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81.
从南京市、马鞍山市和丹阳市的3个污水处理厂采集污泥,在500℃下热解制备炭化污泥,测定了污泥和炭化污泥的性质和重金属含量,研究了污泥和炭化污泥对酸性红壤改良效果,并探讨了炭化污泥中重金属的环境风险。结果表明,污泥和炭化污泥中含有一定量的碱,添加炭化污泥可提高红壤的p H和交换性钙、镁和钾含量,降低土壤交换性铝和交换性H+含量。但污泥中大量铵态氮的硝化作用释放质子,抵消了污泥对红壤酸度的改良作用。添加污泥和炭化污泥提高了土壤有机碳、有效磷和速效钾的含量,提高了土壤肥力。污泥炭化后重金属含量有所增加,但大部分重金属的有效态含量下降,说明热解过程可以降低部分有毒重金属的活性。与对照相比,添加炭化污泥会增加土壤中部分重金属有效态含量,特别是有效态锌含量显著增加,因此炭化污泥农业利用存在一定的环境风险。建议将炭化污泥用于酸化的森林红壤的改良。 相似文献
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Characterization of Treatment Processes and Mechanisms of COD, Phosphorus and Nitrogen Removal in a Multi-Soil-Layering System 总被引:3,自引:0,他引:3
Kuniaki Sato Tsugiyuki Masunaga Toshiyuki Wakatsuki 《Soil Science and Plant Nutrition》2005,51(2):213-221
Characteristics of the treatment processes inside a MSL system were investigated by using a laboratory-scale MSL system, which was set up in a D 10 × W 50 × H 73 cm acrylic box enclosing "soil mixture blocks" alternating with permeable zeolite layers. For the study of the treatment processes inside the system, wastewater, with mean concentrations (mg L−1 ) of COD: 70, T-N: 12, T-P: 0.9, was introduced into the system at a loading rate of 1,000 L m−2 d−1 . Treatment processes in the MSL system were different for the COD, P and N pollutants. Eighty percent of COD was removed in the 1st soil layer among the 6 layers, and the removal rate increased as water moved down and finally reached 90% in the last layer of the system. Phosphorus concentration was lower under the soil mixture layers than under the permeable layers, presumably because P was adsorbed mainly by soil and mixed iron particles. The P concentration in water gradually decreased in the lower layers of the system. The concentration of PO4 3- -P was generally lower in the aerated MSL system than in the non-aerated one. NH4 + -N was adsorbed and nitrified in the upper part of the system. The NO3 − -N concentration was lower in water under the soil mixture layers than under the permeable layers, indicating that denitrification mainly occurred in the soil mixture layers. 相似文献
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针对猪场污水厌氧处理出水的有机物浓度高,后续处理困难的问题,该试验对石灰混凝法处理猪场高浓度厌氧出水的效果进行了测试,并与氧化塘的处理效果进行比较分析。试验中选择了1g/L和5g/L两种石灰投加剂量,对沉淀1、2、3、4、5和6h的净化效果进行取样分析;并对氧化塘猪场污水处理工艺连续取样三天,分析处理效果。结果表明:石灰混凝法投加剂量为5g/L、沉淀时间为5h时,对COD的去除率高达57.8%,明显好于氧化塘的去除效果;但对氨氮的去除率低于氧化塘。石灰混凝法沉淀时间短,基建投资小,可作为猪场污水进入二级处理或深度处理工艺前的可选择性过渡工艺。 相似文献
87.
The purpose of this paper is to investigate the impact of nitrogen sludge load and dissolved oxygen(DO) on nitrite nitrification system. The following conclusions have been drawn based on the experimental data and analysis results: 1) The ammonium degradation rate and the nitrous accumulation rate of high concentration nitrous nitrifying system decline with the increase of NH+4-N sludge load. When HRT is less than two days, the ammonium degradation rate rapidly declines to 25%~29% with the increase of NH+4-N sludge load. When HRT is beyond two days, the ammonium rate of the system slowly falls to 50%~60% with the NH+4-N sludge load increased. When HRT is 2.5 days or 3 days, the declined trend of the system nitrous accumulation rate is not obvious with the NH+4-N sludge load increased. When HRT is 5 days, the decrease of nitrous accumulation rate is caused by the adaptation of sludge. So the NH+4-N sludge load of high concentration nitrous accumulation system should not be too high; 2)With the increase of DO, the ammonium degradation of high concentration nitrous nitrifying system is gradually increased. When the DO is less than 0.7 mg/L, it is not conductive to the ammonium degradation. When the DO is higher than 2 mg/L, the oxide of NH+4-N is changed into the increased of NO3-N and the nitrous accumulation rate declined. If the concentration of DO is controlled within 0.7to 1.3 mg/L, the high concentration nitrous nitrifying system can have a good NH+4-N degradation rate and nitrous accumulation rate. 相似文献
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电化学方法处理含硫废水的过程和特性 总被引:2,自引:0,他引:2
采用管式电气浮装置处理人工模拟含硫废水并研究其过程和特性,探讨在两相厌氧处理富邻居唷酸盐高浓度有机废水工艺中采用电化学方法处理含硫废水的可行性。 相似文献
90.
采用单因子试验,初步探讨了赤泥改性温度、煤矿废水pH值、固液比、振荡频率、MnO2投加量等5个因素对赤泥去除煤矿废水中Fe,Mn,Cu,Zn,Cd等污染物效果的影响.结果表明:赤泥对煤矿废水中污染物均有较高去除效率;当固液比为50 g/L,MnO2投加量为3 g/L,振荡频率为185 r/min,振荡时间为1 h,煤矿废水pH为4.0,赤泥改性温度为700℃时,废水中Fe,Mn,Cu,Zn,Cd的去除效率分别为99.86%,99.09%,93.62%,94.04%和93.05%. 相似文献