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Two new together with 32 known compounds were isolated from the leaves of Lycium barbarum . Their structures were elucidated using 1D and 2D NMR, HRESIMS, and ECD spectroscopic techniques. Compounds 1–34 were evaluated for their anti-rheumatoid arthritis activities in a lipopolysaccharide (LPS)-induced MH7A cells inflammatory model. As a result, compounds 1– 3 , 6 , 8 , 10 , 14 , 17–19 , 29 and 31 inhibited the activity of lactate dehydrogenase (LDH) and nitric oxide (NO) at concentrations 20 μM. Among them, compound 1 showed the best effectiveness, with inhibition rates of 46.7% for NO and 32.8% for LDH. Graphical Abstract

In this work the fluctuating-lattice Boltzmann method was adopted to numerically investigate the Brownian motion of particles in a fluid with inhomogeneous temperature field. It has been found that the Brownian particles are preferential to randomly move into a cold fluid area. Once the particles go into the cold area, the boundary between the hot fluid and cold fluid acts like a temperature barrier, preventing the particles from going out. Most important of all, the Brownian particles can be captured or collected by the cold fluid area if the temperature of cold fluid is lower than a critical value. In addition, the dependence of this critical value on the fluid viscosity is studied.

Identification of precursory characteristics is a key issue for rock burst prevention. The aim of this research is to provide a reference for assessing rock burst risk and determining potential rock burst risk areas in coal mining. In this work, the microseismic multidimensional information for the identification of rock bursts and spatial–temporal pre-warning was investigated in a specific coalface which suffered high rock burst risk in a mining area near a large residual coal pillar. Firstly, microseismicity evolution prior to a disastrous rock burst was qualitatively analysed, and the abnormal clustering of seismic sources, abnormal variations in daily total energy release, and event counts can be regarded as precursors to rock burst. Secondly, passive tomographic imaging has been used to locate high seismic activity zones and assess rock burst hazard when the coalface passes through residual pillar areas. The results show that high-velocity or velocity anomaly regions correlated well with strong seismic activities in future mining periods and that passive tomography has the potential to describe, both quantitatively and periodically, hazardous regions and assess rock burst risk. Finally, the bursting strain energy index was further used for short-term spatial–temporal pre-warning of rock bursts. The temporal sequence curve and spatial contour nephograms indicate that the status of the danger and the specific hazardous zones, and levels of rock burst risk can be quantitatively and rapidly analysed in short time and in space. The multidimensional precursory characteristic identification of rock bursts, including qualitative analysis, intermediate and short-time quantitative predictions, can guide the choice of measures implemented to control rock bursts in the field, and provides a new approach to monitor and forecast rock bursts in space and time.

Temporal stability analysis of fiber suspended shear flow is performed. After introducing the second order structure tensor to determine the Folgar-Tucker inter-fiber interactions based on the Langevin?s equation, a system governing the flow stability is derived in conjunction with the fiber orientation closure. Effect of the inter-fiber interactions on the dynamic stability is studied by solving the general eigenvalue problem. Results show that fiber interaction has significant stabilizing effects on the flow. The most unstable wave number changes with the interaction coefficient. For given interaction coefficient, wave number and other relevant parameters, there is a Re number which corresponds to the critical flow. This Re number is related to the wave number. nema

A better understanding of rockburst precursors and high stress distribution characteristics can allow for higher extraction efficiency with reduced safety concerns. Taking the rockburst that occurred on 30 January 2015 in the Sanhejian Coal Mine, Jiangsu Province, China, as an example, the mechanism of rockburst development in a roadway was analysed, and a combined method involving b values and seismic velocity tomography was used to assess the rockburst in both time and space, respectively. The results indicate that before the rockburst, b values dropped significantly from 0.829 to 0.373. Moreover, a good agreement between a significant decrease in b values and the increase of the number of strong tremors was found. Using seismic tomography, two rockburst risk areas were determined where the maximum velocity, maximum velocity anomaly and maximum velocity gradient anomaly were 6 km/s, 0.14 and 0.13, respectively. The high-velocity regions corresponded well with the rockburst zone and large seismic event distributions. The combination of b values and seismic tomography is proven to have been a promising tool for use in evaluating rockburst risk during underground coal mining.

To investigate the effect of high temperature ageing on the microstructure and mechanical properties of S31042steel,solid solution treatment at 700℃ was carried out for various time from 10to 6 000h.Experimental results showed that the change of mechanical properties is closely related to the amount of precipitated phases.During ageing from 10to 300h,precipitation in the tested steel increases rapidly,and correspondingly,the high temperature yield strength and room temperature hardness of tested steel increase rapidly.Meanwhile,the thickness of the secondary phase on grain boundaries widens sharply and the room temperature Charpy impact absorb energy decreases.Ageing beyond 300h,the precipitation in the steel increases gradually and the precipitates coarsen to a certain extent.The high temperature yield strength of the steel keeps stable,and the room temperature Charpy impact energy and hardness decrease slowly.Ageing beyond 3 000h,the mechanical properties of the steel tend to be stable.The main precipitates are M23C6,NbCrN and NbC in the tested steel.

This paper introduces measurement principle, structure and technical indicators of the fullbore turbine flowmeter, presents application examples and measurement results in Daqing oilfield, analyzes and discusses the result chart of measurement, and puts forward relevant insights on the flowmeter.

In this study, 12 crude oil samples were collected and analyzed from the Ordovician reservoir in the Ha- lahatang Depression, Tarim Basin, China. Although the density of oil samples varies considerably, based on saturated hydrocarbon gas chromatographic （GC）, saturated and aromatic hydrocarbon gas chromatographic-mass spectromet- ric （GC/MS） and stable carbon isotopic composition analyses, all the samples are interpreted to represent a single oil population with similar characteristics in a source bed or a source kitchen, organic facies and even in oil charge his- tory. The co-existence of a full suite of n-alkanes and acyclic isoprenoids with UCM and 25-norhopanes in the crude oil samples indicates mixing of biodegraded oil with fresher non-hiodegraded oil in the Ordovician reservoir. More- over, according to the conversion diagram of double filling ratios for subsurface mixed crude oils, biode- graded/non-biodegraded oil ratios were determined as in the range from 58/42 to 4/96. Based on oil density and oil mix ratio, the oils can be divided into two groups： Group 1, with specific density 〉0.88 （g/cm3） and oil mix ratio 〉1, occurring in the north of the Upper Ordovician Lianglitage and Sangtamu Formation pinchout lines, and Group 2, with specific density 〈0.88 （g/cm3） and oil mix ratio 〈1, occurring in the south of the pinchout lines. Obviously, Group 2 oils with low densities and being dominated by non-biodegraded oils are better than Group 1 oils with re- spect to quality. It is suggested that more attention should be paid to the area in the south of the Upper Ordovician Lianglitage and Sangtamu Formation pinchout lines for further exploration.

The study of snow and ice melt （SIM） is important in water-scarce arid regions for the assessment of water supply and quality. These studies involve unique difficulties, especially in the calibration of hydro-models because there is no direct way to continuously measure the SIM at hydrostations. The recursive digital filter （RDF） and the isotopic hydro-geochemical method （IHM） were coupled to separate the SIM from eight observed series of alpine streamflows in northwestern China. Validation of the calibrated methods suggested a good capture of the SIM characteristics with fair accuracy in both space and time. Applications of the coupled methods in the upper reaches of the Hei River Basin （HRB） suggested a double peak curve of the SIM fraction to streamflow for the multi-component recharged （MCR） rivers, while a single peak curve was suggested for the rainfall-dominant recharged （RDR） rivers. Given inter-annual statistics of the separation, both types of the alpine rivers have experienced an obvious decrease of SIM since 196os. In the past 10 years, the SIM in the two types of rivers has risen to the levels of the 1970s, but has remained lower than the level of the 1960s. The study provided a considerable evidence to quantify the alpine SIMbased on the separation of observed data series at gauge stations. Application of the coupled method could be helpful in the calibration and validation of SIM-related hydro-models in alpine regions.

Gingival adenoid cystic carcinoma （ACC） is a rare malignancy： We describe the diagnosis and treatment of a 43 yearold woman who presented with a persistent oral ulcer for approximately 1 year, and subsequent pain in the left posterior maxillary region. Clinical examination revealed an ulcer in the left upper molar gingiva, with swelling in the region from the second premolar to the third molar. X-ray images demonstrated the involvement of the maxillary alveolar bone. The histopathological and immunohistochemical features were diagnostic of ACC. ACC is often presented as a gingival lesion; thus, it may easily be neglected by patients. The identification of this tumor using specific pathological analyses prevents misdiagnosis and enables clinicians to determine the appropriate treatment. In this case, no recurrence or distant metastasis was observed after 2 years of follow-up.