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.

Fe^(2+)/Mn^(2+)活化亚硫酸盐降解盐酸土霉素的机理研究

盐酸土霉素常被用于治疗畜禽疾病,但是它不能被畜禽完全代谢,残留的盐酸土霉素进入水体危害水环境的健康。铁锰作为常见的过渡金属,通常以二价态活化亚硫酸盐来降解有机污染物,反应条件温和、操作简单,但是单独的二价铁与二价锰氧化还原电势低,活化亚硫酸盐效果较差。本研究采用Fe^(2+)/Mn^(2+)共活化Na_(2)SO_(3)降解水中的盐酸土霉素,考察药剂用量、pH、溶解氧、氯离子、碳酸根及腐殖酸对Fe^(2+)/Mn^(2+)/Na_(2)SO_(3)体系降解盐酸土霉素的影响;通过焦磷酸盐实验、自由基淬灭实验和EPR实验分析Fe^(2+)/Mn^(2+)/Na_(2)SO_(3)体系中的活性物种;利用紫外可见光谱、傅里叶红外光谱、气相色谱-质谱联用仪识别盐酸土霉素的官能团及其降解中间产物的变化,推断盐酸土霉素的降解途径。结果表明:当Fe^(2+)/Mn^(2+)/Na_(2)SO_(3)浓度比为1∶4∶20(浓度分别为0.1、0.4和2 mmol/L)时,在反应45 min、pH为9.0条件下,盐酸土霉素的去除率和矿化率最高,分别达到94%和49%。随着溶解氧从9 mg/L下降至1.89 mg/L,盐酸土霉素去除率从94%下降至17%;氯离子、腐殖酸和碳酸根均对盐酸土霉素的降解产生抑制作用。Mn(Ⅲ)和SO_(4)·^(-)是降解盐酸土霉素的主要活性氧化剂,盐酸土霉素的降解经过电子转移、开环与酰基化等过程。

电协同Fe^(2+)活化过硫酸盐处理偶氮染料废水的研究

偶氮染料废水会对自然环境和人类健康产生巨大危害。文章研究电协同Fe^(2+)活化过硫酸盐体系高效处理偶氮染料废水,以金橙G废水为处理对象,考察不同反应条件例如pH、Fe^(2+)投加量、过二硫酸盐(PDS)投加量、电流密度等因素对处理效果的影响,采用响应曲面法优化反应条件并确定最佳反应条件下的处理效果。结果表明,在pH为3、极板间距为9 cm、电流密度为15 mA/cm^(2)、PDS投加量为6.66 mmol/L、Fe^(2+)投加量为2 mmol/L、Na_(2)SO_(4)投加量为89.39 mmol/L的条件下,金橙G废水色度平均去除率为93.03%,COD平均去除率为85.80%。分析电协同Fe^(2+)活化过硫酸盐体系起主要作用的自由基及降解机理,证实了电和Fe^(2+)的协同作用。该研究可为电协同Fe^(2+)活化过硫酸盐体系在偶氮染料废水处理领域的应用提供技术支撑。

Fe^(2+)、Cu^(2+)诱导工艺对柞木表板颜色变化规律的影响

木材中的木质素、抽提物等物质具有能与金属盐溶液产生颜色反应的特性。利用这一特性以硫酸亚铁、硫酸铜溶液作为诱导剂,通过正交试验得到色差最大时的工艺参数,探究金属Fe^(2+)、Cu^(2+)的诱导剂质量分数、诱导时间、干燥时间、干燥温度对实木复合地板柞木表板颜色变化的影响。结果表明:Fe^(2+)、Cu^(2+)的诱导剂质量分数对柞木表板色彩色调的影响极为显著(F值分别为20.4453、8.8442);柞木表板的明度色品指数(L^(*))、红绿轴色品指数(a^(*))、黄蓝轴色品指数(b^(*))均随着Fe^(2+)、Cu^(2+)的诱导剂质量分数、诱导时间、干燥时间的增加而逐渐减少,总色差(ΔE^(*))逐渐增大,最大为31.53、9.90,表板色调逐渐偏暗、偏绿、偏蓝;随着干燥温度的增加,Fe^(2+)、Cu^(2+)诱导时的柞木表板总色差都逐渐减小。

外源Fe^(2+)浓度和矿物粒径对生物浸铀的影响

为改善以往生物浸铀效率不高的缺陷,通过添加外源Fe^(2+)及改变矿物粒径来提高生物对铀的浸出率。研究结果表明:外源Fe^(2+)浓度分别为0、0.5、1.0和2.0 g/L时,铀浸出率分别为87.34%、88.27%、91.23%、89.13%,当浸出体系中Fe^(2+)浓度为1.0 g/L时,铀矿石会产生部分溶解且表面粗糙孔隙明显,有利于铀的浸出,溶浸液中存在适量的Fe^(2+)对生物浸铀的能力具有提升效果。另外,外源Fe^(2+)对铀矿生物浸出符合固体产物层控制模型,浸出过程主要受扩散控制。当粒径<-2 mm和-5 mm时铀浸出率分别为91.23%和83.70%,矿物粒径适当减小可增大颗粒比表面积,同样利于铀的浸出。

Fe^(2+)螯合剂对羟脯氨酸发酵的影响

为解决反式-4-羟基脯氨酸发酵过程中Fe^(2+)供应不足、产酸效率低等问题。该研究以大肠杆菌HYP-08为供试菌株,首先通过单因素实验探究Fe^(2+)螯合剂种类及添加量对羟脯氨酸发酵生产的影响,并通过5 L发酵放大验证,以羟脯氨酸产量、生物量,糖酸转化率为指标,进一步探究其在放大过程中的影响,结果表明葡萄糖酸亚铁对羟脯氨酸发酵效果最好,流加发酵生产中,最终确定了10 h开始持连续流加的补料方式,反式-4-羟基脯氨酸生物量及产量达到最高,分别为146.2、118.6 g/L,较优化前提高了12.1%和4.2%,副产物乙酸减少到1.05 g/L,葡萄糖酸亚铁的添加有效增强了菌体活力,提高了羟脯氨酸的产量和糖酸转化率,为微生物发酵生产羟脯氨酸提供了依据。

以研促教:利用荧光探针检测Fe^(2+)的实验设计

本文以荧光探针的设计合成和监测亚铁离子(Fe^(2+))应用于分析化学拓展实验教学为主题,介绍了一种新型的荧光探针DCM-Fe,其通过引入N-氧化物基团有效抑制了分子内电荷转移的发生,实现了对Fe^(2+)荧光“turn on”型检测。本文还阐述了在实验教学中,通过本实验的设计和实施,学生可以深入理解荧光探针的设计合成原理和荧光检测技术的应用,在实践中掌握荧光探针的合成、分析和应用,并培养了学生的实验技能和创新意识。本实验教学可为分析化学实验教学的拓展提供一种新思路和方法。

学科育人视角下“Fe^(3+)、Fe^(2+)的检验与转化”教学

在学科育人的视角下,以“新打开的铁肥和久置的铁肥哪个效果更好”为驱动型问题,在实验探究过程中开展“Fe^(3+)、Fe^(2+)的检验与转化”教学。通过“了解植物叶片变黄的原因、探究新打开的铁肥和久置的铁肥中铁的存在形式、提出减缓铁肥变质的方法”等三个核心活动,落实Fe^(3+)、Fe^(2+)的检验与转化等核心知识;在减缓铁肥变质的实际问题中培养学生的创新精神、严谨的科学态度和社会责任感。

营养液不同浓度Fe^(2+)对水培小白菜生长发育及品质的影响

为筛选适宜水培小白菜生长的Fe^(2+)浓度,该文以苏州青为试验材料,开展了不同浓度Fe^(2+)对小白菜生长发育及品质的影响试验。试验结果表明,水培营养液Fe^(2+)浓度为0.03 mmol/L处理,水培小白菜株高、茎粗均显著高于其他处理,地上部鲜质量、地上部干质量、地下部鲜质量、地下部干质量最大,较对照分别提高92.5%、266.7%、115.5%、357.9%,叶绿素含量(57.12 mg/g)、维生素C含量[92.15 mg/(100 g)]、可溶性糖含量(0.43%)最高,较对照分别提高77.67%、50.44%、30.30%,小白菜丙二醛含量最低(11.06 nmol/g),较对照降低39.33%。综上,营养液Fe2+浓度为0.03 mmol/L时,水培小白菜生长势最旺、品质最佳、抗逆性最强。

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%.

不同因素对Fe^(3+)-TiO_(2)/ACF降解NH_(3)的影响

为了探究不同因素对Fe^(3+)-TiO_(2)/活性炭纤维(ACF)降解氨气(NH_(3))的影响规律,采用Fe^(3+)-TiO_(2)/ACF复合材料,以NH_(3)为目标降解物,研究初始浓度、流速、光催化剂负载量以及光照强度对Fe^(3+)-TiO_(2)/ACF降解NH_(3)的影响,并进行了相应的反应动力学分析。结果表明:随着初始浓度的增加,NH_(3)降解率呈现略微降低的趋势,光催化过程基本符合L-H一级反应动力学模型;随着流速的增加,NH_(3)降解率表现为先升高后降低,其光催化过程也基本符合L-H一级反应动力学模型;随着光催化剂负载量以及光照强度的增加,NH_(3)降解率表现为略微增加的趋势。

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.

H_(2)O_(2)与Fe^(2+)作用的实验探究

由两道高考试题引出对Fe^(2+)与H_(2)O_(2)反应的探究。结果发现,不同的亚铁盐与H_(2)O_(2)作用的结果与实验条件有关:在无外加酸碱时FeSO_(4)溶液与H_(2)O_(2)作用会得到碱式硫酸铁和氢氧化铁沉淀的混合物;FeCl_(2)溶液与H_(2)O_(2)作用会得到聚合氯化铁胶体。在酸性较强时Fe^(2+)与H_(2)O_(2)作用主要生成Fe^(3+);在酸性不太强时主要得到胶体,往往得不到沉淀。亚铁盐与H_(2)O_(2)混合除了发生Fe^(2+)与H_(2)O_(2)之间的氧化还原反应外,同时含铁物质会催化H_(2)O_(2)的分解,H_(2)O_(2)分解放热还会促进Fe^(3+)的水解得到胶体或者沉淀。

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.

Zn^(2+)/Zn和Fe^(3+)/Fe^(2+)的电化学行为及其在液流电池中的应用

锌铁液流电池采用成本低廉的锌、铁元素作为活性物质,有望成为下一代高性价比储能电池。本文利用循环伏安法测试锌、铁离子在碳毡电极表面的电化学活性,计算Zn^(2+)/Zn与Fe^(3+)/Fe^(2+)的扩散系数与反应速率常数。结果表明,锌离子与铁离子在多孔碳毡上具有良好的电化学性能,可以作为锌铁液流电池的活性物质。充放电测试结果表明,锌铁液流电池的充放电性能良好,它具有较高的电流效率、电压效率和能量效率。

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.