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排序方式: 共有167条查询结果,搜索用时 31 毫秒
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[目的]为降低发酵过程中氨气释放及氮素损失,在室内条件下对城市生活垃圾进行好氧发酵研究。[方法]利用正交试验设计研究初始条件对发酵过程中氨气释放的影响,优化发酵过程氨气释放条件。[结果]正交试验结果表明,初始C/N和环境温度对氨气释放影响最为显著;最佳发酵工艺参数组合为:含水率60%,C/N为40∶1,pH值7.0,温度25℃。[结论]该研究为降低发酵过程氮的损失、减少空气污染提供了理论依据。 相似文献
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Effect of the addition of municipal solid-waste compost on microbial biomass and enzyme activities in soil 总被引:2,自引:0,他引:2
P. Perucci 《Biology and Fertility of Soils》1990,10(3):221-226
Summary Changes in the content of C, N, P, and S in the soil biomass and in phosphatase, urease, protease, deaminase, and arylsulphatase activity, induced by amendment with municipal solid-waste compost, were determined in a clay loam soil during 1 year of incubation at 25° and 35°C.In the unenriched soil (control) decreasing trends in biomass C, biomass N, and biomass S were observed at both temperatures. In the enriched soil, these values increased, reaching a maximum after 1 month. Biomass P, probably due to a slower process of P immobilization, showed different trends. Alkaline phosphomonoesterase, phosphodiesterase, and deaminase activity remained constant after reaching maximum values (3–5 months). Arylsulphatase, urease, and protease activity tended to return to baseline after reaching a maximum (2–3 months).Atrazine, though applied at a dose that was 10 times higher than the recommended field rate, did not modify the chemical and biochemical properties of either the control or the enriched soil.Significant positive and negative correlations between changes in biomass values and changes in enzyme activity were found. The negative correlations are attributed to the delay in the enzymatic response compared with the changes in microbial biomass. 相似文献
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Urban street trees provide many benefits to surrounding communities, but our ability to assess such benefits relies on the availability of high-quality urban tree data. While these data are numerous, they are not available in an easily accessible, centralized place. To fill this gap, we aggregated public and private data into a single, comprehensive inventory of urban trees in California called the California Urban Forest (CUF) Inventory. These data are offered to the public (aggregated to ZIP code) via an online data portal, which at the time of publication contained over 6.6 million urban tree records. In this study, we first describe the assembly and utility of the inventory. Then, we conduct the most comprehensive assessment of the diversity and structure of California’s urban forest to date at statewide, regional, and local spatial scales. These analyses demonstrate that California’s urban forests are highly diverse and among the most diverse urban forests in the world. We present a new and intuitive metric of species diversity, the top diversity or TD-50 index, which represents the cumulative number of species accounting for the top 50 % abundance of trees in an urban forest. We used species abundance data from 81 well-inventoried cities to demonstrate that the TD-50 index was a robust metric of diversity and a good predictor of comprehensive metrics like the Shannon Index. We also found that small-statured trees, such as crape myrtles (Lagerstroemia cv.) dominate California’s urban forests. This aggregated inventory of one of the world's largest urban forests provides the data necessary to assess the structure, diversity, and value of California’s urban forests at multiple spatial scales. The inventory’s presentation to the public and the information that can be gained from its analysis can be a model for urban forest management worldwide. 相似文献
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垃圾堆肥厂臭气的生物脱臭技术综述 总被引:3,自引:0,他引:3
目前垃圾堆肥臭气治理主要采用生物脱臭工艺,着重介绍了4种生物除臭法,即生物过滤法、生物洗涤法、生物滴滤法和曝气式生物除臭法的各自特点和技术进展。最后认为由于垃圾堆肥恶臭成分的多样性,单一的处理方法往往效果有限,两种或两种以上的方法联用具有较好的发展前景。 相似文献
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采用温室盆栽试验,研究了城市固体废弃物堆肥与化肥配合施用对黑麦草生长的影响。结果表明:堆肥和化肥可明显增加黑麦草干物质产量,阳春和大安2种土壤50 t/hm2堆肥处理黑麦草干物质产量分别增加39.53%和109.38%,而NPK处理分别增加267.44%和406.25%;堆肥和化肥的配施处理(阳春土壤处理③和大安土壤处理④)产量最高;堆肥处理能明显提高土壤pH、有机碳、有效磷、钾、铁、锰、锌、铜含量。 相似文献