From killer to carer: steroid hormones and paternal behaviour     

Ruan de Bruin  Andre Ganswindt  Aliza le Roux 《African Zoology》2016,51(4):173-182

Mammalian parental investment (i.e. care of descendant offspring) is largely biased towards maternal contributions due to the specific feeding needs of mammalian offspring; however, varying degrees of paternal investment have been reported in about 10% of all mammalian species. Within the order Carnivora, paternal contribution to rearing offspring is particularly high: an estimated 32% of all studied carnivore species exhibit direct paternal care. Despite the prominence of paternal investment in carnivores, the endocrine basis of this behaviour is not well understood. This review examines the current – highly constrained – state of knowledge about the endocrine basis of carnivore paternal investment. We attempt to link changes in androgen and glucocorticoid levels with variation in direct and indirect paternal care behaviour making specific predictions regarding the way forward. Well-studied species, such as bat-eared foxes (Otocyon megalotis), dwarf mongoose (Helogale parvula) and meerkats (Suricata suricatta), where social dynamics are relatively well understood, can act as ideal model systems through which we may further investigate the endocrine basis of paternal investment in carnivores.  相似文献   

Using morphometrics to identify sex in the eastern blue-tongued skink (Tiliqua scincoides)     

A Bird  D Monks  IP Hughes 《Australian veterinary journal》2023,101(7):282-290

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Research on Relationship between the Level of Urbanization and the Growth of Real Estate Investment          下载免费PDF全文

XIANG Wei -min  LI Jiao 《保鲜与加工》2007,(1):106-109

The population proportion index is usually introduced to measure the level of urbanization, which is an important index to the national economy. The fast development of urbanization would inevitably cause the increase of the investment in real estate industry. Introducing the Granger Test of Causality analytical method, in this paper the relationship between the level of urbanization and the investment in real estate industry from 1986 to 2003 in China is analyzed. It reveals that both of them are on the stage of constant up - rising, and the correlation index of 0. 205 shows that the relationship between them is a mutual promoting causality.  相似文献   

Optimization of Curve Fitting Used in Development of Magic Formula Tire Model     

REN Guang-sheng 《保鲜与加工》2001,(3):22-25

Characteristics of a tire are the foundation of vehicle dynamics studying, especially play a vital role in vehicle handling study. It is necessary to establish a tire model in the simulation for vehicle handling because the tire characteristics got by test can not be satisfied.The optimization of fitting to the tire test data curves by Magic Formula is discussed, included the digitalization of tire test data curves, designing objective functions and optimization processes,etc. Finally the parameters in Magic Formula tire model are obtained and they lay a foundation for the development of vehicle handling aftertime.  相似文献   

A PRIMARY STUDY ON A LIFTING PERFORMANCE CURVE ADAPTED FOR THE MECHANICAL LOAD MOMENT LIMITER     

Ren Yuanzhi 《保鲜与加工》1994,(1)

The condition when forces are applied to load mechnical mornent limiter of tow-er cranes is analysed and disctissed in this paper.A lifting performance curve adapted for the me-chanical load moment limiter is also obtained.And finally,the curve drawing method is explainedthrough the practical example.  相似文献   

Discussion on Evaluation Standards for Feasibility Study Report of Wastewater Treatment Plant     

LI Wei-min  DENG Rong-sen  HU Feng-ping  WANG Tao 《保鲜与加工》2002,(3):47-52

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Two-dimensional Optimum Cutting Stock Method Based on Internet and Its Implementing Technique     

YAN Chun ping  LIU Fei  Liu Xi gang 《保鲜与加工》2001,(5):1-4

Two dimensional Optimum Cutting Stock is a NP complicated problem. Each of optimum software gets the cutting results by using proximate and heuristic methods. But different optimum methods and their optimum software may not realize perfect effect according to certain data framework. Furthermore, enterprises can not buy lots of optimum software to choose the most optimized plan. Because of such problems, this paper provides a two dimensional optimum cutting stock method based on Internet and offers the real implementing technique of such method. The experiments, show that this method promotes the general optimum effect of two dimensional optimum cutting stock greatly.  相似文献   

Probing into Real Estate Investment Fund and Its Practice     

《保鲜与加工》2003,(3):91-95105

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The Monitoring Measurements and Country Rock Control of NATM in Tunnel of Express Road during Construction     

Liu Li Tang Janxin 《保鲜与加工》1995,(5):113-119

In this paper the author' s study on the monitoring measurement technique of NATM,the regularity and conditions of the country rock deformation are analysed based on the site measurement data in the west section of Zhongliangshan tunnel. The regression analysis of measure data for different measure lines of vavious country rock is done by the use of self-compiled CRAP program. The stability criterion for various rockmass and optimum time for primary and permanent support are provided. The conclusion available could conduct the theoretical research of NATM deeply as well as tunnel design and construction.  相似文献   

OPTIMAL CONTROL ELIMINATING SWING FOR THE LIFTING CAPACITY     

Yao Jiafei 《保鲜与加工》1994,(2)

This paper discusses the model for lifting capacity of the crane and optimal con-trol of eliminating swing in lifting process. One half loop control method is presented, which is onlyto examine and measure the trolley speed for eleiminating swing.The fact shows this methOd is sim-ple and practicle for enginceering.  相似文献