浅谈如何降低盐耗

食盐是电解法生产烧碱的主要原料。目前我国氯碱厂所用食盐以海盐为主。也有的氯碱厂使用当地的湖盐、岩盐及井盐。综合国内有关氯碱厂的实际生产状况,每吨烧碱的盐耗量相差较大。低的为1600kg/t NaOH(100％)左右:高的达到1900kg/t NaOH(100％)左右。

高速公路常见病害成因分析与防治

本文介绍了高速公路的常见病害及一些新型病害 ;较详细的分析了病害产生的原因 ,并提出了相应的防治措施。

Effect of Fouling in Daya Bay Scallop chlamys nobilis (reeve) Cultivation:Food Competition and Nutrient Release

Biofouling is an important factor that affects bivalve farming industry. Fouling organisms may reduce growth and survival rate of the cultured species. Fouler are often filter feeders, so they are potential competitors for food resource with the cultured species. The present study was conducted to measure the impact of fouling on food uptake and nutrient release in April, 2006 in Daya Bay near Guangzhou, China. Results showed that fouling organisms had significant effect on food uptake and nutrient release. The chlorophyll a uptake rate of fouled scallops was 7.53 / Lh ±1.416 / Lh in April, significantly higher than those of cleaned scallops, Le., 4.23 / Lh±2.744 / Lh. The consumption of total particulate matter by fouled scallops in April was 5.52 / Lh± 0.818 / Lh; the corresponding results for cleaned scallops are 2.49 / Lh ±0.614 / Lh Fouling increased ammonia release significantly. The ammonia release rate of fouled scallops was 33.81/Lh ±7.699 / Lh in April, while cleaned scallops released 2.46 / Lh ±0.511 / Lh ammonia. Phosphate uptake of fouled scallops was 2.01± 0.699 / Lh and cleaned scallops released phosphate 6.01 / Lh ＋ 0.876 / Lh in April. There was not significant difference in nitrate consumption between fouled and cleaned scallops. According to the phytoplankton classification of input and output water samples, fouled scallops filtered more phytoplankton species than cleaned scallops. Therefore, this study showed that fouling contributed much to phytoplankton depletion and concentration increase of ammonia in water.

Glutamine is highly effective in preventing in vivo cobalt-induced oxidative stress in rat liver

AIM: To evaluate the in vivo effect of glutamine on cobaltgenerated oxidative stress and (HO-1) induction in rat liver.METHODS: Fasted female Wistar rats received a single injection of cobalt chloride (375 μmol/kg body weight) and then were killed at different times. Lipid peroxidation and soluble and enzymatic antioxidant defense system (reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD)) were measured in liver homogenates. Ferritin and ferritin iron contents as well as heme oxygenase-1 (HO-1) activity and expression were also determined. The antioxidant properties of glutamine (Gin) were also evaluated. RESULTS: Cobalt chloride increased lipid peroxidation (50% over control values) 1 h after treatment. GSH reached a minimum at 3 h (40%) increasing thereafter. Twelve hours after CoCl2 injection, the antioxidant enzymes CAT, GSH-Px and SOD also diminished by about 30%. Heme oxygenase-1 induction was observed 6 h after treatment reaching a maximum value of 14-fold over the controls, 12 h after cobalt treatment. A 1.7-fold increase in ferritin and ferritin-bound iron 24 h after treatment were also obtained. Administration of glutamine (300 mg/kg body weight) by gavage 24 h before CoCl2 treatment entirely prevented the increase in thiobarbituric acid reactive substances (TBARS) content, the decrease in GSH levels, and partially reverted heme oxygenase-1 induction. CONCLUSION: These results suggested that a natural product such as glutamine prevents glutathione depletion and consequently heme oxygenase induction.

Study on Leaching Loss of Nitrogen in Ricefields by Using Large Undisturbed Monolith Lysimeters

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A power function model for simulating creep mechanical properties of salt rock

In this paper,a new micro-creep model of salt rock is proposed based on a linear parallel bonded model(LPBM)using the two-dimensional particle flow code(PFC2D).The power function weakening form is assumed to describe the variation of the parallel bonded diameter(PBD)over time.By comparing with the parallel-bonded stress corrosion(PSC)model,a smaller stress fluctuation and smoother creep strain−time curves can be obtained by this power function model at the same stress level.The validity and adaptability of the model to simulate creep deformation of salt rock are verified through comparing the laboratory creep test curves and the Burgers model fitting result.The numerical results reveal that this model can be capable of capturing the creep deformation and damage behavior from the laboratory observations.

Experimental study on repair characteristics of damaged rock salt of underground gas storage

Damage in rock salt has significant implication on permeability, which affects the tightness of underground salt cavern gas storage in further. During the leaching of a salt cavern, the brine with formation temperature and pressure can promote the self-healing of rock salt in the excavation damage zone (EDZ). Laboratory tests were conducted to study the promoting effect. The permeability of two intact rock salt specimens was tested. Then they were damaged into two kinds of the state respectively through uniaxial compression. After that, they were put in saturated brine (with a temperature of 50℃ and pressure of 12 MPa, which we called the repair environment in this paper) for 7 d. Finally, the permeability and mechanical properties were obtained after the damaged specimens being repaired. The results show that the permeability of intact rock salt is below 10^-19 m^2;the permeability increases by more than two orders because of damage;the permeability decreases significantly after being repaired, which can be comparable to its intact state. Discussions of the repair mechanisms are presented (especially the mechanism of recrystallization), which may help to provide significant guidance for the study of the tightness and stability of gas storage facilities in China.

Railway tunnel concrete lining damaged by formation of gypsum,thaumasite and sulfate crystallization products in southwest of China

The railway tunnel concrete lining exposed to sulfate-bearing groundwater beyond 40 years in southwest of China was investigated. Field investigation, sulfate ions content and corroded products analysis, macro/microscopic test were carried out. Results show that under the tunnel concrete lining structure and its served environmental conditions, sulfate solutions permeate concrete lining and accumulate on windward-side of concrete lining, resulting in the increase of sulfate ions content on windward-side and the diffusion of sulfate ions from windward-side to waterward-side, which cause the concrete lining of windward-side damaged seriously but the waterward-side of concrete lining is still in perfect condition. It is confirmed that structural characteristic of tunnel and environmental conditions lead to physical attack with the leaching of concrete and sodium sulfate crystallization as well as chemical corrosion with formation of gypsum in high sulfate concentration and formation of thaumasite in proper temperature rather than formation of ettringite. These achievements can provide academic and technical supports for understanding the deterioration mechanism of concrete lining as well as constructing railway tunnel under sulfate attack.

Efficacy of MK615 for the treatment of patients with liver disorders

AIM： To investigate the hepatoprotective effect of MK615, a Japanese apricot extract, in an animal model, and its clinical therapeutic effect. METHODS： Wistar rats were administered physiologi- cal saline （4 mL/kg） or MK615 solution （4 mL/kg） for 7 d. On the sixth d, acute hepatic injury was induced by administering a single intraperitoneal injection （ip） of D-galactosamine hydrochloride （D-GaIN） （600 mg/kg）. Plasma levels of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） were determined, and liver tissues were used for histopathological analy- sis. Fifty-eight patients with liver disorders [hepatitis C （n = 40）, non-alcoholic fatty liver disease （n = 15）, and autoimmune liver disease （n = 3）] were orally admin- istered commercially available Misatol ME-containing MK615 （13 g/d） daily for 12 wk. Blood and urine were sampled immediately before and 6 wk, 12 wk, and 16 wk after the start of intake to measure various bio- chemical parameters. The percentage change in ALT and AST levels after 12 wk from the pre-intake baseline served as a primary endpoint. RESULTS： D-GaIN effectively induced acute hepatic injury in the rats. At 48 h after the ip injection of D-GaIN, the plasma levels of ALT （475.6 ：t： 191.5 IU/L vs 225.3 ＋ 194.2 IU/L, P 〈 0.05） and AST （1253.9：1：223.4 IU/L vs 621.9 ＋ 478.2 IU/L, P 〈 0.05） in the MK615 group were significantly lower than the control group. Scattered single cell necrosis, loss of hepatocytes, and extensive inflammatory cell infiltration were observed in hepatic tissue samples collected from the control group. However, these findings were less pronounced in the group receiving MK615. At the end of the clinical study, serum ALT and AST levels were significantly de- creased compared with pre-intake baseline levels from 103.5 ：l： 58.8 IU/L to 71.8 ＋ 39.3 IU/L （P 〈 0.05） and from 93.5 ：E 55.6 IU/L to 65.5 ＋ 34.8 IU/L （P 〈 0.05）, respectively. A reduction of 〉~ 30% from the pre-study baseline ALT level was observed in 26 （45%） of the 58 patients, while 25 （43%） patients exhibited similar AST level reductions. The chronic hepatitis C group exhibit- ed significant ALT and AST level reductions from 93.4：1： 51.1 IU/L to 64.6 ＋ 35.1 IU/L （P 〈 0.05） and from 94.2 ＋ 55.5 IU/L to 67.2：1：35.6 IU/L （P 〈 0.05）, respective- ly. A reduction of 〉~ 30% from the pre-study baseline ALT level was observed in 20 （50%） of the 40 patients.ALT levels in both the combined ursodeoxycholic acid （UDCA） treatment and the UDCA uncombined groups were significantly lower after Misatol ME administration. MK615 protected hepatocytes from D-GaiN-induced cytotoxicity in rats. Misatol ME decreased elevated ALT and AST levels in patients with liver disorders. CONCLUSION： These results suggest that MK615 and Misatol ME are promising hepatoprotective agents for patients with liver disorders.

Self-recovery ability of stress-damaged salt rock experiment

After being compressed to different plastic deformation stages, the salt rock samples with lateral stress damage of 0.2, 0.3, 0.4, and 0.5 were selected. Ultrasonic technology was used to monitor the wave velocity variation law of stress-dam-aged salt rock during the self-recovery experiment under different temperatures to analyze the influence of initial stress damage and temperature during the self-recovery of salt rock. The experiment shows that the change of salt rock axial wave velocity is smaller than that of lateral wave velocity. The sample ultrasonic velocity is positively correlated with the time of self-recovery, and the damage had been recovered to a certain extent. In the first 200 hours of self-recovery stage, the salt rock lateral damage recovers fast, and then the damage remains almost unchanged. The value of lateral stable damage is positively correlated with the value of lateral initial stress damage. With the increase of temperature, the recovery of lateral damage speeds up and the value of stable damage decreases; the axial damage of salt rock almost remains unchanged during the self-recovery experiment.

Alanyl-glutamine dipeptide inhibits hepatic ischemiareperfusion injury in rats

AIM： To investigate the protective effect and mechanism of alanyl-glutamine dipeptide （Ala-GIn） against hepatic ischemia-reperfusion injury in rats. METHODS： Rats were divided into group C as normal control Group （/7=16） and group G as alanyl-glutamine pretreatment 07=16）. Rats were intravenously infused with 0.9% saline solution in group C and Ala-GIn -enriched （2% glutamine） 0.9% saline solution in group G via central venous catheter for three days. Then all rats underwent hepatic warm ischemia for 30 min followed by different periods of reperfusion. Changes in biochemical parameters, the content of glutathione （GSH） and the activity of superoxide dismutase （SOD） in liver tissue, Bcl-2 and Bax protein expression and morphological changes of liver tissue were compared between both groups. RESULTS： One hour after reperfusion, the levels of liver enzymes in group G were significantly lower than those in group C （P〈0.05）. Twenty-four hours after reperfusion, the levels of liver enzymes in both groups were markedly recovered and the levels of liver enzyme in group G were also significantly lower than those in group C （P〈0.01）. One and 24 h after reperfusion, GSH content in group G was significantly higher than that in group C （P 〈0.05）. There was no statistical difference in activities of SOD between the two groups. One and 24 h after reperfusion, the positive expression rate of Bcl-2 protein was higher in group G than in group C （P〈0.05） and the positive expression rate of Bax protein was lower in group G than in group C （P〈0.05）. Histological and ultrastructural changes of liver tissue were inhibited in group C compared to group G. CONCLUSION： Our results suggest that Ala-GIn pretreatment provides the rat liver with significant tolerance to warm ischemia-reperfusion injury, which may be mediated partially by enhancing GSH content and regulating the expression of Bcl-2 and Bax proteins in the liver tissue.

Response of Two Jerusalem Artichoke (Helianthus tuberosus)Cultivars Differing in Tolerance to Salt Treatment

To explore genetic variability for two Jerusalem artichoke cultivated with 75% seawater irrigation for six years） and N7 （Helianthus tuberosus） cultivars, N1 （the sixth-generation （a general variety）, a experiment was conducted to study the changes in physiological attributes under different concentrations （0%, 10% and 25% of seawater concentration in greenhouse and 0%, 30% and 50% of seawater concentration in the field） of seawater salinity stress. In the greenhouse experiment, decreases of dry growth rate, but increases of dry matter percentage and membrane injury occurred in both the genotypes at 10% and 25% seawater treatments, although lesser cell membrane damage was observed in N1 than N7. N1 accumulated greater contents of Na^＋, Cl^-, soluble sugar and proline in leaves compared with NT. In the field experiment, the yields of shoot, root and tuber, and the contents of total-sugar and inulin in tubers of N1 were higher than those of N7. Lesser degree of salt injury in N1 indicated that the relatively salt-tolerant cultivar had higher K^＋/Na^＋ ratio, lower Na^＋/Ca^2＋ ratio, and the salt-induced enhancement of osmotic adjustment.

Damage model of fresh concrete in sulphate environment

A model of damage to fresh concrete in a corrosive sulphate environment was formulated to investigate how and why the strength of corroded concrete changes over time. First, a corroded concrete block was divided into three regions: an expanded and dense region; a crack-development region; and a noncorroded region. Second, based on the thickness of the surface corrosion layer and the rate of loss of compressive strength of the corroding region, a computational model of the concrete blocks' corrosion-resistance coefficient of compressive strength in a sulphate environment was generated. Third, experimental tests of the corrosion of concrete were conducted by immersing specimens in a corrosive medium for 270 d. A comparison of the experimental results with the computational formulae shows that the calculation results and test results are in good agreement. A parameter analysis reveals that the corrosion reaction plays a major role in the corrosion of fresh concrete containing ordinary Portland cement,but the diffusion of the corrosion medium plays a major role in the corrosion of concrete mixtures containing fly ash and sulphate-resistant cement. Fresh concrete with a high water-to-cement ratio shows high performance during the whole experiment process whereas fresh concrete with a low water-to-cement ratio shows poor performance during the late experiment period.

Ultrasonic testing and microscopic analysis on concrete under sulfate attack and cyclic environment

The damage process of concrete exposed to sodium sulfate attack and drying-wetting cycles was investigated. The water to binder(W/B) ratio and the concentration of sulfate solution were taken as variable parameters. Through the experiment, visual change, relative dynamic modulus of elasticity(RDME) and the surface damage layer thickness of concrete were measured.Furthermore, SEM and thermal analysis were used to investigate the changing of microstructure and corrosion products of concrete.The test results show that the ultrasonic velocity is related to the damage layer of concrete. It approves that an increase in damage layer thickness reduces the compactness and the ultrasonic velocity. The deterioration degree of concrete could be estimated effectively by measuring the surface damage layer and the RDME of concrete. It is also found that the content of gypsum in concrete is less than that of ettringite in test, and some gypsum is checked only after a certain corrosion extent. When the concrete is with high W/B ratio or exposed to high concentration of sulfate solution, the content of ettringite first increases and then decreases with corrosion time. However, the content of gypsum increases at a steady rate. The content of corrosion products does not correspond well with the observations of RDME change, and extensive amount of corrosion products can be formed before obvious damage occurs.

Effect of toll-like receptor 3 agonist poly I:C on intestinal mucosa and epithelial barrier function in mouse models of acute colitis

AIM To investigate potential effects of poly I:C on mucosal injury and epithelial barrier disruption in dextran sulfate sodium (DSS)-induced acute colitis. METHODS Thirty C57BL/6 mice were given either regular drinking water (control group) or 2% (w/v) DSS drinking water (model and poly I:C groups) ad libitum for 7 d. Poly I:C was administrated subcutaneously (20 mu g/mouse) 2 h prior to DSS induction in mice of the poly I:C group. Severity of colitis was evaluated by disease activity index, body weight, colon length, histology and myeloperoxidase (MPO) activity, as well as the production of proinflammatory cytokines, including tumor necrosis factor-a (TNF-alpha), interleukin 17 (IL-17) and interferon-. (IFN-gamma). Intestinal permeability was analyzed by the fluorescein isothiocyanate labeled-dextran (FITC-D) method. Ultrastructural features of the colon tissue were observed under electron microscopy. Expressions of tight junction (TJ) proteins, including zo-1, occludin and claudin-1, were measured by immunohistochemistry/immunofluorescence, Western blot and real-time quantitative polymerase chain reaction (RT-qPCR). RESULTS DSS caused significant damage to the colon tissue in the model group. Administration of poly I:C dramatically protected against DSS-induced colitis, as demonstrated by less body weight loss, lower disease activity index score, longer colon length, colonic MPO activity, and improved macroscopic and histological scores. It also ameliorated DSS-induced ultrastructural changes of the colon epithelium, as observed under scanning electron microscopy, as well as FITC-D permeability. The mRNA and protein expressions of TJ protein, zo-1, occludin and claudin-1 were also found to be significantly enhanced in the poly I:C group, as determined by immunohistochemistry/immunofluorescence, Western blot and RT-qPCR. By contrast, poly I:C pretreatment markedly reversed the DSS-induced up-regulated expressions of the inflammatory cytokines TNF-alpha, IL-17 and IFN-gamma. CONCLUSION Our study suggested that poly I:C may protect against DSS-induced colitis through maintaining integrity of the epithelial barrier and regulating innate immune responses, which may shed light on the therapeutic potential of poly I:C in human colitis.

Friction and Wear Behaviors of Nano-Silicates in Water

Nano-metric magnesium silicate and zinc silicate with particle size of about 50-70nm were prepared in water by the method of chemical deposition. The antiwear and friction reducing abilities of the nano-silicates, as well as their composites with oleic acid tri-ethanolamine （OATEA）, were evaluated on a four-ball friction tester. The topographies and tribochemical features of the worn surfaces were analyzed by scanning electron microscope （SEM） and X-ray photoelectron spectroscope （XPS）. Results show that nano-silicates alone provide poor antiwear and friction reducing abilities in water, but exhibits excellent synergism with OATEA in reducing friction and wear. The synergism in reducing friction and wear between nano- silicates and OATEA does exist almost regardless of particte sizes and species, and may be attributed, on one hand, to the formation of an adsorption film of OATEA, and, on the other hand, to the formation oftribochemical species of silicon dioxide and iron oxides on the friction surfaces. Tribo-reactions and tribo-adsorptions of nano-silicates and OATEA would produce hereby an effective composite boundary lubrication film, which could efficiently enhance the anti-wear and friction-reducing abilities of water.

Acetaminophen-induced hepatotoxicity in rats is correlated with the accumulation of bile acids: an underlying mechanism

In the present study, we aimed to investigate the underlying mechanism of acetaminophen（APAP）-induced hepatotoxicity by measuring the expression levels of liver transporters and concentrations of bile acids（BAs） in rat plasma and liver. SD rats（42） were randomly assigned into six groups, including 6-h control group, APAP 6-h group, 12-h control group, APAP 12-h group, 24-h control group and APAP 24-h group. The estimation study of BAs in plasma and liver was performed on LC-MS/MS. The levels of bile salt export pump（Bsep）, multidrug resistant protein 2（Mrp2）, multidrug resistant protein 4（Mrp4）, Na＋/taurocholate cotransporting polypeptide（Ntcp） and organic anion transporting polypeptide 2（Oatp2） in the liver were analyzed by Western blotting analysis. Compared with the corresponding control groups, no difference was found in the BA levels and the expressions of BA transporters in the plasma and liver after 6 h of APAP administration. While BA levels were significantly decreased in the plasma and increased in the liver after 12 h of APAP administration（P0.05）; and the expressions of Bsep and Mrp2 were significantly reduced（P0.05）. After 24 h of APAP administration, BA levels were both greatly increased in the plasma and liver（P0.05）; and the expressions of Mrp4 and Oatp2 were significantly decreased（P0.05）. In response to over-dose APAP, Bsep, Mrp2, Mrp4 and Oatp2 levels were reduced at different time points, causing the accumulation of BAs, and such accumulation may ultimately lead to the severe liver injury, which could be an underlying mechanism of the APAP-induced hepatotoxicity.

Normal saline for intravenous fluid therapy in critically ill patients

The efficacy and safety of normal saline （HS） for fluid therapy in critically ill patients remain controversy. In this review, we summarized the evidence of randomized controlled trials （RCTs） which compared NS with other solutions in critically ill patients. The results showed that when compared with 6% hydrox- yethyl starch （HES）, NS may reduce the onset of acute kidney injury （AKI）. However, there is no significant different in mortality and incidence of AKl when compared with 10% HES, albumin and buffered crystalloid solution. Therefore, it is important to prescribe intravenous fluid for patients according to their individual condition.

Controlled fabrication and electrical-magnetic properties of Poly(OT-co-AN)/Ba_(0.8)La_(0.2)Al_2Fe_(10)O_(19) composites

Poly（OT-co-AN）/Ba0.8La0.2Al2Fe10O19 （Poly（OT-co-AN）/BLAF） composites were fabricated by in situ polymerization method. It was investigated that of mass rate of momomer （mor/mAN）, polymeration temperature and time, and feeding ratio of BLAF effect on the structures, morphology, conductivity, magnetic property of composites by the orthogonal optimum design. The results indicated that poly （OT-co-AN） copolymer had a better coating on BLAF particles, and there were some interactions between components in the composites. The magnetic properties of the composites were related to content of the magnetic BLAF particles in it. The feeding ratio of BLAF had a significant influence on constitute and conductivity of the composites, followed by the temperature. The reflection loss and the effective bandwidth of composites for electromagnetic wave were at- tributed to the synergistic effect between poly（OT-co-AN） and BLAF. The poly（OT-co-AN）/BLAF composites with mass ratio of BLAF to mix monomer （moT^mAN =1：1） equal to 5/1 at 10 h in 25~C had a maximum synergistic effect between its compo- nents, showed a maximum reflection loss of -26.94 dB at 14.10 GHz and an available bandwidth of 8.54 GHz. It was sug- gested that the composites can be used as a advancing absorption and shielding materials for electromagnetic wave due to their favorable microwave absorption properties.

Recognition of specific types of drug-induced liver injury using random forest algorithm:the importance of individual serum bile acid level

Drug-induced liver injury(DILI)is associated with an imbalance in the homeostasis of bile salts(BAs).However,a clear connection between BAs and different types of DILI remains to be established.In the present study,random forest(RF)machine learning prediction systems were deployed with 17 individual BAs for categorizing DILI.BAs were analyzed via LC-MS/MS in the serum using the model of seven known hepatotoxins(isoniazid,acetaminophen,bendazac,17α-ethinylestradiol,1-naphthylisothiocyanate,tetracycline,and ticlopidine),which caused cholestasis,steatosis,and necrosis in rats.The RF model was validated via leave-one-out cross-validation.The importance of each individual BA with respect to prediction ability was determined.The RF model achieved the best prediction performance,producing accuracy values of 0.98,0.97,and 1.00 for leave-one-out cross-validation,the training set,and the external test set,respectively.The order of descriptor‟s importance was obtained,which was TUDCA>GUDCA>TCA>THDCA.The specificity values for necrosis,cholestasis,and steatosis were 0.94,1.00,and 1.00,respectively.The results indicated the potential value of individual BA level in serum for categorizing DILI.The RF model in the present work was an inexpensive and readily available tool for categorizing DILI.