Global CO_(2) concentration change induced by“trigger-connectors”model,especially since about 24 Ma?A preliminary hypothesis

Background,aim,and scope The tectonic uplift of the Cenozoic Tibetan Plateau has produced a chain effect,which is an excellent location for Earth system science research,and its uplift process,mechanism and environmental effects are the hot spot and frontier of the current research.The“Tibetan Plateau uplift-weathering-CO_(2) concentration-global climate change”model was put forward by Raymo and Ruddiman to interpret the Late Cenozoic climate change.However,there are still some questions suspended,such as does the weathering of the Tibetan Plateau have the ability to control the global climate?How to explain the modern-like global CO_(2) concentration starting at about 24 Ma?Here,a short space was taken to present a brainstorm about the above questions on account of existing geological pieces of evidence.Materials and methods In this paper,we integrate the formation and evolution of the Yangtze River and Pearl River,the origin and development of the Asian inland aridification-monsoon system,the Cenozoic tectonic uplift process of the Tibetan Plateau,and the westerly winds to discuss and analyze the relationship between the Cenozoic CO_(2) concentration changes and the uplift of the Tibetan Plateau and why the CO_(2) concentration similar to the present was formed at about 24 Ma.Results Similar correspondence of the surface uplift history of Xizang,other global mountains,and the declining CO_(2) concentration could support the theory Tibetan Plateau weathering inf luences CO_(2) concentration.Starting from 24 Ma,the most important character was the uplift and erosion of Xizang and Himalaya,collaborating with Ocean Iron Fertilization(OIF)together as an entity to control the atmospheric CO_(2) concentration because the great Asian rivers,Asian monsoons,and westerlies connected Xizang and surrounded seas together through materials transportation.Discussion Paleogeographic reconstructions from 40 Ma to 20 Ma illustrate that the main topographic change occurred in the Andes,Cordillera orogenic belt,and Xizang.We comprise a comprehensive set of evidence from independent data,which correspond temporally with the tipping point(about 24 Ma)of the atmospheric CO_(2) and we noticed that modern-like Asia monsoon,inland aridity,Asian great rivers,and climate zone formed at about 24 Ma and also there are tectonic activities for the Andes and Rockies.We raised the possibility that the modern-like atmospheric CO_(2) concentration at about 24 Ma was caused by the above geological factors.Here the rivers,monsoon,and westerlies are termed as“connectors”.In addition,these Asian rivers originated from Xizang,the monsoon,and inner Asian aridification are strongly a function of the uplift and growth of Xizang,thus,Xizang here is named as“trigger”.The distinct character of“trigger-connectors”model is that this not only takes the monsoon,westerlies,and the global great rivers into consideration but also expands the range which inf luences atmospheric CO_(2) concentration,from local points to a vast area since about 24 Ma,such as from Tibetan Plateau to Asia,including surrounded seas,after about 24 Ma.However,because the opening of the Late Oligocene-Early Miocene Antarctic periphery straits is highly coincident with the onset of modern-like global atmospheric CO_(2) concentration,we are forced to consider that they also had a significant impact on the reduction of atmospheric CO_(2) concentrations at this time.Conclusions“Trigger-connectors”was put forward to explain the Cenozoic CO_(2) variation,especially modern-like global CO_(2) concentration since about 24 Ma.Recommendations and perspectives Here we use the“trigger-connectors”model to explain the formation of modern-like CO_(2) concentrations starting at about 24 Ma,but there are still some problems.The most important premise for the“trigger-connectors”model is the constructed Cenozoic CO_(2) concentration record is reliable,which is the foundation of our hypothesis.In the future,potential improvements should focus on topographic reconstructions of Xizang and the global mountains.Here we have concentrated on Xizang in the considered timeslices but still,pay less attention to other global orogenic belts.Collaborations with geologist experts in those regions could provide valuable feedback to evaluate their potential role of them in CO_(2) evolution.What is more,considerable progress may be achieved with the addition and consideration of more and new geological data.

C50混凝土的制备及其对Cs^(+)、Ni^(2+)的吸附性能研究

为研究处置库屏障材料混凝土对放射性核素的阻滞能力,制备了C50混凝土材料并研究其对放射性核素的吸附能力。发现屏障材料C50混凝土主要由含钙和铝的硅酸盐矿物组成,其在微观尺度下呈现不规则多面体与板层结构,比表面积为2.786 m^(2)·g^(-1),且具有较强的非定形特征。通过吸附试验,发现实验条件下C50混凝土对Cs^(+)、Ni^(2+)具有较好的吸附能力,达到平衡后对Cs^(+)的K_(d)值达到19.400 L·mg^(-1),吸附容量达到0.316 mg·g^(-1);吸附Ni^(2+)的K_(d)值达到465.142 L·mg^(-1),吸附容量达到96.375 mg·g^(-1)。随着Cs^(+)、Ni^(2+)初始浓度的增大,C50混凝土对Cs^(+)的K_(d)值逐渐减小后趋于稳定,对Ni^(2+)的K_(d)值逐渐减小后稳定增大,吸附容量均逐渐增大。通过环境因素影响试验,发现实验条件下pH对C50混凝土吸附Cs^(+)的影响相对较小,C50混凝土对Ni^(2+)的能力随着pH上升而增大。不同离子对Cs^(+)抑制作用由大到小的顺序依次为:K^(+)、Ca^(2+)、Mg^(2+)、SO_(4)^(2-)、Cl^(-)、NO_(3)^(-),随着温度的升高,C50混凝土对Cs^(+)的吸附能力缓慢减小;对Ni^(2+)抑制作用从大到小的顺序依次为:Mg^(2+)、Ca^(2+)、SO_(4)^(2-)、CO_(3)^(2-)。Ni^(2+)的吸附能力随着温度上升缓慢增大。研究结果可为处置库的建设提供基础数据支持。

Al/Ga离子替换提升Ni^(2+)掺杂尖晶石结构MgAl_(x)Ga_(2-x)O_(4)近红外二区发光特性

近红外荧光转换发光二极管(pc-LED)在成像和检测领域的快速发展突显了对近红外二区(NIR-Ⅱ区)发光材料的迫切需求。然而,商用紫外LED芯片激发的高效NIR-Ⅱ荧光材料匮乏,制约了近红外光谱技术的应用。本文通过高温固相法成功制备了MgAl_(x)Ga_(2-x)O_(4)∶Ni^(2+)荧光材料,该材料的激发波长为390 nm,发射峰位于1300 nm,覆盖了NIR-Ⅱ区域。半高宽约为220 nm的超宽带NIR发射是由于Ni^(2+)处于一个弱晶体场环境中,这种环境是由于MgAl_(x)Ga_(2-x)O_(4)基体中[(Al/Ga)O_(6)]八面体中心周围的高电荷极化导致的空间不对称畸变造成的。通过改变体系中Al^(3+)与Ga^(3+)的离子比例,将NIR-Ⅱ区的发射强度大大提高,发光强度提升为原来的9倍左右。着重研究了Ni^(2+)掺杂最优比例MgAl_(1.5)Ga_(0.5)O_(4)的光谱特性。探讨了体系的温度特性,使用掺Ni^(2+)的近红外荧光粉和商业高效紫外LED芯片(@395 nm)构建了NIR pc-LED,研究表明该材料体系可能在pc-LED光谱技术中展现出较大潜力。这种阳离子调制策略将给近红外发光材料的性能提升提供有效的方法。

Uniform deposition of ultra-thin TiO_(2) film on mica substrate by atmospheric pressure chemical vapor deposition: Effect of precursor concentration

The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pressure chemical vapor deposition(APCVD) was investigated. The precursor concentration significantly affected the deposition and morphology of TiO_(2) grains assembling the film. The deposition time for fully covering the surface of mica decreased from 120 to 10 s as the TiCl_(4) concentration increased from 0.38%to 2.44%. The grain size increased with the TiCl_(4) concentration. The AFM and TEM analysis demonstrated that the aggregation of TiO_(2) clusters at the initial stage finally result to the agglomeration of fine TiO_(2) grains at high TiCl_(4) concentrations. Following the results, it was suggested that the nucleation density and size was easy to be adjusted when the TiCl_(4) concentration is below 0.90%.

蓝光激发的KMgF_(3)∶Cr^(3+)/Ni^(2+)基透明微晶玻璃超宽带近红外发光

近红外光谱技术在食品科学、信息安全、生物医疗等重大国计民生领域的应用对近红外光源提出了越来越高的要求。研发具有高效超宽带发射的近红外光源因此成为一项重要且迫切的研究课题。本文采用熔融淬火法在氟硅酸盐玻璃体系SiO_(2)-K_(2)CO_(3)-KF·2H_(2)O-MgF_(2)中成功析出了钙钛矿型KMgF_(3)纳米晶体。通过改变玻璃组分和热处理温度可以调控氟化物纳米晶相的析出,得到析晶和透明度最佳的微晶玻璃样品。玻璃中KMgF_(3)纳米晶体为Cr^(3+)和Ni^(2+)提供了稳定的八面体配位和低声子能量发光环境,在450 nm蓝光激发下,基于Cr^(3+)到Ni^(2+)的能量传递实现了Cr^(3+)(700~1200 nm)和Ni^(2+)(1400~1700 nm)双宽带近红外发射,并且双宽带近红外发光强度随离子掺杂浓度而可调变化。荧光光谱和荧光衰减曲线表征证明了Cr^(3+)到Ni^(2+)的能量传递过程,对应的能量传递效率为52.2%,能量传递机制为电子偶极-四极相互作用。研究结果不仅可以为系统掌握透明光学材料的超宽带发光规律提供基础数据,同时有助于设计开发低成本、高效率的近红外宽带光源。

Spatial Inhomogeneity of Atmospheric CO_(2) Concentration and Its Uncertainty in CMIP6 Earth System Models

This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospheric carbon dioxide(CO_(2))concentration.The multi-model ensemble mean(MME)can reasonably simulate the increasing trend of CO_(2) concentration from 1850 to 2014,compared with the observation data from the Scripps CO_(2) Program and CMIP6 prescribed data,and improves upon the CMIP5 MME CO_(2) concentration(which is overestimated after 1950).The growth rate of CO_(2) concentration in the northern hemisphere(NH)is higher than that in the southern hemisphere(SH),with the highest growth rate in the mid-latitudes of the NH.The MME can also reasonably simulate the seasonal amplitude of CO_(2) concentration,which is larger in the NH than in the SH and grows in amplitude after the 1950s(especially in the NH).Although the results of the MME are reasonable,there is a large spread among ESMs,and the difference between the ESMs increases with time.The MME results show that regions with relatively large CO_(2) concentrations(such as northern Russia,eastern China,Southeast Asia,the eastern United States,northern South America,and southern Africa)have greater seasonal variability and also exhibit a larger inter-model spread.Compared with CMIP5,the CMIP6 MME simulates an average spatial distribution of CO_(2) concentration that is much closer to the site observations,but the CMIP6-inter-model spread is larger.The inter-model differences of the annual means and seasonal cycles of atmospheric CO_(2) concentration are both attributed to the differences in natural sources and sinks of CO_(2) between the simulations.

Effects of Controlled Atmospheres with High_O_2 or High_CO_2 Concentrations on Postharvest Physiology and Storability of "Napoleon" Sweet Cherry

Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively.

STRUCTURAL RESPONSE OF SOYBEAN LEAF TO ELEVATED CO_2 CONCENTRATION

The effects of CO 2 concentration on the morphological and anatomical characters of soybean (Glycine max) leaf were investigated by means of light microscopy and SEM.It was noticed that exomorphology did not show dramatic change,while stomatal density decreased with increasing CO 2 concentration.Under SEM,no epicuticular wax was observed on both abaxial and adaxial sides of the control group as well as on adaxial side of the treatment group.However,leaf surface of abaxial side was noticed to be densely covered with microasterisk epicuticular wax when they were exposed to CO 2 enriched environment.The epicuticular wax deposition was present in equal abundance on both stomatal and nonstomatal areas.Furthermore,leaf thickness increased significantly due largely to the origin of an extra layer of palisade in the treatment group.The results confirmed that CO 2 enrichment might enhance cell division and induce greater quantity of epicuticular wax.

Effects of Ca^(2+)concentrations on accumulations of mineral elements in the components of Pteroceltis tatarinowii

The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii were studied under controlled conditions. The types ofHoagland nutrient solution with three Ca^(2+) concentrations levels (200, 400 and 600 μg·g^(-1))and a control (without Ca^(2+)) were designed to culture Pteroceltis tatarinowii. After 6 months,contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and barkwere analyzed. The results indicated that Ca accumulations content in the root, leaf and bark hadpositively relation with Ca^(2+) concentrations (200, 400, 600 μg · g^(-1)), and the order of theCa content in the three components was root>leaf>bark. Ca content in the root treated with 600 μg·g^(-1) Ca^(2+) concentrations was 5.5 times as high as that of the control, and about 1.4 times ashigh as that of the root treated in 200 and 400 μg/g Ca^(2+) concentrations respectively. On thecontrary, K and Mg contents in the root, leaf and bark were negatively related to Ca^(2+)concentrations, especially in the bark, and their accumulation trend followed the order ofleaf>root>bark. K content in the bark treated with 600 μg ·g^(-1) Ca^(2+) concentrations was 39.3%of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 μg ·g^(-1)and 400 μg ·g^(-1) Ca^(2+) concentrations respectively; Mg content in the bark treated with 600μg ·g^(-1) Ca^(2+) concentrations was 23.4% of that of the control, and was 27.1% and 35.4% ofthat of the bark treated with 200 and 400 μg·g^(-1) Ca^(2+) concentrations respectively. Comparedwith the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca^(2+)concentrations and their contents were in the order: root>leaf>bark. Based on the results of thisstudy, the experiment has been useful for providing academic bases in improving the bark quality ofPteroceltis tatarinowii on non-limestone soil.

Effects of Doubled_CO_2 Concentration on Ultrastructure, Supramolecular Architecture and Spectral Characteristics of Chloroplasts from Wheat

Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.

RELATIONSHIPS OF STARCH CONCENTRATION WITH SPECIFIC LEAF WEIGHT AND MINERAL CONCENTRATIONS IN POTATO LEAVES UNDER VARIED CO_2 AND TEMPERATURE

Foliar concentrations of starch and major nutrients N, P, K, Ca, and Mg along with specific leaf weight (SLW) were determined in the potato (Solanun tuberosum L.) cvs "Denali", "Norland "'and "Russet Burbank" grown for 35 days under the CO2 concentrations of 500, 1 000, 1 500 and 2 000 mol mol-1 at both 16 and 20℃ air temperature. The starch concentration, pooled from the three cultivars, increased with increasing CO2 concentration at both 16 and 20℃,, and was consistently higher at 16℃ than at 20℃. The SLW (g m-2) was positively related to the foliar starch concentration on the basis of leaf area or dry weight. The concentrations of N, P, Ca, and Mg in leaves were negatively related to starch concentration under 14% starch on a dry weight basis. Above 14%, there was no significant relationship between nutrient and starch concentrations . The similar patterns were seen when the SLW and nutrient concentrations were expressed on a starch-free basis. In contrast, the leaf concentration of K was not closely related to the starch concentration. The results indicated that the changes in SLW and concentrations of N, P, Ca, and Mg in potato leaves only partially resulted from the changed starch concentration.

Prediction of SO_2 Concentration in Urban Atmosphere Based on B-P Neural Network

Base on the principle and method of B-P neural network,the prediction model of SO2 concentration in urban atmosphere was established by using the statistical data of a city in southwest China from 1991 to 2009,so as to forecast atmospheric SO2 concentration in a city of southwest China.The results showed that B-P neural network applied in the prediction of SO2 concentration in urban atmosphere was reasonable and efficient with high accuracy and wide adaptability,so it was worthy to be popularized.

活性炭电极的改性及对Co^(2+),Mn^(2+)和Ni^(2+)的电吸附性能

以商用活性炭(AC)为原料,分别采用磷酸和氢氧化钠改性的方法制备了两种不同的改性活性炭电极材料.采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、Brunauer-Emmett-Teller(BET)测试、傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)等手段以及电化学分析方法,对改性前后活性炭材料的表面性质和电化学性能进行了探究.结果表明,H_(3)PO_(4)改性使活性炭的孔隙分布更加密集,NaOH改性使活性炭表面的孔隙结构更加清晰均匀;H_(3)PO_(4)和NaOH改性均使活性炭的比表面积增加.循环伏安测试结果表明,改性前后活性炭电极在低扫描速率下均具备良好的双电层特性,并且两种改性处理均能提高活性炭电极的比电容;当扫描速率为5 mV/s时,未改性、H_(3)PO_(4)以及NaOH改性活性炭电极的比电容分别为36.51,77.25和85.19 F/g.电吸附实验结果证明,两种改性活性炭电极对Co^(2+),Mn^(2+)和Ni^(2+)均有较好的去除效果,电吸附过程均更加符合Langmuir模型,在初始浓度、电压和pH相同的条件下,NaOH改性电极对Co^(2+),Mn^(2+)和Ni^(2+)具有更高的去除率和吸附容量,去除率可分别达到96.84%,94.37%和96.90%,吸附容量分别为140.8,111.4和108.5 mg/g.

Fe_(3)O_(4)/CS/EDTA对水溶液中Cu^(2+)和Ni^(2+)的吸附研究

分析了自制的Fe_(3)O_(4)/CS/EDTA纳米粒对水溶液中的重金属离子Cu^(2+)和Ni^(2+)的吸附性能和吸附机理。研究了pH值、溶液初始浓度、反应时间等对吸附性能的影响,结合红外、XPS和比表面分析结果确定了参与吸附配位的功能基团及可能发生的络合反应。结果表明:Fe_(3)O_(4)/CS/EDTA对Cu^(2+)和Ni^(2+)的吸附等温线均符合Langmuir模型,对Cu^(2+)的吸附效果要优于Ni^(2+),这可能与Ni^(2+)的离子半径较Cu^(2+)小以及Ni^(2+)与吸附剂形成的金属螯合物的稳定性较Cu^(2+)低有关;Fe_(3)O_(4)/CS/EDTA对Cu^(2+)和Ni^(2+)的吸附机理类似于N·O型螯合剂,并非一般的物理吸附,而是一种以金属离子为中心的吸附螯合。

基于改进INFO-Bi-LSTM模型的SO_(2)排放质量浓度预测

针对火电机组SO_(2)排放质量浓度的影响因素众多,难以准确预测的问题,提出一种改进向量加权平均(weighted mean of vectors,INFO)算法与双向长短期记忆(bi-directional long short term memory,Bi-LSTM)神经网络相结合的预测模型(改进INFO-Bi-LSTM模型)。采用Circle混沌映射和反向学习产生高质量初始化种群,引入自适应t分布提升INFO算法跳出局部最优解和全局搜索的能力。选取改进INFO-Bi-LSTM模型和多种预测模型对炉内外联合脱硫过程中4种典型工况下的SO_(2)排放质量浓度进行预测,将预测结果进行验证对比。结果表明:改进INFO算法的寻优能力得到提升,并且改进INFO-Bi-LSTM模型精度更高,更加适用于SO_(2)排放质量浓度的预测,可为变工况下的脱硫控制提供控制理论支撑。

混凝强化型好氧颗粒污泥对Ni^(2+)吸附性能及机理研究

为强化好氧颗粒污泥(AGS)对重金属Ni^(2+)的吸附效能,利用聚合氯化铝(PAC)和天然混凝剂(SNC)的特性培养形成混凝强化型AGS,并探究AGS对Ni^(2+)的吸附性能及机理。结果表明:PAC型和SNC型AGS对Ni^(2+)均具有良好的吸附性能且存在特异性,Ni^(2+)质量浓度为0~25 mg/L时,PAC型AGS吸附效能较优;Ni^(2+)质量浓度为100~150 mg/L时,SNC型AGS吸附性能较优。模型拟合结果表明:混凝强化型AGS对Ni^(2+)的吸附以物理-化学吸附为主,对于吸附量及吸附速率,SNC型AGS均大于PAC型AGS。傅里叶红外变换光谱(FT-IR)结果表明,吸附过程中混凝强化型AGS存在大量羟基、羧基和氨基等基团与Ni^(2+)吸附结合,实现了Ni^(2+)的有效去除;同时,SNC能强化AGS中的官能团,提高吸附性能。

换热器T2紫铜管在水线部位的腐蚀机理研究

目的基于对换热器中T2紫铜管因受残留水作用而出现泄漏降压现象的研究,分析换热器T2紫铜管在水线部位的腐蚀机理。方法通过T2紫铜管的润湿试验,对腐蚀样品进行宏观和微观形貌观察,对点蚀坑部位的腐蚀产物进行EDS和XPS等表征手段分析,探究腐蚀产物的成分和结构,从而推导出反应机理。结果铜管水线上部位和下部位都以均匀腐蚀为主,但是颜色有所差异。水线部位以点蚀为主,肉眼即可见排成直线的斑点状腐蚀坑,腐蚀产物的颜色主要为黑色和绿色。根据表征分析结果可知,腐蚀体系中含有HCO_(3)^(-)和SO_(4)^(2-)。腐蚀产物的组成有,内层Cu_(2)O,外层CuO,水线部位和水线以下部位铜管表面还有一层CuCO_(3)Cu(OH)_(2)膜。结论根据腐蚀产物的元素分析可知,在HCO_(3)^(-)和SO_(4)^(2-)共同存在的环境中,铜具有很高的点蚀敏感性,T2紫铜管很容易发生局部腐蚀,加之氧浓差电池的作用,水线部位铜管发生严重的点蚀以致穿孔失效。

Effects of Ca2+concentrations on accumulations of mineral elements in the components of Pteroceltis tatarinowii

The bark of Pteroceltis tatarinowii is a raw material for manufacturing Xuan Paper. The effects of Ca2+ concentrations on the accumulation of mineral elements in the bark, leaf and root of Pteroceltis tatarinowii were studied under controlled condi-tions. The types of Hoagland nutrient solution with three Ca2+ concentrations levels (200, 400 and 600 靏g-1) and a control (without Ca2+) were designed to culture Pteroceltis tatarinowii. After 6 months, contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and bark were analyzed. The results indicated that Ca accumulations content in the root, leaf and bark had positively relation with Ca2+ concentrations (200, 400, 600 靏g-1), and the order of the Ca content in the three components was root】leaf】bark. Ca content in the root treated with 600 靏g-1 Ca2+ concentrations was 5.5 times as high as that of the control, and about 1.4 times as high as that of the root treated in 200 and 400 靏/g Ca2+ concentrations respectively. On the contrary, K and Mg contents in the root, leaf and bark were negatively related to Ca2+ concentrations, especially in the bark, and their accumulation trend followed the order of leaf】root】bark. K content in the bark treated with 600 靏g-1 Ca2+ con-centrations was 39.3% of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 靏g-1 and 400靏g-1 Ca2+ concentrations respectively; Mg content in the bark treated with 600 靏g-1 Ca2+ concentrations was 23.4% of that of the control, and was 27.1% and 35.4% of that of the bark treated with 200 and 400 靏g-1 Ca2+ concentrations respectively. Com-pared with the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca2+ concentrations and their contents were in the order: root】leaf】bark. Based on the results of this study, the experiment has been useful for providing academic bases in improving the bark quality of Pteroceltis tatarinowii on non-limestone soil.

pH对δ-MnO_(2)吸附硫酸锰溶液中Co^(2+)、Ni^(2+)的影响

硫酸锰溶液中重金属离子的深度净化,一直是锰行业研究的热点和重点。利用X射线衍射(XRD)、扫描电镜(SEM)和红外光谱(FT-IR)等手段对所制备的δ-MnO_(2)进行表征,利用Visual Minteq软件模拟硫酸锰溶液中Mn、Co和Ni的离子形态随pH的变化关系,研究不同pH条件对δ-MnO_(2)吸附硫酸锰溶液中Co^(2+)、Ni^(2+)的影响。结果表明:δ-MnO_(2)结晶性较差,缺陷和空隙较多,表面羟基丰富。随着硫酸锰溶液pH升高,δ-MnO_(2)对于Co^(2+)和Ni^(2+)吸附率逐渐增加,Co^(2+)比Ni^(2+)更容易被吸附。在低pH下,δ-MnO_(2)吸附效果受结构缺陷和空隙影响,pH高于5时,在表面负电荷和羟基的共同作用下大量吸附Co^(2+)和Ni^(2+),Co^(2+)、Ni^(2+)吸附率最高达到99.98%、89.53%。对吸附后δ-MnO_(2)进行XRD和FT-IR分析进一步验证了吸附机理,为解决锰系电池原材料硫酸锰溶液中重金属杂质离子难去除问题提供一定基础。

1979-2022年北极海冰变化及影响因素分析

海冰是海洋-大气交互系统的重要组成部分,是全球气候变化的指示器。深入分析海冰演变规律,探索全球气候变化与海冰范围之间的关联,对应对和减缓全球气候变化具有重要的理论意义。本文以北极海冰为研究对象,深入分析了1979-2022年北极海冰范围的季节、年际和年代际变化特征,并构建向量自回归模型(Vector AutoRegressive Model,VAR)检验全球平均气温、大气CO_(2)浓度与北极海冰范围之间的因果关系,并分析影响程度。结果表明:(1)北极海冰范围季节变化特征明显,一般在3月达到最大,9月达到最小,这主要与太阳辐射的年变化周期相关;(2)1979-2022年,北极海冰范围总体呈减小趋势,年变化量为5.3万km^(2);(3)北极海冰范围在年代际尺度上逐渐减小,2000-2009年,北极海冰范围较上一个十年减小最多(减少67万km^(2));(4)全球平均气温和大气CO_(2)浓度均对北极海冰范围变化造成了显著影响;(5)全球平均气温和大气CO_(2)浓度与北极海冰范围均有显著负相关关系,相关系数分别为-0.92和-0.95。