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1.
为了解设施蔬菜种植年限对土壤矿质氮含量及硝化强度的影响及各指标间的相关关系,以露地菜田土壤(0年)为对照,以不同种植年限设施菜田土壤(5、10、15、20年)为供试土壤,分别测定其铵态氮含量、硝态氮含量及硝化强度,以明确设施蔬菜种植年限对土壤自身速效养分供应能力的影响,为不同年限设施菜田定点施肥管理措施的制定提供依据。结果表明,无论是露地栽培还是设施栽培,0～20 cm土层的土壤铵态氮含量、硝态氮含量和硝化强度均高于相同种植年限20～40 cm土层,且设施种植年限越长,矿质氮的表聚特征越明显。与露地菜田相比,相同土层各设施菜田土壤的矿质氮含量均显著提高,随种植年限的增加,呈先升后降的趋势,0～20 cm土层矿质氮含量(w,后同)于15年时达最大值513.45 mg·kg-1,20～40 cm土层矿质氮含量于10年时达最大值353.21 mg·kg-1。硝化强度与铵态氮含量呈显著正相关,除种植年限为15年的设施菜田外,其余设施菜田土壤的硝化强度均高于相同土层露地菜田土壤,以10年设施菜田最大。应减少设施菜田氮肥投入,并控制其硝化强度,避免蔬菜产... 相似文献
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以3个不同种植年限(0、13年和21年)的设施菜田土壤为研究对象,通过36 d培养试验,研究了添加不同外源氮条件下土壤铵态氮、硝态氮及矿质氮的含量,明确设施蔬菜种植年限和添加外源氮对土壤矿质氮含量的影响,以期为设施菜田减肥、高效施肥管理措施的制定提供参考依据。结果表明:在培养过程中,随设施菜田种植年限的增加,土壤铵态氮、硝态氮和矿质氮含量均表现为增加趋势,但施氮对土壤矿质氮含量的增加效果则随之减弱,种植年限为0、13年和21年的设施菜田土壤矿质氮含量在培养期间的最大增量分别为90.77、83.66 mg·kg-1和74.03 mg·kg-1,硝化速率常数随种植年限的增加而减小。而同一种植年限下,土壤铵态氮、硝态氮和矿质氮含量总体表现为随施氮量的增加而增加,且同一施氮量下,全部施用无机肥处理大于有机无机配施处理,硝化速率常数表现出相同的趋势。该研究可通过施氮量和肥料种类的变化来直接调控土壤矿质氮含量,以减少氮素损失。 相似文献
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种植年限对设施菜田土壤pH及养分积累的影响 总被引：8，自引：0，他引：8
本试验以山东省寿光地区设施菜田为研究对象,分析了不同种植年限设施菜田土壤pH值以及有机质、无机氮、有效磷和有效钾含量状况。结果表明,寿光地区设施菜田各土层土壤pH值随着种植年限的增加而下降,与露地小麦土壤相比降幅达0.05～0.69个单位,其中尤以0～20 cm土层降幅最大,并且随着种植年限的增加,下层土壤pH值下降明显,种植10 a后20～40 cm土层土壤pH由8.67下降至7.99。0～20 cm土层土壤有机质随着种植年限的增加明显增加,1～3、4～6、7～9、≥10 a种植年限设施菜田土壤有机质与露地小麦土壤相比分别增加了6.1%、46.4%、66.5%、125.3%。土壤无机氮含量明显高于露地小麦土壤,但种植年限影响不大。各土层土壤有效磷和有效钾含量随着种植年限的增加显著增加,1～3、4～6、7～9、≥10 a种植年限设施菜田0～20 cm土层有效磷含量分别是露地小麦土壤的8.9、14.8、18.1、18.3倍,有效钾含量分别是露地小麦土壤的2.8、3.2、3.5、3.5倍。设施菜田各土层土壤pH值随种植年限的增加而下降,但与已有研究结果相比土壤pH值有上升趋势。 相似文献
4.
我们调查了张家港市蔬菜主产区设施内不同种植年限0~20cm土壤耕作层的理化性状,研究随种植年限增加设施蔬菜土壤理化性状的变化特点。调查结果表明,设施内常年旱作土壤的pH值低于露地,其EC值、硝态氮及土壤有机质、速效钾、速效氮等养分含量均高于露地;连续旱作6年土壤的pH值低于连续旱作4年的土壤,其EC值、硝态氮、养分含量随着种植年限的增加而提高。 相似文献
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以辣椒品种"美园"为试材,通过田间试验和室内化验分析相结合的方法,研究了设施条件下不同处理(常规施肥、减氮15%、减氮30%、减氮45%、不施氮肥)对土壤硝态氮含量的影响。结果表明:随着土层深度的增加,土壤硝态氮含量逐渐降低,土壤0~40cm土层硝态氮含量波动较大,40~100cm土层硝态氮含量波动较小;随着氮肥施用量的减少,土壤硝态氮含量逐渐降低,减量施肥较常规施肥在不同土层深度土壤硝态氮含量波动小。随着采样日期的增加,土壤硝态氮含量在最终达到最小值,但是土壤硝态氮含量与采样日期不呈线性关系,0~40cm土层硝态氮含量波动较大,40~100cm土层硝态氮含量波动较小。 相似文献
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以"朗庭"番茄为试材,采用田间试验方法,研究了增施微生物菌肥对番茄生长及土壤氮磷累积的影响,以期为设施番茄合理应用微生物菌肥提供参考依据.结果 表明:增施微生物菌肥能够提高番茄产量,增加氮磷养分吸收量,增加土壤硝态氮的累积,降低土壤有效磷向下移动.与常规施肥相比,含有枯草芽孢杆菌的微生物菌肥使番茄产量增加6.70％,氮素吸收量增加36.27％,磷素吸收量增加66.92％;收获期0～60 cm土层土壤硝态氮总累积量增加7.53％,有效磷总累积量降低26.70％,其中40～60 cm土层硝态氮累积量增加20.09％,有效磷累积量降低35.13％;同时增加根系在各土层的分布. 相似文献
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《中国蔬菜》2021,(8)
以种植3、5、7 a的设施菜地和露地蔬菜土壤为研究对象,采用荧光定量PCR和Illumina Miseq高通量测序技术,研究设施菜地种植年限对土壤氨氧化微生物丰度和群落结构的影响。结果表明:不同处理氨氧化古菌(AOA)丰度均大于氨氧化细菌(AOB),AOA/AOB值在17.33～39.16之间。随种植年限延长,AOA和AOB数量逐渐降低。种植年限对AOA和AOB群落结构和多样性有显著影响。二者多样性指数(Chao1指数、ACE指数和Shannon指数)均为种植3 a处理最大,随种植年限延长逐渐降低。在门水平上,AOA群落中奇古菌门为优势类群,AOB群落中变形菌门为优势类群。土壤pH、铵态氮和硝态氮是AOA群落结构变化的主要影响因素。综上,在设施蔬菜种植中,AOA在数量和群落多样性上占主导地位,对环境变化反应较敏感,可能是硝化作用的主要驱动者。 相似文献
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AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β-particles emission from 188Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by 188Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [3H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of 188Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from 188 Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G0/G1 arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation. 相似文献
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多效唑对猕猴桃离体试管苗生长及内源激素的影响 总被引：18，自引：0，他引：18
多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。 相似文献
13.
HU Zhi-cheng ZHU Jia-yuan ZHU Bin GUO Dong CHEN Bin ZHANG Kai HU Kun-hua LI Ming-tao TANG Bing 《园艺学报》2011,27(9):1802-1806
AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars. 相似文献
14.
Duncan Brean W. Boyle Shannon Breininger David R. Schmalzer Paul A. 《Landscape Ecology》1999,14(3):291-309
Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere. 相似文献
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AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis. 相似文献
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Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations
from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations,
dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture
or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near
Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between
November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation
was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme
temperatures (summer maximums, winter minimums). The correlation (r
2) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation
in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences
respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds
that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for
37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest
species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain
the patchy distribution of many species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
AIM: To detect the expression of cytoplasmic inhibitor of apoptosis protein 2 (c-IAP2) and growth arrest-specific gene 1 (GAS1) in Hodgkin's lymphoma (HL) and anaplastic large cell lymphoma (ALCL) and to investigate the role of two genes in the pathogenesis of HL and ALCL.METHODS: HE staining, the antibodies CD30, CD15, CD45RO and CD20 were used to screen the cases of HL and ALCL from 288 cases of lymphoma. The clarified HL and ALCL were subjected for immunohistochemical staining by SP and ABC methods to analyze the expression of c-IAP2 and GAS1. RESULTS: ①The positive rate of c-IAP2 in HL was 25/26(96.1%) while that in ALCL was 6/19(31.6%), there presented statistic significance between HL and ALCL groups(P<0.05), meanwhile the positive rate of GAS1 showed statistic significance between HL and ALCL groups(P<0.05). ②Two cases were showed to be a mixed type combined with large tumor cells of HL and relatively smaller tumor cells of ALCL.CONCLUSION: ①The different expression of c-IAP2 and GAS1 in HL and ALCL implied a different mechanism of oncogenesis and the different defects in the pathway of signal transduction of apoptosis in HL and ALCL;②Few cases showed an overlap and a likely transitional state between HL and ALCL; ③The different expressing manner of GAS1 and c-IAP2 in HL and ALCL implied the potential marks for the differential dignosis of two kinds of lymphoma. 相似文献
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Effects of patch attributes, barriers, and distance between patches on the distribution of a rock-dwelling rodent (Lagidium viscacia) 总被引：1，自引：0，他引：1
We tested whether size of habitat patches and distance between patches are sufficient to predict the distribution of the mountain
vizcacha Lagidium viscacia a large, rock-dwelling rodent of the Patagonian steppe Argentina, or whether information on other patch and landscape characteristics
also is required. A logistic regression model including the distance between rock crevices and depth of crevices, distance
between a patch and the nearest occupied patch, and whether or not there was a river separating it from the nearest occupied
patch was a better predictor of patch occupancy by mountain vizcachas than was a model based only on patch size and distance
between patches. Our results indicate that a simple metapopulation analysis based on size of habitat patches and distance
between patches may not provide an accurate representation of regional population dynamics if patches vary in habitat quality
independently of patch size and features in the matrix alter connectivity.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
19.
Zusammenfassung Die Leistungsprüfungen wurden im Zeitraum 1997 bis 2003 mit den Unterlagen Gisela 4 und 5, den Klonnummern 195/20 und 497/8 aus der Gisela-Serie sowie Weiroot 10, 13, 53, 72 und 158 durchgeführt. Dabei dienten Sämlinge von P1 (bulgarische Selektion aus Prunus mahaleb) als Kontrolle. Alle Unterlagen waren mit der Sorte Stella veredelt und im Dezember 1996 in der Versuchsanlage der Agraruniversität in Plovdiv, Bulgarien, im Abstand von 6 m×4,5 m gepflanzt worden. Dabei erfolgte ein Pflanzschnitt. Nach Abschluss der natürlichen Kronenentwicklung wurde jedes Jahr ein Winterschnitt vorgenommen. Der Boden wurde durch mechanische Bearbeitung offen gehalten und nach dem 4. Standjahr wurden die Baumstreifen mit Herbiziden behandelt. Die Wasserversorgung erfolgte durch eine dem natürlichen Gefälle folgende Überflutung, allerdings nicht immer zum optimalen Zeitpunkt, da keine eigene Wasserquelle zur Verfügung stand.Basierend auf den Ergebnissen bis zum Anfang des 7. Standjahres können die untersuchten Unterlagen in zwei Gruppen differenziert werden: starkwüchsig—Weiroot 10, P1 und Weiroot 13; mittelstarkwachsend bis schwachwüchsig—Gi 497/8, Gisela 4, Weiroot 53, Weiroot 158, Gi 195/20, Weiroot 72 und Gisela 5. Letztere zeichnete sich durch besondere Schwachwüchsigkeit aus. Die meisten Wurzelschosser bildeten Gisela 4, Weiroot 10 und Weiroot 13. Weiroot 53, Weiroot 72 und Weiroot 158 entwickelten deutlich weniger und P1, Gisela 5, Gi 195/20 sowie Gi 497/8 keine Wurzelschosser. Den frühesten Blühbeginn induzierte Gisela 4. Die anderen Unterlagen führten, in Abhängigkeit von den Temperaturbedingungen des jeweiligen Jahres, zu einer Verspätung der Blüte: P1 und Weiroot 10 um 1–2 Tage; Gi 497/8, Weiroot 13 und Weiroot 158 um 2–4 Tage; Weiroot 72 um 2–7 Tage; Gi 195/20 um 3–6 Tage; Weiroot 53 um 3–8 Tage und Gisela 5 um 3–10 Tage. Die Reifezeit der Früchte war bei den Bäumen auf Gisela 5 im Vergleich zu den anderen Varianten um 2–3 Tage verspätet. Gisela 5, Weiroot 72 und Gisela 4 induzierten bei der aufveredelten Sorte die höchsten Ertragsleistungen, P1 die geringsten. Bei den Bäumen auf Gisela 5 war die Fruchtgröße geringer als bei den anderen Unterlagen. Bäume auf Gisela 5 brauchen intensive Pflege. Nur wenn alle Produktionsfaktoren und kulturtechnischen Maßnahmen optimiert werden, kann das hohe Ertragspotenzial dieser Unterlage ausgeschöpft werden. 相似文献
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