全文获取类型
收费全文 | 170篇 |
免费 | 8篇 |
专业分类
林业 | 10篇 |
农学 | 12篇 |
基础科学 | 2篇 |
56篇 | |
综合类 | 14篇 |
农作物 | 21篇 |
水产渔业 | 6篇 |
畜牧兽医 | 30篇 |
园艺 | 13篇 |
植物保护 | 14篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 3篇 |
2018年 | 14篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 23篇 |
2012年 | 18篇 |
2011年 | 12篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 9篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有178条查询结果,搜索用时 31 毫秒
51.
Rashid HB Chaudhry M Rashid H Pervez K Khan MA Mahmood AK 《Tropical animal health and production》2008,40(6):463-467
The present work was conducted to study the comparative efficacy of two anti-protozoan (babesicidal) drugs on the recovery and health of horses. A total of 80 horses, showing typical clinical symptoms of the disease, were selected for this study; the presence of babesiosis was confirmed through blood smear examination. These animals were divided into two groups i.e. A and B. Horses of Group A, were treated with diminazene diaceturate, while horses of Group B were treated with diminazene aceturate. Efficacy of the drugs was determined by the reversal of clinical signs and a negative blood smear examination. The efficacy of diminazene diaceturate was demonstrated to be 80% while diminazene aceturate was found to have 90% efficacy against babesiosis. 相似文献
52.
K. Mahmood D. Peters 《European journal of plant pathology / European Foundation for Plant Pathology》1973,79(4):138-147
A slightly modified procedure for purifying pea enation mosaic virus (PEMV) is described. Essential features are the adding of Mg++ ions to the extraction buffer and the use of polyethylene glycol for concentrating the virus; Mg++ ions seem to protect virus infectivity. Both components of PEMV were found to be infectious. The infectivity of each component in its band on a sucrose gradient was directly proportional to its optical density. The infectivity was not enhanced when both components were simultaneously inoculated ontoChenopodium album. It is concluded that each component carries a complete genome of the virus.Samenvatting Een methode, die was beschreven om erwte-enatiemozaïekvirus (PEMV) te zuiveren, werd gewijzigd. De toevoeging van Mg++-ionen bleek gunstig te zijn voor de zuiverheid van het preparaat en voor de infectiositeit van het virus. Het virus kan met polyethyleenglycol worden geconcentreerd zonder dat NaCl behoeft te worden toegevoegd.Gezuiverde preparaten van PEMV bestaan uit twee componenten met sedimentatiecoëfficienten van 107 en 96 S (Fig. 1). Beide componenten bleken na zuivering infectieus te zijn (Tabel 4). Bij scheiding van de componenten op een suikergradiënt waren de optische dichtheid en de infectiositeit van beide componenten op gelijke wijze over de gevormde zones verdeeld (Fig. 2). Bovendien bleek dat de infectiositeit van beide componenten niet kon worden verhoogd door toevoeging van de een aan de ander (Tabel 5).Wanneer het virus op een CsCl-gradiënt werd gecentrifugeerd werd alleen de bodemcomponent teruggevonden. Deze bleek infectieus te zijn. De topcomponent wordt waarschijnlijk vernietigd door CsCl.In de agargeldiffusietoets bleek het virus-antigeen homogeen te zijn. Het virus viel in twee componenten uiteen bij immuno-elektroforese. Mogelijk is dit te verklaren door het bestaan van twee centrifugale componenten.The senior author was a visiting research worker from March 1965 till May 1967. 相似文献
53.
T. Mahmood R. Ali M. I. Sajjad M. B. Chaudhri G. R. Tahir F. Azam 《Biology and Fertility of Soils》2000,31(3-4):270-278
In a 2-year field study, denitrification loss was measured from an irrigated sandy-clay loam under cotton receiving urea-N
at 158–173 kg ha–1. An acetylene inhibition-soil core method was employed for the direct measurement of denitrification, considering also the
N2O entrapped in the soil. Taking into account the N2O evolved from soil cores and that entrapped in the soil, a total of 65.7 kg N ha–1 and 64.4 kg N ha–1 was lost due to denitrification during the 1995 and 1996 cotton-growing seasons, respectively. Most (>70%) of the denitrification
loss occurred during June–August, a period characterized by high soil temperatures and heavy monsoon rains. On average, 35%
of the denitrification-N2O was found entrapped in the soil and the amount of entrapped N2O was significantly correlated with head space N2O concentration and with water-filled pore space. 15N-balance during the 1996 growing season revealed a loss of 71.8 kg N ha–1. It was concluded that a substantial proportion of the fertilizer-N applied to irrigated cotton is lost under the semiarid
subtropical climatic conditions prevailing in the Central Punjab region of Pakistan and that denitrification is the major
N loss process under irrigated cotton in this region.
Received: 8 March 1999 相似文献
54.
Salinity and sodicity are prime threats to land resources resulting in huge economic and associated social consequences in several countries. Nutrient deficiencies reduce crop productivity in salt‐affected regions. Soil fertility has not been sustainably managed in salt‐affected arid regions. Few researchers investigated the crop responses to phosphorus and potassium interactions especially in saline–sodic soils. A research study was carried out to explore the effect of diammonium phosphorus (DAP) and potassium sulphate (K2SO4) on sugar beet (Beta vulgaris L.) grown in a saline–sodic field located in Kohat district of Pakistan. The crop was irrigated with ground water with ECiw value of 2.17–3.0 dS/m. Three levels each of K2O (0, 75 and 150 kg/ha) as K2SO4 and P2O5 (0, 60 and 120 kg/ha) as DAP were applied. The application of P significantly affected fresh beet and shoot yield while K fertilizers had significant effect on fresh beet yield and ratio of beet:shoot, while non‐significant effects on the fresh shoot were observed. The application of K1 and K2 promoted sugar beet shoot yield by 49.2 and 49.2% at P1 and 64.4 and 59.7% at P2, respectively over controls. In comparison with controls, fresh beet yield was increased (%) by 15 and 51, 45 and 84, and 50 and 58 for corresponding K1 and K2 at P0, P1 and P2, respectively. Addition of P1 and P2 increased beet yield by 37 and 47% over control. The shoot [P] (mmol/kg) were achieved as 55.2, 73.6 and 84.3 at P0, P1 and P2, respectively. The shoot [Mg] and [SO4] tended to decrease with increasing P levels, while [SO4] was markedly reduced at P2. The effect of P on leaf [Na] was non‐significant, but increasing levels of K decreased [Na] substantially at P0 and P1, but there was no difference in the effect of K level on [Na] at P2. Consequently, K application reduced leaf Na:K ratios. Fresh shoot yield was weakly associated with leaf [P] (R2 = 0.53). The leaf Na:K ratio showed a negative relationship (R2 = 0.90) with leaf [K]. A strongly positive relationship (R2 = 0.75) was observed between leaf [K] and fresh beet yield. The addition of K2SO4 also enhanced [SO4] and SO4:P ratios in leaf tissues. The ratio of Na:K in the shoot decreased with increasing K application. These results demonstrated that interactions of K and P could mitigate the adverse effects of salinity and sodicity in soils. This would contribute to the efficient management of soil fertility system in arid‐climate agriculture. 相似文献
55.
Ansar Mahmood Dr.Asma Hassan Iram Maqsood Tang Li-jie Syed Mohsin Bukhari Khalil-Ur-Rehman and Shahla Andleeb 《东北农业大学学报(英文版)》2014,21(1):45-51
An experiment was carried out to assess the phosphorus status of free grazing goats at Faisalabad,Pakistan.Samples were collected fortnightly during summer and winter seasons of 2010 from soil and plants.The highest(118±0.54 mg·kg-1)levels of feces phosphorus were recorded in lactating goats during winter and(9.87±0.99 mg·kg-1)in urine of male during winter.Similarly maximum(71.0±0.88 mg·kg-1)phosphorus concentration was observed in the plasma of lactating animals.Milk contained(31.0±0.36)mg·L-1 in winter while during the months of summer the highest values recorded in forages,soils,canal and tube well waters were(755±1.98)mg·kg-1,(785±4.98)mg·kg-1,(0.97±8.78)mg·L-1 and(4.12±0.55)mg·L-1,respectively.It was revealed from the current results that fecal matter,forage,milk,tube well and canal water contained lower amounts of P,while P levels in blood plasma was found within the critical limits.Therefore,phosphorus supplementations were required in the area under experimentation to meet the requirements of the animals for their normal growth. 相似文献
56.
A laboratory study was conducted in order to explain successive extractions of reserved potassium by using concentrated HCI under reflux for 13 surface and sub-surface soil samples representing three chosen pedons of soil series (472 ECC Bashika, 463 EKC Rabeaa and 461 ECC Talafar) locations of Nineveh Province in Northern of Iraq. The aim is to investigate role of clay minerals on release of reserved potassium from soils. Results showed that dominated clay minerals were (smectite 〉 illite 〉 kaolinite 〉 chlorite) for both 472 ECC and 461 ECC soil series and were (illite 〉 smectite 〉 kaolinite 〉 chlorite) for 463 EKC soil series. Also results appeared that exchangeable K+ released values were 2,483-4,575 mg/kg at 461 ECC and 463 EKC soil series, respectively; non-exchangeable phase ranged from 752-1,390 mg/kg at 461 ECC and 472 ECC soil series, respectively. Soil fertility was evaluated according to its K+ mica release referring for high K+ release content with range between 3,324-5,516 mg/kg at 461 ECC and 463 EKC soil series, but rate ofK~ released was very law according to parabolic diffusion me,del with range from 195-359 mg/kg at latter soil series respectively. Results reflect effect of clay minerals on potassium release as amount and rates in arid and semi-arid regions. It can be concluded the study soils have a high amount of potassium content with low rate release of it, in turn these soil need particular management. 相似文献
57.
Carbon availability and microbial biomass in soil under an irrigated wheat-maize cropping system receiving different fertilizer treatments 总被引:2,自引:0,他引:2
Seasonal changes in carbon availability and microbial biomass were studied in soil under an irrigated wheat-maize cropping
system receiving different fertilizter treatments over the past 10 years. Treatments included N-100 and N-200 (urea at 100
and 200kgNha–1 year–1, respectively), FYM-16 and FYM-32 (farmyard manure at 16 and 32tha–1 year–1, respectively) and a control (unfertilized). Aerobically mineralizable carbon (AMC; C mineralized after 10 days aerobic incubation
at 30°C) increased (13–16%) under wheat at both rates of urea whereas under maize it increased (22%) only with the lower rate
of urea. Farmyard manure also increased the content of soil AMC under both crops, the effect being two- to threefold higher
under wheat than under maize. Urea application caused an 32–78% increase in the specific respiratory activity (SRA) under
wheat but caused an 11–50% decrease during the maize season. Farmyard manure also resulted in a higher SRA under both crops
but only at the higher application rate. Under wheat, microbial biomass C (MBC) decreased in urea-treated plots but showed
a slight increase at the higher rate of FYM. During the maize season, MBC was higher under both urea (42–46%) and FYM (36–47%)
treatments as compared to the control. Microbial biomass turnover rate was highest for FYM-32 (2.08), followed by FYM-16 and
urea treatments (1.35–1.49); control plots showed a turnover rate of 0.82. The higher AMC and SRA during the active growth
period of wheat than that of maize indicated that root-derived C from wheat was higher in amount and more easily degradable.
Received: 16 April 1996 相似文献
58.
Foliar uptake of 15NH3 applied at two growth stages (tillering and anthesis) and the subsequent 15N-labelled vegetative-N distribution in different plant components at maturity was investigated in three rice cultivars, IR-6, NIAB-6 and Bas-385. Rice plants absorbed 22–30% and 18–24% of the 15NH3 applied at tillering and anthesis stages, respectively. Of the total 15NH3 absorbed at tillering stage, IR-6 and Bas-385 showed higher recovery (71%) in different plant components at maturity as compared to NIAB-6 (48% recovery). At maturity, percent recovery of the 15NH3 absorbed at anthesis stage was almost comparable in different cultivars, but it was lower (46–55%) than that absorbed at the tillering stage. Recovery of the absorbed 15NH3-N in the soil was negligible and ranged from 0.3–1%. At maturity, the cultivars IR-6 and Bas-385 showed a higher loss (45–53%) of 15NH3 absorbed at anthesis than at the tillering stage (29% loss), whereas for NIAB-6, the corresponding figures were comparable for the two growth stages (tillering, 51% loss; anthesis, 49% loss). Results indicated a variable potential of the tested rice cultivars for foliar uptake of atmospheric 15NH3 and distribution of 15N-labelled vegetative-N in different plant components. 相似文献
59.
The effect of GnRH administration on superovulatory response of ewes treated with equine chorionic gonadotrophin (eCG) in
breeding and nonbreeding seasons and the contribution of laparoscopic insemination to the improvement of fertilization and
embryo recovery were investigated. Twenty-four nonpregnant Awassi ewes of 3–4 years of age were randomly allocated into two
groups (n = 12). Each ewe was treated with a progesterone impregnated intravaginal sponge for 12 days. The following superovulation
treatment was used: ewes of group 1 received 1,200 IU of eCG once as an intramuscular injection 48 h prior to sponge withdrawal;
ewes of group 2 also received 1,200 IU of eCG once as an intramuscular injection, 48 h prior to sponge withdrawal and after
24 h of sponge removal. Ewes were injected with 80 μg of GnRH. Ewes of groups 1 and 2 were further subdivided into four equal
groups (n = 6). Subgroups A and C (superovulated with eCG and eCG plus GnRH, respectively) were mated naturally at least two times
with Awassi rams of proven fertility at 8-h intervals. Subgroups B and D (same as A and C) had intrauterine insemination at
44–46 h after sponge removal, under laparoscopic visualization of uterine horns, depositing 1 ml of diluted semen containing
100 × 106 motile sperm in the distal portion of each uterine horn. Ovarian response was assessed by determining the number of corpora lutea by laparoscopy at day 6 after mating. Embryo recovery was performed by using a semi-laparoscopic flushing procedure in both
uterine horns. Results of the present study showed that ewes treated in breeding season with eCG plus GnRH has a higher number
(P < 0.05) of corpora lutea than eCG alone as 7.33 ± 0.54 and 4.33 ± 0.39, respectively. There was no significant difference in the number of corpora lutea in nonbreeding season when ewes treated with eCG and eCG plus GnRH. The number of unovulated follicles was significantly
higher (P < 0.05) in eCG treated ewes than in ewes treated with eCG plus GnRH, both in the breeding and nonbreeding seasons. The number
of recovered embryos from ewes treated with eCG plus GnRH and eCG differ significantly (P < 0.05) as 4.32 ± 0.56 and 1.06 ± 0.26, respectively, in the breeding seasons. No significant difference was observed when
these hormones used for superovulation in the nonbreeding season. A higher number of unfertilized ova (P < 0.05) was observed in ewes when naturally inseminated than in ewes inseminated using the intrauterine laparoscopic technique.
Higher rate of embryo recovery (P < 0.05) was achieved when ewes were inseminated via intrauterine (4.66 ± 0.66) compared with ewes naturally mated (2.16 ± 0.74).
The fertilization rate in ewes inseminated intrauterine using laparoscopic techniques and naturally mated were 91.5% and 44.8%,
respectively. Fertilization failure in ewes inseminated intrauterine using laparoscopic techniques and naturally mated were
8.4% and 55.2%, respectively. It could be concluded that administration of GnRH 24 h after sponge removal increased ovulation
rate of Awassi ewes treated with eCG for superovulation in the breeding season. The use of eCG to induce superovulation in
Awassi ewes combined with laparoscopic intrauterine insemination increases the fertilization rate. 相似文献
60.
Ali Saeed Qaiser Mahmood Khan Usman Waheed Memoona Arshad Muhammad Asif Muhammad Farooq 《Comparative immunology, microbiology and infectious diseases》2011,34(2):95-101
FMD clinically positive 250 tissue samples (mouth and hoof epithelium and vesicle swabs, tongue tissue) and 175 secretion samples (milk, saliva, serum, plasma) were evaluated by RT-PCR for the diagnosis of FMD with different pair of universal and serotype-specific primers from 2006 to 2007 in Punjab, Pakistan. Universal primer pair P1/P2 from VP1 gene detected FMD in 182 out of 250 (72.8%) tissues and 92 out of 175 (52.6%) secretion samples, while universal primer 1F/1R from 5′UTR region detected FMD in 218 out of 250 (87.2%) tissues and 142 out of 175 (81.1%) secretion samples. 1F/1R proved better than the P1/P2 primer pair for primary diagnosis of FMD, direct from the clinical positive samples. Direct sequencing of the universal primer pair P1/P2 revealed that O serotype of FMD was circulating in this region. O serotype of FMD was detected with O-1C(ARS4)/PNK 61, AU(O)/AU(rev), AU(O)/PNK61 primer pairs, these primer pairs also compared with each other. AU(O)/AU(rev) and AU(O)/PNK61 detected O serotype of FMD in 88.9% tissue and swab (mouth and hoof vesicle swabs) samples and 71.9% different secretion (milk, saliva, serum, plasma) samples, while O-1C(ARS4)/PNK 61 detected 48.1% tissue and swab (mouth and hoof vesicle swabs) samples and 37.5% different secretion (milk, saliva, serum, plasma) samples. AU(O)/AU(rev), AU(O)/PNK61 primer pairs detected 40.8% more tissue and swab samples, while these pairs detected 34.4% more secretion samples. Cloning of PCR product of AU(O)/AU(rev) VP1 gene and sequencing for phylogenetic studies revealed that O serotype of FMD circulating in Punjab, Pakistan was genetically very diverse from the ‘O’ serotype in Middle East and Europe. The dendrogram showed that Pakistan ‘O’ serotype was very much similar genetically to its neighbor countries (Sri Lanka, India, Iran, Iraq, and China) and PanAsia 1 lineage which caused 2001-outbreak in UK and 1994-outbreak in Saudi Arabia, etc. 相似文献