“钉头磷磷”的“磷磷”释义平议

对于杜牧《阿房宫赋》"钉头磷磷,多于在庾之粟粒"中"磷磷"一词,学界有不同解释,其中以大学教材采用的"光彩耀目貌"和高中教材选用的"形容突出的钉头"这两种观点最为流行。本文赞同前一种观点。通过对"磷"的字义的回溯、对文本的分析以及对"钉头"的解释,认定"钉头磷磷"的"磷磷"应释义为"光彩鲜明貌,形容梁柱上方的钉头光彩耀目"。

再释“钉头磷磷”

《阿房宫赋》之“磷磷”存有三种说法:“有棱角的样子。这里形容突出的钉头”“密集”“色彩鲜明的样子”。“钉头”存在“梁钉”“门钉”两种说法。从训诂、语境、建筑、考古等方面考证,钉头指门钉,磷磷应该解释为:突出貌,兼有密集、整齐、色彩鲜明义。

富磷金属磷化物电催化性能的研究进展

近年来,电催化分解水技术越来越得到广泛关注。提高速率的关键是要找到高效的电催化剂,其中过渡金属磷化物表现出优秀的催化活性和长期稳定性。富磷化合物具有催化活性较大但导电性较差的特点,在实际应用中可合理调控磷化物的电子结构,以获得导电性、催化效能俱佳的电催化剂。综述了近年来电解水析氢的研究进展,重点集中在富磷金属磷化物的研究上,阐述了其合成方法与微结构调控策略,及其在当前电催化材料研究领域面临的挑战和未来的发展前景。

Damage effect and mechanisms of cyclophosphamide to human neuroblastoma SH-SY5Y cells

OBJECTIVE To investigate the damage effect and mechanisms of cyclophosphamide(CTX)and its active metabolite derivative 4-hydroperoxycyclophosphamide(4-HC)to human neuroblas⁃toma SH-SY5Y cells.METHODS SH-SY5Y cells were treated with CTX[0(cell control),0.01,0.1,1,5,10,20,40 and 80 mmol·L^(-1)]and 4-HC[0(cell control),0.01,0.1,1,5,10,20,40 and 80μmol·L^(-1)]for 48 h.Cell confluence and morphology were observed by the IncuCyte ZOOM system.Cell viability was assessed by CCK-8 assay.Lactate dehydrogenase(LDH)release was measured by LDH assay kit.SH-SY5Y cells were treated with CTX(0,1,5,10 and 20 mmol·L^(-1))and 4-HC(0,1,5,10 and 20μmol·L^(-1))for 48 h before cell proliferation was analyzed by 5-ethynyl-2′-deoxyuridine(EdU)staining assay.Immunofluorescence was employed to assess the levels of the DNA double-strand break markerγ-H2AX and to evaluate changes in mitochondrial membrane potential.SH-SY5Y cells were treated with CTX(0,1,5 and 10 mmol·L^(-1))and 4-HC(0,1,5 and 10μmol·L^(-1))for 48 h,and the alterations in glycolysis and oxidative phosphorylation levels were analyzed using the Seahorse XFe96 Analyzer.RESULTS Compared with the cell control group,cell confluence and cell viability were significantly reduced in the CTX and 4-HC groups(P<0.01),and the half-maximal inhibitory concentrations(IC50)for CTX and 4-HC were 4.44 mmol·L^(-1) and 4.78μmol·L^(-1),respectively.The release rate of LDH was signif⁃icantly increased while the percentage of EdU+cells was significantly reduced in the CTX and 4-HC groups(P<0.01).The percentage ofγ-H2AX+cells was significantly increased and mitochondrial membrane potential significantly decreased in the CTX and 4-HC group(P<0.05).Treatment with CTX and 4-HC resulted in reduced levels of maximum glycolytic capacity,glycolytic reserve,maximal respi⁃ration,and ATP production(P<0.05).CONCLUSION CTX and 4-HC exert significant cytotoxic effects on SH-SY5Y cells by disrupting cell membrane structure,impeding cell proliferation,and reducing cell viability.The mechanisms underlying these effects may involve intracellular DNA damage,disturbance of energy metabolism and mitochondrial dysfunction.

气相色谱分析辛硫磷、水胺硫磷、灭多威混合农药

本文研究建立了辛硫磷、水胺硫磷和灭多威混合制剂的气相色谱分析方法。三种农药用同一色谱柱和同一检测器进行分析，方法的精密度和回收率均能达到农药制剂分析的需要。

ATP的神经递质作用

最近几年的研究表明，神经末梢突触囊泡内储存着ＡＴＰ并可使之释放，细胞膜上有ＡＴＰ的特异性受体存在，ＡＴＰ在细胞间隙内可被迅速地酶解清除。现认为ＡＴＰ不仅是组织细胞的供能物质，而且还是一种具有兴奋性作用的神经递质。

急性低氧对心室肌ATP敏感钾电流的影响

目前，ATP敏感钾通道在心律失常发生中的作用还不十分清楚。在心肌缺血时，细胞内钾丢失及其引起的细胞外钾积聚可导致严重的室性心律紊乱。本实验观察到，在正常细胞外钾离子水平下，急性低氧只能引起部分钾离子外流减少，该部分电流对ATP敏感钾通道阻断剂优降糖（glibenclamide，5×10－3mmol／L）不敏感。在高钾灌流下，低氧10min后即能引起外向钾电流的明显增加，同时细胞发生不可逆的收缩。I－V曲线随复极增加呈线性变化，并能被优降糖抑制。这提示该部分钾电流是ATP敏感的，并被细胞外钾积聚所易化。

Mechanism of phosphorus removal in beneficiation of high phosphorous oolitic hematite by direct reduction roasting with dephosphorization agent

High phosphorous oolitic hematite ore is one of typical intractable iron ores in China, and the conventional beneficiation methods are found to be impracticable to , remove phosphorus from the ore effectively. Better beneficiation index were gotten by direct reduction roasting with dephosphorization agent followed by two stages of grinding and magnetic separation. P content decreases from 0.82% in the raw ore to 0.06% in the magnetic concentrate, and the total iron grade increases from 43.65% to 90.23%, the recovery of iron can reach 87%. Mechanisms of phosphorus removal in the beneficiation of high phosphorous oolitic hematite ore by direct reduction roasting with dephosphorization agent were studied using XRD, SEM and EPMA. The results showed that about 20% of the apatite in the raw ore transferred into phosphorus and volatilized with the gas in the process of reduction roasting, while the rest 80% apatite was not involved in the reaction of generation of phosphorus, and remained as apatite in the roasted products, which was removed to tailings by grinding and magnetic separation. A small amount of phosphorus existed in the magnetic concentrate as apatite. The oolitic texture of raw ore was partly changed during roasting, resulting in the formation of nepheline in the reaction between the dephosphorization agent, SiO2 and Al2O3 in the raw ore, which greatly improved the liberation degree of minerals in the roasted products, and it was beneficial to the subsequent grinding and magnetic separation.

大型粉状MAP国产化装置建设的回顾和展望

回顾了贵州宏福实业开发有限总公司大型DAP装置联产 2 0 0kt/a粉状MAP装置的建设过程 ,从项目构思到装置竣工不到一年 ,月产量基本达到了设计能力。介绍了该装置采用的技术路线、创新技术、预期和实现的目标、技术经济优越性等相关情况 。

Identification of the Rice Vacuolar ATPase B Subunit Gene and Its Expression Pattern Analysis Under Phosphorus Deficiency

A vacuolar ATPase (V-ATPase.) B subunit gene has been cloned and characterized front a phosphorus starvation induced rice root subtractive cDNA library by suppression subtractive hybridization (SSH) method and RT-PCR amplification. This gene encodes a polypeptide of 487 amino acid residues, containing a conservative ATP binding site and with a molecular weight of 54.06 kD and an isoelectric point of 4.99, southern analysis of the. genomic DNA indicates that V-ATPase B subunit is encoded by a single gene in rice genome. The amino acid homologies of V-ATPase B subunits among different organisms range from 76% to 97% and reveals that the evolution of V-ATPase B subunit is accompanied with the biological evolution. Expression pattern analysis indicated that the maximal expression of V-ATPase B subunit gene occurred at an early stage (6 - 12 h) after phosphorus starvation in roots, and lately stage (24 - 48 It) in leaves. Under phosphorus deficiency, the up-regulated expression of V-ATPase gene was presumed to strengthen the proton transport and provide the required energy to maintain an electrochemical gradient across the tonoplast to facilitate Phosphorus transport.

Thermodynamic study on phosphorus removal from tungstate solution via magnesium salt precipitation method

The thermodynamic equilibrium diagrams of Mg2＋- 3-4PO - ＋4NH -H2O system at 298 K were established based on the thermodynamic calculation. From the diagram, the thermodynamic conditions for removing phosphorus from the tungstate solution by magnesium salt precipitation were obtained. The results show that when the concentration of total magnesium increases from 0.01 mol/L to 1.0 mol/L, the optimal pH for the phosphorus removal by magnesium phosphate decreases from 9.8 to 8.8. The residual concentration of total phosphorus almost keeps the level of 4.0×10-6 mol/L in the system. MgHPO4, Mg3（PO4）2 and the mixture of Mg3（PO4）2 and Mg（OH）2 are stabilized in these system, respectively. However, increasing the total concentration of magnesium has little effect on phosphorus removal by magnesium ammonium phosphate, while it is helpful for phosphorus removal by increasing the total ammonia concentration. The calculated results demonstrate that the residual concentration of total phosphorus can decrease to 5.0×10-7 mol/L as the total concentration of ammonia reaches 5.0 mol/L and the optimal pH value is 9-10. Finally, verification experiments were conducted with home-made ammonium tungstate solution containing 50 g/L WO3 and 13 g/L P. The results show that when the dosage of MgCl2 is 1.1 times of the theoretical amount, the optimum pH for removing phosphorus is 9.5, which matches with the results of the theoretical calculation exactly.

Thermal decomposition of magnesium ammonium phosphate and adsorption properties of its pyrolysis products toward ammonia nitrogen

High-purity magnesium ammonium phosphate （MAP） was precipitated by controlling pH value of the reaction system of 9.0-9.5. The thermal decomposition behavior of MAP and the adsorption properties of its pyrolysis products toward ammonia-nitrogen were also studied by XRD, SEM, TGA-DTA and FT-IR methods. The results indicated that high-purity MAP was obtained at pH value of 9.0-9.5. Upon heating to 100-120℃ for 120 min, MAP was thermally decomposed, losing water and ammonia concomitantly with a reduction in grain size and crystallinity. The capacity of pyrolysis products for ammonia nitrogen adsorption reached 72.5 mg/g, with a removal rate of up to 95% from an 800 mg/L solution. The characteristic diffraction peaks corresponding to MAP mainly appeared in their XRD patterns after adsorption of ammonia nitrogen. The pyrolysis products of MAP at 100-120 ℃ could be recycling-used as the chemical treatment regents of ammonia nitrogen in the practical application.

Separation behavior and mechanism of hematite and collophane in the presence of collector RFP-138

The reverse flotation separation performance and mechanism of hematite and cellophane in the presence of RFP-138, a newly synthesized dephosphorization collector, were studied. Reverse flotation tests on monominerals and artificially mixed minerals of hematite and collophanite show that, this anionic collector performs excellently in reducing the phosphorus content in hematite. It can decrease the content of P in artificially mixed minerals from 1.05% to 0.12% and achieve the TFe recovery rate of 91.30%. The chemical behavior of solution and infrared spectra of RFP-138 were investigated to explore the selective collecting mechanism of RFP-138 to these two minerals.

Difference in Absorption of N, P and K among Different-Phosphorus Efficiency Soybean Genotypes at the Seedling Stage

The low-phosphorus efficiency soybean genotypes, D03, D05, D17 and D18, and the high-phosphorus efficiency soybean genotypes, D31, D34, D37 and D38 were selected. The soil culture experiment was conducted. There were 2 treat- ments, high phosphorus （＋P） and low phosphorus （-P）. The difference in absorption of N, P and K among different-phosphorus efficiency soybean genotypes at the seedling stage was analyzed. The results showed in the low phosphorus （-P） treat- ment, the P absorption amount differed among roots, stems and leaves of different high-phosphorus efficiency genotypes. The P absorption amount was positively relat- ed （P〈0.05, P〈0.01） to the dry weights of root, stem and leaves, but was negative- ly related to the utilization efficiency of phosphorus （P〉0.05）. The N and K absorp- tion amounts of root, stem and leaves all trended to decrease. The low phosphorus stress would inhibit the absorption of N, P and K in soybean plants at the seedling stage. However, the adaptability of the high-phosphorus efficiency soybean geno- types to low phosphorus stress was significantly higher than that of low-phosphorus efficiency genotypes.

The Initial Reactions of HaPO4 and NaH2PO4 Supported on Silica： A Joint Experimental and Theoretical Study

A combination of X-ray powder diffraction, thermogravimetric analysis, diffuse reflection infrared Fourier transform, and ^31p magic-angle spinning nuclear magnetic resonance techniques with density function computation was used to elucidate the products and mecha- nism of the reactions among silica, H3PO4, and NaH2PO4 during the preparation of silica supported H3PO4 and NaH2PO4 catalysts. The spectral test results indicate that besides polyphosphoric acid, silicon phosphates on silica supported H3PO4 are also formed. On silica supported NaH2PO4 only sodium polyphosphates are present. Density functional theory （DFT） simulations indicate that in the initial stage, reaction of H3PO4 with silanol groups on the silica support is more favorable than that between H3PO4 itself. In contrast, dimerization and trimerization of NaH2PO4 are predicted to be the predominant initial reactions for the silica supported NaH2PO4 catalyst.

Phosphorus Starvation-induced Expression of Leaf Acid Phosphatase Isoforms in Soybean

Leaf acid phosphatase (APase) activities of 274 soybean genotypes were surveyed under field conditions with two levels of P supplies, and a nutrient solution culture experiment with eight selected genotypes was subsequently conducted under greenhouse conditions to further characterize APase activity and its isoform expression induced by P starvation. Results from the field experiment showed that there was a great genotypic variation for leaf APase activity among the tested soybean genotypes from different origins, and APase activity in many of the tested genotypes (about 60%) was generally increased in the treatment without P fertilizer addition. Results from the nutrient solution culture experiment showed that APase activity in all the eight tested genotypes was generally enhanced by P starvation. Six isoforms of APases were detected in isoelectric focusing gels with samples from both young and old leaves. The activity of all the six isoforms was increased by P starvation, but no new APase isoform was induced. Our results suggest that leaf APase activity could serve as an enzymatic indicator of P starvation for soybean; the increase in leaf APase activity under low P stress was mainly caused by the increase in the activity of existing isoforms but not by the induction of new isoforms.

Differentiation of Barley Genotypes with High Phosphorus Efficiency under Low Phosphorus Stress

[Objective] This study aimed to investigate differences in phosphorus effi-ciency between two-rowed barley and multiple-rowed barley and differences in phos-phorus efficiency among various agronomic traits, and to explore the relationship be-tween agronomic traits and row type with phosphorus efficiency. [Method] Under available phosphorus mass fractions of 1.32 and 36.6 mg/kg, 172 barley varieties, including 79 two-rowed foreign barley, 22 multiple-rowed foreign barley, 58 two-rowed Chinese barley and 13 multiple-rowed Chinese barley, were selected to com-pare differences in phosphorus efficiency-related agronomic traits. Plant height, spike length, number of unfil ed grains, number of unfil ed grains, main panicle weight, to-tal panicle weight, total stem weight, weight of aerial part and heading stage were surveyed for statistical analysis. [Result] The results showed that, various agronomic traits were larger under fertilization condition than under non-fertilization condition ex-cept number of unfil ed grains and heading stage. Plant high, spike length, weight of aerial part and heading stage varied greatly under non-fertilization condition; number of fil ed grains, number of unfil ed grains and total stem weight varied greatly under fertilization condition. In two-rowed barley, plant height and number of fil ed grains of Chinese varieties were higher than those of foreign varieties, while other agronomic traits such as spike length, number of unfil ed grains, main panicle weight, total panicle weight, total stem weight, weight of aerial part and heading stage of foreign varieties were higher than those of Chinese varieties. Spike length and weight of aerial part in multiple-rowed and two-rowed foreign barley were higher than those in Chinese barley. In multiple-rowed barley, plant height, number of unfil ed grains, total panicle weight and total stem weight of foreign varieties were higher under non-fer-tilization condition and lower under fertilization condition compared with those of Chi-nese varieties; number of fil ed grains, main panicle weight and heading stage of foreign varieties were lower under non-fertilization condition and higher under fertil-ization condition compared with those of Chinese varieties. [Conclusion] Heading stage, number of fil ed grains, number of unfil ed grains and total stem weight are more sensitive to phosphorus efficiency. Multiple-rowed barley is more sensitive to phosphorus efficiency than two-rowed barley.

Comparison on Responses of Different Phosphorus-Efficient Wheat Varieties to Phosphorus-Deficiency Stress

Six wheat (Triticum aestivum L.) varieties with different phosphorus (P) efficiency, selected according to their relative yield in P-deficient soil to that in P sufficient soil, were used to compare their responses to P deficiency in growth, root and shoot P content and P concentration in leaf phloem exudates in solution culture. Results showed that P deficiency repressed shoot growth, whereas stimulated root growth. Accordingly, root-shoot dry weight ratio of the P deficient plants was relatively larger than that of the P-sufficient plants. Comparing with P-inefficient varieties, the growth rate of shoot and roots of P-efficient varieties was relatively low both under P-sufficient and -deficient conditions. Phosphorus deficiency also resulted in decrease in shoot and root P content. The rate of decrease in shoot was faster than in root. Difference in P partitioning in shoot and root between P-efficient and -inefficient varieties could not be observed. However, a negative relationship between P concentration in leaf phloem exudates of nine-day-old seedlings of these wheat varieties and their degrees of P efficiency were found under the P-sufficient condition, with higher in P-inefficient varieties but lower in P-efficient varieties. The reduce rate of P concentration in leaf phloem exudates of P-efficient varieties was rather slower than that of P-inefficient varieties, showing higher relative P concentration in leaf phloem exudates. The relative P concentration in leaf phloem exudates under P deficiency ranged from 35.9% of the P-sufficient controls in P-inefficient varieties to 59.0% in P-efficient varieties on the 10th day after the treatments.

Analysis on Activity of Immunity-related Enzymes in First Familiar Generation and Self Cross F1 of Platichthys stellatus Pallas

[Objective] The aim was to study the activity of immunity-related enzymes in each tissue of self cross F1 of Platichthys stellatus Pallas and first familiar generation of P.stellatus ♀×Verasper variegates ♂.[Method] The activity difference of three important non-specific immunity-related enzymes：acid phosphatase （ACP）,alkaline phosphatase （AKP） and superoxide dismutase （SOD） existed in muscle,liver,spleen and intestine of first familiar generation and self cross F1 of P.stellatus was compared.[Result] The activity of ACP and AKP in muscle,liver and intestine of first familiar generation was higher than that of self cross F1,while the activity of ACP and AKP in liver of first familiar generation showed no significant difference with that of self cross F1; the SOD activity decreased significantly in tissues expected for muscle.[Conclusion] The result had provided theoretic basis for the breeding of P.stellatus.

Microbially induced deposition of barium phosphates and its ingredient,morphology and size under different pH values

A phosphate-mineralization microbe was used to induce barium phosphates precipitation, and the precipitates with different types were obtained under different pH values. The average crystallite size of the barium phosphates was calculated by particle size distribution curves, and the size of the products was 33.40, 29. 37, 24. 13, 47.76 and 96. 53 μm when the pH values of the mixed solution are 7, 8, 9, 10 and 11, respectively. The results of X-ray diffraction （XRD） show that the structures of the particles controlled by the mixed solution are mainly BaaPO4 when pH 〈 10; the barium phosphates are synthesized by biological deposition which is the mixture of BaHPO4 and Ba5 （PO4）3OH when pH = 10; when pH = 11, the barium phosphates are also the mixtures, which are Ba5 （PO4）3OH and BaNaPO4. The above results indicate that the phosphate-mineralization microbe can produce a certain enzyme which constantly hydrolyzes phosphate monoester in the mixed solution, and then PO4^3- ions are obtained.