后的相对危险度3.13,95%可信区间1.43～6.85)和18个月(校正后的相对危险度2.65,95%可信区间1.25～5.59)时体重的标准差值;1岁时体重增加值(校正后的相对危险度1.06,95%可信区间1.02～1.10,体重每增加100g);出生体重,每100g(校正后的相对危险度1.05,95%可信区间1.03～1.07);3岁时睡眠不足(<10.5小时,校正后的相对危险度1.45,95%可信区间1.10～1.89)。结论儿童期肥胖可能与8项危险因素有关。