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1.
Smallholder rubber and swidden agriculture in Borneo: A sustainable adaptation to the ecology and economy of the tropical forest 总被引:1,自引:0,他引:1
Michael R. Dove 《Economic botany》1993,47(2):136-147
This is a study of the role of Para rubber cultivation in a system of swidden agriculture in Indonesian Borneo. Such smallholdings
produce most of Indonesia’s rubber, which is the country’s largest agricultural generator of foreign exchange. Rubber integrates
well into Bornean systems of swidden agriculture: the comparative ecology and economy of Para rubber and upland swidden rice
result in minimal competition in the use of land and labor — and even in mutual enhancement — between the two systems. Rubber
occupies a distinct niche in the farm economy: it meets the need for market goods, while the swiddens meet subsistence needs.
The intensity of production on these smallholdings is, as a result, characteristically low (and may even vary inversely with
market prices). This reflects the independence of these smallholders from external economic and political influences, which
has been the key to their historical success. The special virtues of such “composite systems” merit greater attention by development
planners.
Penilitian ini mempelajari peranan karet rakyat sebagai pasangan bagi sistem perladangan di Kalimantan-Indonesia. Perkebunan
karet rakyat merupakan penghasil utama karet Indonesia, yang merupakan penyumbang pertanian terbesar bagi devisa negara. Karet
rakyat membaur dengan baik dalam sistem perladangan di Kalimantan: pembandingan ekologi dan ekonomi antara karet rakyat dan
sistem perladangan menunjukkan persaingan yang minimum dalam pemakaian lahan dan tenaga kerja—dan bahkan saling menguntungkan—antara
kedua sistem tersebut. Karet rakyat menempati kedudukan yang penting dalam ekonomi usaha para peladang: yaitu memenuhi kebutuhan
barang-barang pasar, sedangkan sistem perladangan memenuhi kebutuhan pokok hidup. Intensitas produksi perkebunan karet rakyat
oleh karena itu, brasanya agak rendah (yang kadang-kadang berbeda berbalikan dengan harga pasar). Hal ini menggambarkan ketidak-bergantungan
petani karet pada pengaruh-pengaruh ekonomi dan politik dari luar, dan ini merupakan kunci sukses mereka. Hal-hal khususyang
menguntungkan dari sistem terpadu inipatut mendapatkanperhatian yang lebih besar dari perencana-perencana pembangunan. 相似文献
2.
3.
Charles A. Maynard 《In vitro cellular & developmental biology. Plant》1994,30(1):64-69
Summary A field test was established in 1987 to evaluate the growth of micropropagated black cherry plantlets and control seedlings.
The study also evaluated effects of two container types on initial survival and growth and of pruning on stem form and growth.
At the time of field establishment, plantlets had more extensive root systems than the control seedlings. Survival and height
growth were not influenced by container size. Through the first three growing seasons, seedlings were larger than micropropagated
plants, but growth differences diminished in the fourth through sixth seasons. Pruning increased the length of clear stem
by nearly five-fold but adversely affected diameter growth.
Although all clones were from ortet trees more than 50 yr old, none showed plagiotropic growth. Six-year results showed that
in a well-prepared and maintained plantation, black cherry trees derived from tissue culture can have at least 80% survival,
and growth rates in excess of 1 m per year. 相似文献
4.
5.
Biological nitrogen fixation (BNF) has an assured place in agriculture, mainly as a source of nitrogen for legumes. Legumes are currently grown mostly as a source of vegetable oil and as food for humans and animals, but not as nitrogen source.Other crops with BNF capability may be eventually be developed eventually. Such crops will also need mineral fertilizers to maintain a good status of soil nutrients, but their possible effects to the environment is also a concern. Fertilizers, however, will remain a necessary and sustainable input to agriculture to feed the present and increasing human population. It is not a case of whether BNF is better or worse than mineral fertilizers because both plays an important role in agriculture. 相似文献
6.
《Endocrine practice》2021,27(12):1232-1241
ObjectiveWell-controlled glucose levels (ie, 70-180 mg/dL) have been associated with lower mortality from COVID-19. The addition of dexamethasone to COVID-19 treatment protocols has raised concerns about the potential negative consequences of dexamethasone-induced hyperglycemia.MethodsWe developed a protocol to guide the management of dexamethasone-induced hyperglycemia in hospitalized patients with COVID-19. Two of the 4 medical teams managing patients with COVID-19 at a tertiary center in Saudi Arabia used the protocol and the other 2 teams continued to manage hyperglycemia at the discretion of the treating physicians (protocol and control groups, respectively). The glycemic control and clinical outcomes in 163 patients hospitalized with COVID-19 and dexamethasone-induced hyperglycemia between July 5th and September 30th, 2020, were retrospectively compared between the 2 groups.ResultsCompared to the control group, the protocol group had higher proportions of patients with well-controlled glucose across all premeals and bedtime glucose readings throughout the hospital stay. The differences in glycemic control between the 2 groups were statistically significant for fasting glucose on days 4, 5, and the discharge day; prelunch glucose on the discharge day; predinner glucose on days 3, 5, and the discharge day; and bedtime glucose on day 1 (all P < .05). After adjusting for age, sex, nationality, body mass index, Charlson score, and diabetes status, patients in the protocol group were more likely to have well-controlled glucose levels compared with those in the control group. Moreover, the in-hospital mortality was significantly lower in the protocol group (12.93%) compared to the control group (29.93%) (P < .01).ConclusionThe implementation of a protocol to manage dexamethasone-induced hyperglycemia in hospitalized patients with COVID-19 resulted in more patients achieving well-controlled glucose levels and was associated with lower mortality from COVID-19. 相似文献
7.
《Expert review of proteomics》2013,10(4):415-424
In the past decade, analysis of the urinary proteome (urinary proteomics) has intensified in response to the need for novel biomarkers that support early diagnosis of kidney diseases. In particular, this also applies to acute kidney injury, which is a heterogeneous complex syndrome with a still-increasing incidence at the intensive care unit. Unfortunately, this major need remains largely unmet to date. The current report aims to explain why attempts to implement urinary proteomic-discovered acute kidney injury diagnostic candidates in the intensive care unit setting have not yet led to success. Subsequently, some key notes are provided that should enhance the chance of translating selected urinary proteomic candidates to valuable tools for the nephrologist and intensivist in the near future. 相似文献
8.
我国三大城市群地区城市和农业用地地表热环境效应对比研究 总被引:1,自引:0,他引:1
以大中小城市协同发展为特征的城市群已成为我国城市化发展的主要形式,城市化和农业作为城市群地区最主要的土地利用活动,其气候效应是国际研究的热点。然而过去研究多关注大城市的热岛效应,对更为普遍的农业活动以及中小城市城市化的气候效应认识十分薄弱。基于MODIS地表温度数据,以自然林地为参照,提出了一种可逐像元估算土地利用地表热环境效应的新方法,进而对比分析了我国三大城市群地区(京津冀、长三角和珠三角)城市和农业用地地表热环境效应及其驱动因子差异。结果表明各城市群白天城市热岛效应明显,地级以上城市年平均热岛强度达3.2℃以上,但最强热岛均未发生在核心城市。夜晚热岛效应明显减弱,京津冀和长三角部分城市甚至出现冷岛效应。农业用地在白天亦表现出明显的增温效应,特别是在京津冀地区,而在夜晚除珠三角城市群外,降温效应明显,京津冀和长三角地区平均降温2.3℃和0.7℃。虽然城市用地平均增温强度大于农业用地,但农业用地因面积优势对区域温度变化起控制作用。白天城市和农业用地整体导致各城市群温度明显增加,京津冀增温最高(4.0℃),夜晚二者导致长三角和京津冀地区平均温度降低。研究还发现各城市群城市和农业用地地表热环境效应时空异质性极大,主要受植被、地表反照率、气候背景和人口密度控制。本文对制定缓解气候变化的土地利用策略具有重要的指导意义。 相似文献
9.
Behnam Sadeghi Elham Roshandel Ali Pirsalehi Sepide Kazemi Ghazaleh Sankanian Mohammad Majidi Maryam Salimi Nasser Aghdami Hoda Sadrosadat Sarvenaz Samadi Kochaksaraei Farshid Alaeddini Olle Ringden Abbas Hajifathali 《Journal of cellular and molecular medicine》2021,25(22):10554-10564
Acute respiratory distress syndrome (ARDS) is the most common cause of death in COVID-19 patients. The cytokine storm is the main driver of the severity and magnitude of ARDS. Placenta-derived decidua stromal cells (DSCs) have a stronger immunosuppressive effect than other sources of mesenchymal stromal cells. Safety and efficacy study included 10 patients with a median age of 50 (range 14–68) years with COVID-19-induced ARDS. DSCs were administered 1–2 times at a dose of 1 × 106/kg. End points were safety and efficacy by survival, oxygenation and effects on levels of cytokines. Oxygenation levels increased from a median of 80.5% (range 69–88) to 95% (range 78–99) (p = 0.012), and pulmonary infiltrates disappeared in all patients. Levels of IL-6 decreased from a median of 69.3 (range 35.0–253.4) to 11 (range 4.0–38.3) pg/ml (p = 0.018), and CRP decreased from 69 (range 5–169) to 6 (range 2–31) mg/ml (p = 0.028). Two patients died, one of a myocardial infarction and the other of multiple organ failure, diagnosed before the DSC therapy. The other patients recovered and left the intensive care unit (ICU) within a median of 6 (range 3–12) days. DSC therapy is safe and capable of improving oxygenation, decreasing inflammatory cytokine level and clearing pulmonary infiltrates in patients with COVID-19. 相似文献
10.
《中国科学:生命科学英文版》2014,(8)
<正>Aims and scope SCIENCE CHINA Life Sciences(Sci China Life Sci)is a journal published monthly in English by the Chinese Academy of Sciences,and co-sponsored by the National Natural Science Foundation of China.It is published in both printed and electronic forms by Science China Press and Springer.The journal publishes high-quality papers from a wide range of areas in life sciences,including biology,medicine,and agriculture and ecology.Six categories of papers are published:Review,Research Paper,CUSBEA Article Series,Insight,Letter to the Editor,and News and Views. 相似文献