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We established a rapid detection method based on recombinant enzyme polymerase amplification (RPA) for the simultaneous detection and identification of Actinobacillus pleuropneumoniae (A. pleuropneumoniae) and Streptococcus suis (S. suis). A pair of primers and corresponding probes were designed for the glutamate dehydrogenase (gdh) gene of S. suis and the ApxIV gene of A. pleuropneumoniae to establish a dual RPA-LFD detection method for the rapid identification of S. suis and A. pleuropneumoniae. The specificity test showed that the amplification results for Pasteurella, E. coli, Salmonella, S. aureus, H. parasuis and A. hydrophila were all negative, indicating the good specificity of the method. The sensitivity test showed that the lowest nucleic acid concentration that was detectable with this method was 10− 5 ng/µL, which was significantly higher than that of PCR and RPA-Basic. S. suis and A. pleuropneumoniae reference strains, clinical isolates and 45 clinical lung tissue samples were detected with this method. The results showed that this method detected all reference strains and clinical isolates, which was consistent with the PCR detection results. Among the 45 clinical samples, 19 cases of S. suis and 1 case of A. pleuropneumoniae were detected, and there were no mixed infections. The detection rate was higher than that of bacterial isolation and the conventional PCR method, indicating that this method is very practical and suitable for the rapid clinical detection of S. suis and A. pleuropneumoniae. Compared with the traditional method, the dual RPA-LFD method has several advantages including a high specificity, high sensitivity, fast speed (detection time of 20 min) and minimal requirement for instruments and equipment; in addition, the method can realize the synchronous and rapid detection of S. suis and A. pleuropneumoniae and is helpful for the preliminary screening of clinical diseases.

Aiming at the defects of traditional curing agent in strengthening soft clay, a new type of inorganic binder type soil curing agent has been developed. Compared with P.O 42.5 cement, the new soil stabilizer has smaller fineness and larger specific surface area. The strength of the soil solidified by the new curing agent is lower at the initial stage, but it increases rapidly after 24 hours. When the dosage is 10%, the 28-day strength of the soil solidified by the new curing agent is 2.1 times that of the soil solidified by cement. The soil solidified by the new curing agent can form more calcium hydroxide crystals and hydrated calcium silicate gel with more compact structure. After solidification, there are fewer fine particles in the soil.

Despite its widespread applications in geology, all osmium isotope ratio measurements are either uncalibrated or rely on the veracity of the uncalibrated 1937 Nier values by adopting them as normalizing constants typically in conjunction with an exponential mass bias correction model. In this study, isotope ratios of osmium were determined in six commercial osmium materials, including the DROsS standard and a new NRC isotopic osmium reference material OSIS-1, by MC-ICPMS. We use a previously optimized and validated regression mass bias correction model to correct instrumental isotope fractionation effects which does not rely either on Nier’s values or on a strictly mass-dependent behavior of the isotopes. Deviations from mass-dependent fractionation (mass independent fractionation) were observed for osmium isotopes in MC-ICPMS with the most dramatic effect occurring for 187Os, wherein, on average, close to half-percent bias in the isotope ratio 187Os/188Os was observed as a result of imposing Russell’s law.

A novel and automated flow injection (FI) system using a commercially available anion-exchange resin was developed for the online determination of rhenium in seawater by inductively coupled plasma–mass spectrometry (ICP–MS). The flow rate, reagent concentration, and sample volume were optimized. The rhenium concentration was determined using the integrated peak area through interpolation of standard addition calibration curves. The relative standard deviation was less than 2.45% (n = 5), the recoveries were from 94.59 to 104.11%, and the linear dynamic range of the method was up to 998 ng kg−1. There was a good agreement between the rhenium concentrations in a standard measured in this work with results from previous studies. The limit of detection was 0.11 ng kg−1 for a sample volume of 7.5 mL and one cycle required 8.33 min. The developed FI–ICP–MS method was used to determine rhenium in seawater from the Jiulong River Estuary and Taiwan Strait.

In order to ensure the feasibility and economy of the construction scheme of cement mixing piles for track foundation, a cement-soil indoor mix ratio test was carried out. Selected ordinary Portland cement and sulfate-resistant cement, groundwater and tap water, three mixing ratio experiments were carried out. The experimental study found that the cement-soil has high strength, which can fully meet the bearing capacity requirements of the track foundation, and the cement content can be appropriately reduced. The strength of the solidified soil increases with the increase of the cement content, and the groundwater has no adverse effect on the strength of the cement-soil. The strength of solidified soil with P.HSR 42.5 cement is not significantly higher than that of P.O42.5 cement. Even in BDQ1 and BD4 track foundations, the strength of solidified soil with P.O42.5 cement is significantly higher than that of P.O42.5 cement.

Temperature and relative humidity affect the test of geomembrane. Here, using mathematical statistics, we analyzed the influence of temperature and relative humidity during state regulation and test on the results. The test data of geomembrane were obtained by changing the temperature and relative humidity ranging from 18°C to 25°C and from 50% to 70% respectively. Variation characteristics of discreteness and numerical value of test results with temperature and relative humidity are obtained by statistical analysis method. The results show that the influence of temperature and relative humidity on the test results stability is the change of numerical value and distribution characteristics. Under different temperature and relative humidity, the coefficient of variation of the test value of mass per unit area is 3.4% ∼ 4.1%, and the coefficient of variation of average value is 0.3%, which shows good stability; the coefficient of variation of thickness test value is 2.9% ∼ 7.0%, and the coefficient of variation of average value is 6.8%, and the value decreases with the increase of temperature.

The temperature and humidity of conditioning and test environment are one of the important factors affecting the test results of geosynthetics. The raw materials of geosynthetics are various, and the manufacturing processes are different, so the sensitivity to temperature and humidity is quite different. Determining reasonable temperature and humidity control requirements are of great significance to the quality control of geosynthetics. In order to grasp the status quo of temperature and humidity control in geosynthetics testing, a statistical analysis was carried out on the temperature and humidity control requirements in 55 geosynthetics tests and product standards, and the temperature and humidity control status of 29 laboratories were investigated.

Using mathematical statistics, we analyzed the influence of temperature and relative humidity during test on the results. The test data of geomembrane were obtained by changing the temperature and relative humidity ranging from 18°C to 25°C and from 50% to 70% respectively. The results show that under different temperature and humidity, the coefficient of variation of the maximum tensile test value is 8.0%∼17.4%, and the coefficient of variation of average value is 6.7%, which is poor in stability; the coefficient of variation of the test value of elongation at break is 4.7% ∼ 11.7%, and the coefficient of variation of average value is 4.6%, and the value increases with increasing temperature; the coefficient of variation of right angle tear strength is 6.0% ∼ 20.7%, and the coefficient of variation of average value is 6.4%; the coefficient of variation of puncture strength test value is 4.2% ∼ 7.3%, and the coefficient of variation of average value is 6.1%, and the value decreases with the increase of temperature. These results will shed light on analyzing the influence of temperature and humidity on the mechanical test results of geomembrane and determining a reasonable temperature and humidity control range for geomembrane testing.

Based on the particle analysis, mineral composition analysis and chemical composition analysis of the flowing mud in Shenzhen port, it is found that the flowing mud in Shenzhen port has fine particles, a lot of colloidal particles, and an obvious increase of colloidal particles after salt washing. The clay mineral content is large, and the highest content is I/M mixed layer, which makes the flowing mud have higher plasticity, greater compressibility and lower permeability. The content of Cl− and Na+ +K+ in the mud of Shenzhen port is high, which belongs to Cl− -Na+ type, which has strong corrosiveness to steel and medium corrosiveness to concrete .

Like many other elements, iridium is lacking a calibrated, SI traceable isotope ratio measurement. In this study we have undertaken absolute isotope amount ratio measurements of iridium by MC-ICPMS using a state-of-the-art regression model to correct for the instrumental fractionation (mass bias) of isotope ratios using both NIST SRM 997 isotopic thallium and NIST SRM 989 isotopic rhenium as primary calibrators. The optimized regression mass bias correction model is based on incrementally increasing plasma power and short (10–30 min) measurement sessions. This experimental design allows fast implementation of the regression method which would normally require hours-long measurement sessions when executed under constant plasma power. Measurements of four commercial iridium materials provide a calibrated iridium isotope ratio R193/191 = 1.6866(6)k=1 which corresponds to isotopic abundance x191 = 0.372 21(8)k=1 and an atomic weight of Ar(Ir) = 192.217 63(17)k=1. In addition, we present data on a new Certified Reference Material from NRC Canada IRIS-1 which fulfills the requirements of a delta zero reference for iridium isotope ratio measurements.

In order to analyze the special engineering properties of the super soft dredger fill, experimental studies had been done on the physical-mechanical properties of that in Shenzhen, especially for its consolidation properties. The test results indicated that the super soft dredger fill had the properties of high water content, high void ratio and high clay content; When the confining pressure applied to the sample was less than 200kPa, the change of deformation and void ratio of it was more obvious; When the confining pressure applied to the sample was less than 80kPa, the chang of permeability coefficient of that was more significant.

Based on static load test results, with consideration of the small-strain stiffness characteristic of soils, the bearing capacity of bored piles with pile-toe and pile-shaft post-grouting have been analyzed using HS-small model and HS model of Plaxis program. The analysis reveals that: the small-strain stiffness of soil is not negligible in analyzing pile and soil interaction; with post-grouting, the interface between pile and surrounding soil are strengthened and the performance of bored pile is improved with increased bearing capacity and reduced settlement.

Using the hierarchical clustering method, we present comprehensive analyses of water masses and their seasonal variations based on substantial in situ observations in the eastern Beibu Gulf, a shallow sea with a depth mostly less than 100 m. Besides traditional physical parameters (salinity and temperature), chemical and biological parameters are also used for the water mass classification and analyses, which include dissolved oxygen, alkalinity, nitrite, reactive silicate, and chlorophyll a. Consequently, the eastern Beibu Gulf water is classified into five water masses in the study area, namely the diluted water, the mixed water, the surface water, the subsurface water, and the bottom water. The diluted water is located in the area along the Guangxi coast; the mixed water mainly occupies the northern study area; the surface water resides in the central and southern study area; the subsurface water exists just near the Gulf mouth; and the bottom water appears in the lower layer east of Bailongwei Island, which is different from the Beibu Gulf cold water mentioned in previous studies. The parameter properties and spatial distribution of most water masses in the eastern Beibu Gulf exhibit strong seasonal variability which is mainly modulated by circulations and solar radiation.

A one‐pot and convenient synthesis of multisubstituted pyrazolo[3,4‐b]pyridines in moderate to high yields has been achieved by a two‐step reaction: diazo‐transfer of 5‐azido‐1‐phenylpyrazole‐4‐carboxaldehydes to ketones in ethanolic KOH to give 5‐amino‐1‐phenylpyrazole‐4‐carboxaldehyde and subsequent Friedlaender reaction of 5‐amino‐1‐phenylpyrazole‐4‐carboxaldehyde with ketones.

A facile synthesis of isoindolo[2,1-a]quinolin-11-one has been developed to attain new molecules of this family via [4+2] reactions of N-acyliminium cation, produced from 2,3-dihydro-3-hydroxy-2-arylisoindol-1-one, in the presence of BF3·OEt2 with olefins in moderate to good yields at ambient temperature.

Marine colloids could be an important source of nitrogen for bacteria and photoplankton. But elevated concentration of colloids may stimulate algal growth and lead to red tides in coastal waters. The effects of colloidal organic carbon (COC) concentration on the growth of photosysthetic bacteria (PSB) were investigated under different colloidal treatments in the laboratory. The PSB growth was inversely proportional to COC concentration and was restricted by high-molecular-weight (HMW) colloids (10 KDa) in treatments with non-nutrient or just inorganic nutrient with low COC concentration (or = 5 microMC). However, the PBS growth was enhanced in the presence of HMW colloids in the treatment with inorganic nutrient and high COC (127 and 255 microMC) or with both inorganic nutrient and low-molecular-weight organic matter. Both bacteria number and bacteria growth ratio increased significantly when the concentration of COC wasor = 5 microMC. Our results suggest that marine colloids can be utilized by bacteria and might regulate primary productivity in coastal waters.