检索结果-南通市图书馆

Leveraging quasi-periodic orbits for trajectory design in cislunar space

在线全文

学校读者我要写书评

暂无评论

Astrodynamics 2021年第2期5卷 139-165页

作者： brian P.Mccarthy Kathleen c.Howell School of Aeronautics and Astronautics Neil Armstrong Hall of EngineeringWest LafayetteIN47907-2045USA

Incorporating quasi-periodic orbits into the preliminary design process offers a wide range of options to meet mission constraints and address the challenges in a complex trade *** this investigation,linear stability and quasi-periodic orbit family continuation schemes are examined to meet various types of *** in eclipse avoidance and transfer design are examined by leveraging quasi-periodic orbits and their associated hyperbolic manifolds in the lunar *** are transitioned to an ephemeris model to validate that geometries are maintained in higher-fidelity *** the natural dynamical structures associated with quasi-periodic orbits are leveraged,novel trajectory solutions can emerge.

关键词： multi-body dynamical systems quasi-periodic orbits trajectory analysis cislunar trajectory design near rectilinear halo orbit ephemeris dynamical model

Mathematical operations and equation solving with reconfigurable metadevices

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2022年第10期11卷 2365-2377页

作者： Dimitrios c.Tzarouchis Mario Junior Mencagli brian Edwards Nader Engheta University of Pennsylvania Department of Electrical and Systems EngineeringPhiladelphiaPA 19104USA University of North carolina at charlotte Department of Electrical and Computer EngineeringCharlotteNC 28223USA

Performing analog computations with metastructures is an emerging wave-based paradigm for solving mathematical *** such devices,one major challenge is their reconfigurability,especially without the need for a priori mathematical computations or computationally-intensive *** equation-solving capabilities are applied only to matrices with special spectral(eigenvalue)*** we report the theory and design of wave-based metastructures using tunable elements capable of solving integral/differential equations in a fully-reconfigurable *** consider two architectures:the Miller architecture,which requires the singular-value decomposition,and an alternative intuitive direct-complex-matrix(DcM)architecture introduced here,which does not require a priori mathematical *** examples,we demonstrate,using system-level simulation tools,the solutions of integral and differential *** then expand the matrix inverting capabilities of both architectures toward evaluating the generalized Moore-Penrose matrix ***,we provide evidence that metadevices can implement generalized matrix inversions and act as the basis for the gradient descent method for solutions to a wide variety of ***,a general upper bound of the solution convergence time reveals the rich potential that such metadevices can offer for stationary iterative schemes.

关键词： equation operations Mathematical

Evaluating the quality of feed fats and oils and their effects on pig growth performance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2016年第3期7卷 330-340页

作者： Gerald c Shurson brian J Kerr Andrea R Hanson Department of Animal Science University of MinnesotaStPaulMN 55018USA usda-ars-national laboratory for agriculture and the environment Ames IA 50011USA svc-research St PeterMN 56082USA

Feed fats and oils provide significant amounts of energy to swine diets, but there is large variation in composition,quality, feeding value, and price among sources. common measures of lipid quality include moisture, insolubles,and unsaponifiables（MIU）, titer, and free fatty acid content, but provide limited information regarding their feeding value. Lipid peroxidation is an important quality factor related to animal growth performance and health, but maximum tolerable limits in various lipids have not been established. Several indicative assays can be used to detect the presence of various peroxidation compounds, but due to the complexity and numerous compounds produced and degraded during peroxidation process, no single method can adequately determine the extent of peroxidation. Until further information is available, using a combination of peroxide value, thiobarbituric acid reactive substances（TBARS）, and anisidine value appear to provide a reasonable assessment of the extent of peroxidation in a lipid at a reasonable cost. However, fatty acid composition of the lipid being evaluated should be considered when selecting specific assays. Predictive tests can also be used to estimate the stability or susceptibility of lipids to peroxidation and include active oxygen method, oil stability index, and oxygen bomb method. A review of 16 published studies with pigs has shown an average decrease of 11.4% in growth rate, 8.8% feed intake fed isocaloric diets containing peroxidized lipids compared to diets containing unperoxidized lipids of the same ***, serum vitamin E content was generally reduced and serum TBARS content was increased when peroxidized lipids were fed in these studies, suggesting that feeding peroxidized lipids negatively affects metabolic oxidative status of pigs. However, it is unclear if antioxidants are useful additions to lipids to maintain optimal nutritional value, or if their addition to swine diets is beneficial in overcoming a met

关键词： Growth Indicative tests Lipids Metabolic oxidation Peroxidation Pigs

Subaqueous early eruptive phase of the late Aptian Rajmahal volcanism,India:Evidence from volcaniclastic rocks,bentonite,black shales,and oolite

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2017年第4期8卷 809-822页

作者： Naresh c.Ghose Nilanjan chatterjee brian F.Windley G/608 Raheja ResidencyKoramangala Department of Earth Atmospheric and Planetary SciencesMassachusetts Institute of Technology Department of Geology The University of Leicester

The late Aptian（118-115 Ma） continental flood basalts of the Rajmahal Volcanic Province（RVP） are part of the Kerguelen Large Igneous Province,and constitute the uppermost part of the Gondwana Supergroup on the eastern Indian shield *** lower one-third of the Rajmahal volcanic succession contains thin layers of plant fossil-rich inter-trappean sedimentary rocks with pyroclasts,bentonite,grey and black shale/mudstone and oolite,whereas the upper two-thirds consist of sub-aerial fine-grained aphyric basalts with no inter-trappean *** the eastern margin and the north-central sector of the RVP,the volcanics in the lower part include rhyolites and dacites overlain by enstatite-bearing basalts and *** pyroclastic rocks are largely felsic in composition,and comprise ignimbrite as well as coarse-grained tuff with lithic clasts,and tuff breccia with bombs,lapilli and ash that indicate explosive eruption of viscous rhyolitic *** rhyolites/dacites（〉68 wt.%） are separated from the andesites（〈 60 wt.%） by a gap in silica content indicating their formation through upper crustal anatexis with only heat supplied by the basaltic *** the other hand,partially melted siltstone xenoliths in enstatite-bearing basalts suggest that the enstatite-andesites originated through mixing of the upper crust with basaltic magma,crystallizing orthopyroxene at a pressure-temperature of ~3 kb/1150℃.In contrast,the northwestern sector of the RVP is devoid of felsic-intermediate rocks,and the volcaniclastic rocks are predominantly mafic（basaltic） in ***,the presence of fine-grained tuffs,tuff breccia containing sideromelane shards and quenched texture,welded tuff breccia,peperite,shale/mudstone and oolite substantiates a subaqueous *** on these observations,we conclude that the early phase of Rajmahal volcanism occurred under predominantly subaqueous *** presence of grey and black shale/mudstone in the lower one-third of

关键词： Rajmahal basalt Andesite Rhyolite Pyroclast Black shale Oolite

characteristics of lipids and their feeding value in swine diets

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2016年第3期7卷 249-271页

作者： brian J.Kerr Trey A.Kellner Gerald c.Shurson USDA-ARS-National Laboratory for Agriculture and the Environment AmesIA 50011USA Department of Animal Science Iowa State UniversityAmesIA 50011USA Department of Animal Science University of MinnesotaSt.PaulMN 55108USA

In livestock diets, energy is one of the most expensive nutritional components of feed formulation. Because lipids are a concentrated energy source, inclusion of lipids are known to affect growth rate and feed efficiency, but are also known to affect diet palatability, feed dustiness, and pellet quality. In reviewing the literature, the majority of research studies conducted on the subject of lipids have focused mainly on the effects of feeding presumably high quality lipids on growth performance, digestion, and metabolism in young animals. There is, however, the wide array of composition and quality differences among lipid sources available to the animal industry making it essential to understand differences in lipid composition and quality factors affecting their digestion and metabolism more fully. In addition there is often confusion in lipid nomenclature, measuring lipid content and composition, and evaluating quality factors necessary to understand the true feeding value to animals. Lastly, advances in understanding lipid digestion, post-absorption metabolism, and physiological processes（e.g., cell division and differentiation, immune function and inflammation）; and in metabolic oxidative stress in the animal and lipid peroxidation, necessitates a more compressive assessment of factors affecting the value of lipid supplementation to livestock diets. The following review provides insight into lipid classification, digestion and absorption, lipid peroxidation indices, lipid quality and nutritional value, and antioxidants in growing pigs.

关键词： Digestion Energy Lipids Peroxidation Pigs

comparative Study of Hyperacuity and Retinometer Tests for the Evaluation of Vision in Patients with Advanced cataract

在线全文

学校读者我要写书评

暂无评论

眼科学报 1997年第3期13卷 164-166,161页

作者： George c Woo brian Brown University of Waterloo WaterlooHong Kong Polytechnic University CanadaHong Kong

Objective: To investigates the clinical application value of hyperacuity test for evaluating vision through dense ***: Ten normal subjects (20 years) were tested both with Bailey-Lovie type chart and three points vernier acuity test (one of the hyperacuity test) ; and retinometer test were performed preoperatively and postoperatively in 30 patients (31 eyes) with senile cataract. These patients' lens opacity was classified with LOGS III ***: The correlation of vernier acuity and visual acuity of normal subjects is significant. The result of difference compression of pre-surgical and post-surgical vernier acuity of 30 cataract patients is not significant. The correlation of retinometer findings with post-surgical visual acuity shows not statistically significant. Our result shows that there is good correlation between vernier acuity and post-surgical visual ***: It appears that hyperacuity is a good test for foveal function behind dense cataract and other ocular

关键词：听觉过敏视网膜病白内障视力评估

Instability after total hip arthroplasty

在线全文

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2012年第8期3卷 122-130页

作者： brian c we.ne. Thomas E Brown Department of Orthopedic Surgery University of Virginia School of Medicine Charlottesville VA 22908 United States

Instability following total hip arthroplasty(THA) is an unfortunately frequent and serious problem that requires thorough evaluation and preoperative planning before surgical intervention. Prevention through optimal index surgery is of great importance, as the management of an unstable THA is challenging even for an experienced joints surgeon. However, even after well-planned surgery, a significant incidence of recurrent instability still exists. Non-operative management is often successful if the components are well-fixed and correctly positioned in the absence of neurocognitive disorders. If conservative management fails, surgical options include revision of malpositioned components; exchange of modular components such as the femoral head and acetabular liner; bipolar arthroplasty; tripolar arthroplasty; use of a larger femoral head; use of a constrained liner; soft tissue reinforcement and advancement of the greater trochanter.

关键词： Instability Total hip arthroplasty Revision constrained liner Bipolar arthroplasty Large femoral head

Optimized stateful material implication logic for three- dimensional data manipulation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2016年第12期9卷 3914-3923页

作者： Gina c. Adam brian D. Hoskins Mirko Prezioso Dmitri B. Strukov Electrical and computer Engineering Department University of California Santa Barbara Santa Barbara CA 93106 USA Materials Department University of California Santa Barbara Santa Barbara CA 93106 USA

The monolithic three-dimensional integration of memory and logic circuits could dramatically improve the performance and energy efficiency of computing systems. Some conventional and emerging memories are suitable for vertical integration, including highly scalable metal-oxide resistive switching devices （＂memristors＂）. However, the integration of logic circuits has proven to be much more challenging than expected. In this study, we demonstrated memory and logic functionality in a monolithic three-dimensional circuit by adapting the recently proposed memristor-based stateful material implication logic. By modifying the original circuit to increase its robustness to device imperfections, we experimentally showed, for the first time, a reliable multi-cycle multi-gate material implication logic operation and half-adder circuit within a three- dimensional stack of monolithically integrated memristors. Direct data manipulation in three dimensions enables extremely compact and high-throughput logic- in-memory computing and, remarkably, presents a viable solution for the Feynman Grand challenge of implementing an 8-bit adder at the nanoscale.

关键词： material implication logic memristor resistive random-accessmemory (ReRAM) three-dimensionalintegration

State-of-the-Art management of knee osteoarthritis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of clinical cases 2015年第2期3卷 89-101页

作者： Kenton H Fibel Howard J Hillstrom brian c Halpern Department of Medicine Primary Care Sports MedicineHospital for Special Surgery Leon Root Motion Analysis Laboratory Department of RehabilitationHospital for Special Surgery

Osteoarthritis(OA) is the most common type of arthritis found in the United States' population and is also the most common disease of joints in adults throughout the world with the knee being the most frequently affected of all joints. As the United States' population ages along with the increasing trends in obesity prevalence in other parts of the world, it is expected that the burden of OA on the population, healthcare system, and overall economy will continue to increase in the future without making major improvements in managing knee OA. Numerous therapies aim to reduce symptoms of knee OA and continued research has helped to further understand the complex pathophysiology of its disease mechanism attempting to uncover new potential targets for the treatment of OA. This review article seeks to evaluate the current practices for managing knee OA and discusses emerging therapies on the horizon. These practices include non-pharmacological treatments such as providing patient education and self-management strategies, advising weight loss, strengthening programs, and addressing biomechanical issues with bracing or foot orthoses. Oral analgesics and anti-inflammatories are pharmacologicals that are commonly used and the literature overall supports that some of these medications can be helpful for managing knee OA in the short-term but are less effective for long-term management. Additionally, more prolonged use significantly increases the risk of serious associated side effects that are not too uncommon. Diseasemodifying osteoarthritis drugs are being researched as a treatment modality to potentially halt or slow disease progression but data at this time is limited and continued studies are being conducted to further investigate their effectiveness. Intra-articular injectables are also implemented to manage knee OA ranging from corticosteroids to hyaluronans to more recently plateletrich plasma and even stem cells while several other injection therapies are presently b

关键词： Disease-modifying osteoarthritis drugs Knee osteoarthritis Disease-modifying osteoarthritis drugs Osteoarthritis management Non-steroidal antiinflammatory drugs Hyaluronic acid Arthroscopy Platelet-rich plasma corticosteroids Stem cells