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131.
The maximum consumption of the larvae of the pest and vector mosquitoCulex quinquefasciatus by the predatory mosquitoCulex (Lutzia) raptor was studied at various instars of both the predator and the prey. The prey preferences of the predator when given lavae of different instars were also investigated. The IVth instar of the predator consumed the maximum number of Ist instar and the maximum biomass of IVth instar larvae of the prey. Instars I and II of the predator preferred the Ist of the prey; instars III and IV of the predator preferred instars II and III of the prey respectively.The predator consumed an average of 157.1 larvae during its whole larval period, when each instar of the predator was given its preferred instar of the prey.  相似文献   
132.
用子波变换分析方法实时监测视觉诱发电位的潜伏期   总被引:1,自引:0,他引:1  
诱发电位的实时监测在临床中有重要意义。本文提出利用多分辨率子波分析技术来实时监测视觉诱发电位的潜伏期。为克服随机噪声的影响,我们引入相邻响应的相关系数来修正所检测得的潜伏期的偏移,并应用前一次响应的波峰位置来决定当前的搜寻范围。实验表明,本方法能实时监测视觉诱发电位的潜伏期。  相似文献   
133.
针对二进制第Ⅱ类混合自动请求重传差错控制系统流量偏低的问题,提出了基于Reed-Solomon(RS)码的多进制混合自动请求重传方案.该方案将信息经RS码编码后,采用多进制调制,信息部分与校验部分分开传输,码的可逆性使得仅由无误的校验部分便可恢复出信息,利于提高流量.数值结果表明,该方案在Rician衰落信道下的流量比传统的二进制方案有了明显提高,同时可靠性依然保持与二进制方案相同的水平.  相似文献   
134.
The pericratonic sedimentary Jaisalmer Basin, west of the Aravalli Ranges, on the westerly dipping eastern flank of the Indus Shelf, is a principal structural element of Rajasthan. Jurassic sediments in the SE comprise non-marine sandstones and conglomerates to nearshore, brackish to marine sands, silts, clays and carbonates, grouped lithostratigraphically into the Lathi, Jaisalmer, Baisakhi, and Bhadasar formations. The Late Bajocian to Oxfordian Jaisalmer Formation is divided, in ascending order, into the Hamira, Joyan, Fort, Badabag, Kuldhar, and Jajiya members. Fossil records providing a Bajocian to Bathonian age for the lower and middle parts of the formation include: a Late Bajocian coral Isastraea bernardiana (d’Orbigny) in the uppermost Joyan Member; Bathonian ammonite Clydoniceras in the basal part of the Badabag Member; Bathonian foraminiferal/bivalve assemblages in the Fort Member. The topmost bed of the Joyan Member represents the peak of first marine transgression of the Jaisalmer Basin, probably contemporaneous with the Late Bajocian one in the neighbouring Kachchh Basin. Based on faunal studies Bajocian to Bathonian sediments of the Jaisalmer Basin can be broadly correlated with those of the Kachchh Basin. The Fort and Badabag members represent the following depositional environments, in chronological order: (a) brackish to shallow fully marine; (b) fully marine with rapidly fluctuating water energy and sedimentation rates; (c) near-shore to lower shoreface with fluctuating energy conditions, salinity and sedimentation rates; (d) near-shore to shoreface channels and storm-dominated marine above fair-weather wave-base; (e) lagoon with fluctuating low to moderate energy, salinity and sedimentation rates; (f) stormdominated shelf to lower shoreface.  相似文献   
135.
论信息市场环境下的图书馆营销观   总被引:3,自引:1,他引:3  
分析了信息市场的发展对图书馆信息资源建设、信息技术的开发以及信息传播方式和获取手段所产生的影响,探讨了面对激烈的市场竞争图书馆引入营销观念的必要性,并对具体的营销策略做了详尽的阐述。  相似文献   
136.
层次分析法在西藏日土地区旅游资源评价中的应用   总被引:13,自引:0,他引:13  
旅游资源评价是科学开发旅游资源的基础.以西藏日土地区为例,运用层次分析法对其旅游资源进行评价,在系统分析基础上建立综合评价模型,经一致性检验后计算各因子的相对权值并模糊打分.结合权值结果和得分,分析了旅游品质、主次因子和旅游潜力.评价结果表明,日土地区旅游品质较高,在生态容量和环境容量框架内系统有序地开发当地旅游资源现实可行.为进一步开发日土地区旅游资源提供了可行性论证和参考措施.  相似文献   
137.
Nomenclature ki integral action coefficient[s-1]kp speed proportional gain[s-1]kv position proportional gain[s-1]kf feed forward factor of the speed loop[%]M axis mass[kg]V speed[m/s]F driving effort[N]Rc radius of curvature[m]d distance to the apex[m]o lateral offset[m]εcontouring error[m]ωm lowest mechanical resonant frequency[s-1]ζdamping coefficient[-]r inertia ratio[-]μmembership function[-]αcorner angle[rad]x,y horizontal and vertical coordinates[m]?angle to the normal line[rad]1.I…  相似文献   
138.
Crushing is a size reduction process that plays a key role in both mineral processing and crushing-screening plant design. Investigations on rock crushability have become an important issue in mining operations and the manufacture of industrial crusher equipment. The main objective of this research is to quantify the crushability of hard rocks based on their mineralogical and mechanical properties. For this purpose, the mineralogical, physical, and mechanical properties of various hard rocks were determined. A new compressive crushing value (CCV) testing methodology was proposed. The results obtained from CCV tests were compared with those from mineralogical inspections, rock strength as well as mechanical aggregate tests. Strong correlations were found between CCV and several rock and aggregate properties such as uniaxial compressive strength (UCS), the brittleness index (S20), and aggregate impact value (AIV). Furthermore, the relationship between the mineralogical properties of the rocks and their CCVs were established. It is concluded that the proposed testing methodology is simple and highly repeatable and could be utilized as a pre-design tool in the design stage of the crushing process for rock quarries.  相似文献   
139.
The pig-nosed freshwater turtle Carettochelys insculpta Ramsay, 1886 has paddle-shaped foreflippers that resemble those of sea turtles. These turtles exhibit a wide range of swimming capabilities. As well as swimming by the action of synchronized foreflippers alone, they sometimes used alternate hindlimb action at the same time. They could swim by ipsilaterally synchronized action of all four limbs, or by hindlimb action alone (combined with stabilizer/lift function of the foreflippers). The turtles also showed flexibility in bottom-walking. Besides the ipsilaterally synchronized quadrupedal action characteristic of other freshwater turtles, they exhibited a bipedal walking mechanism never previously described. Propelled by alternate action of the hindlimbs, the animals held the head and plastron above the substratum, with the large foreflippers acting to provide anterior lift and stability against roll and yaw. Because both hindlimbs were sometimes off the substratum simultaneously during bipedal locomotion, their duty factors were < 0.5, implying a bipedal run.  相似文献   
140.
The Deterministic Input Noisy Output “AND” gate (DINA) model and the Deterministic Input Noisy Output “OR” gate (DINO) model are two popular cognitive diagnosis models (CDMs) for educational assessment. They represent different views on how the mastery of cognitive skills and the probability of a correct item response are related. Recently, however, Liu, Xu, and Ying demonstrated that the DINO model and the DINA model share a “dual” relation. This means that one model can be expressed in terms of the other, and which of the two models is fitted to a given data set is essentially irrelevant because the results are identical. In this article, a proof of the duality of the DINA model and the DINO model is presented that is tailored to the form and parameterization of general CDMs that have become the new theoretical standard in cognitively diagnostic modeling.  相似文献   
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