Solid-liquid phase equilibrium for the system ammonium polyphosphate-urea ammonium nitrate-potassium chloride-water at 273.2 K

Based on the dynamic method,a quaternary system of ammonium polyphosphate (APP)-urea ammonium nitrate (UAN,CO(NH_(2))_(2)-NH_(4)NO_(3))-potassium chloride (KCl)-H_(2)O and its subsystems (APP-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O,KCl-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O and APP-KCl-H_(2)O) were systematically investigated at the temperature of 273.2 K.Each ternary phase diagram contains one invariant point and three crystallization regions.The crystallization regions are:(1)(NH_(4))_(3)HP_(2)O_(7),(NH_(4))_(4)P_(2)O_(7)and ((NH_(4))_(3)HP_(2)O_(7)+(NH_(4))_(4)P_(2)O_(7)) for APP-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O diagram;(2) KCl,KNO_(3)and(KCl+KNO_(3)) for KCl-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O diagram and (3)(NH_(4))_(3)HP_(2)O_(7),KCl and((NH_(4))_(3)HP_(2)O_(7)+KCl) for APP-KCl-H_(2)O diagram.The quaternary phase diagram of APP-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-KCl-H_(2)O has no quaternary invariant point but includes four solid phase crystallization regions,i.e.,(NH_(4))_(3)HP_(2)O_(7),(NH_(4))_(4)P_(2)O_(7),KNO_(3)and KCl,in which the KNO_(3)region occupies the largest area.The maximum total nutrient content (N+P_(2)O_(5)+K_(2)O) existing as ionic forms in the APP-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O,KCl-[CO(NH_(2))_(2)-NH_(4)NO_(3)]-H_(2)O,APP-KCl-H_(2)O and quaternary systems is 44.70%,32.86%,45.56%and 46.23%(mass),respectively,indicating that the maximum nutrient content can be reached using raw materials of the corresponding systems to prepare liquid fertilizer.In the quaternary system,the content of NH_(4)~+-N ascends with the increase of the total nutrient content,while the contents of NO_(3)^(-)-N and CO(NH_(2))_(2)-N increase with elevated total N.This work can help optimize the operating parameters for the production,storage and transportation of liquid fertilizers.

Leaching calcium from phosphogypsum desulfurization slag by using ammonium chloride solution: Thermodynamics and kinetics study

Phosphogypsum(PG) desulfurization slag is a calcium-rich residue from reductive decomposition of PG using sulfur as the reductant. We proposed a technology of preparation light calcium carbonate with PG desulfurization slag, which mainly contains two steps: leaching and carbonizing. In this work, we concentrated on the former, in which ammonium chloride aqueous solution was utilized as leaching agent to extract calcium from the slag, and conducted thermodynamics and kinetics study on it. Fact Sage software was employed to do thermodynamic and phase equilibrium diagram calculations. The influence of leaching conditions including agitation speed, initial concentration of leaching solution, reaction temperature, and liquid/solid ratio on the calcium leaching rate was discussed in detail by means of experiment optimal design. A kinetic model developed from the shrinking core model was given to describe the leaching process. The apparent kinetic activation energy(Ea) of the leaching reaction was calculated to be 10.58 kJ·mol^-1.

Solubility and solution thermodynamics of ammonium dihydrogen phosphate in the water–methanol system

The solubility of ammonium dihydrogen phosphate(MAP)in the water–methanol system is essential for antisolvent crystallization studies.To investigate the effect of methanol on the solubility of MAP in water,the solubility of MAP in the water–methanol system was determined by dynamic method and static equilibrium method at temperatures ranging from 293.2 to 343.2 K at atmospheric pressure.Results showed that the solubility of MAP increased with the increase of temperature and the increase of water mole fraction in the water–methanol system.The experimental solubility data were correlated with the modified Apelblat equation,the combined nearly ideal binary solvent/Redlich–Kister(CNIBS/R–K)model and the Jouyban–Acree model.The calculated results based on these three models were in very good agreement with the experimental data with the average relative deviations of 0.65%,0.97%,and 5.38%,respectively.Simultaneously,the thermodynamic properties of the MAP dissolution process in the water–methanol system,including Gibbs energy change,enthalpy,and entropy were obtained by the Van’t Hoff equation,which can be used to assess the crystallization process.

构建服务全民终身学习教育体系的本质思考——基于“自我导向学习”的视角

《中国教育现代化2035》提出了构建服务全民终身学习教育体系的明确目标,这也是"十四五"规划期间确立的重大教育方针。但就体系构建的具体对策与推进而言,首先需要廓清基本内涵,厘清逻辑关系,由此方能明晰体系构建的要素与目标。据此,通过多维度的综合研判,解析出"自我导向学习"这一服务全民终身学习教育体系构建的基本线索与基本要素。在揭示其内在困境的基础上,就"泛"资源格局、"后"学校组织、"善"价值生态和"优"制度框架的创制等本土策略方面,提出了与构建服务全民终身学习教育体系的内在逻辑与复杂关系相契合的若干建议。

磷酸二氢铵-磷酸氢二铵-聚磷酸铵-水四元体系相平衡的实验与计算

利用Schreinemaker湿渣法,通过离子色谱和质量守恒方程联立得到各组分在饱和液相和湿渣相中的分布,从而得到25℃下磷酸二氢铵-磷酸氢二铵-聚磷酸铵-水四元空间相图,解释了聚磷酸铵水溶液结晶、沉淀的问题,对聚磷酸铵作为高效水溶肥料使用、储存具有指导意义。同时为快速获得聚磷酸铵其他体系相图,引入电解质溶液局部组成模型回归了实验体系的溶剂(盐)-盐相互作用能量参数,通过回归参数计算所得的相图与实验相图吻合较好,可用于其他聚磷酸铵体系相图的预测。

Antimicrobial peptide LL-37 forms complex with bacterial DNA to facilitate blood translocation of bacterial DNA and aggravate ulcerative colitis

Bacterial DNA(bacDNA) is frequently found in serum of patient with ulcerative colitis(UC) and Crohn's disease, even blood bacterial culture is negative. How bacDNA evades immune elimination and is translocated into blood remain unclear. Here, we showed that bacDNA avoids elimination and disables bacteriakilling function of antimicrobial peptide LL-37(Cramp in mice) by forming complex with LL-37, which is inducible after culture with bacteria or bacterial products. Elevated LL-37-bacDNA complex was found in plasma and lesions of patients with UC. LL-37-bacDNA promoted inflammation by inducing Th1, Th2 and Th17 differentiation and activating toll-like receptor-9(TLR9). The complex also increased paracellular permeability, which possibly combines its inflammatory effects to promote local damage and bacDNA translocation into blood. Cramp-bacDNA aggravated mouse colitis severity while interference with the complex ameliorated the disease. The study identifies that inflammatogenic bacDNA utilizes LL-37 as a vehicle for blood translocation and to evade immune elimination. Additionally, bacteria may make a milieu by releasing bacDNA to utilize and resist host antimicrobial peptides as a ‘trojan horse'.

Use of additive and pretreatment to control odors in municipal kitchen waste during aerobic composting

The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used20-L reactors and each test lasted 28 days. The objective was to decrease NH3 and H2S emissions during composting. The bulking agent, dry cornstalks, was mixed with the kitchen waste to give a mixture containing 15%（wet weight） bulking agent. A combined treatment was also conducted, in which kitchen waste mixed with the bulking agent was pretreated with ferric chloride（FeC l3）. Less leachate was produced by the composted kitchen waste mixed with bulking agent than by the kitchen waste alone, when the materials had reached the required maturity. The presence of cornstalks also caused less H2 S to be emitted, but had little impact on the amount of NH3 emitted. The FeC l3 was found to act as an effective chemical flocculant,and its presence significantly decreased the amounts of NH3 and H2S emitted. Kitchen waste mixed with cornstalks and treated with FeC l3 emitted 42% less NH3 and 76% less H2 S during composting than did pure kitchen waste.

Anticarin-β shows a promising antiosteosarcoma effect by specifically inhibiting CCT4 to impair proteostasis

Unlike healthy, non-transformed cells, the proteostasis network of cancer cells is taxed to produce proteins involved in tumor development. Cancer cells have a higher dependency on molecular chaperones to maintain proteostasis. The chaperonin T-complex protein ring complex(TRiC) contains eight paralogous subunits(CCT1-8), and assists the folding of as many as 10% of cytosolic proteome.TRiC is essential for the progression of some cancers, but the roles of TRiC subunits in osteosarcoma remain to be explored. Here, we show that CCT4/TRiC is significantly correlated in human osteosarcoma,and plays a critical role in osteosarcoma cell survival. We identify a compound anticarin-β that can specifically bind to and inhibit CCT4. Anticarin-β shows higher selectivity in cancer cells than in normal cells. Mechanistically, anticarin-β potently impedes CCT4-mediated STAT3 maturation. Anticarin-β displays remarkable antitumor efficacy in orthotopic and patient-derived xenograft models of osteosarcoma.Collectively, our data uncover a key role of CCT4 in osteosarcoma, and propose a promising treatment strategy for osteosarcoma by disrupting CCT4 and proteostasis.