煤矿瓦斯水合化分离试验研究进展

针对煤矿瓦斯利用率低造成的能源浪费和环境污染问题,开展煤矿瓦斯分离与储运应用技术研究具有重要意义。综述了煤矿瓦斯水合化分离的优势和主要方法,包括化学法、机械法、外场作用法和复合强化法,探讨了各种方法在不同工艺条件下的分离效果,并分析了其优缺点。最后通过总结瓦斯水合化法分离的研究进展,指出了工业化应用研究的主攻方向。

耐火浇注料水合化过程中能生成结合相的水合氧化物

在20℃和30℃的条件下对水合氧化铝与镁砂和硅灰的二元混合物的水合作用进行了研究,等温传导热量计被用于检测材料的水合化作用(一般是20h)。将干粉料与水进行外混合。纯氧化物的水合产物是拜耳石和水镁石,而水滑石则是相关混合物料水合作用的主要产物。研究表明,镁砂通过水滑石的形成能加速氧化铝的水合作用,在水合作用的同时伴随有超常的总热量析出。在水合化过程中,硅灰表现为有延迟效应,而且未发现有新的水合化产物生成。

THF对低浓度瓦斯水合化分离热力学条件促进作用

利用可视化分离实验装置,测定了3种浓度(1,0.1和0.01 mol/L)四氢呋喃(THF)溶液中低浓度瓦斯水合化分离热力学参数,色谱分析了分离产物中CH4提纯浓度.对CH4-N2-O2-H2O体系水合物生成相平衡参数Chen-Guo模型计算值和本文实验值进行比较.结果表明:THF的添加有效改善了水合物形成热力学条件,例如17.70℃时,添加促进剂THF后水合物生成压力值降低了7.973 MPa;不同浓度THF溶液对瓦斯水合化分离热力学条件的改善效果不同,所研究的3个浓度体系中,1 mol/L浓度的THF溶液促进效果最好.

水合二氟化钴脱水反应动力学的研究

利用非等温热分析方法研究了水合二氟化钴脱水反应动力学．实验数据经ＦｒｅｅｍａｎＣａｒｒｏｌｌ法及ＣｏａｔｓＲｅｄｆｅｒｎ 法处理，获得脱水反应动力学方程为ｄα／ｄｔ ＝ Ａ·ｅｘｐ（ － Ｅ／ ＲＴ）·（１－ α） ，反应级数ｎ ＝ １－０ ，活化能Ｅ＝ １０６－４ ｋＪ／ｍｏｌ；频率因子Ａ ＝ ２－９９８ ×１０１１ｓ－ １ ，用Ｐｈａｄｎｉｓ法对反应机理进行了讨论．

离子色谱法测定水合三氯/溴化铬配合物离子在水溶液中浓度及其水合反应动力学初探

建立了用离子色谱法测定水合三氯/溴化铬配合物离子在水溶液中浓度的方法.选择的色谱条件为:Dionex IonPac CG12型阳离子保护柱(4×50 mm),Dionex IonPac CS12型阳离子分离柱(4×250 mm),流动相为甲磺酸水溶液,其流速为2 mL/min,梯度洗涤,20 mL定量进样环,可见光/紫外线吸收检测器检测波长420 nm.该方法具有良好的线性,操作简单、快速、结果准确可靠,为研究三价铬配合物配位体取代反应动力学及反应机理提供了理想的分析方法.应用此方法对水合三氯/溴化铬的水合反应动力学进行了研究并求得其反应速率常数.

磷酸氢化六水合钴的晶体合成及结构表征

通过水热合成法制得了配合物磷酸氢化六水合钴[Co(H2O)6].HPO4.H2O,用X-射线单晶衍射方法对其进行了晶体结构解析,结果表明,该化合物为斜方晶系,晶胞为Pmn2,晶胞参数:a=6.9412(8),b=6.1490(7),c=11.2321(12),β=90.00,°V=479.40(9)3,Z=2,Mr=281.02,Dc=1.947 g/cm3,T=298(2)K,F(000)=290,μ(Mo Kα)=1.997 mm-1,R=0.0257和ωR=0.0719,通过分子间氢键作用形成了稳定的分子结构。

HPLC法测定水合羟基化头孢克洛杂质研究

目的建立HPLC法测定水合羟基化头孢克洛杂质方法。方法采用C_(18)(4.6 mm×250 mm,5μm)色谱柱;流动相A为0.78%磷酸二氢钠溶液(取磷酸二氢钠7.8 g,加水溶解并稀释至1000 mL,用磷酸调pH至4.0),流动相B为0.78%磷酸二氢钠溶液(pH 4.0)-乙腈(55:45);流速1.2 mL/min;检测波长220 nm;柱温25℃。结果水合羟基化头孢克洛杂质在9.108×10^(-4)~3.4×10^(-2) mg/mL范围内线性关系良好(r=1.0000),平均回收率为104.03%,RSD为0.82%(n=9),定量限为17.721 ng。在回收率试验中加入的水合羟基化头孢克洛杂质,采用外标法和加校正因子的主成分自身对照法的结果一致,该杂质的相对保留时间约为1.11,校正因子为1.02。结论该方法操作简便、准确度高、重现性好,可以采用不加校正因子的主成分自身对照法对水合羟基化头孢克洛杂质进行检测。

基于三相Biot速度应力波动方程的水合物储层波场数值模拟

天然气水合物储层可以看作由骨架、水合物和孔隙水构成的三相孔隙介质。以三相Biot一阶速度应力波动方程作为声波在水合物储层传播的控制方程,用有限差分法(FDTD)进行数值模拟。波场快照可以清楚展现3个纵波和两个横波,与Biot理论相符。根据实测速度优化控制方程参数,使数值速度与实测速度相符。结果表明:孔隙度对水合物剪应力分量影响最显著,对水合物、孔隙水和骨架速度分量的影响次之,所以储层中孔隙度最适合用水合物剪应力分量来分析。骨架速度分量和应力分量受饱和度的影响较小,水合物剪应力分量受饱和度的影响最大,所以分析储层中水合物饱和度的最佳选择是水合物剪应力分量。

水合四氟化锆的工艺研究

介绍了水合四氟化锆的一种生产工艺。讨论了反应晶化过程、蒸发浓缩过程的控制条件。通过本工艺及其相关条件的研究,获得了质量超过美国同类产品水平的高质量水合四氟化锆。此工艺不仅具有成本低、投资少的特点,而且很好地解决了环保问题。

CaO表面更新对微拟球藻催化热解制备生物油的影响

分别以水合化法和热缺陷法对CaO进行表面更新，用N2物理吸附（BET）、X射线衍射（XRD）、扫描电镜（SEM）和CO2吸附技术对表面更新后的CaO进行了结构表征，并利用制备的CaO在管式炉内对微拟球藻进行了催化热解研究。结果表明：两种更新方法均能明显提高CaO的比表面积、介孔数目及孔体积。CaO的表面更新处理没有改变基本的晶相结构，仍为立方晶型。两种更新方法均能显著提高CaO的催化活性，且改善了产物油品的性能。相比较而言，水合CaO的催化脱氧性能较高，催化热解得到的生物油产率为28.65%、含氧量为4.67%、热值高达38.600 kJ·g^-1、运动黏度低（8.011 mm2·s^-1）、含水率低（2.49%），且催化热解后的生物油以C12～C17饱和直链烷烃为主，适合进一步精制为生物柴油。

水分胁迫对苹果苗非结构性碳水化合物组分及含量的影响

对红高富士苹果在轻度、中度、重度水分胁迫条件非结构性碳水化合物进行测定 ,结果表明 :①水分胁迫条件下 ,苹果同化物的积累主要是山梨醇、蔗糖、葡萄糖和果糖。②水分胁迫导致叶片和根系中溶质增加的主要原因是山梨醇含量的升高 ,其在苹果的渗透调解中起重要作用 ,由此可推知山梨醇 /可溶性糖是衡量水分胁迫后溶质变化及苹果对水分胁迫反应的有效指标。③适度水分胁迫处理使苹果叶片和根系中蔗糖含量升高、淀粉含量显著降低 ,表明水分胁迫条件下蔗糖及淀粉的变化在苹果抵御水分胁迫逆境反应中也起一定的作用。同时也为实践上调控干旱、半旱条件下果树的生长发育提供采取措施的基本思路和理论依据。

Electro‑copolymerized film of ruthenium catalyst and redox mediator for electrocatalytic water oxidation

Electro-copolymerized film containing ruthenium complexes as electron-transfer(or redox)mediators and water-oxidation catalysts by an oxidative copolymerization method is presented.The addition of the redox mediator significantly improved the electrocatalytic water-oxidation activity and reduced the overpotential to 220 mV.The prepared electrode showed a water-oxidation catalytic rate constant kobs of 31.7 s^(-1)and an initial turnover frequency of 1.01 s^(-1)in 1000 s by potential electrolysis at 1.7 V applied bias vs NHE(normal hydrogen electrode).The kinetic isotope effect study suggests that the catalytic water oxidation reaction on the electrode surface occurs via a bimolecular coupling mechanism.

Hydration transformation behaviors of CO_(2) and excellent anti-inflammatory activity on RAW 264.7 cell

Skin care products with carbonic acid(H_(2)CO_(3))have gained extensive attention worldwide.However,the conversion of CO_(2) to H_(2)CO_(3) is not stable,and the mechanism of the effect of H_(2)CO_(3) on skin care has not been clearly proved.The hydration-dissolution behaviors of CO_(2) were investigated under different temperature,pH,and pressure conditions.Moreover,based on the phenomenon of CO_(2) hydration transformation,the inflammatory effect of CO_(2) hydrate on macrophages(RAW 264.7)was investigated.The result shows that the increase in temperature weakened the hydration of CO_(2),and the increase in pH and pressure both promoted the water-phase transformation of CO_(2).When pH<6,CO_(2) reacts with water to generate H_(2)CO_(3).When pH was between 6-7,the prompt solution was a mixture of H_(2)CO_(3) and HCO_(3)^(-).When the pH was between 7-9,they mainly generated HCO_(3)^(-).And when pH>9,CO_(2) solubility mainly converts to CO_(3)^(2-).Besides,CO_(2) can inhibit the secretion of inflammatory factors by RAW 264.7 cells by inhibiting the phosphorylation of the p38 protein.CO_(2) hydrate inhibited the expression of pro-inflammatory factors IL-6,TNF-α,and up-regulated the expression of anti-inflammatory factor IL-10.Furthermore,the anti-inflammatory molecular mechanism of CO_(2) hydration inhibited the MAPK signaling pathway by inhibiting the phosphorylation of p38.The hydration-dissolution behavior of CO_(2) was investigated.This work revealed the anti-inflammatory bioeffect of CO_(2) hydrate,providing a theoretical basis and application support for CO_(2) skin care products.

Effect of inorganic salt impurities on seeded precipitation of silica hydrate from sodium silicate solution

To clarify the precipitation of silica hydrate from the real desilication solutions of aluminosilicate solid wastes by adding seeds and improve integrated waste utilization,the seeded precipitation was studied using synthesized sodium silicate solution containing different inorganic salt impurities.The results show that sodium chloride,sodium sulfate,sodium carbonate,or calcium chloride can change the siloxy group structure.The number of high-polymeric siloxy groups decreases with increasing sodium chloride or sodium sulfate concentration,which is detrimental to seeded precipitation.Calcium chloride favors the polymerization of silicate ions,and even the chain groups precipitate with the precipitation of high-polymeric sheet and cage-like siloxy groups.The introduced sodium cations in sodium carbonate render a more open network structure of high-polymeric siloxy groups,although the carbonate ions favor the polymerization of siloxy groups.No matter how the four impurities affect the siloxy group structure,the precipitates are always amorphous opal-A silica hydrate.

In-situ building of multiscale porous NiFeZn/NiZn-Ni heterojunction for superior overall water splitting

The development of efficient nonprecious bifunctional electrocatalysts for water electrolysis is crucial to enhance the sluggish kinetics of the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).A self-supporting,multiscale porous NiFeZn/NiZn-Ni catalyst with a triple interface heterojunction on nickel foam(NF)(NiFeZn/NiZn-Ni/NF)was in-situ fabricated using an electroplating-annealing-etching strategy.The unique multiinterface engineering and three-dimensional porous scaffold significantly modify the mass transport and electron interaction,resulting in superior bifunctional electrocatalytic performance for water splitting.The NiFeZn/NiZn-Ni/NF catalyst demonstrates low overpotentials of 187 m V for HER and 320 mV for OER at a current density of 600 mA/cm^(2),along with high durability over 150 h in alkaline solution.Furthermore,an electrolytic cell assembled with NiFeZn/NiZn-Ni/NF as both the cathode and anode achieves the current densities of 600 and 1000 m A/cm^(2) at cell voltages of 1.796 and 1.901 V,respectively,maintaining the high stability at 50 mA/cm^(2) for over 100 h.These findings highlight the potential of NiFeZn/NiZn-Ni/NF as a cost-effective and highly efficient bifunctional electrocatalyst for overall water splitting.

Electronic Communication Between Co and Ru Sites Decorated on Nitrogen-Doped Carbon Nanotubes Boosting the Alkaline Hydrogen Evolution Reaction

Designing highly efficient Pt-free electrocatalysts with low overpotential for an alkaline hydrogen evolution reaction(HER)remains a significant challenge.Here,a novel and efficient cobalt(Co),ruthenium(Ru)bimetallic electrocatalyst composed of CoRu nanoalloy decorated on the N-doped carbon nanotubes(CoRu@N-CNTs),was prepared by reacting fullerenol with melamine via hydrothermal treatment and followed by pyrolysis.Benefiting from the electronic communication between Co and Ru sites,the as-obtained CoRu@N-CNTs catalyst exhibited superior electrocatalytic HER activity.To deliver a current density of 10 mA·cm^(-2),it required an overpotential of merely 19 mV along with a Tafel slope of 26.19 mV·dec^(-1)in 1 mol·L^(-1)potassium hydroxide(KOH)solution,outperforming the benchmark Pt/C catalyst.The present work would pave a new way towards the design and construction of an efficient electrocatalyst for energy storage and conversion.

Variation in litter decomposition-temperature relationships between coniferous and broadleaf forests in Huangshan Mountain, China

A study was conducted to identify the differences in the decompositions of leaf litter, lignin and carbohydrate between coniferous forest and broadleaf forest at 20℃ and 30℃ in Huangshan Mountain, Anhui Province, China. Results showed that at 20℃ mass loss of leaf litter driven by microbial decomposers was higher in broadleaf forest than that in coniferous forest, whereas the difference in mass loss of leaf litter was not significant at 30℃. The temperature increase did not affect the mass loss of leaf litter for coniferous forest treatment, but significantly reduced the decomposition rate for broadleaf forest treatment. The functional decomposers of microorganism in broadleaf forest produced a higher lignin decomposition rate at 20℃, compared to that in coniferous forest, but the difference in lignin decomposition was not found between two forest types at 30℃. Improved temperature increased the lignin decomposition for both broadleaf and coniferous forest. Additionally, the functional group of microorganism from broadleaf forest showed marginally higher carbohydrate loss than that from coniferous forest at both temperatures. Temperature increase reduced the carbohydrate decomposition for broadleaf forest, while only a little reduce was found for coniferous forest. Remarkable differences occurred in responses between most enzymes （Phenoloxidase, peroxidase, !5-glucosidase and endocellulase） and decomposition rate of leaf litter to forest type and temperature, although there exist strong relationships between measured enzyme activities and decomposition rate in most cases. The reason is that more than one enzyme contribute to the mass loss of leaf litter and organic chemical components. In conclusion, at a community scale the coniferous and broadleaf forests differed in their temperature-decomposition relationships.

Corrosion resistance of in-situ Mg-Al hydrotalcite conversion film on AZ31 magnesium alloy by one-step formation

In situ growth of nano-sized layered double hydroxides （LDH） conversion film on AZ31 alloy was synthesized by a urea hydrolysis method. The formation mechanism of the film was proposed. Firstly, the dissolved Mg2＋ ions deposited into a precursor film consisted of MgCO3 and Mgs（CO3）4（OH）2·4H2O; secondly, the precursor translated into the crystalline Mg（OH）2 in alkaline conditions; finally, the Mg2＋ ions in Mg（OH）z were replaced by A13＋ ions, Mg（OH）2 translated into the more stable LDH structure, simultaneously, the OH- ions in the interlayer were exchanged by CO32-, thus led to the formation of the LDH （Mg6Alz（OHh6CO3·4H2O） film. The results indicated that the LDH film characterized by interlocking plate-like nanostructures and ion-exchange ability significantly improved the corrosion resistance of the AZ31 Mg alloy.

Study on the Changes of Non-structural Carbohydrates and Nitrogen Contents of Quercus aquifolioides Scrub along Different Elevation Gradient

[Objective] The aim was to compare the content changes between the non-structural carbohydrates（NSC）and the total nitrogen in various growing seasons,and to explore the response relationship between altitude and the contents.[Method] Taking Quercus aquifolioides scrub which widely distributed in Zheduoshan in the west of Sichuan as the experimental objects,the changes between NSC and the toal nitrogen in various growing seasons at different altitude were studied.[Result] The results showed that the content of NSC in Quercus aquifolioides underground increased with the lift of elevation in the dormancy,but decreased in the early germination,growing period and growth stage.The content of NSC in the ground tissue changed non-linearly with increasing elevation.In addition,the total nitrogen of Quercus aquifolioides organizations was decreasing with increasing elevation in the dormant period,which did not change significantly in the other periods.This result implied that the content of NSC in Quercus aquifolioides underground was more sensitive to temperature.[Conclusion] The experiment laid basis for the exploration of the physical and ecological mechanism of underground plants adaptability to highland environment,their response to global climate changes and adjustment to high altitude ecological system.