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61.
为研究国产和进口硫酸头孢喹肟注射液(7.5%)在猪体内的药代动力学特征和生物等效性,采用双处理、双周期随机交叉试验设计,将20头健康三元杂交猪随机分成2组,按3mg/kg体重分别单剂量肌内注射受试制剂和参比制剂。采用超高效液相色谱-串联质谱法测定血浆中头孢喹肟的浓度,利用Win Nonlin6.3软件计算主要药动学参数,并评价两种制剂的生物等效性。结果显示,受试制剂和参比制剂的Tmax分别为2.30±0.73h和2.25±0.55h;Cmax分别为2.37±0.34μg/mL和2.45±0.36μg/mL;AUC0-t分别为26.38±2.30μg·h·mL^-1和24.86±2.19μg·h·mL^-1;AUC0-∞分别为26.74±2.34μg·h·mL^-1和25.07±2.20μg·h·mL^-1。硫酸头孢喹肟注射液受试制剂和参比制剂的AUC0-t、AUC0-∞、Cmax、Tmax均无显著性差异(P>0.05)。双单侧t检验结果显示两种制剂生物等效,临床上可相互替代。该试验可为兽医临床合理用药提供参考。 相似文献
62.
研究了四种红壤用硫酸盐溶液处理后SO42-解吸动力学特点及pH和温度的影响。结果显示,其最大解吸量在70%~94%之间。解吸曲线的数据用Elovich方程和双常数方程可以很好的拟合。pH升高时解吸量增加,解吸速度变慢。温度升高时解吸量增加,反应速度加快。根据Arrhenius公式估算出的活化能为23.35 kJ mol-1。 相似文献
63.
Summary Increasing the sulfate concentration and concomitant increases in the organic S concentration failed to exert any effect on organic S mobilization in samples collected from all depths within the mineral soil profile, from 15 sites differing in soil type, vegetation, and geographic location. Mobilization capacities at saturating concentrations of sulfate for organic S formation generally tended to increase with increasing depth. The potentials for the accumulation of organic S with various sulfate inputs exhibited saturation kinetics similar to those observed for organic S formation; values for the former parameter ranged from 3×10-3 to 12.6 mol S g–1 dry weight 24 h-1 for the uppermost (A, E) soil horizons, 3 nmol to 10 mol S g-1 dry weight 24 h–1 for intermediate (primarily AB) soil horizons, and from 3 nmol to 13.4 mol S g-1 dry weight 24 h–1 for the lowermost (B, C) soil horizons. Irrespective of depth, the Fullerton, Tarklin, and Loblolly sites in Tennessee and the Florida site showed the least net accumulation of organic S at saturation (<0.2 mol S g-1 dry weight 24 h–1 for all horizons examined), while the Duke Forest (North Carolina), Douglas Fir (Washington), Whiteface (New York) and the Howland (Maine) sites had the highest potential net accumulation of organic S at saturation (>1.0 mol S g-1 dry weight 24 h-1 for most horizons examined). 相似文献
64.
Awareness is growing of health‐promoting functional foods and the use of various plants as nutraceuticals. Due to a suite of organosulfur compounds, onion, and other vegetable Alliums possess a unique antiplatelet effect that may promote cardiovascular health because aggregating platelets can lead to heart attack and stroke. Investigation of the consequences of S nutrition in onion has primarily focused on levels of S ranging from deficiency to just above sufficiency; however, little work has been conducted to examine the effects of supraoptimal S nutrition on organosulfur‐based traits. Four onion selections were grown in hydroponic solutions with 2, 7, and 12 mM SO42—‐S in greenhouse experiments during 1995—1996 and 1996—1997. Onion plants were separated into root, leaf, and bulb portions and analyzed for mineral content. Onion bulb extracts were assayed for in vitro human antiplatelet activity. Bulb and leaf S were not affected by increasing solution culture S, but root S was increased by 98 % when solution culture S was increased from 2 mM to 12 mM. Similar increases in root Ca and Al were detected, suggesting CaSO4 and AlSO4+ were accumulated in and on the root. No directional change in antiplatelet activity was detected as S was increased from 2 to 12 mM. This lack of significant change in antiplatelet activity with increasing S levels suggests that modification of this trait by simply increasing S levels may not be feasible in a solution culture environment. 相似文献
65.
Eutrophication of surface water is a worldwide concern. Sediments may play an important role in buffering phosphorus (P) concentration in the overlying water column. However, information on the spatial variation of sediment P availability as affected by agricultural water discharge and hydrological conditions is limited. In this study river sediments were sampled in spring, summer, fall and winter, respectively from seven locations along a main tributary (Ten Mile Creek, TMC), which receives surface runoff water from agricultural lands and discharges into the Indian River Lagoon, south Florida, USA, and analyzed for P availability. Simultaneously, hydrological variables were measured on the spot and river water samples were collected for analyses of water quality. The results demonstrated that available P in the sediments of TMC as measured by several commonly used extraction procedures had a large spatial variation. The downstream locations had a greater amount of available P in the sediments than the upstream locations, which is attributable to the settlement of finer particles due to slower water flow and increased influence from salt water in the downstream locations where the fresh river water gradually mixed with salt water from the Indian River Lagoon. Phosphorus availability in the sediments appeared to be related to P sorption by iron and aluminum oxides and the competition for adsorbing sites between SO42− and PO43−. This spatial variation of P availability agrees with the elevation of chlorophyll a (Chla) in overlying water body in the downstream locations of TMC, indicating that the internal P source plays an important role in triggering an algal boom in surface water systems. 相似文献
66.
67.
木松节油和硫酸盐松节油的组成分析及其精馏分离的研究 总被引:1,自引:0,他引:1
本文研究了木松节油、硫酸盐松节油的组成。除α-蒎烯、β-蒎烯外,这两种松节油还分别含有10.73%和8.01%的3-蒈烯。通过两次真空精馏,由木松节油分别得到含89.1%α-蒎烯、含72.3%和含56.3%3-蒈烯的三种馏分,由硫酸盐松节油分别得到含96.7%α-蒎烯,含68.1%β-蒎烯、含59.5% 3-蒈烯三种馏分。在精馏的釜液中,双戊烯含量较高。这为综合利用木松节油和硫酸盐松节油创造了条件。 相似文献
68.
《Communications in Soil Science and Plant Analysis》2012,43(12):1181-1193
Abstract Corn (Zea mays L.) was grown in the greenhouse in a Laughlin (Ultic Haploxeroll) loam soil, with various amounts of N and S added in order to determine possible interactions of these nutrients with the relationship between plant composition and grain yields. Previous field experience and preliminary experiments had shown that this soil gave yield responses to N and S additions. Regression equations were used to describe the relationship between composition of various plant parts and grain yields. The best correlation (R2 = 0.943) was obtained using the total N concentration in leaf samples taken at the silking stage, but excluding data from plants which, based on their amide N concentrations (greater than 500 ppm), were considered S deficient. Calculations using the first derivative of the cubic polynomial indicated that a concentration of 2.5% N in the lower leaves was necessary in order to obtain maximum grain yields. The concentrations of total N in the upper leaves and the stalks at the silking stage also correlated well with the grain yields. The relationship of NO3‐N in the stalks at silking to grain yields could be better described mathematically with an exponential function, but the correlation coefficient was low (R2 = 0.58). The responses of two genotypes, one containing the opaque ‐ 2 gene, the other its normal counterpart, were similar. The total N concentration in the leaves collected at the tassel stage did not correlate quite as well with grain yield as those collected later, but using the exponential model NO3‐N concentrations in the stalks at the earlier stage showed a closer relationship to grain yield than for samples collected at silking. Excluding data for the plants showing S deficiency, a correlation coefficient of 0.90 was obtained. At both tasseling and silking stages, the S deficient plants were characterized by high N:S ratios, with values of 18 to 50 for the stalks, compared to values of less than 10 for the S adequate plants. The marked effect of inadequate S on grain formation was not evident in the amounts of leaves and stalks produced. Field studies will be necessary to evaluate further the merit of the diagnostic procedure indicated by these experiments. 相似文献
69.
70.
几种杀生剂的杀菌规律与作用机理探讨 总被引:1,自引:0,他引:1
[目的]为杀菌剂的复配增效提供参考。[方法]采用绝迹稀释法和平板涂抹计数法,探讨几类常用杀菌剂的杀菌规律和作用机理,并进行复配。[结果]优氯净、季铵盐和双季铵盐类对硫酸盐还原菌(SRB)的杀灭效果较好,甲醛效果较差。优氯净对异养菌的杀灭效果最好,甲醛和异噻唑啉酮效果稍差,其他杀菌剂效果较好。醛类、季铵盐类杀菌剂分别通过亲核加成反应、渗透和扩散杀灭细菌;优氯净以氧化作用而使微生物死亡。复配杀菌剂浓度为10mg/L时可以将细菌含量控制在油田回注水标准之内,50mg/L时能将硫酸盐还原菌和异养菌彻底杀灭。[结论]在充分了解杀菌剂作用机理的基础上,可以进行不同杀菌剂间的复配增效。 相似文献