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1.
介绍了强吸水剂系列中淀粉接枝丙烯腈类吸水剂的制造工艺流程及其原理,并应用过硫酸铵作为引发剂,通过实验制出吸水倍率达1000倍的吸水剂. 相似文献
2.
中国北方农牧交错带是中东部地区重要的生态安全屏障, 由于其系统结构脆弱、生态环境问题多发、土地沙化严重, 开展生态修复工作显得十分重要。植物-土壤水分关系作为土地沙化区生态水文过程的重要组成部分, 研究二者的转化过程对于了解植物吸水模式、确定生态修复的首选植物种非常关键。以河北省张家口市康保县北部为例, 基于雨季的大气降水、地下水、土壤水和植物水的氢氧同位素特征, 分析了主要植物的吸水层位、生态位宽度和水分竞争关系。结果表明, 柠条以吸收80~100 cm深度土壤水为主, 吸水比例最大可达87.7%, 油菜花以吸收0~20 cm深度土壤水为主, 吸水比例最大可达82.3%, 狼针的吸水层位与土壤含水率有关, 在含水率较高的深度吸水比例更大, 栉叶蒿的吸水深度较为均衡, 各植物种的生态位宽度均较大, 但部分植物间存在较强的水分竞争关系。本研究为中国北方农牧交错带土地沙化区的植物水源来源识别和生态修复提供了科学依据。 相似文献
3.
高吸水树脂又称超级吸水剂、强吸水性树脂 ,是一种含强亲水性基团并具有一定交联度的高分子材料。这类材料一方面具有某些独特的性能 ,同时又具有高分子材料的优点 ,有良好的使用性能 ,它不溶于水和有机溶剂 ,但与水接触后在很短时间内溶胀 ,可吸收自重几百至几千倍的水 ,保水能力强 ,并可反复使用。高吸水树脂应用很广 ,可作堵水剂、脱水剂、增粘剂、速凝剂、结露防止剂、土壤改良剂、保水剂、保鲜剂、防臭剂等 ;亦可作为包装材料及凝胶材料使用 ;加入到纸、纸浆或布中 ,可作为尿布、卫生巾、抹布、餐巾、鞋垫和玩具等 ,是近年来研究开发的… 相似文献
4.
采用温湿度测试、石窟造像渗水实验、石窟造像吸水的红外成像、岩石特征分析等手段,对四川广元千佛崖石窟造像表面及其周围环境进行监测,以及对石窟造像岩石特征进行分析.结果表明:进深较大的窟室内外存在2℃～4℃的温差,岩石0～40 mm深度范围内温度与外界气温存在显著相关性;石窟造像岩石主要成分为长石、石英、黑云母及黏土矿物,... 相似文献
5.
为满足深部钻孔防漏、堵漏需求,提出采用具有吸水膨胀特性的丙烯酸高吸水膨胀树脂作为堵漏材料。首先研究了树脂的膨胀堵漏机理;其次通过室内实验,测定其基本性能,如吸水倍数、抗温抗盐性能等,并通过堵漏材料测定仪评价其堵漏性能;最后采用玻璃纤维及硅烷偶联剂作为复合堵漏强化材料进行堵漏实验研究。试验结果表明,丙烯酸高吸水膨胀树脂具有高吸水和良好的抗温保水性能,作为堵漏材料对漏层具有即堵性,但吸水后凝胶强度较低,承压能力较差;采用有机处理剂处理玻璃纤维-树脂复合堵漏材料,极大提高了封堵层承压能力,堵漏效果良好。 相似文献
6.
从甲壳素出发，先制备了3种不同脱乙酰度的壳聚糖，选择过硫酸铵-亚硫酸氢钠为氧化还原体系引发剂，合成了壳聚糖接枝丙烯酰胺聚合物；通过红外光谱，电镜扫描对聚合物进行结构表征，结果表明壳聚糖结构发生了变化，通过在相同条件下比较壳聚糖不同脱乙酰度对接枝率的影响，得出了在脱乙酰度为68．5％时聚合物的接枝率最大为250％，其最佳合成工艺为：m（壳聚糖）：m（丙烯酰胺）=1：5，引发剂用量为体系质量分数的0．3％～0．4％，温度55～60℃，反应时间为2．5～3．0h。 相似文献
7.
提高鲮鱼鱼糜弹性的方法 总被引：1，自引：0，他引：1
研究了影响鲮鱼鱼糜弹性的主要因素和加工工艺条件。研究时采用漂洗鱼肉、添加谷氨酰胺转氨酶以及二段加热方法等工艺来提高鲮鱼鱼糜的弹性。结果表明 :将鲮鱼鱼肉漂洗 2次 ,添加质量分数 0 .2 %的谷氨酰胺转氨酶作为弹性增强剂 ,采用在 4 0℃温度缓慢凝胶化 3h后加热至90℃保持 30min的二段加热方式 ,可明显提高鲮鱼鱼糜的弹性。 相似文献
8.
为精准刻画球形暂堵剂在粗糙裂缝内运移规律及研究颗粒之间相互作用机理,构建具有长度相等的阶梯粗糙裂缝物理模型和CT扫描真实粗糙裂缝模型,基于离散相(DPM)多相流模型表征暂堵剂颗粒之间相互作用,采用流体流动与暂堵剂颗粒运移的双向耦合算法,分析裂缝表面粗糙度、暂堵剂颗粒直径、颗粒体积分数、颗粒速度和暂堵剂携带液黏度对暂堵剂... 相似文献
9.
软岩吸水后其强度大辐度降低,使井巷难以维护。通过在矿井涌水地点就近构建水窝、装备潜水泵、敷设排水管,将矿井水引入水仓进而排出地面;采用特定开采方法和适当加大井巷通风量,加速围岩水分散发等综合技术能有效消除矿井水对井巷维护的不利影响。 相似文献
10.
DABS—C1柱前衍生高效液相色谱法测定对虾肌肉中18种游离氨基酸 总被引：1，自引：0，他引：1
建立一种以DABS-Cl为柱前衍生剂，利用反相高效液相色谱测定对虾肌肉中18种游离氨基酸的方法。结果表明，在50min内18种氨基酸得到完全分离，各氨基酸相关系数均大于0．997，氨基酸的回收率在86．60%-107．27％之间（胱氨酸除外），方法的检出限为0．18~o．66mg／L，相对标准偏差为3．53％-8．51％（天冬氨酸除外）。 相似文献
11.
为了寻求解决辽河盆地杜229断块超稠油油藏在开采过程中水侵严重影响生产的问题,通过研究该区块构造演化史,分析了断层在超稠油成藏过程中的作用,认为该区块的边界断层对油气成藏起侧向封堵作用,后期小断层使油藏复杂化。根据水性分析和示踪剂监测资料,推断水侵的主要原因是部分断层的不封闭。建议在以后超稠油开发生产中,生产井段要距不封闭断层70 m以上。 相似文献
12.
Zelongnong Ravine, a branch ravine of Brahmaputra, is an old large glacier debris-flow ravine. Debris-flows with medium and/or
small scales occur almost every year; multiple super debris-flows have also broken out in history, and have caused destructive
disaster to local residents at the mouth of ravine and blocked Brahmaputra. The huge altitude difference and the steep slope
of the Zelongnong Ravine provide predominant energy conditions for the debris-flow. The drainage basin is located in the fast
uplifted area, where the complicated geologic structure, the cracked rock, and the frequent earthquake make the rocks experience
strong weathering, thus plenty of granular materials are available for the formation of debris-flows. Although this region
is located in the rain shadow area, the precipitation is concentrated and most is with high intensity. Also, the strong glacier
activity provides water source for debris-flow. According to literature reviews, most debris-flows in the ravine are induced
by rainstorms, and their scales are relatively small. However, when the melted water is overlaid, the large scale debris-flows
may occur. Parametric calculation such as the flow velocity and the runoff is conducted according to the monitoring data.
The result shows that large debris-flows can be aroused when the rainstorm and the melted water are combined well, but the
possibility of blocking off Brahmaputra is rare. The occurrence of the super debris-flows is closely related to the intense
glacier activity (e.g., glacier surge). They often result in destructive disasters and are hard to be prevented and cured
by engineering measures, due to the oversized scales. The hazard mitigation measures such as monitoring and prediction are
proposed. 相似文献
13.
SORPTION OF BENZOTHIOPHENE ON MARINE SEDIMENTS 总被引：2，自引：0，他引：2
ImODUcrIONBenzothiophene(acomPoundinp0lycydicarornaticsulfurheterocydespresentincrudeoilsandcoal)isaddedt0marineenvironmentfromavariCtyofsouna,andisofenvironrnentalconcernduetoitSharmfulproperties(Andefssonetal.,l992,Yang,l996).Warner(l975)obtainedsulfur-containingpetroleumcomPonentSsuchasbensothiophenefr0mrnarinesamplesandfoundthatthepolycydicarornaticsuifurheterocydesweremorercadilybioconrmtratedthansulfur-freep0lycydicaromaticcompounds.Yang(l997)foundthatbensothiophenewaspresentinallin… 相似文献
14.
A super El Ni?o event occurred in the equatorial Pacific during 2015-2016,accompanied by considerable regional eco-hydro-climatic variations within the Mindanao Dome(MD)upwelling system in the tropical western Pacific.Using timeseries of various oceanic data from 2013 to 2017,the variability of eco-hydro-climatic conditions response to the 2015/2016 super El Ni?o in the upper 300 m of the MD region are analyzed in this paper.Results showed that during the 2015/2016 super El Ni?o event,the upwelling in the MD region was greatly enhanced compared to those before and after this El Ni?o event.Upwelling Rossby waves and the massive loss of surface water in the western Pacific were suggested to be the main reasons for this enhanced upwelling.De-creased precipitation caused by changes in large-scale air-sea interaction led to the increased surface salinities.Changes in the struc-tures of the thermohaline and nutrient distribution in deep waters contributed to the increased surface chlorophyll a,suggesting a po-sitive effect of El Ni?o on surface carbon storage in the MD region.Based on the above analysis,the synopsis mechanism illustrating the eco-hydro-climatic changing processes over the MD upwelling system responding to the El Ni?o event was proposed.It high-lights the prospect for the role played by El Ni?o in local eco-hydro-climatic effects,which has further profound implications for understanding the influence of the global climate changes on the ocean carbon cycle. 相似文献
15.
文章认为有机污染质已对地下水污染构成威胁,研究有机污染质在地下水系统中的迁移转化机制,建立有效的预测模型,具有十分重要的意义。有机污染质与地下水形成不溶混流体,对其运移进行评价的理论、方法及测试技术都不同于通常对易溶混污染质的评价。这项工作在我国刚刚起步,研究程度较低。文章讨论了有机污染质—地下水体系的一般物理、化学特征和运移控制方程,指出吸附作用是使有机污染质运移滞缓的重要原因,介绍了目前国外研究有机污染质吸附作用的几种试验及结果。 相似文献
16.
采用批量振荡吸附平衡法设计针铁矿和蒙脱石对菲的吸附解吸试验,对比研究了针铁矿和蒙脱石对菲的吸附解吸行为,并考察了不同K+浓度的溶液对蒙脱石吸附菲的影响,比较分析了线性吸附模型和Freundlich吸附模型描述矿物吸附等温线的准确性,并从吸附热力学角度探讨了矿物的吸附机理。结果表明:针铁矿和蒙脱石对菲的吸附解吸均表现出明显的非线性和解吸滞后现象;相对于线性吸附模型来说,针铁矿和蒙脱石对菲的吸附解吸更符合Freundlich吸附模型;与蒙脱石相比,针铁矿对菲的吸附更为显著,且具有更好的稳定性;溶液中软阳离子K+的存在使蒙脱石对菲的吸附能力得到显著提高;菲在蒙脱石和针铁矿上的吸附过程是一个自发放热,同时伴随着熵值减小的过程;随着温度的升高,蒙脱石和针铁矿对菲的吸附能力均减弱。 相似文献
17.
Investigation of phosphorus (P) sorption-desorption characteristics of drainage ditch sediments is important for better understanding on sediment P transport behaviors in ditches. Surface ditch sediment samples were collected from headwater sub-catchment of forestland, sloping cropland, paddy field, and residential area in a representative catchment in the central Sichuan Basin. These sediment samples were used for determination of P sorption-desorption characteristics by a batch equilibrium technique. Results showed that the maximum P sorption capacities (Qm) in the sediments ranged from 159.7 to 263.7 mg/kg, while higher Qm were observed in the ditch sediments from the paddy fields. The Qm was significantly and positively correlated with oxalate-extractable Fe and Al oxides (r=0.97 and 0.98, p < 0.01), clay fraction (r = 0.78, p < 0.05) and organic matter (r = 0.95, p < 0.01). Sediment pH, clay and organic matter influenced the P sorption through amorphous Fe and Al oxides. CaCO3 content was negatively correlated with the Qm (r = -0.83, p < 0.05), implying that saturated CaCO3 (> 50 g/kg) would not increase P sorption capacity in the ditch sediments. The ditch sediments featured a linear desorption curve, suggesting that P release risk would be enhanced with the increase of the P adsorption. The P desorption rate was positively correlated with Olsen P (r = 0.94, p < 0.01), but negatively related to the fine particle-size fractions (r = -0.92, p < 0.01), the sum of the amorphous Fe and Al oxides (r = -0.67, p < 0.05) and the P sorption capacity (r = -0.59, p < 0.05). The ditch sediments from residential area had a higher P release risk than that from the other ditches of forestland, sloping cropland and paddy field. The P sorption index (PSI) derived from single-point measurement was significantly correlated with the P sorption capacity (r = 0.99, p < 0.01), and could be used for estimating Qm as 1.64 times PSI plus 24.0 (Qm = 1.64 PSI + 24.0) for similar sediments with highly calcareous soils and sediments. Ditch cleaning and sediment removal for the ditch in residential area were recommended in this area to reduce the P release risk. 相似文献
18.
平板冻结器超压事故的发生主要由于使用设备时操作不当和设备质量不过关而引起。对设备超压原理分析和平板冻结器在不同温度条件下的充液比例进行理论计算 ,结果表明 ,停机时 ,在室温 35℃的条件下 ,蒸发器中的充液比例达到 0 .86 0 5时 ,会引起蒸发器发生超压而爆炸。当蒸发器中充液比例在 0 .86 0 5以下时发生的超压事故 ,肯定存在设备质量不过关的因素 ;而当充液比例在 0 .86 0 5或以上时发生的超压事故 ,则是由误操作引起。。 相似文献
19.
稠油蒸气—泡沫驱不同油藏区域流体的流变特征 总被引：3，自引：2，他引：1
针对稠油蒸气-泡沫驱蒸气腔驱油区泡沫油体系、热水冷凝区热水油体系,通过模拟实际油藏温度压力条件,利用高温高压流变仪,在0～600s-1剪切速率范围内,研究蒸气相饱和度、泡沫剂质量分数、温度和蒸气干度对泡沫油体系流变特征的影响;在0～100s-1剪切速率范围内,研究热水相饱和度、泡沫剂质量分数和温度对热水油体系流变特征的影响.结果表明,泡沫油体系和热水油体系均为假塑性流体,可用幂律模型来描述,并且随着蒸气相饱和度和泡沫剂质量分数升高,泡沫油体系非牛顿性增强;随着温度和蒸气干度增大,泡沫油体系越接近为牛顿流体;随着热水相饱和度和温度升高,热水油体系越接近为牛顿流体;随着泡沫剂质量分数增加,热水油体系非牛顿性增强. 相似文献
20.
《中国海洋湖沼学报》2021,(5)
The climate variability induced by the El Ni?o-Southern Oscillation(ENSO) cycle drives significant changes in the physical state of the tropical Western Pacific,which has important impacts on the upper ocean carbon cycle.During 2015-2016,a super El Ni?o event occurred in the equatorial Pacific.Suspended particulate matter(SPM) data and related environmental observations in the tropical Western Pacific were obtained during two cruses in Dec.2014 and 2015,which coincided with the early and peak stages of this super El Ni?o event.Compared with the marine environments in the tropical Western Pacific in Dec.2014,an obviously enhanced upwelling occurred in the Mindanao Dome region;the nitrate concentration in the euphotic zone almo st tripled;and the size,mass concentration,and volume concentration of SPM obviously increased in Dec.2015.The enhanced upwelling in the Mindanao Dome region carried cold but eutrophic water upward from the deep ocean to shallow depths,even into the euphotic zone,which disrupted the previously N-limited conditions and induced a remarkable increase in phytoplankton blooms in the euphotic zone.The se results reveal the mechanism of how nutrient-limited ecosystems in the tropical Western Pacific respond to super El Ni?o events.In the context of the ENSO cycle,if predicted changes in biogenic particles occur,the proportion of carbon storage in the tropical Western Pacific is estimated to be increased by more than 52%,ultimately affecting the regional and possibly even global carbon cycle.This paper highlights the prospect for long-term prediction of the impact of a super El Ni?o event on the global carbon cycle and has profound implications for understanding El Ni?o events. 相似文献