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71.
Estimation of actual evapotranspiration for a drip-irrigated Merlot vineyard using a three-source model 总被引:3,自引:3,他引:0
A study was performed in order to evaluate the three-source model (Clumped model) for direct estimation of actual evapotranspiration
(ETa) and latent heat flux (LE) over a drip-irrigated Merlot vineyard trained on a vertical shoot positioned system (VSP) under
semi-arid conditions. The vineyard, with an average fractional cover of 30%, is located in the Talca Valley, Region del Maule,
Chile. The performance of the Clumped model was evaluated using an eddy covariance system during the 2006/2007 and 2007/2008
growing seasons. Results indicate that the Clumped model was able to predict ETa with a root mean square error (RMSE), mean bias error (MBE), and model efficiency (EF) of 0.33, −0.15 mm day−1 and 74%, respectively. Also, the Clumped model simulated the daytime variation of LE with a RMSE of 36 W m−2, MBE of −8 W m−2, and EF of 83%. Major disagreement (underestimated values) between observed and estimated values of ETa was found for clear days after rainfall or foggy days, but underestimated values were less than 10% of the data analysis.
The results obtained in this study indicate that the Clumped model could be used to directly estimate vine water requirements
for a drip-irrigated vineyard trained on a VSP. However, application of the Clumped model requires a good characterization
of the drip-irrigated vineyard architecture. 相似文献
72.
xPC环境下CMAC NN在淀粉生产线液位控制中的应用 总被引:1,自引:1,他引:0
在分析CMAC神经网络的基础上,提出了利用自适应CMAC神经网络来调节淀粉生产线中乳液的液位.通过对淀粉生产线中某一液位回路进行数学建模,然后对常规PID和自适应CMAC神经网络两种控制器进行了设计与仿真.仿真结果表明,自适应CMAC神经网络在控制效果上明显优于常规PID,并且具有很高的鲁棒性.在Matlab实时开发环境xPC Target下建立了液位实时控制系统,采用快速原型控制方式,具有系统组建方便、成本低、开发周期短等特点,该系统可实现精确的过程控制. 相似文献
73.
发酵方法对柿果醋中香气成分的影 总被引:5,自引:2,他引:3
采用顶空固相微萃取法、结合气相色谱质谱联用技术,对自然发酵和常规发酵柿果醋中香气成分进行了分离与分析比较,分别从2种柿果醋中分离鉴定出挥发性化合物63种,均含有酯类、羧酸类、醇类、烃类、醛酮类、酚类及少量其他化合物.常规发酵柿果醋香气成分中含有酯类33.78%、醇类32.38%和烃类1.08%,高于自然发酵柿果醋的含量;自然发酵柿果醋香气成分中含有羧酸类61.25%、醛酮类9.66%和酚类6.13%,高于常规发酵柿果醋的含量.采用常规发酵法生产的柿果醋具有较好的感官质量. 相似文献
74.
75.
Yoshimasa Sugiura Kohji Matsuda Takashi Okamoto Makoto Kakinuma Hideomi Amano 《Fisheries Science》2008,74(1):180-186
To investigate the anti-allergic effects of the brown alga Eisenia arborea. A strain of Brown Norway rats know to strongly respond to immunoglobulin E (IgE) were used as an allergy model animal. The
rats were immunized with ovalbumin by oral administration. The levels of serum IgE and histamine were suppressed in the rats
fed a diet supplemented with dried E. arborea powder. As for the cytokine pattern, the interferon-γ production in the spleens and mesenteric lymph nodes (MLN) was enhanced,
and the interleukin-4 (IL-4) production in the spleens and/or IL-10 production in the spleens and MLN were suppressed. These
results, together with the change in the Th1/Th2 balance, indicate that the rats fed with E. arborea became more anti-allergic, suggesting that E. arborea might possess anti-allergic effects. 相似文献
76.
Differential HSP90α expression in fish hepatocytes from polluted estuary during summer 总被引:2,自引:0,他引:2
The molecular chaperone, heat shock protein 90α (HSP90α), plays an important role in protein folding, degradation of denatured
proteins and steroid activation. It is essential for the maintenance of cellular integrity and survival when induced in response
to environmental, physical and chemical stresses. In the present investigation the effect of environmental stress on HSP90α
expression was examined in grey mullet Mugil cephalus living in either a contaminated (Ennore) or uncontaminated (Kovalam) estuary over two seasons: Hepatocytes were isolated
from grey mullet of both estuaries. Oxidative stress was determined along with HSP90α in these fish. Additionally, immunohistochemical
changes were studied to confirm the HSP90α expression. Comparison of the results revealed enhanced hepatocyte oxidative stress
and HSP90α expressions in fish from Ennore to a significant extent than fish from Kovalam. Also, the results showed significant
seasonal variations with maximum expression observed during summer compared to the monsoon season. Overexpression of HSP90α
in hepatocytes exposed to chronic environmental stress by pollutants may confer differential effects on cell survival by protecting
against oxidative stress induced changes. The results also indicate that seasonal variations have significant effect on the
HSP90α expression. 相似文献
77.
ABSTRACT: Thermal limits, induced thermotolerance and the expression of heat shock protein 70 (Hsp70) in an echinoderm Apostichopus japonicus were studied. The sublethal and lethal temperatures for the juveniles were 30 and 34°C, respectively; a previous sublethal heat shock exposure (30°C, 2 h) could increase the survival rates of the sea cucumbers when they were exposed to 34°C. This induced thermotolerance could last for at least 2 days. Levels of Hsp70 increased substantially after sublethal heat shock exposure and linearly decreased with time. This result indicated that a close relationship existed between the induction of thermotolerance and the levels of Hsp70 in A. japonicus. 相似文献
78.
Muzaffer Mustafa Harlioğlu 《Aquaculture International》2008,16(4):351-360
This review focuses on the present distribution of populations of the crayfish Astacus leptodactylus that are harvested in Turkey. It also examines the history of this harvest and the impact that crayfish plague has had on them. Crayfish plague, caused by the fungus-like organism, Aphanomyces astaci Schikora, 1906, is a severe parasite of freshwater crayfish and has caused a lot of damage to A. leptodactylus populations in Turkey since 1984. Turkey was the largest provider of A. leptodactylus to Western Europe from 1970 (or possibly earlier) until 1986. For example, the peak production was reached in the early 1980s, with over 5,000 tonnes being exported in 1984. On the other hand, as a result of the crayfish plague the harvest of A. leptodactylus was reduced severely in most populations in Turkey after 1985. The harvest was only 320 tonnes in 1991. After the occurrence of crayfish plague in Turkey, in order to increase crayfish production uncontrolled A. leptodactylus stockings have been carried out in many waterbodies throughout Turkey. These introductions have caused an increase in the number of A. leptodactylus populations, but exploitation of A. leptodactylus is still under the pressure of the plague, although there has been a steady increase in crayfish production in recent years. The harvest increased to 2,317 tonnes in 2004. Fortunately, among those populations affected by crayfish plague, large amounts of A. leptodactylus can still be harvested from three lakes, ?znik (Bursa), E?irdir (Isparta) and Çivril (Denizli). Thus, it seems that A. leptodactylus has a degree of resistance to crayfish plague. It is therefore interesting to investigate the resistance of A. leptodactylus caught from these populations to crayfish plague. 相似文献
79.
Youji Wang Menghong Hu Weimin Wang Ling Cao Yi Yang Biping Lü Rongrong Yao 《Aquaculture International》2008,16(6):539-549
The diel feeding rhythm and ontogenesis during early life stage of loach Misgurnus anguillicaudatus were investigated under experimental conditions (light: L 06:00–18:00, D 18:00–06:00 h). Morphological and behavioral developments
of loach from newly hatched to 40 days after hatching were observed. Larvae were able to prey on daphnia 3–4 days after hatching
at 23 ± 0.5°C. As the larvae grew, they showed an increasing feeding capacity and a distinct feeding rhythm. Feeding intensity
and incidence for day-4 larvae were highest at 10:00 and 16:00 h. The highest levels of feeding intensity for day-12 larvae
occurred at 08:00, 12:00, and 18:00 h as did feeding incidence. By day 20, when the larvae metamorphosed, the highest levels
of feeding intensity occurred at 06:00, 18:00, and 24:00 h and were concurrent with the highest feeding incidence. After metamorphosis,
feeding capacity had again increased considerably and, in contrast to the earlier stages before day 20, feeding intensity
for day-30 juveniles peaked at 05:00 and 20:00 h, about 1–2 h after the maximum feeding incidence. The feeding rhythm of loach
juveniles at day 40 was almost the same as the day-30 juveniles. The estimated maximum daily feeding rates were 43.1%, 33.4%,
19.0%, 12.8%, and 5.8% of body weight on days 4, 12, 20, 30, and 40, respectively. Thus, loach was found to have different
feeding rhythms in the pre- and post-metamorphosis stages, with the highest feeding activity in daytime during the larval
planktonic stage before metamorphosis, and intensely nocturnal feeding behavior during the juvenile benthic stage after metamorphosis. 相似文献
80.
所谓噬菌体指的是真菌、放线菌、感染细菌等微生物的细菌病毒总称,它最为显著的特性是个体小、细胞结构不完整、仅有一个核酸。主要对噬菌体在动物疾病方面的应用情况进行了一番详细的论述。 相似文献