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1.
两种壳聚糖的不同配比对草莓保鲜效果的影响 总被引：8，自引：0，他引：8
研究了两种相对分子质量的壳聚糖以不同的比例配比所制的保鲜剂对草莓保鲜效果的影响。结果表明 :当相对分子质量为 3万和 1 70 0的两种壳聚糖以 1∶ 1 (质量比 )配比时 ,所制的保鲜剂对草莓有较好的保鲜效果 ,能使草莓果实的失水率、腐烂率和发霉率显著降低 (P<0 .0 1 ) ;果实体内的可溶性固形物、可溶性糖、可溶性蛋白质、Vc等含量以及糖酸比明显增加(P<0 .0 5) ;超氧化物歧化酶 (SOD)活性增强 ,丙二醛 (MDA)含量减少 (P<0 .0 1 ) ,果实细胞膜稳定性显著提高。 相似文献
2.
用壳聚糖酶降解法对壳聚糖进行降解制备壳低聚糖，研究了温度、pH、底物浓度、脱乙酰度、反应时间对酶促反应的影响。对酶解产物进行HPLC分析，用Bio—Gel P-4柱对酶解产物进行初步分离。结果表明，壳聚糖酶降解壳聚糖的最适温度为45℃，pH为6．0，最适底物质量分数为6％，脱乙酰度越高酶解反应所得产物的数均相对分子质量越小，24h后酶解反应达到平衡，酶解产物壳寡糖水溶性极好。P-4柱分离得到聚合度20以上，10～20，10以下3种壳寡糖。 相似文献
3.
壳低聚糖是小分子量的壳聚糖降解产物,目前在生产和生活中得到广泛应用。本文研究了用亚硝酸降解法制备的壳低聚糖对普通农作物种子生理和生化指标的影响。结果表明:不同浓度的壳低聚糖可不同程度地改善绿豆的生理生化指标,其中,以1.0%浓度的壳低聚糖溶液效果最好。1.0%的壳低聚糖可不同程度地提高种子的发芽指数、活力指数和过氧化物酶活力,对种子萌芽和幼苗均有一定的促生长作用。因此,壳低聚糖作为一种新型植物生长调节剂,可以在农业生产中发挥一定的作用。 相似文献
4.
大叶藻海草场是重要生境但在我国严重退化,亟需研究有效的修复方法。本文以桑沟湾的大叶藻种子为研究对象,探讨了盐度急变(0~30)对种子萌发、萌发后继续发育和存活及幼苗幼叶的光合与呼吸速率的影响,为以种子繁殖修复大叶藻海草场提供参考。结果表明:盐度降低促进种子萌发,盐度15及以下效果显著,盐度0时萌发率最高;盐度0~15中萌发的种子均可发育成幼苗,发育和衰亡的比例和速率受萌发盐度背景和萌发后培养盐度的双重影响——较高萌发盐度有利于种子萌发后的发育和存活,种子萌发后于盐度5~30中均可建成幼苗并存活、但在盐度0或1中发育至不同程度后全部死亡。盐度5~30范围内,幼苗幼叶均有净产氧,光合和呼吸作用及净产氧率具随盐度升高而增强趋势。于盐度0或5中萌发、盐度5~30中进一步培育的变盐育苗策略,最高实现了24%或12%的种子于2个月内建成幼苗并继续发育,可作为种子繁殖法修复大叶藻海草场的技术参考。 相似文献
5.
近几十年来,受到人类活动和气候变化的影响,全球海草床呈现退化趋势,海草床的恢复备受关注。其中,海草种子或幼苗移植由于其对供体海草床破坏和影响较小,并能保证海草的遗传多样性而备受重视。移植区的底质类型是决定海草种子或幼苗移植存活率的重要因子,然而,目前关于热带海草种子萌发和幼苗生长对不同底质类型响应的研究很有限。本研究以热带海草海菖蒲(Enhalus acoroides)种子为研究对象,利用室内模拟实验,分别设置细砂和砂砾底质的处理,探讨不同底质类型对海菖蒲种子萌发和幼苗生长的影响。研究发现,细砂组和砂砾组的萌发率和萌发历期的平均值分别96.3%、3.6 d和95.0%、3.4 d,两个处理组之间差异不显著。萌发后的细砂组海菖蒲幼苗的存活率为97.37%,而砂砾组的幼苗存活率仅为81.58%;另外,海菖蒲幼苗的叶片长度、根长度、叶片生长速率和根生长速率在细砂组均显著高于砂砾组。因此,沉积物粒径的差异对海草种子的萌发率和萌发时间没有显著性影响,但沉积物粒径增大会显著降低萌发后海菖蒲幼苗的存活率和生长速率。因此,未来开展海菖蒲种子或幼苗的野外移植,应选取沉积物粒径较小细砂质区域进行移植,可促进海菖蒲种子或幼苗移植的成活率,提高海菖蒲生态修复的成功率。 相似文献
6.
《中国海洋大学学报(自然科学版)》2017,(5)
大叶藻(Zostera marina L.)是全球分布最广泛的海草之一,曾在山东半岛沿海有广泛分布。然而,自1980年代开始,受自然因素和人类活动的影响,大叶藻场严重衰退,导致黄海近岸海洋生态系统恶化,渔业资源锐减。本研究以中国黄海海域(山东半岛)大叶藻为研究对象,研究不同温度、春化作用时间对大叶藻种子萌发和不同播种深度对种子成苗率的影响,进行了幼苗培育,研制开发幼苗移栽装置和技术。结果表明:春化处理温度对大叶藻种子萌发率具有显著影响(p0.01),4℃春化处理50d的大叶藻种子萌发率最高,平均达55.3%;埋植深度对大叶藻种子萌发率和幼苗成苗率有影响,埋植深度0.5~2.5cm时大叶藻幼苗的出苗率相似,但显著高于埋植深度3~4.5cm的成苗率(p0.01)。依据这些研究结果,成功培育大叶藻苗7.6万株,生长110d,平均幼苗长度达16.3cm,最大长度达22cm;研制了育苗杯大叶藻苗移栽装置,实现了从水面高效栽植大叶藻幼苗。 相似文献
7.
壳聚糖特性粘度的快速测定 总被引：4，自引：0，他引：4
对比不同生产厂家、不同分子量 (或粘度 )、不同脱乙酰度的壳聚糖产品在 2种不同测定条件 (30℃ ,0 .1mol· L-1CH3 COONa- 0 .2 mol· L-1CH3 COOH为溶剂 ;2 5℃ ,0 .2 mol· L-1Na Cl-0 .1mol· L-1CH3 COOH为溶剂 )下利用常规外推法和常用一点法经验公式所得的壳聚糖的特性粘度值表明 :一点法经验公式计算所得的壳聚糖的特性粘度值与用常规外推法所得的特性粘度值间的偏差最小 ,适合于快速测定壳聚糖特性粘度 ,进而可求得其粘均分子量 相似文献
8.
从六十年代始,人们便开始了在农业上应用激光的研究。据报道:美国、加拿大用激光对蚕豆、萝卜和南瓜种子处理后生长明显加快;苏联用He-Ne激光处理蕃茄和黄瓜种子,能提高其发芽率和促进发育。我国激光技术发展也很快,曾有人用各种激光对一些粮食、蔬菜等作物的种子进行了处理,均能不同程度促使种子提前发芽、成熟,达到增产的目的。这些实验为激光在农业上的应用开辟了广阔前景。而激光用于海藻育种方面的实验,很少有报道。我们于1978年开始用海带雌配子体作材料进行激光生物学效应的探索实验。拟为海藻 相似文献
9.
龙须菜琼胶的提取方法研究 总被引：2，自引：2，他引：2
采用多种方法提取了龙须菜(Gracilaria lemaneiformis)中的琼胶,并研究了碱处理、微波处理、超声波处理等方法对龙须菜的琼胶提取率、硫酸基质量分数和多糖质量分数的影响。结果表明:当碱质量分数由2.5%增加到10%时,琼胶产率由15%降低到9.8%,硫酸基质量分数由2.66%降低到2.06%,同时,多糖质量分数由98.3%增加到102.6%;微波和超声波处理在不同程度上增加了琼胶的提取率和多糖质量分数,同时降低了硫酸基质量分数。另外,还从宏观和微观两个角度考察了龙须菜碱处理前后藻体的变化。 相似文献
10.
11.
The analysis of the structure of the cryolithozone, facies, and thicknesses of the Quaternary sediments and the results of the physicochemical mathematical modeling of the modern shelf of the western part of the Laptev Sea support the influence of the Late Pleistocene glaciations on the heat conditions and the distribution of the permafrost in the area. A ～200-m thick glacier formed under aerial conditions from atmospheric precipitation represented the metamorphosed snow cover. According to the modeling, the long-living (from 60?50 to 10?4 ky) glacier reduced the thickness of the permafrost rocks in the reviewed shelf area for 280–360 m. The Holocene marine transgression additionally decreased the thickness from 50–140 m on the inner shelf to 220–350 m on the outer shelf. The modern submarine cryolithozone 450-0 m thick is wide-spread in the studied region from the coast to the shelf boundary (isobaths of 130–140 m), where it pinches out at a distance of ～380 km from the coast at a depth of ～250 m above the sea level. 相似文献
12.
We analyze the components of the carbon system of the Sevastopol bay waters and the balance of main sediment-forming substances
using the data of field investigations in 1998–2008. The interannual variations of total inorganic carbon and the equilibrium
partial pressure of carbon dioxide in the bay water are noted. An increase in the flux of carbon dioxide into the bay and
in the content of organic carbon in bottom sediments is revealed, and an explanation of this phenomenon is given. The priority
accumulation of organic carbon in the sediments of the bay is established. We assess the interannual variation in the relative
abundances of organic and inorganic carbon as an index of the carbon cycle stability. 相似文献
13.
双壳贝类血淋巴中儿茶酚胺的检测方法初步研究 总被引：1，自引：0，他引：1
研究的目的是探索一种检测双壳贝类血淋巴中儿茶酚胺含量的方法。以栉孔扇贝(Chlamysfarreri)和长牡蛎(Crassostreagigas)为实验对象,研究了取样、抗氧化剂、氧化铝用量以及Tris缓冲液用量等对实验结果的影响。结果表明,高效液相色谱电化学检测器法(HPLC-ECD)可以灵敏高效地对双壳贝类血淋巴中儿茶酚胺进行定性、定量检测。实验表明,取样时间最长不超过1.5min;还原性谷胱甘肽作抗氧化剂效果较好;前处理各试剂与血样量的最适配比为血样量1.5mL,Tris缓冲液(1.5mol/L,pH8.6)1mL和氧化铝25mg;水洗后离心并尽可能吸干氧化铝中的水分。去甲肾上腺素、肾上腺素和多巴胺的回收率分别为53%~69%、47%~73%和48%~56%。 相似文献
14.
We generalize and analyze the state of investigations of the influence of river waters on the hydrologic structure of the
Black Sea. Specific features of the water, regime and hydrography of rivers flowing into the sea, data on the discharge of
rivers, and intrayear and interyear variability of the discharge are presented. We discuss and analyze works studying the
transformation of river waters, routes of desalinized sea waters, and their influence on the thermohaline structure and dynamic
regime of the sea.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
15.
为研究黄河入海径流变化条件下河口附近海域盐度扩散特征,以更好地保护河口海域生物资源多样性,本文以黄河下游利津水文站的长序列实测径流数据资料为基础,利用近海水动力模型FVCOM,分析径流变化对黄河口海域盐度的影响规律。结果表明：黄河口与莱州湾之间存在顺时针的环流系统,在余流作用以及涨落潮方向的影响下,黄河冲淡水长期向莱州湾扩散;丰水期黄河冲淡水几乎影响了整个莱州湾,27盐度锋可以到达莱州湾中部,27等盐线的表层包络面积为2 665.61 km2,占莱州湾的1/4左右,枯水期低盐度水只有向南扩散的趋势,27以下的低盐度水集中分布在黄河口门附近,27等盐线的表层包络面积只有199.65 km2;5月份,随着入海径流量增加,27等盐线扩散的范围、距离、方向都会发生明显变化。在对近海生物资源有迫切保护需求的情景下,适当减少其他用水户供水量以增加入海生态径流量,可以有效改善黄河口海域附近的盐度情况,为生物资源的生长繁殖创造良好条件。 相似文献
16.
V. A. Ivanov S. P. Lyubartseva N. Mikhailova N. B. Shapiro 《Physical Oceanography》2001,11(6):509-524
We analyze the results of numerical calculations performed according to the three-dimensional interdisciplinary model of an
ecological system of the Black-Sea shelf zone near the estuary of the Danube. The complete system of equations of hydrothermodynamics
is solved together with transport equations of the advection-diffusion-reaction type used to describe the transformation of
a substance (nitrogen) between the components of the characteristic vectors of the ecosystem: plankton, detritus, and biogenic
elements (nitrates). We describe the distinctive features of the circumcontinental distribution of components obtained as
a result of numerical experiments and present arguments for the conclusion that the ecosystem of the Danube estuary water
area plays the role of a buffer zone between the press of the Danubian biogenic pollutions and the neighbouring areas of the
shelf zone and open sea.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
17.
The authors have previously determined that the effectiveness and failure pattern of the ice cover caused by flexural-gravity waves generated by a submerged body motion near the bottom ice can greatly depend on the depth of the water area. In its turn, the presence of a ledge on the ice surface may affect a wave propagation pattern. This paper presents an experimental study of the bottom contour influence on the deflection and length of flexural-gravity waves. The authors describe a numerical model for the analysis of the deformed state of ice caused by hydrodynamic loads due to a submarine motion, taking into account the bottom contour. The experiments are carried out in the ice tank. The results of calculations and experiments are compared. 相似文献
18.
Ten years of semistationary studies of the interaction of the ice cover and the coastal relief of the Kandalakhsa Gulf in the White Sea allowed us to reveal the peculiarities of these processes in the warm and cold years and the mechanisms of the origination of ice forms, including ice tents, which govern the character of the tidal flats. Three dynamic fast ice zones are distinguished by their geomorphological location, morphology, and ice dynamics. The dependence of the mechanisms and volumes of the enrichment of the fast ice in the sediments on the coastal zone??s relief was established. At the coast of the Kindo Peninsula (Velikaya Salma Strait), the ice mostly contains fine-sandy sediments. Coarser sediments, including boulders, are occasional and frozen into the ice at the contact of the fast ice and the bottom. At the expense of the ice??s spreading by 4?C6 times in the warm years and 2?C4 times in the cold years, several thousand tons of sediments mostly from the tidal flat??s surface (100?C700 m3 from 1 km of coast in the wide tidal flats and <50 m3 on the steep coasts) are delivered to the water area. 相似文献
19.
Relationship between the path of the Kuroshio in the south of Japan and the path of the Kuroshio Extension in the east 总被引：2，自引：0，他引：2
A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry
dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly
goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with
the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then
passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state. 相似文献
20.
I. E. Timchenko A. A. Primalenny V. D. Yarin E. F. Vasechkina E. M. Igumnova 《Physical Oceanography》2001,11(4):367-378
We use many-year archival observations of hydrologic and hydrobiologic state of the Sea of Azov for the identification of
the structure of a model of its ecosystem. The ecosystem model, supplemented with expert estimates of bioresource consumption
(fish reserve), contamination level, and possible ecologic fines for violation of the sea natural state, is formalized by
the method of system dynamics. Hereat, the major part of influence functions is found in terms of observational data with
application of self-organization algorithms. We also present the results of simulated experiments with the model of the ecosystem,
which enable us to analyse scenarios of its behaviour under the influence of various external factors (wind, river discharge,
water exchange with the Black Sea, etc.).
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献