Microscopic study on the key process and influence of efficient synthesis of natural gas hydrate by in situ Raman analysis of water microstructure in different systems with temperature drop

Gas hydrate technology has considerable potential in many fields.However,due to the lack of understanding of the micro mechanism of hydrate formation,it has not been commercially applied so far.Gas hydrate formation is essentially a gas-liquid-solid phase transition of water and gas molecules at a certain temperature and pressure.The key to the hydrate formation is the transformation of water molecule from disordered arrangement to ordered arrangement.In this process,weakly hydrogen bonded water will be correspondingly converted to strongly hydrogen bonded water.Through in situ Raman analysis and experiments,the position change of the corresponding peaks of the strongly hydrogen bonded water and the weakly hydrogen bonded water was compared in this work,and the key microscopic process and influence of gas hydrate formation in different systems were comprehensively studied and summarized.It is found that,with the decrease of temperature,the OAH of the weakly hydrogen bonded water remains unchanged when the temperature drops to a certain value,which is the key to the transformation of water into cage hydrate rather than ice.The conversion from the weakly hydrogen bonded water to the strongly hydrogen bonded water is closely related to the gas-liquid interface force,the hydrophilicity/hydrophobicity of the promoter,the ionization degree of liquid,and the electrostatic field of the system.Among the four most common promoters,tetrahydrofuran(THF)has the highest efficiency in promoting methane(CH4)hydrate formation.Therefore,this study provides a scientific direction and basis for the development of high efficient hydrate formation promoters,which can effectively weaken the hydrogen bond of weakly hydrogen bonded water and promote the conversion of weakly hydrogen bonded water to strongly hydrogen bonded water.

Synthesis of Novel Polymer-Bonded Water-Soluble Metal Porphyrins

The reaction of 5, 10, 15, 20-tetra-(4-pyridyl) porphyrin 1 with triruthenium dodecacarbonyl [Ru3(CO)12], zinc(II) acetate, copper(II) acetate, cobalt(II) acetate afforded complexes 2a?2d respectively. Treatment of 2a?2d with Merrifield’s peptide resin obtained 3a?3d. The compounds 3a?3d reacted with methyl iodide respectively gave 4a?4d. New complexes 4a?4d have been identified by IR, UV-visible spectra, and AES.

Recycling water glass from wet reclamation sewage of waste sodium silicate-bonded sand

Wet reclamation of waste sodium silicate-bonded sand produces much alkaline sewage and causes pollution. Recycling water glass from wet reclamation sewage of the waste sodium silicate-bonded sand can solve pollution issues and generate economic benefits. In this work, the wet reclamation sewage was filtered, and the filtrate was causticized with a quicklime powder to produce a lye. The effects of causticization temperature, causticization time, and the amount of quicklime powder on the causticization rate were studied. The lye was used to dissolve the silica in the filtration residue to prepare a sodium silicate solution. The effects of the mass of filtration residue, dissolution temperature, and dissolution time on sodium silicate modulus were studied. Finally, the recycled water glass was obtained by concentrating the sodium silicate solution, and the bonding strength of the recycled water glass was tested. The results showed that the causticization rate could be improved by increasing the amount of quicklime powder, causticization temperature, and causticization time, and the highest causticization rate was above 92%. Amorphous silica in the filtration residue dissolved in the lye. Increasing the amount of the filtration residue, dissolution temperature, and dissolution time could improve the sodium silicate modulus. The bonding strength of the recycled water glass was close to that of commercial water glass. The recycled water glass could be used as a substitute for the commercial water glass.

The Gravito-Chemical Bond and Structures of Hydrocarbons and Water Molecules with Real Magnetic Charges

Experimental and theoretical studies of the author (period: 1968-present) have shown that true sources of the magnetic field are magnetic fundamental particles (magnetic charges), and not moving electrons. The main reason for ignoring real magnetic charges, as well as true antielectrons in physical science is the hard conditions for confinement of these particles in atoms and substances, which is radically different from the confinement of electrons. Magnetic charges together with electric charges form the shells atoms which are electromagnetic, and not electronic. Namely, electromagnetic shells are sources of gravitational field which is a vortex electromagnetic field and described by the vortex rot [E - H]. Depending on the state polarization of vortex vectors rot [E - H] in compositions of atomic gravitational fields it is subdivided into paragravitational (PGF) and ferrogravitational fields (FGF). The overwhelming number of atoms emits PGF. Between the masses (bodies, atoms, nucleons and others) emitting PGF areas of negative gravitational “Dark Energy” are realized the forces of which press the masses towards each other. Namely, the compression of atoms by the forces of paragravitational “Dark Energy” underlies the chemical bond. The exception here is the ionic bond in ionic crystals. However, all ions have electromagnetic shells that generate the gravitational field. Consequently, ionic bonding is a relatively rare addition to gravito-chemical bond processes. The direct gravito-chemical bond of carbon atoms with hydrogen (1H) is physically forbidden due to the manifestation of the effect of ferrogravitational levitation between them and the repulsion of atoms from each other. Paradoxically, but all existing ideas about the structural device of hydrocarbons are based on such physically forbidden bonds which, moreover, must be realized through ionic bonds which in reality do not exist. Chemical bonding of carbon and hydrogen atoms to form hydrocarbons molecules is possible only if the hydrogen atoms are in the molecular form (1H2). In the composition of water, within the framework of the chemical formula H2O, two stable isomorphic molecular structures are formed. The chemical bond in the first structure is similar to the hydrocarbon scenario described above, i.e. in the process of combining paragravitational oxygen with a hydrogen molecule 1H2. The second molecular structure in water is formed under conditions of ferropolarization of the gravitational field of oxygen atoms under the influence of FGF of neighboring 1H atoms. In this case, the chemical bond is realized under the conditions of ferropolarization of the vortex vectors rot [E - H] of the gravitational fields of all atoms in the molecule and the co-directionality of them vectors Pfp ferropolarization. The gravito-physical properties of the presented molecular structures in the composition of water make it possible to name them, respectively, as heavy and light clusters.

Hydrogen bonds of interfacial water in human breast cancer tissue compared to lipid and DNA interfaces

The paper presents the results for water confined in a human breast cancerous tissue, a single stranded DNA, a double stranded DNA and in phospholipids (DPPC - D-a-Phosphati dylcholine, dipalmitoyl). The interfacial water in DNA and lipids is represented by a double band in the region of the OH stretching mode of water corresponding to the symmetric and asymmetric vibrational modes, in contrast to water confined in the cancerous breast tissue where only one band at 3311 cm-1 has been recorded. The marked red-shift of the maximum peak position of the OH stretching mode confirms that the vibrational properties of the interfacial water observed in restricted biological environment differ drastically from those in bulk water. The change of vibrational pattern of behavior may be due to the decoupling of the vibrations of the OH bonds in water molecule or change of the vibrational selection rules at biological interfaces. According to our knowledge Raman vibrational properties of water confined in the normal and cancerous breast tissue of the same patient have not been reported in literature yet. Here we have also presented the first Raman ‘optical biopsy’ images of the non-cancerous and cancerous (infiltrating ductal cancer) human breast tissues.

一种新型义齿粘结剂使用效果观察及性能分析

为提高牙科用粘结剂的粘接效果和抗菌性能,试验通过树脂基质、纳米氟化钠和二癸基二甲基氯化铵,制备了一种具有抗菌性能的新型义齿粘结剂,并对二癸基二甲基氯化铵添加量和应用效果进行研究。结果表明,二癸基二甲基氯化铵的添加可以使义齿粘结剂亲水性能和抗菌性能提高,粘接性能下降。当二癸基二甲基氯化铵添加量从1.5%增大到7.5%时,水接触角从80.3°减小到60.5°,剪切粘接强度从15.3 MPa降低到12.2 MPa。二癸基二甲基氯化铵添加量为1.5%或3.0%比较适宜。在应用效果方面,含有3%二癸基二甲基氯化铵和3%纳米氟化钠的新型义齿粘结剂有着良好的粘接性能和抗菌性能。

改性大豆蛋白胶黏剂制备及其应用研究进展

目前人造板生产中大量使用的甲醛基树脂胶黏剂已成为室内甲醛污染的首要来源,极大影响着人们的健康与工作、生活质量。近些年来,大豆蛋白胶黏剂因其无毒、可生物降解、成本低、加工方便等优点,在木材胶黏剂领域受到广泛的关注。然而,相较于目前广泛商用的酚醛树脂、脲醛树脂等商用的醛基胶黏剂,大豆蛋白胶黏剂存在胶合强度低、耐水性和防霉性能差等缺陷。针对上述问题,采用交联改性、共混改性、结构改性、水解酶改性和填充改性等物理化学手段对大豆蛋白胶黏剂进行功能化改性进而提升其性能是目前常用的手段。本文综述了不同的功能改性大豆蛋白胶黏剂的方法,总结了不同改性方法所存在的问题,并对其未来的发展提出展望。

胶合板用氯氧镁胶黏剂的改性工艺与性能研究

为了提高氯氧镁胶黏剂制备胶合板的胶合强度及耐水性能,采用磷酸和纳米二氧化硅作为改性剂,分析单一和复合添加改性剂后氯氧镁胶黏剂及其制备胶合板的各项性能。结果表明:磷酸和纳米二氧化硅的加入可以改善氯氧镁胶黏剂的物理力学性能,且两种改性剂在合适比例下复合添加的效果优于单一添加。当同时添加磷酸和纳米二氧化硅,两者添加量(以MgO质量计)分别为1%和3%时,改性氯氧镁胶黏剂的软化系数可达到0.95。傅立叶变换红外光谱仪、X射线衍射仪和扫描电子显微镜分析结果表明,两种改性剂并没有与氯氧镁胶黏剂发生化学反应,而是通过改变518相晶体的状态和纳米级颗粒填充孔隙,阻止518相晶体水解,抑制Mg(OH)2生成,使其具有更致密的结构。改性优化氯氧镁胶黏剂制备的胶合板的干、湿态胶合强度可达到1.51、1.25 MPa,满足GB/T 9846—2015《普通胶合板》≥0.70 MPa的要求。

胶合板用高温花生粕和低温花生粕蛋白基胶黏剂的制备与表征

[目的]以高温花生粕(HPM)和低温花生粕(CPM)为试验原料,通过变性交联提高胶黏剂的胶接性能和耐水性,为花生粕蛋白基胶黏剂的进一步实际应用提供参考。[方法]采用尿素(U)变性和聚酰胺多胺环氧氯丙烷(PAE)树脂交联两步法制备HPM和CPM蛋白基胶黏剂,并比较其在胶合强度、黏度、官能团、热性能和微观形貌方面的差异。[结果]与未变性交联的HPM和CPM胶黏剂相比,变性交联后HPM和CPM胶黏剂制备的杨木胶合板干态胶合强度分别提高134.1%和111.4%,湿态胶合强度分别满足国家标准Ⅰ类和Ⅱ类胶合板要求;变性交联后HPM与CPM胶黏剂黏度分别提高101.5%和70.5%,热分解温度分别提高至316.44和307.57℃,且HPM制备的胶黏剂表面最紧密。[结论]变性交联后HPM胶黏剂的胶合强度、耐水性优于CPM胶黏剂,HPM比CPM更适宜作胶黏剂原料。

一种抗超高温配位键合型低聚物降黏剂

针对高密度水基钻井液高温增稠引发的滤失量大、ECD与内耗高、流动性下降甚至完全丧失难题,在AAAMPS聚有机酸降黏剂分子中引入富含大量邻苯二酚基团的单宁酸,采用自由基聚合法研制了一种抗超高温配位键合型低聚物降黏剂AA-AMPS-TA,并通过正交实验明确了PAAT的最优合成条件。表征并评价了PAAT的降黏性能,结果表明:引入TA后,PAAT的红外光谱出现了源于酚羟基的分子内氢键吸收峰,且因其分子结构中引入了大量苯酚基团,显著提升了热稳定性,分解温度接近500℃;PAAT可降低低浓度膨润土浆和7%膨润土+8%高岭土的高浓度混合黏土浆黏度,在高密度水基钻井液体系中降黏率达26.5%,240℃热滚后降黏率达44.4%。采用Zeta电位与粒径分析验证了PAAT的吸附降黏机理,并在蓬深101井中现场应用,控制了井浆高温下黏度、切力增涨,降黏效果良好。

柱撑壳聚糖的氢键密堆积结构制备生物安全的高性能保润材料

保润剂材料内部含有大量亲水基团,能够增加或长期保持物质的含水量,在医疗保健、食品、化妆品和药品等领域应用广泛.壳聚糖分子具有可生物降解、无毒及抗菌等多种优点,是一种高性能的保润剂.然而,其链中存在多个氢键,这种氢键密堆积结构导致水分子无法储存在颗粒内部,严重削弱了材料的吸水和储水能力.本文采用共价偶联方法,使苯甲酸与壳聚糖发生脱水聚合反应.疏水性苯基结构单元能够将亲水性的柔性链进行柱撑,从而形成水分子的存储空间.基于这种独特的设计,制得材料的比表面积比原来的壳聚糖提高了9倍多,吸水能力也相应提高了3倍多.安全性测试结果表明,小鼠在口服壳聚糖基多孔保润剂后,蛋白质水平均无明显变化,证实了壳聚糖基多孔保润剂没有生物毒性.将壳聚糖多孔保润材料均匀分布在试纸上后,试纸的失水量比商用丙二醇分布的试纸减少了20%.

基于双粘型防水材料的高水压隧道新型堵水限排方案及设计方法

为解决高水压隧道渗漏水病害并减少治理成本,基于双粘型喷膜防水材料,提出一种由注浆加固圈、双粘型防排水系统和防水衬砌3部分组成的新型堵水限排方案。依托数值计算方法,揭示该方案的水压分布特征并论证其有效性,进而分析注浆圈及排水板各参数对隧道涌水量及衬砌水压力的影响规律;在此基础上,提出高水压隧道多级控制型限排方案的设计方法。研究结果表明:1)新型堵水限排方案可通过调节注浆圈及排水板参数使二次衬砌水压力降低到可接受范围;2)与传统高水压隧道主要依靠注浆圈来调节渗水量及衬砌水压力不同,新型限排方案可采用注浆圈+排水板多级调控方法,方案设计更加灵活,其中注浆圈占主导作用;3)注浆圈对降低隧道渗水量及衬砌外水压力均有利,其中渗透系数参数最为重要;4)仅当注浆圈渗透系数得到保障时,才存在合理的排水板间距使衬砌水压力与隧道渗水量控制在合理范围内。

基于多重网络结构的生物质胶黏剂研究进展

现代加工制造业中消耗量最大的醛基胶黏剂,依赖于化石资源并且存在甲醛释放问题。开发环保可再生的生物质资源制备胶黏剂对现代工业发展具有重要意义和应用前景。但利用生物质资源制备的胶黏剂存在涂覆性能差、耐水胶接性能不理想、防霉性能不佳、抗冲击能力差、产品稳定性差等缺点。对此,一系列采用不同改性手段提高胶黏剂性能的研究相继发表,其中很多研究是通过共价键、次价键连接构建多重网络结构提高胶黏剂的物理化学性能及使用应用性能。综述了大豆蛋白胶黏剂、淀粉基胶黏剂、木质素胶黏剂、单宁胶黏剂研究中通过构建多重网络结构提高性能的方案方法,探讨了生物质胶黏剂研究前景和开发应用趋势,对生物质胶黏剂规模化应用提供参考和助力,以期提高生物质胶黏剂替代醛基胶黏剂应用于现代加工制造业的可能性。

聚乙烯醇水基胶对卷烟中空滤棒的粘接强度影响因素研究

为了提高卷烟滤棒生产过程中成型纸与滤棒中空丝束段间的中线胶粘接效果,从性能、施胶方式等全过程各因素探究特定烟用水基胶对上机适用性的影响规律,通过流变研究了不同规格水基胶的流变特性,分析了水基胶膜的热性能和力学性能,进一步评价各水基胶的干燥速度和润湿性能,对水基胶的粘接强度进行测试,推测了最终粘接强度的影响因素。结果表明,在固含量相近的条件下,各水基胶均表现出良好的抗剪切能力,黏度较高的水基胶具有更高的强度和韧性,制备得到的胶膜也具有更高的强度;但水基胶过高的黏度会降低其干燥速度和对滤棒的润湿性,进而影响水基胶的粘接。因此,黏度适中的水基胶具有最好的粘接效果。

增强物理交联提升聚乙烯醇耐湿耐热性能

利用玉米淀粉(CS)和桃胶(PG)协同改性聚乙烯醇(PVA)法,制备了PVA/CS/PG复合膜,考察了PVA分子量、不同CS添加量以及PG添加量(在相同CS添加量条件下)对PVA/CS/PG复合膜耐湿、耐热性能的影响。结果表明:CS与PG的羟基与PVA发生了氢键相互作用,PVA/CS/PG复合膜的晶粒尺寸减小,交联密度增加。同时,随着CS和PG含量的增加,复合膜的网格尺寸逐渐减小,热稳定性能提升。水蒸气透过测试表明,当w(CS)=2%和w(PG)=2%时,PG/CS/PVA复合膜含水率较未处理原膜提升了11.5%,水蒸气透过率下降了43%。

基于水-岩相互作用的富水断层破碎带隧道突涌灾害演化特征

为研究开挖卸荷和水力荷载耦合作用下富水断层破碎带隧道突涌灾害演化特征,以沈白高铁西谷隧道工程为依托,考虑不同富水破碎带构造形式及地下水赋存特征,开展隧道突涌灾害演化过程研究。基于水-岩相互作用原理,建立三维离散元粘合块体-裂隙流耦合模型,明确不同地质构造特征下的隧道突涌灾害模式,分析破碎岩体裂隙扩展和地下水渗流的时空演化规律。研究结果有:引入黏合块体模型和裂隙流组合模型,建立了富水断层破碎带水岩相互作用力学模型,再现了富水破碎带隧道突涌灾害演化过程。不同富水破碎带构造形式引起的突涌灾变模式差异显著,且具有不同的触发条件和表现形式。断层破碎带倾角为45°时,破碎岩体沿掌子面下部溜塌涌入隧道,倾角为90°时,围岩向掌子面挤出,倾角为-45°时,表现为拱顶围岩垮塌。富水破碎带突涌灾害程度随着水头增大而加剧,其中倾角为-45°时,突涌灾害程度受水头高度的影响最显著,倾角为90°时,水头高度影响相对较弱,但突涌灾害程度最严重。

可溶性磷对纸面石膏板板芯强度及纸芯粘结性能的影响

为了促进磷石膏在纸面石膏板中的高效资源化利用,本文采用X射线衍射、微量热分析、扫描电子显微镜等研究了可溶性磷、萘系减水剂(FDN)及改性淀粉(MS)等三者交互作用对纸面石膏板性能的影响。结果表明,在FDN存在下,可溶性磷会加剧对半水石膏的缓凝作用,小幅降低对石膏试样强度的不利影响。MS明显缩短石膏的水化进程,降低石膏试样的强度。在MS和FDN共存下,随着可溶性磷掺量的增加,石膏达到最高放热峰值的时间延长,水化放热峰值和2 h水化放热总量下降。0.50%(质量分数,下同)的可溶性磷可抵消部分MS对石膏的促凝作用,同时大幅降低石膏试样强度。在FDN存在下,可溶性磷使水化产物的长径比明显降低,晶体形貌呈不规则短柱状或块状,结晶接触点较少。在FDN和可溶性磷共存时,MS使水化产物出现细小块状和粗化板状。在0.4%FDN和0.2%MS掺量下,高于0.50%的可溶性磷会对纸面石膏板的纸芯粘结产生较为不利的影响。本研究中,为保障纸芯粘结性能为Ⅰ级,可溶性磷掺量不宜超过0.25%。

聚氯乙烯给水管道破裂粘接修复工艺优化

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