气候变暖对新疆不同秋眠级紫花苜蓿种植适宜性的影响

基于新疆102个气象台站1961−2019年逐日平均气温、最低气温资料,采用统计学方法以及ArcGIS的空间插值技术,在对影响新疆紫花苜蓿种植的主要气候因子 ≥ 5 ℃积温、冬季最低气温时空变化特征分析的基础上,以80%保证率 ≥ 5 ℃积温和90%保证率冬季最低气温作为指标因子,研究了气候变暖背景下,新疆不同秋眠级紫...     

绵羊宿营法防除天然草地灌木杂草研究Ⅲ新鲜羊粪尿对土壤和植物细胞形态结构及生理的影响

采用盆栽试验研究了绵羊新鲜粪尿对植物组织水势、细胞膜透性和细胞形态结构的影响。结果表明 ,在土壤含水量 30 %左右 ,植物无水分胁迫的可能时 ,各处理植物组织水势呈先上升后下降的趋势 ,而对照则呈持续上升趋势。说明绵羊新鲜粪尿加入土壤后 ,土壤溶液浓度升高 ,影响了植物水势。绵羊新鲜粪尿对植物生理影响表明 ,叶片细胞膜透性在 UD处理与对照差异显著 (P<0 .0 5) ,U和 D单处理与对照间差异不显著 (P>0 .0 5)。根细胞膜透性 UD和 U处理与对照差异显著 (P<0 .0 5)。D处理与对照无显著差异 (P>0 .0 5)。植物细胞形态结构显示 ,各处理均无质壁分离现象 ,但 U和 UD处理的皮层细胞出现叶绿体 ,这可能是尿中尿素水解释放的游离氨被植物吸收所致     

Thermographic Eye Temperature as an Index to Body Temperature in Ponies

Infrared thermography (IRT) is a passive, remote, and noninvasive method of measuring surface temperatures. Select surface locations, such as the eye, could indicate body temperature. To investigate whether thermographic eye temperatures were associated with body temperatures and could be used to detect febrile ponies, we measured IRT eye temperatures, rectal temperatures, and implanted thermal microchip temperatures from 24 male ponies daily for 3 consecutive days. Information regarding distance of the pony from the IRT device, presence of direct sunlight during the measurement period, and ambient temperature were also collected. A multivariate linear regression analysis indicated that 60.41% of the variance in IRT was accounted for by rectal temperature, sunlight, and distance between the camera and the pony, with rectal temperature being the major contributor to variance (46.23%). Using a rectal temperature of >38.6°C (101.5°F) as the indicator of febrile status, sensitivity and specificity of the IRT device used to detect the febrile ponies were found to be 74.6% and 92.3%, respectively, when using the maximum IRT eye temperature per pony per day. In conclusion, IRT eye temperature could be a preliminary screening tool to determine whether a more time-consuming, labor-intensive, and invasive method (e.g., rectal temperature) is warranted for fever validation.     

Phenotypic plasticity induced using high ambient temperature during embryogenesis in domesticated zebrafish,Danio rerio

Ambient temperature during early stages of life has a substantial effect on physiological processes, eliciting phenotypic plasticity during zebrafish developmental stages. Zebrafish are known to possess a noteworthy ability to modify their phenotype in dependence of environmental factors. However, there is a poor understanding of the effects of temperature during embryogenesis, which influences the biological functions such as survival ability and masculinization in later developmental stages. Since the middle embryonic phase (pharyngula period) is genetically the most conserved stage in embryogenesis, it is very susceptible to embryonic lethality in developmental processes of vertebrates. Here, we tested the effect of transient perturbations (heat shock) during early development (5–24 hr post‐fertilization; hpf) at 35°C compared to control group at 28°C, on survival ability of zebrafish to study the embryonic and post‐embryonic mortality. We studied the variation of heat‐induced masculinization among and across the families in response to high temperature. Furthermore, morphometric traits of adult zebrafish at different developmental time points were measured in order to estimate the temperature × sex interaction effect. We found the highest embryonic mortality around the gastrula and segmentation periods in both experimental groups, with significantly lower survival ability in the temperature‐treated group (73.30% ± 0.58% vs. 70.19% ± 0.57%, respectively). A higher hatching success was observed in the control group (71.08% ± 0.61%) compared to the heat‐induced group (67.95% ± 0.60%). A distinct reduction in survival ability was also observed in both experimental groups during the first two weeks after hatching, followed by a reduced level of changes thereafter. We found sex ratio imbalances across all families, with 25.2% more males under temperature treatment. Our study on growth performance has shown a positive effect of increased temperature on growth plasticity, with a greater impact on female fish in response to high ambient temperature.     

甘肃省不同区域人工草地土壤肥力特征研究

以甘肃省不同区域人工草地土壤样品为研究对象,测定12个不同区域[民乐县(ML1、ML2)、安定区(AD)、通渭县(TW1、TW2、TW3、TW4)、宁县(NX1、NX2)、靖远县(JY1、JY2、JY3)]人工草地土壤的pH值、有机质、全氮、速效磷、速效氮、速效钾。结果表明:AD的p H值最大,JY3的pH值最小;TW2有机质含量最高,AD有机质含量最低,TW2较AD提高了78.95%,在TW2种植陇东苜蓿对土壤有机质影响大;TW2、TW3速效氮含量较高,约为AD速效氮含量的3倍,在TW2、TW3种植陇东苜蓿对土壤速效氮影响大;JY2速效钾含量是AD的3倍,TW2速效钾的含量最低,在JY2种植陇东苜蓿对速效钾影响大;ML1、ML2速效磷含量较高,NX1、NX2速效磷含量较小,在NX1、NX2种植陇东苜蓿对土壤速效磷影响小;TW2全氮含量最高,较AD提高了85.07%,在TW2种植陇东苜蓿对土壤全氮影响大。综合分析结果显示,TW2土样的关联度值最大(0.787 9),综合肥力最好,为最优土样;NX2土样的关联度最小(0.500 7),综合肥力最差。     

河道整治工程中灌草植物应用研究浅议

河道边坡结构的破坏, 加剧了河坡生态环境恶化。采用生物护坡,尤其是栽植灌木和草本,可明显改善边坡的水土保持能力。植物发达的根系通过锚固作用和加筋作用有效地提高坡面的稳定性。种植植物可以在相对较短的时间内恢复边坡的生态功能,增加其抗侵蚀能力。灌木和草本是用于护坡的主要植物,现阶段用于护坡的灌草大多是根系发达、抗逆性强的植物种。不同土壤、气候条件及不同地区和地域适宜种植的灌草植物不同,因此采用种植灌草护坡应根据当地环境条件选择适宜植物,否则很难成功。分析阐述了植物的生态作用及护坡机理,并总结了在河道整治工程中主要使用的部分灌草种。最后列举了一些适应我国北方地区气候环境的护坡灌草,以期为护坡工程中灌草植物的选用提供一些建议。     

Research on a dynamic tracking model for reservoir water flooding of separated zone water injection

Waterflood is one of the main oil reservoir development ways. Premature flooding of production wells during water flooding process will reduce oil recovery. Therefore,it is particularly important to establish a dynamic tracking model for reservoir water flooding of separated zone water injection. Based on the basic principles of heat and mass transfer,according to well temperature curve to determine the water profile,Poisson process analysis and stochastic process methods are adopted to calculate water saturation,water breakthrough time and water cut of each layer in water flooded reservoir at any one time. When oil reservoir gradually become water flooded,the calculated water cut of model considering micro-pore distribution of the reservoir tends to the measured water cut,and the calculation error is less than 5%. Case study shows that the layer of the higher injection rate,with high flow channel such as micro fracture,where there is the faster increase in water saturation,the shorter water breakthrough time and faster increase in water cut,and vice versa. Research result provides time guarantee to take measures for inhibiting or delaying water breakthrough of production wells.     

低温弱光对苗期紫花苜蓿根颈生理特性的影响

以秋眠级不同的2个紫花苜蓿Medicago sativa品种(巨人201和WL414)为试验材料,研究了其在低温(0~5℃和5~10℃)与弱光[50和100μmol/(m2.s)]互作处理条件下的生理响应。结果表明:紫花苜蓿根颈在低温弱光胁迫下启动了自身应激机制,对逆境胁迫做出了适应性反应,相同弱光条件下,低温0~5℃比5~10℃对根颈的影响显著,过氧化物酶活性上升幅度较小,而超氧化物歧化酶活性的下降和丙二醛含量的增加幅度均较大;相同低温处理,弱光50μmol/(m2.s)处理对根颈生理指标影响更为显著,过氧化物酶活性上升、超氧化物歧化酶活性下降和丙二醛含量增加幅度大于弱光100μmol/(m2.s)处理;巨人201各项指标的变化都优于WL414,表明巨人201抗寒耐弱光能力都可能优于WL414。