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HPLC-ELSD法测定苦杏仁中苦杏仁苷的含量 总被引:1,自引:0,他引:1
建立了苦杏仁中苦杏仁苷的高效液相色谱-蒸发光散射检测器检测方法。采用ZORBAX Eclipse XDB-C18色谱柱(4.6mm×150mm,5μm),流动相为V(甲醇)∶V(水)=40∶60,流速1.0mL/min,柱温40℃;蒸发光散射检测器漂移管温度60℃,载气(空气)压力0.2MPa。在上述条件下测得苦杏仁苷在0.28~5.5μg范围内的线性关系良好(r=0.9975),检出底限达58ng/L,平均加标回收率为96.2%。该方法简便快捷,重现性和准确度良好,可用于实际工作中样品的测定。 相似文献
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A model was developed to examine the effects of sexed semen use in virgin heifers and lactating cows on replacement heifer numbers and rate of herd expansion in a seasonal dairy production system. Five separate herds were established according to the type of semen used: conventional frozen-thawed (Conv), sexed fresh semen used in lactating cows for the first 3 wk of the breeding season (SFre1), sexed frozen-thawed semen used in lactating cows for the first 3 wk of the breeding season (SFro1), sexed fresh semen used in lactating cows for the first 6 wk of the breeding season (SFre2), or sexed frozen-thawed semen used in lactating cows for the first 6 wk of the breeding season (SFro2). In the SFro1, SFre1, SFro2, and SFre2 herds, sexed semen was used for the first and second artificial insemination in virgin heifers. Pregnancy rates achieved with sexed fresh and sexed frozen-thawed semen were assumed to be 94 and 75% of those achieved with conventional frozen-thawed semen, respectively. Initial herd size was 100 cows, which was maintained for the first 2 yr of the 15-yr simulation, after which all available replacement heifers were retained to facilitate herd expansion. Two different scenarios of land availability were examined for each of the 5 herds: land available allowed expansion to a maximum herd size of 150 cows (S1), or land available allowed expansion to a maximum herd size of 300 cows (S2). Once maximum herd size was reached, sexed semen use was discontinued and all excess heifer calves were sold at 1 mo old. All capital expenditure associated with expansion was financed with a 15-yr loan. Each of the 10 different options was evaluated in terms of annual farm profit, annual cash flow, and total discounted net profit. The use of fresh sexed semen generated more replacement heifers, leading to faster herd expansion compared with frozen-thawed sexed semen and conventional frozen-thawed semen. Maximum herd size under S1 was reached in yr 5, 5, 4, 5, and 7 for the SFre1, SFro1, SFre2, SFro2, and Conv herds, respectively. Under S2, maximum herd size was reached in yr 8, 10, 7, 9, and 14 for the SFre1, SFro1, SFre2, SFro2, and Conv herds, respectively. Total discounted net profit under S1 for the SFre2 herd was €4,130, €38,869, €47,231, and €52,089 greater compared with the SFre1, SFro1, Conv, and SFro2 herds, respectively. Under S2, discounted net profit for the SFre2 herd was €44,204, €255,524, €280,373, and €325,815 greater compared with the SFre1, SFro1, SFro2, and Conv herds, respectively. The negative effects of the sexed frozen-thawed semen on herd fertility reduced farm profitability and will prevent its widespread use in lactating cows. 相似文献
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目的 测试食品豆豉和中药淡豆豉样本中的药典成分,分离培养其留存的微生物菌株,分析微生物类别、发酵过程与功能成分的关系。方法 平板筛选培养、菌苔外观和显微镜鉴别微生物菌株,液相色谱法测定大豆异黄酮及苷元成分的含量,纤维平板法测试纤溶酶活性。结果 中药淡豆豉和食品豆豉的微生物以枯草芽孢杆菌最多,其次是霉菌和酵母;样本大豆异黄酮和苷元成分差异较大,有些中药材淡豆豉低于药典标准;个别食品豆豉样本具有纤溶酶活性,中药材淡豆豉少有纤溶酶活性。结论 留存于淡豆豉或豆豉中的微生物丰度顺序如下:枯草芽孢杆菌、霉菌和酵母;大豆异黄酮和苷元成分的含量与发酵过程有关,样本的差异较大;溶栓不是中药材淡豆豉的主要功效。 相似文献
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The objectives of this study were to evaluate the effects of using sex-sorted semen for first AI of heifers on health and productivity during first lactation. Holstein heifers (herd A = 227 and herd B = 1,144) received first artificial insemination (AI) with sex-sorted semen (SX; n = 343) or conventional semen (CS; n = 1,028), and all heifers that displayed estrus after first AI were reinseminated with conventional semen up to 11 times before being culled. Age at first AI was 13.1 ± 0.1 and 13.8 ± 0.1 mo for SX and CS heifers, respectively, in herd A and 12.9 ± 0.1 mo for both SX and CS heifers in herd B. Pregnancy per AI after first AI was greater for CS heifers than for SX heifers (51.8 vs. 40.2%). From heifers initially enrolled, 70.2% calved in herds A (n = 188) or B (n = 774) and first-lactation data were collected. Interval from first AI to calving was greater for SX heifers than for CS heifers (10.2 ± 0.1 vs. 9.9 ± 0.1 mo). Among heifers conceiving to first AI, SX heifers were more likely than CS heifers to deliver a female calf (85.7 vs. 47.7%), but because SX heifers were more likely to deliver a dead calf (8.8 vs. 3.4%), the difference in proportion of SX and CS heifers delivering a live female calf was smaller than expected (SX = 79.1%; CS = 47.2%). Rearing cost from first AI to calving was greater for SX heifers than for CS heifers ($775.3 ± 6.7 vs. $750.0 ± 5.9), but calf revenue tended to be greater for SX heifers ($142.0 ± 7.2 vs. $126.7 ± 6.4) and cost per female calf produced was smaller for SX heifers than for CS heifers ($−809.4 ± 10.8 vs. $−1,249.7 ± 10.9). Treatment did not affect calving difficulty, proportion of heifers needing assistance, and incidence of retained fetal membranes or metritis. Among heifers that conceived to first AI, however, SX heifers were more likely to be culled within 30 DIM (3.3 vs. 1.6%) and tended to be more likely to be culled within 60 DIM (5.5 vs. 3.4%) than CS heifers, but overall replacement cost was not different ($136.8 ± 13.4). Total milk yield (9,245.5 ± 84.7 kg) and income over feed cost ($554.7 ± 5.1) were not different. Overall economic return was greater for SX heifers than CS heifers ($−83.7 ± 36.7 vs. −175.3 ± 33.4). Use of sex-sorted semen for first insemination of virgin heifers reduced the cost per female calf produced and increased the economic return during the first lactation. 相似文献
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Effect of sex-sorted sperm dosage on conception rates in Holstein heifers and lactating cows 总被引:1,自引:0,他引:1
DeJarnette JM Nebel RL Marshall CE Moreno JF McCleary CR Lenz RW 《Journal of dairy science》2008,91(5):1778-1785
Ejaculates were collected by artificial vagina from 3 Holstein sires and sorted to 90% purity for X-chromosome-bearing spermatozoa (range 88 to 93%) using flow cytometry. Sorted sperm were diluted to 2.1, 3.5, or 5.0 × 106 sperm per dose in an egg yolk (20%), Tris, glycerol (7%) extender. Collections were repeated until >600 straws per sperm dose per sire were obtained. Each sperm dose was loaded into color-coded 0.25-mL French straws, with alternate colors used to define treatments across sires. Within sires, straws were packaged at 9 per cane (3 of each color) and strategically allocated to 75 Holstein herds with targets for 50% use in heifers and 50% in lactating cows. Straw color was recorded in the on-farm record-keeping system at the time of insemination. Data were analyzed separately for cows and heifers. Among heifers, a total of 2,125 usable records were retrieved from 51 herds (238 ± 5.5 services/ sperm dose per sire, range: 218 to 263). Conception rates in heifers were influenced by the sire × sperm dosage interaction. Within sire A, conception rates of heifers were greater for the 5 × 106 (59.5%) than for the 2.1 × 106 (46.4%) sperm dose and intermediate for the 3.5 × 106 sperm dose (52.2%). However, across sires, sperm dosage had no effect on heifer conception rates (46.7, 51.2, and 52.5% for the 2.1, 3.5, and 5.0 × 106 sperm dosages, respectively). Among cows, a total of 2,369 services were retrieved from 56 herds (263 ± 8.8 services/sperm dose per sire, range: 233 to 303). Conception rates of cows (29.4%) were not affected by sire or sperm dosage (27.0, 29.1, and 30.3% for the 2.1, 3.5, and 5.0 × 106 sperm dosages, respectively). In conclusion, these data indicate that an increased sperm dosage may enhance virgin heifer conception rates for some (but not all) sires, whereas neither sire nor sexed-sperm dosage affected conception rates of lactating cows. Additional studies of sexed-sperm dosage across a larger sampling of bulls are warranted to determine whether and how such a practice can be implemented cost effectively for the benefit of the dairy industry. 相似文献
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This study was designed to investigate the genetic effects of using sorted semen in a dairy cattle population. Progress was monitored in elite and commercial animals over 20 yr of selection. To study the genetic impact of using sorted semen in commercial herds, a scenario was evaluated in which female-sorted semen was available to commercial herds. Second, to study the genetic impact of using sorted semen in nucleus herds, scenarios were simulated in which female-sorted semen was used only in a centralized nucleus herd, in which multiple ovulation and embryo transfer (MOET) took place. Because of the additional advantage of marker-assisted selection when sorted semen was used in nucleus herds, a second scenario was simulated in which both sorted semen and marker-assisted selection were implemented. In the scenario in which female-sorted semen was used in commercial herds, a large genetic advantage was observed early in commercial cows. The average superiority in first-lactation cows exceeded 30% in yr 11, relative to a base scheme with regular semen, but continued to decrease until it reached 9% in yr 20. The increased selection intensity in commercial cows contributed to the genetic merit of future cows (cow-to-cow contribution), but the contribution of the nucleus grew over time and gradually marginalized the cow-to-cow contribution. The genetic advantage of gender control in MOET schemes was minimal except when marker-assisted selection was also available. Two factors that affected the contribution of marker-assisted selection were studied: 1) within- vs. across-family selection of donors, and 2) the number of loci in the quantitative trait locus component. Schemes that selected donors regardless of their family structure were superior, and the quantitative trait locus component with more loci increased the effectiveness of sorted semen. Finally, we studied a reduced MOET scheme in which the number of harvested females was reduced from 42 to 25/yr. The reduced scheme in combination with female-sorted semen was not found to be genetically inferior to the large scheme in combination with regular semen. 相似文献
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酸枣仁油取自药食同源的酸枣仁,是一种安全的保健食用油,综述近年来有关酸枣仁油的提取工艺、组成成分分析及其生物活性研究,为酸枣仁油的进一步开发与应用提供参考。现有研究表明,酸枣仁油生产工艺简单,成品油中含有大量不饱和脂肪酸,其中油酸和亚油酸含量最高,同时还含有多种脂溶性成分。酸枣仁油具有多种生物活性,如镇静催眠、改善记忆力、抗抑郁、抗氧化、血脂调节及抗肿瘤等,但其发挥生物活性的物质基础及作用机理尚未完全明确,有待进一步研究。酸枣仁油的安全及多活性特点赋予其巨大的开发与应用潜力,相关产品具有广阔的市场前景。 相似文献