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Heat load of a GaAs photocathode in an SRF electron gun

2009中国控制与决策会议

作者： zvi Retchkiman Knigsberg Instituto Politécnico Nacional CIC Mineria 17-2Col.EscandonMexico D.F 11800Mexico

＜正＞In this paper an algorithm for computing a generalized eigenmode of reducible regular matrices over the max-plus algebra is *** a matrix of finite size,the problem consists in giving an algorithm which will tell us how to compute its generalized eigenmode over the max plus algebra. The solution to the problem is achieved by studying some type of recurrent *** fact, by transforming the reducible regular matrix into its normal form,and considering a very specific recurrent equation,an explicit mathematical characterization is obtained,upon which the algorithm is constructed.

关键词： Index terms- Max-Plus Algebra Reducible Matrices Eigenmode Recurrent Equations Algorithm.

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Chinese Physics C 2011年第4期35卷 387-391页

作者：王尔东 Jrg Kewisch Ilan Ben-zvi Andrew Burrill Trivini Rao 吴琼 Animesh Jain Ramesh Gupta Doug Holmes 赵夔 Institute of Heavy Ion Physics Peking University Brookhave National Lab Advance Energy System

A great deal of effort has been made over the last decades to develop a better polarized electron source for high energy physics. Several laboratories operate DC guns with a gallium arsenide photocathode, which yield a highly polarized electron beam. However, the beam’s emittance might well be improved by using a superconducting radio frequency （SRF） electron gun, which delivers beams of a higher brightness than that from DC guns because the field gradient at the cathode is higher. SRF guns with metal and CsTe cathodes have been tested successfully. To produce polarized electrons, a Gallium-Arsenide photo-cathode must be used： an experiment to do so in a superconducting RF gun is under way at BNL. Since a bulk gallium arsenide （GaAs） photocathode is normal conducting, a problem arises from the heat load stemming from the cathode. We present our measurements of the electrical resistance of GaAs at cryogenic temperatures, a prediction of the heat load and verification by measuring the quality factor of the gun with and without the cathode at 2 K. We simulate heat generation and flow from the GaAs cathode using the ANSYS program. By following the findings with the heat load model, we designed and fabricated a new cathode holder （plug） to decrease the heat load from GaAs.

关键词： SRF gun GaAs photocathode heat load 2 K test

<i>Padina pavonica</i>: Morphology and Calcification Functions and Mechanism

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American Journal of Plant Sciences 2018年第6期9卷 1156-1168页

作者： Miriam Benita zvi Dubinsky David Iluz The Mina & amp Everard Goodman Faculty of Life Sciences Bar-Ilan University Ramat-Gan Israel

Padina pavonica is one of the common macro-algae that inhabit coastal inter-tidal zones around the world. It is one of the two brown algae known to science today that calcifies. It precipitates CaCO3 in the microscopy form of Aragonite needle shape seen macroscopically as a vertical ventral stripes. Here we will summarize the information available since the beginning of the 20th century, taking into consideration the algal distribution, macro and micro-morphology, cytology, reproduction, CaCO3 bio-mineralization, and a slight reference to the commercial aspects, i.e., its use in the medical and cosmetic industries. This paper discusses the likely advantages that Padina gains by the calcification and the effect of pH caused by global climate changes on this calcification. We will describe the distribution of Padina, while focusing on the morphology of P. pavonica, as described in the literature, occasionally comparing it to another common species in Tel-Baruch—P. gymnospora. This review is somewhat prolog for the upcoming research.

关键词： Padina Pavonica Morphology Calcification Reproduction

Corporate Social Responsibility （CSR） and Firm Performance

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Journal of Modern Accounting and Auditing 2012年第11期8卷 1691-1703页

作者： zvi Amrousy Ilanit Gavious Hagai Katz Rami Yosef Ben-Gurion University Beersheba Israel

The discourse of corporate social views of the role of the firm in a responsibility （CSR） has grown rapidly over the last decade. There are different society and disagreements as to whether wealth maximization should be the sole goal of a corporation. There is also a debate on whether CSR practices are beneficial for firms. Studies examining the performance of firms that have adopted a CSR policy within a range of sectors in various countries provide inconsistent results. Some studies show excess returns among companies adopting a CSR policy relative to the companies that do not adopt such a policy, while others do not find differences in returns. To further dispel the ambiguity on this issue, the authors explore the relationship between CSR adoption and financial performance of firms＇ shares in Israeli market, with a US market benchmark as a test of specificity. The findings reveal that no significant difference exists between the performance of firms adopting a CSR policy and firms that do not. Thus, the inclusion of investments in socially-responsible firms in an investor＇s portfolio does not appear to significantly impact the portfolio＇s performance. Managers and investors interested in investing in CSR may do so without any concern of the lower returns or performance. This study provides an additional support for the CSR School in that its findings indicate that, on the one hand, investments in firms that integrate social and environmental responsibility are just ＂as good as＂ investments in firms that do not. On the other hand, such investments can be seen as superior, since in addition to the financial returns, investors contribute to changing the face of the global environment and are creating a system for support and enforcement that ensures the existence of a better world for the children in the present and future.

关键词： corporate social responsibility (CSR) firm value performance return

Neck Motion Restriction Negatively Affects Turning Stability in Community-Dwelling Older Adults with and without a History of Falls

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Advances in Aging Research 2022年第2期11卷 35-49页

作者： Luzit Hadad Herman Avner Cohen Netta Kram zvi Kozol Physical Therapy Department School for Community Health Professions Faculty of Health Sciences Ariel University Ariel Israel Rotschild Physiotherapy Department Clalit Health Services Petach-Tikva Israel Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel Pediatric Ambulatory Center General Health Services Petach Tikva Israel

Background: Many older adults fall while turning. During the turning maneuver, rotation of the head precedes the rest of the body, creating a spatial frame of reference. Limitations of the neck rotation, may interfere with the turning mechanism, affect stability, and lead to recurrent falls. However, the association between the range of the neck rotation and turning stability was not explored yet. Purpose: To compare the impact of restricting the neck rotation by a brace, on the turning stability of adults with and without a history of falls. Methods: An observational, cross-sectional study consisting of 59 adults (average age 76 ± 6.9). A group (N = 29) with at least 2 falls (FL) in the last year and a group (N = 30) without a history of falls in the last year (NFL). All participants performed three tests: Timed up and Go (TUG), 180° Turn Test (180 TT) and 360° Turn Test (360 TT) with and without a neck brace. Results: All the scores of the FL were lower than those of the NFL (p Application of the brace worsened the performance of the 180 TT and the 360 TT of both groups (p < 0.05) but there was no interaction between group and bracing. The TUG score of only the NFL was affected by the brace (p < 0.004). Interestingly, only the range of the right neck rotation was correlated with balance tests and number of falls (r = 0.272;p Conclusions: Restricting of the neck mobility worsened the turning stability of both groups but without interaction. The study reinforces the need of considering the neck range of motion when addressing adult stability. A decrease in the range of right neck rotation was identified as a risk factor for loss of balance.

关键词： Balance Turning Neck-Brace Neck-Rotation Fall

Ripple Tectonics—When Subduction Is Interrupted

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Positioning 2020年第3期11卷 33-44页

作者： zvi Ben-Avraham Gerald Schubert Emanuele Lodolo Uri Schattner Department of Geophysics Porter School of the Environment and Earth Sciences Tel Aviv University Tel Aviv Israel Leon H. Charney School of Marine Sciences University of Haifa Haifa Israel Department of Earth Planetary and Space Sciences University of California Los Angeles USA National Institute of Oceanography and Experimental Geophysics Sgonico Italy Dr. Moses Strauss Department of Marine Geosciences Leon H. Charney School of Marine Sciences University of Haifa Haifa Israel

Subduction plays a fundamental role in plate tectonics and is a significant factor in modifying the structure and topography of the Earth. It is driven by convection forces that change over a >100 Myr time scale. However, when an oceanic plateau approaches, it plugs the subduction, and causes slab necking and tearing. This abrupt change may trigger a series of geodynamic (tectonic, volcanic) and sedimentary responses recorded across the convergence boundary and its surrounding regions by synchronous structural modifications. We suggest that a large enough triggering event may lead to a ripple tectonic effect that propagates outwards while speeding up the yielding of localized stress states that otherwise would not reach their threshold. The ripple effect facilitates tectonic, volcanic, and structural events worldwide that are seemingly unrelated. When the world’s largest oceanic plateau, Ontong Java Plateau (OJP), choked the Pacific-Australian convergence zone at ~6 Myr ago, it induced kinematic modifications throughout the Pacific region and along its plate margins. Other, seemingly unrelated, short-lived modifications were recorded worldwide during that time window. These modifications changed the rotation of the entire Pacific plate, which occupies ~20% of the Earth’s surface. In addition, the Scotia Sea spreading stopped, global volcanism increased, the Strait of Gibraltar closed, and the Mediterranean Sea dried up and induced the Messinian salinity crisis. In this paper, we attribute these and many other synchronous events to a new “ripple tectonics” mechanism. We suggest that the OJPincipient collision triggered the Miocene-Pliocene transition. Similarly, we suggest that innovative GPS-based studies conducted today may seek the connectivity between tectonic, seismic, and volcanic events worldwide.

关键词： Plate Tectonics Subduction-Collision Transition Miocene-Pliocene Transition

Essentials of investments 4th ed.

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Mapping What They Know: Concept Maps as an Effective Tool for Assessing Students’ Systems Thinking

2001年

作者： Bodie zvi.

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American Journal of Operations Research 2013年第1期3卷 245-258页

作者： Jaklin Tripto Orit Ben-zvi Assaraf Miriam Amit Department of Science and Technology Education Ben Gurion University of the Negev Beer Sheva Israel

In 2006 anew biology curriculum called “Human Biology: Emphasizing the Role of Homeostasis” was introduced into the Israeli high school system. Complex systems like those that make up the human body have become increasingly important as a focus of high school education. This study examines the effectiveness of the concept map as a assessment tool for students’ systems thinking, a tool that provides researchers with a detailed picture of the systems thinking development taking place within individual students. The content of the students’ concept maps was translated into information about students’ system thinking using the Systems Thinking Hierarchy (STH) model, a model in which system thinking is categorized according to eight hierarchical characteristics or abilities. The goal was to use the maps to characterize Israeli high school students’ understanding of the body’s systemic nature. To do this, we identified the extent to which the students understand three central elements of systems, namely hierarchy, homeostasis, and dynamism, and then analyzed this understanding according to its place within the hierarchical stages of the STH model. The extensive qualitative data analysis of 48 concept maps made by 11th grade biology majors suggest that the strength of the concept map is in its ability to describe the first two levels of system thinking (analysis and synthesis). However, it proved less successful in eliciting evidence of the third and highest level, particularly of students’ understanding of patterns, of homeostasis and their capacity for temporal thinking.

关键词： Human Body System Systems Thinking Concept Map

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中东欧及前苏联国家农村土地改革的比较

世界农业 2001年第11期 15-17页

作者： Csaba Csaki zvi Lerman 杨丽农业部农村经济研究中心

1989-1991年,欧洲和中亚的若干前社会主义国家(简称ECA国家)开始由计划经济向市场经济转型.由于农业在这一地区占有举足轻重的地位,因此以土地改革为主的农业改革成为经济转型的重要内容.这些国家由于受原有制度的桎梏,农业改革在许多... 详细信息

1989-1991年,欧洲和中亚的若干前社会主义国家(简称ECA国家)开始由计划经济向市场经济转型.由于农业在这一地区占有举足轻重的地位,因此以土地改革为主的农业改革成为经济转型的重要内容.这些国家由于受原有制度的桎梏,农业改革在许多方面都具有相似性.宏观上都需要解除中央的集权控制,放开价格,引入严格预算约束机制;微观上则需要在市场经济的框架内实行土地私有化,变集体农业为家庭农业,减小农场规模.最终提高农业的生产率和效益,建立起高效、竞争的农业.

关键词：中东欧前苏联国家农村土地改革