Cu-based heterojunction catalysts for electrocatalytic nitrate reduction to ammonia

Copper-based catalysts have garnered wide attention in the field of electrocatalytic nitrate reduction for ammonia production due to their low hydrogen precipitation activity and high ammonia selectivity.However,they still face challenges pertaining of poor stability and low activity,which hinder their further application.Herein,we present a Cu_(2)O/Cu heterojunction catalyst supported on nitrogen-doped porous carbon for nitrate reduction.High resolution transmission electron microscopy(HRTEM)and X-ray Diffraction(XRD)results confirm the presence of Cu_(2)O/Cu heterojunctions,which serve as an active phase in catalysis.The nitrogen-doped porous carbon as a carrier not only enhances the catalyst’s stability,but also facilitates the exposure and dispersion of active sites.At-1.29 V(vs.RHE),the maximum production rate of ammonia reaches 8.8 mg/(mg·h)with a Faradaic efficiency of 92.8%.This study also elucidates the effect of Cu_(2)O-to-Cu ratio in the heterojunction on catalytic performance,thereby providing valuable insights for designing efficient nitrate reduction catalysts for ammonia production.

氨水在HF/HNO_3/H_2O系统中对硅片刻蚀的影响

研究了晶体硅太阳电池酸绒面制备中,NH3.H2O在HF/HNO3/H2O体系中对硅片刻蚀速度的影响.实验结果表明,当NH3.H2O加入量较少时,硅片刻蚀速度随NH3.H2O含量增加而变大;NH3.H2O含量大于某值时,硅片刻蚀速度随NH3.H2O含量增加而减小.最后,用气泡搅拌理论以及扩散层理论对实验中的现象进行了理论分析,其结果对多晶硅太阳能电池酸绒面制备有一定指导意义.

Mesoporous Carbon Nanofibers Loaded with Ordered PtFe Alloy Nanoparticles for Electrocatalytic Nitrate Reduction to Ammonia

Highly dispersed bimetallic alloy nanoparticle electrocatalysts have been demonstrated to exhibit exceptional performance in driving the nitrate reduction reaction(NO_(3)RR)to generate ammonia(NH_(3)).In this study,we prepared mesoporous carbon nanofibers(mCNFs)functionalized with ordered PtFe alloys(O-PtFe-mCNFs)by a composite micelle interface-induced co-assembly method using poly(ethylene oxide)-block-polystyrene(PEO-b-PS)as a template.When employed as electrocatalysts,O-PtFe-mCNFs exhibited superior electrocatalytic performance for the NO_(3RR)compared to the mCNFs functionalized with disordered PtFe alloys(D-PtFe-mCNFs).Notably,the NH_(3)production performance was particularly outstanding,with a maximum NH_(3)yield of up to 959.6μmol/(h·cm~2).Furthermore,the Faraday efficiency(FE)was even 88.0%at-0.4 V vs.reversible hydrogen electrode(RHE).This finding provides compelling evidence of the potential of ordered PtFe alloy catalysts for the electrocatalytic NO_(3)RR.

Effect of Foliar Application of Amino Acid on the Quality and Enzyme Activity of Flowering Chinese Cabbage(Brassica parachinensis Bailey)

A pot experiment was conducted to study the influences of foliar application of glycine,alanine,lysine,and glutamic acid in 200 mg/kg or 500 mg/kg upon the quality and enzyme activity of flowering Chinese cabbage（Brassica parachinensis Bailey）.The results showed that all the application of these four amino acids could increase the yield of flowering Chinese cabbage,significantly raise the content of soluble sugar,and reduce the accumulation of nitrate.The applications of three other amino acids except alanine can increase the content of soluble proteins and decrease the accumulation of oxalic acid.However,the application of amino acid has insignificant influences on the SPAD number of chlorophyll,and causes the decrease of Vitamin C content.Meanwhile,the application of amino acid can improve the activity of nitrate reductase（NR） and glutamate dehydrogenase（GDH） as well.It shows that the application of amino acid is beneficial to improve ammonia metabolism,reduce the accumulation of nitrate and oxalic acid,increase the content of soluble sugar and soluble proteins,and improve the quality of flowering Chinese cabbage.

Correlation Analysis between Abundance of Trichodina spp. and Water Quality Parameters

To understand the correlations between the abundance of Trichodina spp. and the water quality parameters, the abundance of Trichodina spp. on the gill of yellow catfish in aquaculture water was investigated. Meanwhile, the temperature and total phosphorus, available phosphorus, total nitrogen, nitrite and ammonia nitro- gen contents of the aquaculture water were measured and determined. The results showed that the abundance of Trichodina spp. on the gill of yellow catfish was negatively correlated with the total phosphorus, available phosphorus and total nitro- gen contents in the aquaculture water, and was positively correlated with the nitrite content in the aquaculture water （P〈0.05）; there were no significant correlations between the abundance of Trichodina spp. and the temperature and ammonia nitrogen content of the aquaculture water （P〉0.05）.

Study on the Microorganisms Related with Nitrogen Cycle in Sediments of Hongfeng Lake

Hongfeng Lake,a key drinking-water source located in Karst areas,was selected to analyze the microorganisms associated with nitrogen cycle.Dilution plate method and most probable number method were used to determine the distribution condition of ammonifier,ammonium-oxidizing bacteria,nitrite-oxidizing bacteria and denitrifier in surface sediment in eight sites.The results showed that the amount of ammonifier,ammonium-oxidizing bacteria,nitrite-oxidizing bacteria and denitrifier in eight sites were 104-106 CFU/g,105-107 MPN/g,105-108 MPN/g and 105-109 MPN/g,respectively.The sampling site with the largest amount of denitrifier was Daposhang,and the other sampling sites had no significant difference;the sampling site of Huyudong bridge had the largest amount of ammonium-oxidizing bacteria;the amount of nitrite-oxidizing bacteria in Xinzhuang was higher than that of other sampling sites;the sampling site of Daposhang had the larger amount of denitrifier.

N-nitro-L-arginine Attenuates Morphine and Dihydroetorphine-induced Place Preference in Mice

Opiate dependence has become one of the most urgent problems of modernsociety. Opiate dependence involves physical and psychical dependence. Although many addicts can bedetoxified, the relapse ratio of 95% in 5 a demonstrates that opiate psychical dependence is aproblem more troublesome. It has been reported that acute and chronic administration of L- NNA canmarkedly retard the development of tolerance to physical dependence on morphine, and suppress theabstinence syndromes precipitated by naloxone in opiate dependent rodents, and even reverse theexisting morphine tolerance. However, the effect of L-NNA on the positive reinforcement ofpsychically active substances and its possible mechanism have not yet been reported. In presentstudy, the effect of L- NNA en the psychical dependence induced by opiates was evaluated on thebasis of conditioned place preference.

化肥标识不清致瓜农受损纠纷案

【案情简介】 两位菜农张某与李某于2005年12月种植了1200多m^2青瓜（其中张某种植930多m^2、李某种植260多m^2）。2006年2月份为了给青瓜增加“营养”达到增收的目的，两人分别向某农资经营部购买了4包由福建珠山某化肥有限公司生产的硝酸氨钙化肥，支付款项360元。购买化肥后两人按照以往的经验将肥料稀释喷施在大棚内的青瓜秧上，没想到施用该化肥不到十天，

氧化炉安全运行的继电器联锁保护

介绍为保证氧化炉长周期运行而设计的一套自动联锁保护装置的工作原理。

国务院办公厅关于进一步加强民用爆炸物品安全管理的通知

一段时间以来,涉及民用爆炸物品的刑事案件和安全生产事故多有发生,危及生产安全和公共安全,给国家财产、人民群众生命财产造成严重损失,对社会稳定带来极大危害。针对目前民用爆炸物品安全管理中存在的问题,急需采取相应的管理措施。经国务院同意,现就有关问题通知如下:

DYNAMIC CHANGES OF INORGANIC NITROGEN AND ASTAXANTHIN ACCUMULATION IN HAEMATOCOCCUS PLUVIALIS

This study on dynamic changes of culture color, astaxanthin and chlorophylls, inorganic N including N NO - 3, N NO - 2 and N NH + 4 in batch culture of Haematococcus pluvialis exposed to different additive nitrate concentration showed (1) ast/chl ratio was over 0.8 for brown and red algae, but was usually less than 0.5 for green and yellow algae; (2) N NO - 3, in general, was unstable and decreased, except for a small unexpected increase in nitrate enriched treatment groups; (3) measurable amounts of N NO - 2 and N NH + 4 were observed respectively with three change modes although no external nitrite and ammonia were added into the culture; (4) a non linear correlation between ast/chl ratio (or color) changes and the levels of N NO - 3 , N NO - 2 , N NH + 4 in H. pluvialis culture; (5) up and down variation of the ast/chl ratio occurred simultaneously with a perceptible color change from yellow to brown (or red) when N NO - 3, N NO - 2 and N NH + 4 fluctuated around 30, 5, 5 μmol/L respectively; (6) existence of three dynamic modes of N NO - 3, N NO - 2 and N NH + 4 changes, obviously associated with initial external nitrate; (7) the key level of total inorganic N concentration regulating the above physiological changes during indoor cultivation was about 50 μmol/L; and (8) 0.5-10 mmol/L of nitrate was theoretically conducive to cell growth in batch culture.

Inducible nitric oxide synthase, nitrotyrosine and apoptosis in gastric adenocarcinomas and their correlation with a poor survival

AIM: To detect the presence of inducible nitric oxide synthase (iNOS), nitrotyrosine (NT) and apoptosis in gastric adenocarcinomas and their possible correlations with the clinicopathological characteristics and prognosis of gastric adenocarcinoma.METHODS: Sixty-six specimens of gastric adenocarcinoma and corresponding adjacent normal gastric tissues were studied. Immunohistochemistry was employed to localize iNOS and NT protein and an immunohistochemical scoring system was used. The occurrence of apoptotic cell death (apoptotic index [AI]) was analyzed by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick-end labeling (TUNEL) method. RESULTS: Results showed that iNOS expression wasdetected at an intermediate or high level in 41 of 66 (62%) specimens of gastric adenocarcinoma. NT expression was 58%. Neither of them was found in the normal gastric tissues; there were significant positive correlations among iNOSexpression, NT expression and AI. Many clinicopathologic characteristics of gastric adenocarcinoma, such as tumor size, depth of invasion, lymph node metastasis and TNM staging, were related to iNOS and NT expressions (P＜0.05). In 66 surviving patients, the 5-year survival rate of 41 patients who had tumors with intermediate or high iNOS expressions and high Ais (4.09%; 19.96%) was significantly lower than that of 25 patients who had tumors with negative or low iNOS expressions and low Ais (0.79%; 47.14%) (P= 0.001). COX's multivariate analysis revealed that the iNOS expression was identified as one of the significant independent prognostic factors predictive of a poor survival (relative risk [RR] = 2.69).CONCLUSION: NO produced by iNOS may play a stronger role in promoting gastric adenocarcinoma growth than in suppressing its growth. iNOS and NT expressions by gastric adenocarcinoma may correlate with a poor survival.

Effect of a nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester on invasion of human colorectal cancer cell line SL-174T

AIML To investigate the effect and mechanism of action of the nitric oxide synthase （NOS） inhibitor NG-nitro-L-arginine methyl ester （L-NAME） on invasion and metastasis of human colorectal cancer cell line SL-174T. METHODS： Human colorectal cancer cel4 line SL-174T was cultured and treated separately with four different dosages of L-NAME for 72 h, Nitric oxide （NO） production was measured with Griess reagent, The effect of L-NAME on invasion and migration of SL-174T cells were evaluated by using Transwell chambers attached with polycarbonate filters and reconstituted basement membrane （Matrigel）, RT-PCR was performed to determine the mRNA levels of matrix metalloproteinase-2 （MMP-2） and tissue inhibitor metalloproteinase-2 （TIMP-2）,RESULTS： L-NAME could significantly inhibit NO production of SL-174T in a dose-dependent manner. After being treated for 72 h with 0.2, 0.4, 0.8, and 1.0 mmol/L L- NAME, respectively, the ability of the L-NAME treated SL- 174T cells to invade the reconstituted basement membrane decreased significantly （t = 8.056, P〈0.05; t= 14.467, P〈0.01; t= 27.785, P〈0.01; and t= 29.405, P〈0.01, respectively） and the inhibition rates were 10.29%, 19.62%, 34.08%, and 42.23%, respectively. Moreover, L-NAME could inhibit migration of SL-174T cells, and the inhibition rates were 20.76%, 24.95%, 39.43%, and 46. 85% for L-NAME at 0.2, 0.4, 0.8, and 1.0 mmol/L, respectively （t = 15.116, P〈0.01）. In addition, after treatment with L-NAME, expression of MMP-2 mRNA was significantly decreased （t = 71.238, P〈0.01） and that of TIMP-2 mRNA was markedly increased （t = -13.020, P〈0.01）. CONCLUSION： L-NAME exerts anti-invasive and anti- metastatic effects on SL-174T cell line via downregulating MNP-2 mRNA expression and upregulating TIMP-2 mRNA expression.

Tolerance of ciliated protozoan Paramecium bursaria (Protozoa, Ciliophora) to ammonia and nitrites

The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in order to determine the lethal concentrations. Linear regression analysis revealed that the 2h-LC50 value for ammonia was 95.94 mg/L and for nitrite 27.35 mg/L using probit scale method (with 95% confidence intervals). There was a linear correlation between the mortality probit scale and logarithmic concentration of ammonia which fit by a regression equation y=7.32x–9.51 (R2=0.98; y, mortality probit scale; x, logarithmic concentration of ammonia), by which 2 h–LC50 value for ammonia was found to be 95.50 mg/L. A linear correla- tion between mortality probit scales and logarithmic concentration of nitrite is also followed the regression equa- tion y=2.86x+0.89 (R2=0.95; y, mortality probit scale; x, logarithmic concentration of nitrite). The regression analysis of toxicity curves showed that the linear correlation between exposed time of ammonia-N LC50 value and ammonia-N LC50 value followed the regression equation y=2 862.85e-0.08x (R2=0.95; y, duration of exposure to LC50 value; x, LC50 value), and that between exposed time of nitrite-N LC50 value and nitrite-N LC50 value followed the regression equation y = 127.15e-0.13x (R2=0.91; y, exposed time of LC50 value; x, LC50 value). The results demonstrate that the tolerance to ammonia in P. bursaria is considerably higher than that of the larvae or juveniles of some metozoa, e.g. cultured prawns and oysters. In addition, ciliates, as bacterial predators, are likely to play a positive role in maintaining and improving water quality in aquatic environments with high-level ammonium, such as sewage treatment systems.

Oral administration of S-nitroso-N-acetylcysteine prevents the onset of non alcoholic fatty liver disease in rats

AIM： To evaluate the potential of S-nitroso-N-acetylcysteine （SNAC） in inhibition of lipid peroxidation and the effect of oral SNAC administration in the prevention of nonalcoholic fatty liver disease （NAFLD） in an animal model.METHODS： NAFLD was induced in Wistar male rats by choline-deficient diet for 4 wk. SNAC-treated animals （n=6） （1.4 mg/kg/day of SNAC, orally） were compared to 2 control groups： one （n=6） received PBS solution and the other （n=6） received NAC solution （7 mg/kg/d）. Histological variables were semiquantitated with respect to macro and microvacuolar fat changes, its zonal distribution, foci of necrosis, portal and perivenular fibrosis, and inflammatory infiltrate with zonal distribution. LOOHs from samples of liver homogenates were quantified by HPLC. Nitrate levels in plasma of portal vein were assessed by chemiluminescence. Aqueous low-density lipoprotein （LDL） suspensions （200 pg protein/mL） were incubated with CuCl2 （300 μmol/L） in the absence and presence of SNAC （300 μmol/L） for 15 h at 37 ℃ Extent of LDL oxidation was assessed by fluorimetry. Linoleic acid （LA） （18.8 μmol/L） oxidation was induced by soybean lipoxygenase （SLO） （0.056 μmol/L） at 37 ℃ in the presence and absence of N-acetylcysteine （NAC） and SNAC （56 and 560 pmol/L） and monitored at 234 nm. RESULTS： Animals in the control group developed moderate macro and microvesicular fatty changes in periportal area. SNAC-treated animals displayed only discrete histological alterations with absence of fatty changes and did not develop liver steatosis. The absence of NAFLD in the SNAC-treated group was positively correlated with a decrease in the concentration of LOOH in liver homogenate, compared to the control group （0.7±0.2 nmol/mg vs 3.2±0.4 nmol/mg protein, respectively, P〈0.05）, while serum levels of aminotransferases were unaltered. The ability of SNAC in preventing lipid peroxidation was confirmed in in vitro experiments using LA and LDL as model substrates. CONCLUSION： Oral administration of SNAC prevents the onset of NAFLD in Wistar rats fed with cholinedeficient diet. This effect is correlated with the ability of SNAC to block the propagation of lipid peroxidation in vitro and in vitro.

STUDY ON THE FACTORS AFFECTING REDUCTION CAPACITIES OF ACTIVATED CARBON FIBERS

The reduction adsorption of silver diamminonitrate on different kinds of activated carbon fibers (ACF) has been studied in this paper. The effect of different parameters, including adsorption temperature, concentrations of activation agents, and activation time on the silver adsorption capacities of activated carbon fibers has been investigated. The results show that higher temperature in which the silver complex interacts with ACF, or higher concentration of activation agent, will make higher reduction adsorption capacities of ACFs. More over, ACFs activated with phosphoric acid have higher reduction capacities than those activated with zinc chloride or steam.

Advanced purification of filtered water by aerobic IBAC

Conventional water purified processes have low removal efficiencies for low concentrations of ammonia nitrogen, nitrite nitrogen and micro-pollutants. The efficiency and mechanisms of a novel immobilized biological activated carbon (IBAC) process to remove those pollutants from treated potable water was investigated. Operated at a hydraulic retention time of 24 minutes, the IBAC process achieved ammonia nitrogen, nitrite nitrogen and organic micro-pollutants (measured as COD equivalent) removal efficiencies of 95%, 96% and 37%, respectively. A GC/MS analysis of the organic micro-pollutants revealed that the initial 24 organic compounds in the in-coming water were reduced to 7 after the IBAC treatment. The organic micro-pollutant removal efficiency decreased with decreasing in-coming concentrations. Pollutant reduction in the IBAC process was achieved by a rapid physical adsorption on the activated carbon, which effectively retained the pollutants in the system despite the short hydraulic retention time, followed by a slower biological enzymatic degradation of the pollutants.

Effects of Different Carbon Sources on the Water of Aristichthys nobilis Richardson Aquaculture by Biofloc

In order to explore the effects of different carbon sources on the water of Aristichthys nobilis Richardson culture by biofloc as well as regular,glucose,sucrose,dextrin,brown sugar and molasses 5 soluble carbon source were added into the water of Aristichthys nobilis Richardson culture containing a certain amount of ammonia nitrogen,nitrite nitrogen to research their effects on pH value,dissolved oxygen,ammonia-nitrogen,nitrite nitrogen value.The results showed that sucrose had the best effect in converting ammonia nitrogen and nitrite nitrogen;glucose and dextrin had significant effect in converting ammonia nitrogen.However,compared with sucrose,glucose and dextrin had bad effect in converting nitrite nitrogen molasses had bad effect in converting ammonia nitrogen and nitrite nitrogen,and had little effect on pH value and dissolved oxygen;glucose,sucrose and dextrin had significant effect in decreasing pH value and dissolved oxygen;brown sugar had good effect in converting nitrite nitrogen,whereas it had little effect in converting ammonia nitrogen.Therefore,sucrose was the best carbon source,and if the cost factor was taken into account,glucose also had a high cost performance.

Preparation and Crystal Structure of Sarcosine 5-Nitrosalicylic Acid Organic Adduct

The title compound (C10H12N2O7, Mr = 272.22) crystallizes in triclinic, space group P1 with a = 5.532(2), b = 9.760(4), c = 11.731(5) ?, α = 68.107(7), β = 89.179(7), γ = 77.830(7)o, V = 573.1(4) ?3, Z = 2, Dc = 1.578 g/cm3, F(000) = 284 and μ(MoKa) = 0.136 mm-1. The final R = 0.0400 and wR = 0.0951 for 1468 observed reflections with I > 2σ(I). The title compound is a 1:1 adduct of sarcosine and 5-nitrosalicylic acid. The nitrogen atom of sarcosine is protonated, and the proton is from the carboxyl group of sarcosine and 5-nitrosalicylic acid with the probability of 50 percent for each. The 5-nitrosalicylic acid and sarcosine molecule of the title adduct are ABAB arranged along the c axis. There exist a lot of hydrogen bonds in the structure, linking sarcosine and 5-nitrosalicylic acid to form a three-dimensional network.