共查询到20条相似文献，搜索用时 78 毫秒
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商洛市日光温室加地膜栽培辣椒 ,8月下旬- 9月初播种 ,1 1月定植 ,翌年 1月采收 ,6月拉秧 ,生长期达 1 0月之多。1 栽培品种选择 日光温室栽培辣椒 ,品种选择非常重要。必须选择株型紧凑 ,较耐寒 ,适应性强 ,抗病、高产、品质好 ,深受消费者欢迎的优良品种。在商洛市冬春气候条件下 ,应选择沈椒 1号、辽椒 2号、利生保椒、羊角椒、农发等品种栽培 ,能够取得较高的经济效益。2 辣椒栽培适用技术2 .1 播种育苗2 .1 .1 苗床准备 冬春茬辣椒在 8月下旬播种较为适宜 ,此时光热条件有利于培育壮苗。方法是育苗前先将育苗地深翻耙平 ,做好 … 相似文献
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辣椒是我县大宗蔬菜生产项目,常年栽培面积1.5万亩,其中以杂交种为主的早熟辣椒约占三分之一,其余为本地晚熟黄椒.1992、1993连续两年出现辣椒严重枯萎死苗,尤其是早栽早熟品种大面积过早毁园,1993年更甚.其特点是,早熟重于晚熟种,杂交种重于常规种,杂交品种间没有明显差别. 相似文献
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在亚热带地区,若按常规的栽培方法,春菜（茄子、辣椒、著茄等）要在春分一清明播种,7月上旬前后才能收获。这样,越冬秋荣与春菜的收获期相距甚远,因而就会出现明显的“青黄不接”时段,即所谓“淡季”。为了解决这个矛盾,近年来对春菜栽培进行改革,采用了“三部曲”（温 相似文献
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塑料大棚增施CO_2气肥,既能保证棚室蔬菜光合作用对CO_2的需要和提高光合效率,又是蔬菜保护地栽培的重要丰产措施。1995年10月至1996年6月在武汉市东西湖区蔬菜技术推广站种有辣椒的大棚内进行了增施和不施CO_2气肥对比试验。 相似文献
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线辣椒栽培要选择纯度较高，株型紧凑，综合抗性强，较耐寒，丰产性突出，市场前景广阔，消费者喜爱的优良品种。适宜渭北西部气候条件的优良品种有8819、98-1、2002、七寸红等。 相似文献
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用灰色系统关联度及统计方法对玻璃温室内辣椒生长状况、生物量与室内１０种气象要素进行定量分析,得出影响辣椒生产各气象要素的指标。 相似文献
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Louis M. Michaud 《Meteorology and Atmospheric Physics》2012,118(1-2):21-29
Warm seawater is the energy source for hurricanes. Interfacial sea-to-air heat transfer without spray ranges from 100?W?m?2 in light wind to 1,000?W?m?2 in hurricane force wind. Spray can increase sea-to-air heat transfer by two orders of magnitude and result in heat transfers of up to 100,000?W?m?2. Drops of spray falling back in the sea can be 2–4?°C colder than the drops leaving the sea, thus transferring a large quantity of heat from sea to air. The heat of evaporation is taken from the sensible heat of the remainder of the drop; evaporating approximately 0.3?% of a drop is sufficient to reduce its temperature to the wet bulb temperature of the air. The heat required to evaporate hurricane precipitation is roughly equal to the heat removed from the sea indicating that sea cooling is due to heat removal from above and not to the mixing of cold water from below. The paper shows how case studies of ideal thermodynamic processes can help explain hurricane intensity. 相似文献
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Edwin Kessler 《Dynamics of Atmospheres and Oceans》1998,27(1-4)
Condensation oscillations in showers and thunderstorms are represented by variations in the vertical air currents that are induced by the accumulation and fallout of condensed water. A simple analytic theory of condensation oscillations and calculations on more complete numerical models indicate that their period is approximately proportional to the inverse square root of the condensation function, i.e. the amount of condensate produced per unit rise of saturated air, and that the period is independent of the magnitude of thermal buoyancy. 相似文献
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G. Kruspe 《Boundary-Layer Meteorology》1977,11(1):55-63
From direct measurements of vertical fluxes of moisture representing conditions in extremely different areas, parameterization according to the simple linear Dalton-formula leads to an apparent negative moisture flux. It is argued that this effect can be traced to deviations of moisture conditions at the interface from the saturation value according to the subsurface sea-temperature. The measurements presented were taken over the German Bight and the Baltic sea using a microwave-refractometer, a sonic-anemometer and a fine platinum wire thermometer. The BOMEX-and San Diego measurements (Phelps and Pond, 1971) have been added to the sample. 相似文献
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Michael Longuet-Higgins 《Dynamics of Atmospheres and Oceans》1982,7(1):33-46
Long range acoustic soundings with triads of transducers can determine accurately the vorticity integrated over the corresponding triangular areas of the ocean. However, for a given number n of transducers not all such observations are independent. In this note we show, first, that the number N of possible independent observations is in fact N = (n ? 1) (n ? 2)/2 Secondly, we shall show such observations are in principle able to provide estimates of the vorticity field and its derivatives up to order m = (n ? 3). Thus four transducers yield an accurate estimate of the scalar vorticity ω and its horizontal gradient δ ω, while five transducers will yieldalso the Laplacian δ2ω. 相似文献
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On the ENSO Mechanisms 总被引：23，自引：0，他引：23
Chunzai Wang 《大气科学进展》2001,18(5):674-691
The El Nino-Southern Oscillation (ENSO) is an interannual phenomenon involved in the tropical Paci fic Ocean-atmosphere interactions. The oscillatory nature of ENSO requires both positive and negative ocean-atmosphere feedbacks. The positive feedback is dated back to Bjerknes＇ hypothesis in the 1960s, and different negative feedbacks have been proposed since the 1980s associated with the delayed oscillator, the western Pacific oscillator, the recharge-discharge oscillator, and the advective-reflective oscillator. The de layed oscillator assumes that wave reflection at the western boundary provides a negative feedback for the coupled system to oscillate. The western Pacific oscillator emphasizes equatorial wind in the western Pacific that provides a negative feedback for the coupled system. The recharge-discharge oscillator argues that discharge and recharge of equatorial heat content cause the coupled system to oscillate. The advective-re flective oscillator emphasizes the importance of zonal advection associated with wave reflection at both the western and eastern boundaries. All of these physics are summarized in a unified ENSO oscillator. The de layed oscillator, the western Pacific oscillator, the recharge-discharge oscillator, and the advective-reflec tive oscillator can be extracted as special cases of the unified oscillator. As suggested by this unified oscillator, all of the previous ENSO oscillator mechanisms may be operating in nature. 相似文献
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L. Kristensen 《Boundary-Layer Meteorology》1979,16(3):145-153
It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how the scale of turbulence, the displacement between observation sites and the turbulence intensity influence the results. The limitations of the theory are discussed. 相似文献
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S. L. Weber 《Climatic change》2001,48(2-3):465-485
The steady state solution of the Daisyworld modelof Watson and Lovelock (1983) is examined in detail. Focus is on the two-daisy state, which exhibits homeostasis overa large range of solar luminosities. The analytical approach usedmakes clear the dependence of the steady state and the size of thedomain over which it exists on the various parameters of the system as well as the mechanism for its attractivity.It is shown that the self-regulatory effect of the biota is basedon a priori specifying a relation between the equilibrium effectivetemperature T
eq
e and the equilibrium effective albedoA
eq
e. This relation originates first, from the assumption that the local temperature contrast between the black and white daisies is given by the local albedo contrast, and second, from the requirement that the equilibrium expansion rates of the black and white daisies are equal.The regulation is found to work best when the local albedo contrast is large and when the system is capable of redistributing heatin an efficient manner. It is shown that the attractivity of the steady stateis due to the temperature-dependence of the expansion rate of thedaisies, i.e., the close-coupling between climate and the biota. Some aspects of the Daisymodel seem fairly realistic, such as the conditions for optimal temperature regulation. On the other hand, the basic assumptions of the modelgive rise to local temperatures (of the regions of black daisies, white daisies and uncovered ground) which are independent of the incoming radiation.This property of fixed local temperatures and the associatedheat transport mechanism itself do not seem to have parallels in the real Earth system. 相似文献
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L. Kristensen 《Boundary-Layer Meteorology》1979,16(2):145-153
It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence
in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how
the scale of turbulence, the displacement between observation sites and the turbulence intensity influence the results. The
limitations of the theory are discussed. 相似文献
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Summary Starting fromK. Ångström's original work, a theory of the compensation pyrheliometer is given. This theory is based on the fact that the instrument consists of two similar parts, and it develops a similarity condition which replaces the assumption made hitherto that both parts are identical. This condition contains not only the qualities of the strips of the pyrheliometer, but as well the effects of the heat exchange between the strips and their surroundings. Deviations from the similarity condition and their measurement are discussed.In successive steps the treatment is refined in order to show how effects of unequal heat exchange in case of irradiation or of compensating electrical heating can be covered. The merits of single-and of double-system pyrheliometers are compared and the superiority of the compensation pyrheliometer over the bolometer system is demonstrated.In an Appendix a treatment of the edge-effect of the pyrheliometer is given.
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The work described in this paper was carried out in 1946 and 1947, while the author was working at the Observatory of Davos, and it was laid down in a series of internal reports to the Observatory and to Dr.A. Ångström who kindly helped to ease the work by a grant from the Swedish Research Council which was gratefully acknowledged. The ever increasing enterprises of the Observatory did not permit a publication in the following time. The author finds now much pleasure in revising the work and presenting it in a partly enlarged, but mostly condensed form to Dr.W. Mörikofer, the Director of the Observatory of Davos, at the occasion of his seventieth birthday. 相似文献
Zusammenfassung Ausgehend vonK. Ångströms Originalarbeit wird eine Theorie des Kompensationspyrheliometers gegeben. Zunächst wird in Betracht gezogen, daß das Instrument aus zwei ähnlichen Teilen besteht, und eine Ähnlichkeitsbeziehung entwickelt, welche die bisherige Annahme einer Gleichheit der beiden Teile ersetzt. In diese Beziehung gehen nicht nur die Eigenschaften der Streifen des Pyrheliometers, sondern auch die des Wärmeaustausches zwischen ihnen und der Umgebung ein. Abweichungen von der Ähnlichkeit und ihre Messung werden diskutiert.In aufeinanderfolgenden Schritten wird die theoretische Behandlung verteinert, um zu zeigen, wie Effekte eines ungleichen Wärmeaustausches im Fall von Bestrahlung bzw. von kompensierender elektrischer Heizung erfaßt werden können. Die Vorzüge von Einfach- und von Doppelsystem-Pyrheliometern werden verglichen, und es wird gezeigt, weshalb das Kompensationspyrheliometer dem Bolometer überlegen ist.In einem Anhang wird der Randeffekt des Pyrheliometers behandelt.
Résumé A partir du traité original deK. Ångström, on présente une théorie du pyrhéliomètre à compensation. En tenant compte du fait, que l'instrument consiste en deux parties semblables, on développe une condition d'analogie qui remplace l'identité supposée des deux parties. Cette condition ne comprend pas seulement les qualités des lamelles du pyrhéliomètre, mais aussi de l'échange de chaleur entre les lamelles et leur entourage. On discute des déviations de l'analogie et leur mesure.Dans des étapes successives, la théorie est approfondie, et l'on démontre de quelle manière on peut exprimer les effets d'un échange de chaleur inégal lors de l'irradiation d'un côté et le chauffage électrique compensateur de l'autre côté. On compare les qualités des pyrhéliomètres à système simple ou double et on démontre la supériorité du pyrhéliomètre à compensation sur le bolomètre.Dans un Appendice, on traite l'effet de bord du pyrhéliomètre.
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The work described in this paper was carried out in 1946 and 1947, while the author was working at the Observatory of Davos, and it was laid down in a series of internal reports to the Observatory and to Dr.A. Ångström who kindly helped to ease the work by a grant from the Swedish Research Council which was gratefully acknowledged. The ever increasing enterprises of the Observatory did not permit a publication in the following time. The author finds now much pleasure in revising the work and presenting it in a partly enlarged, but mostly condensed form to Dr.W. Mörikofer, the Director of the Observatory of Davos, at the occasion of his seventieth birthday. 相似文献