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1.
以北太平洋鱿鱼加工废弃的边角料为原料,采用双螺杆挤压技术,利用响应面分析方法研究了主要操作参数物料含水量、机筒温度和螺杆转速对鱿鱼蛋白挤出物的水分含量和堆积密度的影响,分别建立挤出物水分含量、堆积密度与操作参数的回归拟合方程。结果表明,物料含水量对挤出物水分含量的影响非常明显,两者呈现正相关关系,物料含水量和机筒温度的交互作用对挤出物的水分含量和堆积密度的影响均呈显著性;水分含量、堆积密度与操作参数的回归拟合方程的相关系数R2分别是0.952和0.819,拟合的统计模型具有较高的可信度。  相似文献   
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【目的】通过在三个不同气候地区的试验,研究气候因素对农用氧化型降解地膜降解的影响,为此类降解地膜在不同地区的应用而调整添加剂配方提供指导。【方法】太阳辐射、温度和湿度是控制降解速度的主要因素,通过红外光谱分析,力学性能和分子量测试来评估他们对降解的影响。【结果】太阳辐射强度对氧化型降解地膜的降解影响最大。经过6个月太阳照射后,含有高浓度添加剂的降解膜,降解速率快。【结论】氧化型农用降解地膜的降解速率主要受太阳辐射强度控制,温度和湿度对降解速率影响较轻。当分子量小于5道尔顿时,降解膜碎片能够被微生物消化。  相似文献   
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An immunosuppressive factor(s) which is heat stable, and dialysable, with a molecular weight less than 10,000 molecular weight, and is not species specific, has been shown to be produced during the in vitro culture of Onchocerca gibsoni microfilariae. The factor(s) is capable of abolishing lymphocyte mitogenesis induced by Con A in bovine lymphocytes and PHA in human lymphocytes. The factor(s) may play a role in establishing the microfilariae in the tissues of the host by depressing cell mediated immune reactions during invasion.  相似文献   
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The d-wave pairing symmetry in high-critical temperature superconductors makes it possible to realize superconducting rings with built-in pi phase shifts. Such rings have a twofold degenerate ground state that is characterized by the spontaneous generation of fractional magnetic flux quanta with either up or down polarity. We have incorporated pi phase-biased superconducting rings in a logic circuit, a flip-flop, in which the fractional flux polarity is controllably toggled by applying single flux quantum pulses at the input channel. The integration of p rings into conventional rapid single flux quantum logic as natural two-state devices should alleviate the need for bias current lines, improve device symmetry, and enhance the operation margins.  相似文献   
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Context

In response to predominantly local and private approaches to landscape change, landscape ecologists should critically assess the multiscalar influences on landscape design.

Objectives

This study develops a governance framework for Nassauer and Opdam’s “Design-in-Science” model. Its objective is to create an approach for examining hierarchical constraints on landscape design in order to investigate linkages among urban greening initiatives, patterns of landscape change, and the broader societal values driving those changes. It aims to provide an integrative and actionable approach for landscape sustainability science.

Methods

This framework is examined through an ethnographic study of public policy processes surrounding the urban tree initiatives in Boston, MA; Philadelphia, PA; and Baltimore, MD.

Results

These initiatives demonstrate the impact of political and economic decentralization on urban landscape patterns. Their collaborative governance approach incorporates diverse resources to implement programming at a fine-scale. The predominant tree giveaway program fragments the urban and regional forest.

Conclusion

Spatial and temporal fragmentation undermines the long-term security of urban greening programs, and it suggests reconsideration of the role of state regimes in driving broad scale spatial planning.
  相似文献   
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Antimicrobial resistance is a public health emergency, placing veterinary antimicrobial use under growing scrutiny. Antimicrobial stewardship, through appropriate use of antimicrobials, is a response to this threat. The need for antimicrobial stewardship in Australian veterinary practices has had limited investigation. A 2016 survey undertaken to investigate antimicrobial usage patterns by Australian veterinarians found that antimicrobial dose rates were varied and often inappropriate. Doses of procaine penicillin in horses and cattle were often low, with 68% and 90% of respondents, respectively, reporting doses that were unlikely to result in plasma concentrations above minimum inhibitory concentrations for common equine and bovine pathogens. Frequency of penicillin administration was also often inappropriate. Gentamicin doses in horses were largely appropriate (89% of dose rates appropriate), but 9% of respondents reported twice daily dosing. Amoxycillin and amoxycillin‐clavulanate were administered at the appropriate doses, or above, to dogs and cats by 54% and 70% of respondents, respectively. Here, we explore the potential reasons for inappropriate antimicrobial dose regimens and report that antimicrobial labels often recommend incorrect dose rates and thus may be contributing to poor prescribing practices. Changes to legislation are needed to ensure that antimicrobial drug labels are regularly updated to reflect the dose needed to effectively and safely treat common veterinary pathogens. This will be especially true if changes in legislation restrict antimicrobial use by veterinarians to the uses and doses specified on the label, thus hampering the current momentum towards improved antimicrobial stewardship.  相似文献   
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Morphological variation of the skull was examined in the northern treeshrew (Tupaia belangeri) from various localities across Southeast Asia. Through a multivariate analysis, the treeshrews from South Vietnam exhibited distinct morphological characteristics compared to other populations from Thailand and Laos, and Malaysia. The plots of the specimens of North Vietnam are not randomly mixed with Thailand plots segregation in the scatteregrams of canonical discriminant analysis. Since the skulls of the population from North Vietnam were morphologically similar to those form central Laos and northern and northeastern Thailand, the zoogeographical barrier effect of Mekong River was not clearly confirmed. The population of the Kanchanaburi in western Thailand is clearly smaller in size compared to the other populations. The southern border of the distribution of this species is determined by the Isthmus of Kra or Kangar-Pattani Line. In the northern treeshrew, which is distributed from southern China to Bangladesh and southern Thailand, we have detected osteometrical geographical variation driven by geography. These results indicate that the skull morphology in the Tupaia glis-belangeri complex distinctively differs in South Vietnam, western Thailand, and southern Thailand. The zoogeographical barrier and factor separating these districts are expected to clarify in the future.  相似文献   
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