流动沙丘表面输沙率的理论计算方程   总被引：5，自引：1，他引：5  

拓万权  杨根生 《干旱区资源与环境》1996,10(4):50-54

本文研究流动沙丘表面上输沙率的理论计算，得出输沙率是风速的二次函数且与沙丘表面沙粒平均粒度的１．４３次方成反比的新结论。  相似文献   

C-reactive protein, tumor necrosis factor α, and interleukin-6 in dogs with pyometra and SIRS     

Boel A. Fransson  DVM  PhD  DACVS    Anne-Sofie Lagerstedt  DVM  PhD    Annika Bergstrom  DVM    Ragnvi Hagman  DVM  MSc  PhD    Jean S. Park  PhD    Boon P. Chew  DVM  PhD    Marc A. Evans  Claude A. Ragle  DVM  DACVS  DABVP 《Journal of Veterinary Emergency and Critical Care》2007,17(4):373-381

Objective: To determine the frequency of the systemic inflammatory response syndrome (SIRS) in canine pyometra and to evaluate the relationship between C‐reactive protein (CRP), tumor necrosis factor α (TNFα), interleukin‐6 (IL‐6), and SIRS. Design: Prospective clinical study. Setting: Veterinary teaching hospital. Animals: Fifty‐three clinical cases of canine pyometra and 19 healthy control bitches. Interventions: Upon admission to the veterinary hospital, history and physical examination findings, including previously defined clinical SIRS parameters, were documented. Blood samples were obtained for hematology and biochemical tests and for CRP, TNFα, and IL‐6 analysis. The diagnosis of pyometra was confirmed by histopathology of the uterus after ovariohysterectomy. After surgery, clinical SIRS parameters, length of hospitalization, and mortality were recorded. Measurements and main results: Pyometra dogs were grouped as SIRS positive (30/53; 57%) or SIRS negative (23/53; 43%). Logistic regression showed that CRP was the only parameter that significantly related to SIRS apart from the clinical criteria that define this syndrome. The mortality rate was low (2/53; 3.8%), and conclusions regarding association with SIRS could not be drawn. A positive SIRS status, high plasma CRP concentration, and high body temperature were variables that related to increased morbidity reflected by the length of hospitalization. Conclusions: SIRS was seen in 57% of canine pyometra cases and a positive SIRS status showed a positive association with prolonged hospitalization. The mortality rate was low (3.3%) among SIRS positive dogs, indicating that progression to multiple organ dysfunction syndrome (MODS) rarely occurs in surgically treated cases of pyometra. CRP was associated with SIRS and with prolonged hospitalization. Further studies of plasma CRP may be warranted in canine intensive care cases susceptible to development of SIRS and MODS.  相似文献   

仲丁威三种测定方法的比较     

傅德玲  黄路 《农药科学与管理》1998,19(1):13-14

本文采用反相高效液相色谱法和改进的气相色谱法对仲丁威含量进行了测定,并与ＣＩＰＡＣ采用的正相高效液相色谱法测定了进行了比较。结果表明,反相液相色谱法与正相液相色谱法等效,气相色谱法经改进后降低了仲丁威的热分解,三种方法对仲丁威原药及乳油含量的测定结果的相对误差在允许的范围之内。  相似文献   

Growth modelling including size heterogeneity: Application to the intensive culture of white shrimp (P. vannamei) in freshwater     

《Aquacultural Engineering》2013

This article models the growth of a population in aquaculture, including the phenomenon of size heterogeneity. Experimental observations of six initial densities (90, 130, 180, 230, 280 and 330 shrimps m⁻²) in an intensive culture of Penaeus vannamei in freshwater were used to fit a growth model. For this, three mathematical functions were analysed (Gompertz, von Bertalanffy and Pütter), which were modified in order to include the effect of initial density. Two models were constructed, one assuming the hypothesis of homogeneous individual growth and the other including size-heterogeneity throughout the culture cycle. For the second case, a stabilisation time was evaluated which defines the future heterogeneity of the cohort. In each initial density, the stabilisation phase was reached at approximately 2 g. However, the time taken for this phase to start increased with increasing initial culture density. The modified von Bertalannfy function was the most effective of the three equations in predicting growth. The weight predictions, assuming homogeneity and variability of sizes, presented low Percentage Root Mean Square Errors (PRMSE). However, the inclusion of size variability in the fit produced better statistical results than when they were not included (PRMSE decreased from 16% to 12%). This confirms the importance of taking into account size heterogeneity at an intensive level. Particularly at the technical level when the aquaculture producer is required to make stocking and harvest plans.  相似文献   

厚层基材喷播技术在北方半干旱区岩石边坡植被恢复中的应用——以京承高速公路(三期)植被恢复工程为例     

李义强  王英宇  宋桂龙  关超 《草原与草坪》2012,32(3):58-64

以京承高速公路(三期)岩石边坡植被恢复工程为例,研究厚层基材喷播技术的施工工艺及植被恢复效果,从抗旱乡土植物的筛选与配置、技术适宜性评价以及养护措施效果方面,综合分析归纳出厚层基材喷播技术,在北方半干旱地区岩石边坡植被恢复中的应用效果及关键技术,对于完善我国裸露边坡植被恢复理论体系,指导裸露坡面工程绿化,都具有非常重要价值。  相似文献   

我国会计电算化应用的发展变化     

蒋淑芝 《林业科技情报》2008,40(2):124-125

随着现代信息技术的发展，计算机技术在我国会计工作中也被普遍应用。并经历了从初级电算化过渡到高级电算化这样一个长期而艰巨的演变过程，我国会计电算化事业已向规范化、制度化方向发展。  相似文献   

The progamic phase and seed formation in Armoracia rusticana     

K. Winiarczyk    J. Bednara 《Plant Breeding》2008,127(2):203-207

The progamic phase is a period of specific interaction between the male gametophyte and the pistil tissues and is very important for proper seed development in plants. The aims of this study were to investigate the events during the progamic phase in Armoracia rusticana, to examine a plant’s capability of sexual reproduction and to obtain vital seeds under natural conditions. There were very few pollen grains on the stigmas at anthesis stage. The incompatibility reaction between the stigma cells and pollen grains was observed by using fluorescence microscopy. A series of ovary cross‐sections revealed a high accumulation of Periodic Acid Schiff (PAS)‐positive globules in all the embryo sacs. About 33% of ovules in the ovary were fertilized, but only 3% of them were able to germinate into seedlings.  相似文献   

Determining the optimum digestible isoleucine to lysine ratio for Ross 708 x Ross YP male broilers from 0 to 18 d of age     

A.T. Brown  J. Lee  R. Adhikari  K. Haydon  K.G.S. Wamsley 《The Journal of Applied Poultry Research》2022,31(1):100217

  相似文献   

光皮桦幼林生长节律的观察研究   总被引：4，自引：1，他引：4       下载免费PDF全文

曹健康  方乐金 《林业科学研究》2006,19(3):404-407

光皮桦(Betuta luminifera H.Winkl)又称亮皮桦,系桦木科(Betulaceae)桦木属(Betula L)落叶乔木树种.木材呈淡黄或淡褐色,材质细致坚韧、切面光滑、不挠不裂,为优良的军工、航空、建筑、家具和室内装饰用材,也可用于造纸.  相似文献   

对当前监理工作的几点思考     

顾钧  刘凯 《林业科技情报》2005,37(3):83-83,85

监理是建设工程不可缺少的一个环节，如何重视监理工作是亟待解决的一个问题。  相似文献