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From time immemorial people dealt with size reduction processes (mill, mineral liberation, etc.). As time has passed industrial units for comminution processes have become larger and more sophisticated, but still they perform with low efficiencies [1], [2] and [3]. The strength of a particle is one of its most crucial characteristics due to the mechanical stresses experienced by each particle within an industrial unit. This is because the final size of particles is mostly dependant on the strength distribution of the raw material [4]. In this present study, the ability of a number of statistical formulations to accurately describe the strength distribution of particles was examined. Additionally, selected equations were analyzed and a general expression including the effect of the material and particle size was developed. A number of approaches to define particle strength were considered, and strength in terms of crushing force was chosen. Particle strength in terms of force and in terms of energy was also compared and found to be size independent. Finally, particle strength in terms of stress was examined and compared to the particle strength in terms of force.The ability to describe the compression strength distribution will significantly improve the accuracy of the comminution processes simulation, design and optimization. 相似文献
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Conceptual design is a crucial system lifecycle stage; but systematic methods for conceptual design evaluation are not well developed, and existing approaches are not satisfactory. In this work we describe implementation and assessment of an advanced simulation environment that can serve conceptual design evaluation purposes using Object‐Process Methodology (OPM). The simulation exploits two major advantages of the OPM modeling language: its integration of the structural and behavioral aspects of the system in a single type of diagram and the hierarchical organization of the model diagrams. Simulation of the system model is instrumental in understanding and exploring the behavioral aspects of the system under study and uncovering logical and conceptual problems, such as incorrect control flow, logical errors, and missing structural relations among objects. Understanding the model and correcting it are achieved via an intuitive user interface and a host of debugging capabilities, including “lifespan” and “Debug Info” components. Using these components, one can explore the state of any OPM entity and be aware of a variety of potential problems that are manifested during the simulation process. © 20133 Wiley Periodicals, Inc. Syst Eng 16 相似文献
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High-performance fluidic lenses with an adjustable focal length spanning a very wide range (30 mm to infinite) are demonstrated. We show that the focal length, F-number, and numerical aperture can be dynamically controlled by changing the shape of the fluidic adaptive lens without moving the lens position mechanically. The shortest focal length demonstrated is less than 30 mm for a 20-mm lens aperture. The fluidic adaptive lens has a nearly perfect spherical profile and shows a resolution better than 40 line pairs/mm in a plano-convex structure and 57 line pairs/mm in a biconvex structure. 相似文献
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Magnetic accumulating core counters having large capacity and good linearity can be built by using the flux flyback in rectangular-hysteresis-loop cores for forming constant flux increments. Such counters can be used as analog memory and adaptive elements for building contactless controllable linear resistors with memory, etc. Their use in accumulating logical matrices for statistical processing of stochastic signals is considered. 相似文献
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Marco Fillo Stephen W. Keckler William J. Dally Nicholas P. Carter Andrew Chang Yevgeny Gurevich Whay S. Lee 《International journal of parallel programming》1997,25(3):183-212
The M-Machine is an experimental multicomputer being developed to test architectural concepts motivated by the constraints
of modern semiconductor technology and the demands of programming systems. The M-Machine computing nodes are connected with
a 3-D mesh network; each node is a multithreaded processor incorporating 9 function units, on-chip cache, and local memory.
The multiple function units are used to exploit both instruction-level and thread-level parallelism. A user accessible message
passing system yields fast communication and synchronization between nodes. Rapid access to remote memory is provided transparently
to the user with a combination of hardware and software mechanisms. This paper presents the architecture of the M-Machine
and describes how its mechanisms attempt to maximize both single thread performance and overall system throughput. The architecture
is complete and the MAP chip, which will serve as the M-Machine processing node, is currently being implemented. 相似文献
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Teng Su Ke Huang Hong Ma Hongxia Liang Phuong‐Uyen Dinh Justin Chen Deliang Shen Tyler A. Allen Li Qiao Zhenhua Li Shiqi Hu Jhon Cores Brianna N. Frame Ashlyn T. Young Qi Yin Jiandong Liu Li Qian Thomas G. Caranasos Yevgeny Brudno Frances S. Ligler Ke Cheng 《Advanced functional materials》2019,29(4)
Cardiovascular disease is the leading cause of mortality worldwide. While reperfusion therapy is vital for patient survival post‐heart attack, it also causes further tissue injury, known as myocardial ischemia/reperfusion (I/R) injury in clinical practice. Exploring ways to attenuate I/R injury is of clinical interest for improving post‐ischemic recovery. A platelet‐inspired nanocell (PINC) that incorporates both prostaglandin E2 (PGE2)‐modified platelet membrane and cardiac stromal cell‐secreted factors to target the heart after I/R injury is introduced. By taking advantage of the natural infarct‐homing ability of platelet membrane and the overexpression of PGE2 receptors (EPs) in the pathological cardiac microenvironment after I/R injury, the PINCs can achieve targeted delivery of therapeutic payload to the injured heart. Furthermore, a synergistic treatment efficacy can be achieved by PINC, which combines the paracrine mechanism of cell therapy with the PGE2/EP receptor signaling that is involved in the repair and regeneration of multiple tissues. In a mouse model of myocardial I/R injury, intravenous injection of PINCs results in augmented cardiac function and mitigated heart remodeling, which is accompanied by the increase in cycling cardiomyocytes, activation of endogenous stem/progenitor cells, and promotion of angiogenesis. This approach represents a promising therapeutic delivery platform for treating I/R injury. 相似文献
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The supermolecular structures of natural bitumens of the thermal consequent row asphaltites ⇒ lower kerites (albertites) ⇒ higher kerites (impsonites) ⇒ anthraxolites from the Timan-Pechora petroleum province and Karelian shungite rocks, Russia, were studied in details.The experimental technique used was atomic force microscopy (AFM), following fracture preparation. The element distribution of the sample surfaces was analyzed by an X-ray microanalyser “Link ISIS”, combined with a scanning electron microscope (SEM).In this work, we characterized the supermolecular evolution of natural solid bitumens in the carbonization sequence by quantitative parameters. We showed that supermolecular structure can be important in defining to which classification group solid bitumens belong. 相似文献
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Diamond Gary M.; Lipsitz Joshua D.; Fajerman Zvi; Rozenblat Ornit 《Canadian Metallurgical Quarterly》2010,41(2):103
Reports an error in "Ongoing traumatic stress response (OTSR) in Sderot, Israel" by Gary M. Diamond, Joshua D. Lipsitz, Zvi Fajerman and Omit Rozenblat (Professional Psychology: Research and Practice, 2010[Feb], Vol 41[1], 19-25). In the article “Ongoing Traumatic Stress Response (OTSR) in Sderot, Israel,” by Diamond, Lipsitz, Fajerman and Rozenblat (Professional Psychology: Research and Practice, 2010, Vol. 41, No. 1., pp. 19–25), due to a production error, the last author’s name was misspelled in the byline and the author note. The correct spelling is Ornit Rozenblat. (The following abstract of the original article appeared in record 2010-02467-003.) In Sderot, a small city in southern Israel, seven years of continuous missile attacks have led to dramatic increases in treatment seeking for anxiety symptoms. For some clients, the clinical picture is consistent with a diagnosis of post traumatic stress disorder (PTSD). For other clients, however, the onset and constellation of symptoms are less typical of PTSD. In these cases, anxiety symptoms seem to evolve gradually and be associated with ongoing, daily stress about imminent attacks, rather than with a discrete, past traumatic event. Much of their avoidance behavior is reality based. They report hyperarousal, severe distress, and loss of control during and immediately following actual missile attacks. However, they are less likely to exhibit reexperiencing symptoms. Furthermore, in contrast to the typical presentation of PTSD, their symptoms tend to diminish dramatically or completely resolve when they are no longer within harm’s way. We suggest that this clinical presentation may be best understood as an ongoing traumatic stress response (OTSR), rather than PTSD or PTSD symptoms. We consider diagnostic features which discriminate between these two phenomena as well as implications for treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献