全文获取类型
收费全文 | 153篇 |
免费 | 1篇 |
专业分类
安全科学 | 2篇 |
废物处理 | 6篇 |
环保管理 | 11篇 |
综合类 | 90篇 |
基础理论 | 14篇 |
污染及防治 | 19篇 |
评价与监测 | 3篇 |
社会与环境 | 8篇 |
灾害及防治 | 1篇 |
出版年
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1964年 | 1篇 |
1959年 | 1篇 |
1957年 | 2篇 |
1956年 | 2篇 |
1955年 | 4篇 |
1951年 | 3篇 |
1947年 | 1篇 |
1946年 | 1篇 |
1943年 | 3篇 |
1942年 | 1篇 |
1941年 | 2篇 |
1938年 | 3篇 |
1936年 | 3篇 |
1935年 | 1篇 |
1934年 | 6篇 |
1933年 | 5篇 |
1932年 | 3篇 |
1931年 | 2篇 |
1930年 | 3篇 |
1929年 | 2篇 |
1927年 | 4篇 |
1926年 | 4篇 |
1925年 | 2篇 |
1924年 | 4篇 |
1923年 | 2篇 |
1922年 | 2篇 |
1916年 | 1篇 |
排序方式: 共有154条查询结果,搜索用时 0 毫秒
21.
22.
Friedrich Rinne Albrecht Hase A. Loewy Werner Gottstein 《Die Naturwissenschaften》1926,14(18):389-391
23.
24.
25.
26.
27.
28.
Y. Liang H.T. Gollany R.W. Rickman S.L. Albrecht R.F. Follett W.W. Wilhelm J.M. Novak C.L. Douglas Jr. 《Ecological modelling》2009
Soil carbon (C) models are important tools for examining complex interactions between climate, crop and soil management practices, and to evaluate the long-term effects of management practices on C-storage potential in soils. CQESTR is a process-based carbon balance model that relates crop residue additions and crop and soil management to soil organic matter (SOM) accretion or loss. This model was developed for national use in U.S and calibrated initially in the Pacific Northwest. Our objectives were: (i) to revise the model, making it more applicable for wider geographic areas including potential international application, by modifying the thermal effect and incorporating soil texture and drainage effects, and (ii) to recalibrate and validate it for an extended range of soil properties and climate conditions. The current version of CQESTR (v. 2.0) is presented with the algorithms necessary to simulate SOM at field scale. Input data for SOM calculation include crop rotation, aboveground and belowground biomass additions, tillage, weather, and the nitrogen content of crop residues and any organic amendments. The model was validated with long-term data from across North America. Regression analysis of 306 pairs of predicted and measured SOM data under diverse climate, soil texture and drainage classes, and agronomic practices at 13 agricultural sites having a range of SOM (7.3–57.9 g SOM kg−1), resulted in a linear relationship with an r2 of 0.95 (P < 0.0001) and a 95% confidence interval of 4.3 g SOM kg−1. Using the same data the version 1.0 of CQESTR had an r2 of 0.71 with a 95% confidence interval of 5.5 g SOM kg−1. The model can be used as a tool to predict and evaluate SOM changes from various management practices and offers the potential to estimate C accretion required for C credits. 相似文献
29.
Ecological problems are mainly caused by growth processes. The energy input is a key indicator for ecosystems. In this context, the use of the most valuable kind of energy is of special importance. Economic systems may be considered as special ecosystems. The most valuable kind of energy used in economic systems of industrialised countries is electricity. For some industrialised countries the growth pattern of electricity consumption and its relation to the gross domestic product is considered in this contribution. A linear relation between both indicators for about 3 decades after the Second World War and a coupling of these indicators starting at 1973 has been found. The aim of the contribution is to present this relation and to initiate a discussion about its reason and its interpretation. 相似文献
30.