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亚马逊告诉机器人如何堆装货物

科技纵览 2023年第3期 10-11页

作者： evan Ackerman 不详

仓库中的操作机器人大多数都用于从箱子里取出物品.这种拣货操作可能很困难,特别是不同类型物品的数量达到数百万时.但机器人越来越擅长这种工作.此外,它们也开始擅长将物品放入箱子的堆装操作.

关键词：机器人堆装货物亚马逊物品操作

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守护月球门户空间站的机器人

科技纵览 2022年第5期 5-7页

作者： evan Ackerman 不详

月球门户空间站是美国国家航空航天局(NASA)在这个十年内再次将宇航员送上月球计划的重要组成部分,这将是人类在近地轨道之外的首个永久性前哨站。该项目由美国国家航空航天局、加拿大太空总署(CSA)、欧洲太空总署和日本宇航局合作建设... 详细信息

月球门户空间站是美国国家航空航天局(NASA)在这个十年内再次将宇航员送上月球计划的重要组成部分,这将是人类在近地轨道之外的首个永久性前哨站。该项目由美国国家航空航天局、加拿大太空总署(CSA)、欧洲太空总署和日本宇航局合作建设,目的是支持星探索的补给站.

关键词：近地轨道空间站美国国家航空航天局机器人月球宇航员太空 NASA

Physical Properties of SiC Nanostructure for Optoelectronics Applications

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journal of Renewable Materials 2021年第9期9卷 1519-1530页

作者： Mayyadah H.Mohsin Najwan H.Numan evan T.Salim Makram A.Fakhri Applied Science Department University of Technology-IraqBaghdad10066Iraq Laser and Optoelectronic Engineering Department University of Technology-IraqBaghdad10066Iraq

A SiC nanofilms have been deposited and investigated on quartz and silicon substrates using pulsed laser deposition technique with the 300 pulses of Nd:YAG laser at two different laser wavelengths of 1064 nm and 532 *** structural,morphological,and optical properties of the deposited nanostructure SiC were prepared and characterized as a function of the wavelengths of the used *** structural result shows four different pecks at(111),(200),(220),and(311)planes related to Nano *** transmission result presents that the optical energy gap value for the SiC nanostructure is depended on the wavelength of the used laser and it is found about the range(3.03 eV–3.23 eV).The investigations of the SEM and AFM show that the prepared SiC Nano-films having a grain size range(36.34–48.75)nm and roughness about 4.462 to 3.062 ***/Si hetero-junction devices show an enhanced performance at 532 nm.

关键词： Pulsed Laser deposition nanostructure 4H-SiC PLD heterostructure nanofilms

Effect of pumping chamber on performance of non-overload centrifugal pump

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journal of Central South University 2015年第8期22卷 2989-2997页

作者：谷云庆牟介刚代东顺郑水华吴登昊蒋兰芳施瀚昱 WANG evan College of Mechanical and Engineering Zhejiang University of Technology Engineering Research Center of Process Equipment and Its Re-manufacturing of Ministry of Education(Zhejiang University of Technology) Zhijiang College Zhejiang University of Technology Institut National Polytechnique of Grenoble Joseph Fourier University

In order to specify the characteristics of un-overloaded centrifugal pumps, the IH100-65-200 pump was chosen as the model pump. Different calculation models for centrifugal pumps were established under different pumping chamber sectional parameters. In the numerical simulation of the centrifugal pumps flow field, the shaft power, head, efficiency, and the changes of the internal flow field under different sectional areas and sectional shapes were studied with the RNG k-ε turbulence model, and the influence of the pumping chamber section characteristics of the non-overloaded centrifugal pumps were analyzed. The results show that sectional areas have a significant impact on the non-overload characteristics of centrifugal pumps. The shaft power and head of centrifugal pump are increasing with a lager sectional area, by which the gradient of head curves decreases. The efficiency is improved under a large flow rate condition, but the head and the efficiency are reduced at a small flow rate. It is also observed that the sectional shapes have less influence on the shaft power, the hydraulic performance and flow field characteristics of a centrifugal pump.

关键词：离心泵泵性能气室超负荷 k-ε湍流模型内部流场截面形状轴功率

Beyond first-line chemotherapy for advanced pancreatic cancer:An expanding array of therapeutic options?

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World journal of Gastroenterology 2014年第9期20卷 2224-2236页

作者： evan j Walker Andrew H Ko University of California Helen Diller Family Comprehensive Cancer Center San Francisco CA 94115 United States

While an increasing number of therapeutic options are now available for the first-line treatment of locally advanced or metastatic pancreatic cancer,the optimal choice for treatment in the second-line setting and beyond is less well defined.A variety of cytotoxic agents,either alone or in combination,have been evaluated,although primarily in the context of small single-arm or retrospective *** regimens have been associated with median progression-free survival rates in the range of 2-4 mo and overall survival rates between 4-8mo,highlighting the very poor prognosis of patients who are candidates for such *** therapies studied in this chemotherapy-refractory setting,meanwhile,have produced even worse efficacy *** the current article,we review the clinical evidence for treatment of refractory disease,primarily in patients who have progressed on front-line gemcitabine-based *** the process,we highlight the limitations of the available data to date as well as some of the challenges in designing appropriate clinical trials in this salvage setting,including how to select an appropriate control arm given the absence of a wellestablished reference standard,and the importance of incorporating predictive biomarkers and quality of life measures whenever possible into study design.

关键词： Pancreatic cancer Refractory Second-line chemother

Characteristics and mechanism investigation on drag reduction of oblique riblets

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journal of Central South University 2017年第6期24卷 1379-1386页

作者：谷云庆范天星牟介刚吴登昊郑水华 evan Wang College of Mechanical and Engineering Zhejiang University of TechnologyHangzhou 310014China Zhijiang College Zhejiang University of TechnologyHangzhou 310024China Institute National Polytechnique of Grenoble Joseph Fourier UniversityGrenoble 38031France

This work primarily focuses on the drag reduction characteristics and mechanism investigation of oblique riblets. First, a calculation model of the oblique riblets surface is established, and Reynolds stress model(RSM) turbulence model is used for numerical simulation of the oblique riblets flow field. Subsequently, the influence of inclination angle between flow direction and arrangement direction of riblets on friction resistance and drag reduction rate is further analyzed. Through the investigation of the distribution of shear stress, pressure stress and velocity in oblique riblets boundary layer, the oblique riblets drag reduction mechanism is finally revealed. Results show that, with increase of velocity and inclination angle, the pressure resistance increases obviously, along with the decreasing of the viscous resistance distinctly. The maximum drag reduction rate of the oblique riblets is 7.33%. Moreover, when the inclination angle increases, the wall shear stress reduces on oblique riblets surface; while differential pressure increases at both sides of oblique riblets tips. In addition, when inclination angle is small, the secondary vortex at oblique riblets tips will disappear soon. New vortices will be formed inside the oblique riblets and cause the decrease of viscosity resistance. Thus, oblique riblets show a better drag reduction effect and have an effective control on boundary layer.

关键词： oblique riblets drag reduction Reynolds stress model (RSM) secondary vortex numerical simulation

High-efficiency,large-area,topologyoptimized metasurfaces

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Light(Science & Applications) 2019年第1期8卷 749-757页

作者： Thaibao Phan David Sell evan W.Wang Sage Doshay Kofi Edee jianji Yang jonathan A.Fan Department of Electrical Engineering Stanford UniversityStanfordCA 94305USA Department of Applied Physics Stanford UniversityStanfordCA 94305USA Universite Clermont Auvergne Institut PascalBP 10448F-63000 Clermont-FerrandFrance CNRS UMR 6602Institut PascalF-63177 AubiereFrance

Metasurfaces are ultrathin optical elements that are highly promising for constructing lightweight and compact optical *** their practical implementation,it is imperative to maximize the metasurface *** optimization provides a pathway for pushing the limits of metasurface efficiency;however,topology optimization methods have been limited to the design of microscale devices due to the extensive computational resources that are *** introduce a new strategy for optimizing large-area metasurfaces in a computationally efficient *** stitching together individually optimized sections of the metasurface,we can reduce the computational complexity of the optimization from high-polynomial to *** a proof of concept,we design and experimentally demonstrate large-area,high-numerical-aperture silicon metasurface lenses with focusing efficiencies exceeding 90%.These concepts can be generalized to the design of multifunctional,broadband diffractive optical devices and will enable the implementation of large-area,high-performance metasurfaces in practical optical systems.

关键词： topology optimization surface

Head trauma and olfactory function

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World journal of Otorhinolaryngology-Head and Neck Surgery 2018年第1期4卷 39-45页

作者： jessica Howell Richard M. Costanzo evan R. Reiter Department of Otolaryngology - Head & Neck Surgery Virginia Commonwealth UniversityRichmondVAUSA Department of Physiology & Biophysics Virginia Commonwealth UniversityRichmondVAUSA

Olfactory impairment is a well-established sequela of head injury. The presence and degree of olfactory dysfunction is dependent on severity of head trauma, duration of post-traumatic amnesia, injuries obtained, and as more recently established, age. Deficits in smell can be conductive or neurosensory, contingent on location of injury. The former may be amenable to medical or surgical treatment, whereas the majority of patients with neurosen-sory deficits will not recover. Many patients will not seek treatment for such deficits until days, weeks, or even months after the traumatic event due to focus on more pressing injuries. Eval-uation should start with a comprehensive history and physical exam. Determination of the site of injury can be aided by CT and MRI scanning. Verification of the presence of olfactory deficit, and assessment of its severity requires objective olfactory testing, which can be accomplished with a number of methods. The prognosis of posttraumatic olfactory dysfunction is unfortu-nate, with approximately only one third improving. Emphasis must be placed on identification of reversible causes, such as nasal bone fractures, septal deviation, or mucosal edema/hema-toma. Olfactory loss is often discounted as an annoyance, rather than a major health concern by both patients and many healthcare providers. Patients with olfactory impairment have diminished quality of life, decreased satisfaction with life, and increased risk for personal injury. Paramount to the management of these patients is counseling with regard to adoption of compensatory strategies to avoid safety risks and maximize quality of life. Practicing otolar-yngologists should have a thorough understanding of the mechanisms of traumatic olfactory dysfunction in order to effectively diagnose, manage, and counsel affected patients.

关键词： Anosmia Head injury Smell

Protective role of Triphala, an Indian traditional herbal formulation, against the nephrotoxic effects of bromobenzene in Wistar albino rats

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journal of Integrative Medicine 2015年第2期13卷 115-121页

作者： Udhaya Lavinya Baskaran Sherry joseph Martin Rasool Mahaboobkhan Sabina evan Prince School of Biosciences and Technology VIT University

OBjECTIVE： The purpose of the present study was to evaluate the nephroprotective and antioxidant properties of Triphala against bromobenzene-induced nephrotoxicity in female Wistar albino rats. METHODS： Animals were divided into five groups of six rats and treated as follows： Group I was a normal control and received no treatment, Group II received only bromobenzene （10 mmol/kg）, Groups III and IV received bromobenzene and Triphala （250 and 500 mg/kg, respectively）, Group V received Triphala alone （500 mg/kg）, and Group VI received bromobenzene and silymarin （100 mg/kg） Antioxidant status and serum kidney functional markers were analyzed. RESULTS： Bromobenzene treatment resulted in significant （P 〈 0.05） decreases in the activities of antioxidant enzymes such as catalase, superoxide dismutase, glutathione-S-transferase and glutathione peroxidase as well as total reduced glutathione. There was a significant （P 〈 0.05） increase in lipid peroxidation in kidney tissue homogenates. There were significant （P 〈 0.05） reductions in the levels of serum total protein and albumin as well as significant （P 〈 0.05） increases in serum creatinine, urea and uric acid. The oral administration of two different doses （250 and 500 mg/kg） of Triphala in bromobenzene-treated rats normalized the tested parameters. The histopathological examinations of kidney sections of the experimental rats support the biochemical observations. CONCLUSION： Triphala treatment alleviated the nephrotoxic effects of bromobenzene by increasing the activities of antioxidant enzymes and reducing the levels of lipid peroxidation and kidney functional markers.

关键词： bromobenzene Triphala plant extracts antioxidants rats