Does the long-term application of calcium superphosphate lead to an increase of the soil rare earth element contents？

In order to test whether the long-term application of calcium superphosphate leads to an increase of the soil rare earth element contents, superphosphate fertilized soils were sampled and compared with superphosphate-free soils. Spectrophlame inductively coupled argon plasma atomic emission spectrophotometer （ICP-AES） was applied to quantify the rare earth elements （REEs）. The total rare earth element contents in calcium superphosphate from Zhijin County, west part of Guizhou Province, China （produced by the sulphuric acid treatment of the apatites） are about 2.54 mg/g. Between 38 and 189 gREEs/hm^2 per year （available for plants, estimated by 2% citric acid） will be introduced into the soil solution when applying 320 kg superphosphate/hm^2 per year. The long-term application of the latter will increase the REE content by about 18% in the soil surface layer in these areas. A statistically significant increase of the content of the rare earths in some cultivated soils should not be neglected.

Effects of Copper-Zinc Alloy Doped with Rare Earth Elements on Crystal of Calcium Carbonate

A copper-zinc alloy doped with rare earth elements was prepared and the mechanism was demonstrated in a simulating boiler and circulating cooling water with rigidity 1 mmol·L-1. The polar curve and scale inhibiting ability of the alloy was tested by a corrosion measurement system and a scale inhibition evaluation system, respectively. Scale samples were characterized with SEM and XRD. It is found that the transfer of cations could be promoted by doping with proper rare earth elements, and the corrosion potentials descend by 25～126 mV. The results indicated that the copper-zinc alloy doped with rare earth elements has higher scale inhibiting ability of CaCO3. The growth of calcite was affected by zinc ions dissolved because of primary battery reaction, and the transition of calcium carbonate from aragonite to calcite was hampered resulting in the proportion of aragonite to calcite is changed from 1.7∶1 to 2.7∶1.

Spectroscopic Measurements of Physiological Elements in Microdialysis Samples from Rat Brain,Flowering Plum Fruit and Pea

The basal levels of magnesium and copper in rat brain and flowering plum fruit dialysates, and the background concentration of calcium in pea dialysates have been determined with sensitive spectroscopic techniques including atomic absorption spectrometry and spectrophotometry based on amino G acid chlorophosphonazo. It is found that the magnesium level in flowering plum fruit dialysates is much lower than that in rat brain dialysates, indicating a considerable composition difference present between a plant dialysate and an animal one.

Alleviation of Calcium on Toxicity of Cadmium to Rice Seedlings by Inhibiting Cadmium Accumulation and Relieving Oxidative Damage

Accumulation characteristics and antioxidant enzyme activities in rice seedlings from a high-cadmium(Cd)-accumulating cultivar Tyou705(705)and low-Cd-accumulating cultivar Xiangzao 24(X24)were studied,based on hydroponic experiment.Three levels of calcium(Ca)(0,1.0 and 2.0 mmol?L-1)and two levels of Cd(0 and 2.7μmol·L^-1)were designed in this study.Experimental results showed that the tolerance of rice seedlings to Cd stress was significantly improved by adding 1.0 or 2.0 mmol·L^-1 Ca.Comparing with Cd control,adding 1.0 mmol·L^-1 Ca made the seedling biomass of 705 and X24 increased by 68.9%and 116.2%,respectively.Addition of 2.0 mmol·L^-1 Ca was more effective than that of 1.0 mmol·L^-1 Ca in promoting rice biomass,root tip number,total root length,and total root surface area.After addition of 2.0 mmol·L^-1 Ca and Cd contents in roots and shoots of 705 decreased by 23.5%and 35.2%,Cd in roots and shoots of X24 decreased by 22.2%and 18.7%,respectively.Addition of Ca significantly promoted the accumulation of Mg,K and Zn in shoots and roots of X24 under Cd stress environment and eliminated the inhibitory effect of Cd on the uptake of these elements.Both 1.0 and 2.0 mmol·L^-1 Ca significantly decreased the activities of superoxide dismutase(SOD)and peroxidase(POD)in rice seedlings under Cd stress.These results indicated that 1.0-2.0 mmol·L^-1 Ca could significantly reduce Cd content in rice roots and shoots,promote the uptake and accumulation of essential elements and alleviate the oxidative damage caused by Cd stress in rice seedlings.

A Survey on the Contents of Calcium and Its Interaction Elements in Pig Feeds in Guangdong Province

[Objective]The paper was to study the contents of calcium(Ca)and its interaction elements in pig feeds in Guangdong Province.[Method]Creep feed,nursery feed,piglet feed,pregnant sow feed and lactating sow feed were randomly taken from different manufacturers for testing.[Result]The average contents of copper(Cu),iron(Fe),manganese(Mn),zinc(Zn),magnesium(Mg),and vitamin D,(VD)in all kinds of feeds exceeded the Chinese feed additive standards.The contents of trace elements like Cu,Fe,Mn,and Zn were significantly higher than the standard additions.The contents of Cu,Fe,and Mn in piglet feeds were increased by 27.16 times,4.47 times and 24.27 times,respectively,and that of Zn was increased by 16.99 times;the ratio of Mg average addition amount to the standard addition was 4.18-5.38;the average contents of Ca and phosphorus(P)in feeds were lower than the standard additions,among which Ca decreased by 0.18%-0.44%,P decreased by 0.07%-0.32%,and the proportions of Ca and P were lower than the standard proportion except piglet feed;VD;addition in pig feeds was significantly higher than the standard addition,in which the content of creep feed was 20.76 times of the standard addition;the average addition of fluorine(F)was increased with the increase of age,and the highest was up to 20.06 mg/kg.[Conclusion]There is a great dfference in the addition of each element in pig feeds,and most of them are higher than the standard additions.

白云石粉与氧化镁肥对植烟土壤与烟叶钙镁营养元素的影响

研究施用白云石粉与氧化镁肥对植烟土壤交换性钙、镁含量和烟叶钙、镁等营养元素的影响,为烟区优化施肥措施提供科学支撑。在植烟土壤交换性钙、镁偏低的典型区域,采用随机区组试验设计,设置不同白云石粉、氧化镁肥施用量,通过田间小区试验,测定各处理烟草不同生育期土壤交换性镁、交换性镁、速效氮磷钾与烟叶钙、镁、氮、磷、钾的含量,观测最大叶长、最大叶宽、株高、茎围、节距等农艺性状。结果表明,施用3000 kg/hm^(2)白云石粉在烟叶生长48、68 d和烟叶收获后的土壤交换性镁含量均显著高于其他处理,在烟叶收获后的土壤交换性钙含量显著高于其他处理,该处理在烟叶收获后上部烟叶和中部烟叶的镁含量、上部烟叶的钙含量也高于其他处理。针对植烟土壤交换性钙、镁偏低的区域,施用白云石粉3000 kg/hm^(2)有利于提升植烟土壤交换性钙、交换性镁和烟叶钙、镁含量。

苹果sMdCAX11基因的功能分析与鉴定

【目的】深入分析苹果sMdCAX11(去掉NRR区域的MdCAX11)基因功能。【方法】分别利用蜜脆苹果果实和拟南芥材料,采用过表达sMdCAX11的试验方法,观察果实、叶片等各组织的表型,并测定不同组织的矿质元素含量,同时对苹果MdCAX11基因启动子区域进行预测分析以及启动子转录活性分析。【结果】瞬时过表达sMdCAX11的苹果果肉颜色变褐,并出现皱缩;同时过表达sMdCAX11的苹果果肉和拟南芥叶片的总Ca含量明显下降,且元素比值(K+Mg)/Ca明显升高。【结论】sMdCAX11基因过表达可导致植株组织的元素分配不均,不同元素间的比例失衡。

不同营养元素对秋月梨木栓病的影响

秋月梨是一种于2002年引自日本的中晚熟砂梨品种,因其品质优良而深受消费者和果农喜爱。然而,秋月梨果实木栓病严重影响其品质,给市场销售带来不利影响,成为制约该品种发展的关键因素。为了明确秋月梨果实木栓病发生的原因,并探索相应的防治技术,以秋月梨为试材,喷施不同浓度的钙、硼、硅、氨基酸复配剂,然后调查果实发病率,并进行生理生化分析试验研究。结果表明,无水氯化钙0.2%、硼酸0.02%、有机硅0.025%和氨基酸0.07%复配组合对秋月梨木栓病的综合防治效果最佳。

滇东北地区下寒武统龙王庙组白云石化模式研究:来自钙同位素模拟结果

滇东北地区桧溪剖面位于四川盆地南缘外侧,剖面龙王庙组地层白云石化活动强烈,广泛发育泥晶灰岩、砂屑灰岩、泥晶白云岩、云质灰岩和灰质云岩等岩性。剖面3个灰岩过渡岩性白云岩旋回中具有混积特征,石英颗粒大量发育。阴极发光下,3个岩性旋回主要呈暗红色,可见石膏。地球化学测试显示:旋回1中灰岩白云岩碳同位素为-0.78‰~-0.49‰,氧同位素为-9.28‰~-8.96‰,锶同位素为0.70979554~0.71218318,钙同位素为0.54‰~1.12‰;旋回2中灰岩白云岩碳同位素为0.37‰~0.41‰,氧同位素为-9.76‰~-9.64‰,锶同位素为0.71008711~0.71374167,钙同位素为0.63‰~0.81‰;旋回3中灰岩白云岩碳同位素为-0.03‰~0.23‰,氧同位素为-9.90‰~-9.24‰,锶同位素为0.70990934~0.71237617,钙同位素为0.56‰~0.94‰;3个旋回中灰岩锶、钙同位素测试结果明显偏低,白云岩锶、钙结果明显偏高。钙同位素对流、缓冲模型模拟结果显示,旋回1白云石化流体Mg^(2+)浓度为2倍海水当量(105.64 mmol/kg,Mg^(2+)/Ca^(2+)=1.99),旋回2白云石化流体Mg^(2+)浓度为7倍海水当量(369.74 mmol/kg,Mg^(2+)/Ca^(2+)=6.79),旋回3白云石化流体Mg^(2+)浓度为2.3倍海水当量(121.48 mmol/kg,Mg^(2+)/Ca^(2+)=2.29)。温度模拟显示,白云石化流体温度主要为30℃。综合岩石学、常规地球化学及钙同位素模拟结果,滇东北地区龙王庙组白云岩为渗透回流模式成因。

高海拔地区低体重儿发生状况及影响因素分析

目的探讨高海拔地区低体重儿的发生情况及影响因素。方法选取我院帮带西藏自治区安多县人民医院(当地平均海拔5200 m)在2022年4月至2023年4月分娩的活产儿340例,统计低体重儿发生情况,并分析母亲一般资料、妊娠期及围生期合并症、妊娠晚期血清5种金属元素(Ca、Fe、Mg、Zn、Cu)水平对低体重儿发生的影响。结果本次调查发现低体重儿发生率为18.24%(62/340)。母亲年龄、孕次、产次、妊娠初期BMI、不良孕产史、妊娠期糖尿病及新生儿性别与低体重儿发生情况无明显关系。妊娠期高血压、妊娠期肝内胆汁淤积症、妊娠期贫血、胎膜早破、羊水过少、早产组低体重儿发生率分别高于无妊娠期高血压、无妊娠期肝内胆汁淤积症、无妊娠期贫血、无胎膜早破、无羊水过少、足月产组,差异有统计学意义(均P<0.001);低体重儿组母亲妊娠晚期血清Ca、Fe、Mg、Zn和Cu水平低于非低体重儿组,差异有统计学意义(均P<0.001)。多因素logistic回归分析结果显示,妊娠期高血压、妊娠期肝内胆汁淤积症、胎膜早破、早产及母亲妊娠晚期血清Ca、Zn和Cu水平是引起低体重儿的影响因素(均P<0.001)。结论高海拔地区低体重儿的发生受妊娠期高血压、妊娠期肝内胆汁淤积症、胎膜早破、早产等多种因素的影响,同时与母亲妊娠晚期血清Ca、Zn和Cu水平有关。

醋酸改质钢渣制备高钙基吸附材料及动力学研究

为提高钢渣的资源综合利用并减少钢铁冶炼过程排放的CO_(2),采用浸出-高温烧结工艺对转炉钢渣进行改质。通过浸出过程,将含钙组分制备成钙基吸附材料,同时富集回收浸出渣含铁组分。考察了浸出参数对钙基吸附剂组成的影响,为探究钢渣颗粒中钙的浸出过程,采用收缩核模型对钢渣颗粒在弱酸性溶液中的浸出速率进行了分析。研究了浸出渣经高温改质物相结构变化,并分析铁元素转变规律。此外,通过使用XRD和SEM分析钙基材料的物相结构。最后,测算钙基材料的吸附性能。结果表明,浸出温度和醋酸浓度对钙基材料中CaO含量影响较大。在较大的粒径下,最佳的浸出参数为酸浓度1 mol/L、固液比1∶10、浸出温度70℃以及时间2 h,此条件下CaO含量最高达86.3%。动力学结果表明,在搅拌条件下,钙浸出过程由内扩散控制。在40~70℃内,钙浸出过程的速率控制步骤未发生变化,仍由内扩散控制。制备的钙基材料CaO纯度较高,且CO_(2)吸附量随着CaO含量增加而增大,在常压条件下最高可达60.6 mg/g。对浸出渣高温改质后,Ca_(2)Fe_(2)O_(5)相转变成了尖晶石相(Fe_(3)O_(4)、MgFe_(2)O_(4)),钙铁元素得到了很好的分离和富集回收。

含钙质充填节理的砂岩电阻率特性数值模拟研究

钙质充填节理是一种填隙物以钙元素为主的节理,节理的存在会影响到砂岩储层孔隙度估算和渗透率的准确度。本文利用COMSOL Multiphysics软件模拟钙质充填节理在砂岩中的发育情况,研究节理厚度,节理角度,平行节理间距及交错节理交叉点偏心位置对砂岩电阻率的影响。结果表明,节理厚度与节理角度的改变对砂岩电阻率的影响较大,节理厚度的增大和节理角度的增大分别导致砂岩电阻率呈近线性的上升和二次函数的下降;平行节理间距与交错节理的交叉点偏心位置的改变对砂岩电阻率影响很小。本文为探究节理在岩石中的电阻率响应特征提供了有益参考。

基于CFD-DEM的超细碳酸钙螺旋输送仿真分析

【目的】为提高螺旋输送机的输送效率,降低输送机的功耗与磨损,探究在不同进料速率、螺旋轴转速与几何体摩擦系数下,超细碳酸钙在水平变径变距螺旋输送机内的颗粒流动状态、出口质量流量、输送机功耗与磨损分布。【方法】使用计算流体动力学(computational fluid dynamics,CFD)与离散单元法(discrete element method,DEM)双向耦合数值模拟的方法,对螺旋输送机在不同转速下的质量流率进行分析对比,验证数值模型的正确性。【结果】摩擦系数对颗粒的运动有较大影响,颗粒流的轴向速度峰值和质量流率峰值随着摩擦系数的增加先增大再减小;随着下料速度和摩擦系数的增大,输送机功率明显增大,且摩擦系数在高进料速度与低转速的情况下对功耗的影响相对于低进料速度和高转速更加明显;磨损较严重的区域集中在下料口处的螺旋轴与螺旋叶片的边缘处。【结论】简单增大或减小摩擦系数并不能提高颗粒的轴向速度和质量流量,而是存在一个局部最优参数组合;适当地提高转速能够减小颗粒密实度与颗粒停留时间,从而减小输送机的功耗与几何体磨损。

基于静态和动态休止角的超细碳酸钙离散元参数标定

【目的】获得超细碳酸钙准确的仿真模型参数,实现超细碳酸钙的可靠仿真研究。【方法】将超细碳酸钙精简为软质球形粒子,使用颗粒接触缩放原理与量纲分析进行颗粒缩放,采用Hertz-Mindlin with JKR接触模型,结合物理实验和离散元软件EDEM仿真实验对超细碳酸钙的静态和动态休止角进行接触参数标定。首先利用单因素实验排除对静态和动态休止角影响不显著的参数。采用Box-Behnken实验搭建静态和动态的休止角和显著性参数之间的回归模型。将实际测定的静态和动态休止角作为响应值,进而对静态和动态休止角回归模型求解获得最佳的仿真参数组合,并对得到的仿真参数进行物理实验验证。【结果】得到显著性参数的最佳组合为:超细碳酸钙-超细碳酸钙静摩擦系数和滚动摩擦系数为0.36、0.31,超细碳酸钙-不锈钢静摩擦系数和滚动摩擦系数为0.38、0.22,离散元仿真实验所得到的静态动态休止角分别为42.5°和61.3°,与实测值的误差分别为0.96%和1.32%,无明显差异。【结论】参数标定后的接触参数能够应用于超细碳酸钙离散元仿真。

野生欧李果实发育期不同叶位叶片中主要矿质元素含量的变化

以野生欧李为试材,研究了欧李果实发育期不同叶位成熟叶片中Ca与其他主要矿质元素的变化及其相关特性,为揭示欧李果实钙素吸收机制提供基础资料。结果表明,果实发育期新梢不同叶位叶片中Cu、Mn、Ca、Mg(均值)逐渐增加,Fe、Zn、K(均值)逐渐下降;果实成熟增长期新梢中不同部位叶片由下至上Cu、Zn、Mn、K呈增加趋势,Fe、Ca呈递减趋势,Mg无明显变化;不同叶位叶片中Ca变化相互间均呈显著或极显著正相关,与新梢上位叶片中Zn、Fe、K变化呈显著或极显著负相关,与新梢上位和下位叶片中Mn、Mg变化呈显著或极显著正相关。研究提出,新梢上位成熟叶片中主要矿质元素的变化可以表征新梢叶片中钙素吸收和累积的变化规律。

采前钙处理对猕猴桃果实和叶片营养元素含量的影响

为探明采前钙处理对猕猴桃果实和叶片矿质元素含量的影响,明确施钙浓度与各营养元素含量间的相关性,通过设置6种不同钙浓度,比较了喷施和浸果两种施钙方式对猕猴桃果实和叶片钙及各营养元素含量的影响。结果表明:钙处理可有效提高猕猴桃叶片Ca,Mg,Cu含量,且与钙浓度呈正相关;叶片中的K含量随着钙浓度的提高呈递减趋势;叶片中Zn,P含量经过钙处理后虽然也有提高,但和Fe,Mn含量一样与钙浓度无明显相关性。钙处理同样也有效提高了猕猴桃果实中Ca,Mg,Zn含量,且与钙浓度呈正相关;Cu,Fe含量虽有所增加,但与P,Mn含量一样,与钙浓度均未表现出相关性。喷施比浸果能更好地提高果实中Mg含量,而对于提高果实中Fe和Zn含量,浸果的效果要优于喷施。

儿童全血微量元素含量及补充现状调查

目的了解都江堰市儿童微量元素含量基本情况以及补充情况,指导父母合理补充微量元素。方法回顾并统计分析3 769名1个月～12岁门诊儿童的微量元素检测结果,随机抽查其中200名进行问卷调查。结果 3 769名儿童中有1 113例(30.0%)锌缺乏、553例(14.7%)铁缺乏、358例(9.5%)钙缺乏;另有964例(25.4%)钙含量偏高、149例(3.9%)锌含量偏高。参与调查问卷的200名儿童中有92名儿童(46.0%)的父母曾为子女补充微量元素,其中补钙占85%、补锌占41%、补铁占18%。补充微量元素的原因中受媒体引导的占51.0%,凭自己经验的占34.8%,遵从医嘱的仅占18.5%。结论都江堰市儿童微量元素摄入情况并不乐观,锌、铁、钙缺乏较普遍且未得到合理补充,建议儿童定期检测,合理调配幼儿的饮食,适当补充营养,以确保幼儿正常发育。

钙减缓植物矿质元素毒害的机理

因土壤酸化、盐碱化、重金属污染等多因素导致的矿质元素毒害严重限制了作物生长.钙作为植物必需的元素,在减缓植物矿质元素毒害中起着十分重要的作用.其减缓矿质元素毒害的主要机理可归纳为:施用某些含钙物质如石灰可提高土壤pH值;钙对有害矿质元素的颉颃作用;维持细胞结构和功能的稳定性;维持较高的保护酶系统活力;改善植物的光合作用和呼吸作用以及发挥钙信使系统的功能.

钙镁元素缺乏对一年生何首乌块根矿质元素含量的影响

为了探索钙镁元素缺乏对一年生何首乌块根矿质元素含量的影响,采用砂培的方法,以何首乌扦插苗为材料,对其块根氮、磷、钾、钙、镁、铜、铁、锰、锌等元素的含量进行研究。结果表明:钙、镁元素缺乏处理何首乌块根氮、钾、镁和铜等元素的含量与正常处理的差异不大,均未达显著水平;钙元素缺乏处理有利于何首乌块根对磷、锌、锰和铁等元素的吸收;镁元素缺乏处理降低了何首乌块根对钙、锰和铁等元素的吸收。

钙对大蒜生理特性及主要矿质元素吸收的影响

【目的】研究不同钙水平对大蒜生理特性及N、P、K、Ca、Mg吸收的影响,为大蒜合理施肥和提高钙肥利用率提供参考。【方法】设定6个钙浓度,在设施拱棚内对大蒜进行水培试验。【结果】钙浓度在0—3.0 mmol·L-1内,大蒜的生长量(株高、假茎粗、假茎鲜质量及叶片鲜质量)、色素含量、净光合速率(Pn)、蒸腾速率(E)及气孔导度(Gs)均随钙浓度的升高而增大,当钙浓度在3.0—5.0 mmol·L-1时,这些指标随钙浓度的升高而减小;另外,大蒜叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、硝酸还原酶(NR)活性以及大蒜的根系活力均随钙浓度的升高呈现先增强后减弱的趋势,在3.0 mmol·L-1钙浓度下达到最强,而叶片中丙二醛(MDA)含量的变化趋势与之相反;同时,大蒜蒜薹和鳞茎的鲜质量及N、P、K、Mg的吸收量也在3.0 mmol·L-1钙浓度下最大,而Ca的吸收量与钙浓度呈显著正相关。【结论】水培条件下,对大蒜生长发育最有利的钙浓度为3.0 mmol·L-1。