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Vision-language navigation is a task that requires an agent to follow instructions to navigate in environments. It becomes increasingly crucial in the field of embodied AI, with potential applications in autonomous navigation, search and rescue, and human-robot interaction. In this paper, we propose to address a more practical yet challenging counterpart setting - vision-language navigation in continuous environments (VLN-CE). To develop a robust VLN-CE agent, we propose a new navigation framework, ETPNav, which focuses on two critical skills: 1) the capability to abstract environments and generate long-range navigation plans, and 2) the ability of obstacle-avoiding control in continuous environments. ETPNav performs online topological mapping of environments by self-organizing predicted waypoints along a traversed path, without prior environmental experience. It privileges the agent to break down the navigation procedure into high-level planning and low-level control. Concurrently, ETPNav utilizes a transformer-based cross-modal planner to generate navigation plans based on topological maps and instructions. The plan is then performed through an obstacle-avoiding controller that leverages a trial-and-error heuristic to prevent navigation from getting stuck in obstacles. Experimental results demonstrate the effectiveness of the proposed method. ETPNav yields more than 10% and 20% improvements over prior state-of-the-art on R2R-CE and RxR-CE datasets, respectively. Our code is available at https://github.com/MarSaKi/ETPNav., Comment: Project page: https://github.com/MarSaKi/ETPNav

With the emergence of varied visual navigation tasks (e.g, image-/object-/audio-goal and vision-language navigation) that specify the target in different ways, the community has made appealing advances in training specialized agents capable of handling individual navigation tasks well. Given plenty of embodied navigation tasks and task-specific solutions, we address a more fundamental question: can we learn a single powerful agent that masters not one but multiple navigation tasks concurrently? First, we propose VXN, a large-scale 3D dataset that instantiates four classic navigation tasks in standardized, continuous, and audiovisual-rich environments. Second, we propose Vienna, a versatile embodied navigation agent that simultaneously learns to perform the four navigation tasks with one model. Building upon a full-attentive architecture, Vienna formulates various navigation tasks as a unified, parse-and-query procedure: the target description, augmented with four task embeddings, is comprehensively interpreted into a set of diversified goal vectors, which are refined as the navigation progresses, and used as queries to retrieve supportive context from episodic history for decision making. This enables the reuse of knowledge across navigation tasks with varying input domains/modalities. We empirically demonstrate that, compared with learning each visual navigation task individually, our multitask agent achieves comparable or even better performance with reduced complexity., Comment: Accepted to NeurIPS 2022; Code: https://github.com/hanqingwangai/VXN

Inflammation plays a key role in the pathogenesis of depression and antidepressant therapies. Astragalin (AST) is a bioactive flavonoid that possesses an anti-inflammatory property. However, the antidepressant action of astragalin has not been addressed. In this study, we explored the antidepressant effects of astragalin and its underlying mechanism. Our results showed that AST significantly improved the behavioral defects in chronic unpredictable mild stress (CUMS) model, promoted SIRT1 expression, and decreased the protein levels of NF-κB p65, NLRP3, cleaved capase-1, cleaved IL-1β and cleaved gasdermin D in the hippocampus. Immunohistochemistry revealed AST mitigated CUMS-induced microglia overactivation. In vitro, AST profoundly increased the cell viability in lipopolysaccharides (LPS) and adenosine triphosphate (ATP) treated BV2 cells, with upregulated SIRT1 expression and downregulated protein levels of nuclear NF-κB p65, NLRP3, cleaved capase-1, and cleaved gasdermin D. Declined cleavage of gasdermin D was observed after AST administration in immunocytochemistry. Nevertheless, the in vivo and in vitro effects of AST were compromised by SIRT1 inhibitor EX-527. These results indicated that AST possessed an antidepressant property, which was dependent on SIRT1 signaling modulated NLRP3 inflammasome deactivation.

Background The NLRP3-mediated pyroptosis, which could be regulated by miRNA-27a, is a key player in the development of depression. Isoliquiritin is a phenolic flavonoid compound that has been demonstrated to suppress NLRP3-mediated pyroptosis. However, it is still unknown whether isoliquiritin could confer antidepressant activity via decreasing NLRP3-mediated pyroptosis by stimulating miRNA-27a. Thus, in the current study, we explored the antidepressant activity of isoliquiritin and its underlying mechanism. Methods Expression of miRNA-27a in depressed patients or mice was measured using qRT-PCR. Luciferase reporter assay was performed to illustrate the link between miRNA-27a and SYK. Lipopolysaccharide (LPS) and chronic social defeat stress (CSDS) depression models were established to investigate the antidepressant actions of isoliquiritin. Changes in miRNA-27a/SYK/NF-κB axis and NLRP3-mediated pyroptosis were also examined. The role of miRNA-27a in isoliquiritin-related antidepressant effect was further investigated by using miRNA-27a inhibitors and mimics of miRNA-27a. Results Our results showed the miRNA-27a expression was downregulated in the serum of depressed patients, and decreased serum and hippocampus expression of miRNA-27a were observed in rodent models of depression. SYK gene expression was significantly reduced by miRNA-27a mimic incubation. Isoliquiritin profoundly attenuated LPS or CSDS-induced depressive symptoms, as well as CSDS-induced anxiety behavior. In the hippocampus, LPS and CSDS decreased miRNA-27a mRNA expression; increased the protein levels of SYK, p-NF-κB, and NLRP3: cleaved Caspase-1, IL-1β, and GSDMD-N: and elevated the concentration of IL-1β, IL-6, and TNF-α, which were all restored by isoliquiritin administration. Meanwhile, isoliquiritin upregulated the hippocampal NeuN protein level, improved the survival and morphology of neurons, and decreased pyroptosis-related neuronal cell death. Moreover, isoliquiritin protected primary microglia against LPS and adenosine triphosphate (ATP) elicited NLRP3 inflammasome activation in vitro, evidenced by declined protein levels of p-NF-κB, NLRP3; cleaved Caspase-1, IL-1β, and GSDMD-N; upregulated miRNA-27a mRNA expression; and decreased the mRNA and protein levels of SYK. Nevertheless, miRNA-27a inhibitors significantly reversed isoliquiritin-generated therapeutic efficacy in CSDS mice and in vitro. Furthermore, the cytoprotective effect of isoliquiritin was similar to that of miRNA-27a mimics in LPS and ATP-treated primary microglia. Taken together, these findings suggest that isoliquiritin possesses potent antidepressant property, which requires miRNA-27a/SYK/NF-κB axis controlled decrease of pyroptosis via NLRP3 cascade.

Vision-language navigation (VLN) is the task of entailing an agent to carry out navigational instructions inside photo-realistic environments. One of the key challenges in VLN is how to conduct a robust navigation by mitigating the uncertainty caused by ambiguous instructions and insufficient observation of the environment. Agents trained by current approaches typically suffer from this and would consequently struggle to avoid random and inefficient actions at every step. In contrast, when humans face such a challenge, they can still maintain robust navigation by actively exploring the surroundings to gather more information and thus make more confident navigation decisions. This work draws inspiration from human navigation behavior and endows an agent with an active information gathering ability for a more intelligent vision-language navigation policy. To achieve this, we propose an end-to-end framework for learning an exploration policy that decides i) when and where to explore, ii) what information is worth gathering during exploration, and iii) how to adjust the navigation decision after the exploration. The experimental results show promising exploration strategies emerged from training, which leads to significant boost in navigation performance. On the R2R challenge leaderboard, our agent gets promising results all three VLN settings, i.e., single run, pre-exploration, and beam search., Comment: ECCV2020 (changed with improved perfromance on Pre-Explore and Beam Search settings); website: https://github.com/HanqingWangAI/Active_VLN

Introduction Different parts of Sophora alopecuroides L. (Fabaceae) have historically been used in traditional Chinese medicine for the treatment of dysentery and enteritis. This plant is also utilised as an important resource for industrial preparation of quinolizidine alkaloidal pharmaceuticals. Objective Establish a reliable, simple and fast analytical method for the quantitative determination of the quinolizidine-type alkaloids and extend understanding of the metabolism of quinolizidine-type alkaloids in S. alopecuroides. Methods Hydrophilic interaction chromatography coupled with triple-quadrupole tandem mass spectrometry (HILIC-TQ-MS/MS) in multiple-reaction monitoring (MRM) mode were used to determine seven quinolizidine-type alkaloids and their biosynthetic precursor, lysine, in S. alopecuroides. Results A good separation was obtained on an ultra high-performance liquid chromatography (UHPLC) amide column within 7 min. The overall limits of detection (LODs) were between 1.13 and 2.81 ng/ml, and limits of quantitation (LOQs) were between 3.80 and 8.48 ng/ml. The developed method was successfully applied to 21 samples of S. alopecuroides. The seeds had the highest concentration of alkaloids among the different plant parts. Oxymatrine and oxysophocarpine were the two most abundant alkaloids in all of the different parts and at different phenological growth stages. The contents of quinolizidine alkaloids showed correlations with lysine. Conclusion A rapid and sensitive analytical method was established for the simultaneous determination of seven quinolizidine-type alkaloids and their biosynthetic precursor, lysine, in S. alopecuroides; the content of lysine may be used as a marker to predict alkaloid production.

Quinolizidine alkaloids are the main bioactive components in Sophora alopecuroides L. This study reports a novel ultrasound-assisted enzymatic hydrolysis method for the extraction of these important alkaloids. Box-Behnken design, a widely used response surface methodology, was used to investigate the effects of process variables on ultrasound bath-assisted enzymatic hydrolysis (UAEH) extraction. Four independent variables, pH, extraction temperature (°C), extraction time (min) and solvent-to-material ratio (mL/g), were studied. For the extraction of sophocarpine, oxysophocarpine, oxymatrine, matrine, sophoramine, sophoridine and cytisine, the optimal UAEH condition was found to be a pH of 5, extraction temperature of 54 °C, extraction time of 60 min and solvent-to-material ratio of 112 mL/g. The experimental values obtained under optimal conditions were fairly consistent with the predicted values. UAEH extraction was then compared with reflux heating, enzymatic extraction and ultrasound-assisted extraction. Of these extraction methods, UAEH extraction under optimal conditions produced the highest yield for seven types of alkaloids. In addition, UAEH extraction resulted in lower ingredient degradation than reflux heating extraction.

Licorice is known as a botanical source in medicine and a sweetening agent in food products. Commercial licorice is from the source of wild and cultivated G. uralensis. It was recognized that the material basis of wild and cultivated licorice is different. This study systematically investigated the difference between them by multidimensional analysis technology. The results showed that the content of starch grain, total dietary fibre (TDF), and 11 secondary metabolite components was significantly different in wild and cultivated licorice. principal component analysis (PCA) and orthogonal partial least square (OPLS-DA) analyses showed that the wild and cultivated licorice samples could be clearly separated based on the acquired data of microscopic, macromolecular substance and secondary metabolite analysis. The main markers were starch grain, isoliquiritin apioside, liquirtin apioside and TDF. Additionally, NIR spectroscpy combined with PLS-DA has demonstrated a suitable, fast and nondestructive methodology for authentication of wild and cultivated licorice.

Capillary number theory is very important for chemical flooding enhanced oil recovery. The difference between microscopic capillary number and the microscopic one is easy to confuse. After decades of development, great progress has been made in capillary number theory and it has important but sometimes incorrect application in EOR. The capillary number theory was based on capillary tube bundles and Darcy’s law hypothesis, and this should always be kept in mind when used in chemical flooding EOR. The flow in low permeability porous media often shows obvious non-Darcy effects, which is beyond Darcy’s law. Experiments data from ASP flooding and SP flooding showed that remaining oil saturation was not always decreasing as capillary number kept on increasing. Relative permeability was proved function of capillary number; its rate dependence was affected by capillary end effects. The mobility control should be given priority rather than lowering IFT. The displacement efficiency was not increased as displacement velocity increased as expected in heavy oil chemical flooding. Largest capillary number does not always make highest recovery in chemical flooding in heterogeneous reservoir. Misuse of CDC in EOR included the ignorance of mobility ratio, Darcy linear flow hypothesis, difference between microscopic capillary number and the microscopic one, and heterogeneity caused flow regime alteration. Displacement of continuous oil or remobilization of discontinuous oil was quite different.

Quinolizidine alkaloids, a main form of alkaloids found in the genus Sophora, have been shown to have many pharmacological effects. This review aims to summarize the photochemical reports and biological activities of quinolizidine alkaloids in Sophora. The collected information suggested that a total of 99 quinolizidine alkaloids were isolated and detected from different parts of Sophora plants, represented by lupinine-type, cytisine-type, sparteine-type, and matrine-type. However, quality control needs to be monitored because it could provide basic information for the reasonable and efficient use of quinolizidine alkaloids as medicines and raw materials. The nonmedicinal parts may be promising to be used as a source of quinolizidine alkaloid raw materials and to reduce the waste of resources and environmental pollution. In addition, the diversity of chemical compounds based on the alkaloid scaffold to make a biological compound library needs to be extended, which may reduce toxicity and find new bioactivities of quinolizidine alkaloids. The bioactivities most reported are in the fields of antitumor activity along with the effects on the cardiovascular system. However, those studies rely on theoretical research, and novel drugs based on quinolizidine alkaloids are expected.

To study the air exchange efficiency of rooms while air conditioning equipment are running and window is open, this paper used the experiments of tracer gas CO2 to measure its concentration variations indoor after opening window. At the same time, the corresponding cases were simulated numerically with computational fluid dynamic (CFD). The experimental results showed that after opening window, the combined action of wind pressure and pressure due to the differences of the air density can cause obvious air exchange between the indoor and the outdoor. Indoor CO2 concentration was continuously reduced as proceeding of the air infiltration and there is an optimized width of window opening which resulted in a fastest decay rate of CO2 concentration. Furthermore, results of simulation and experiment indicated that larger temperature difference between the indoor and outdoor lead to faster indoor CO2 exhausted rates. Air exchange rate of air-conditioned rooms is affected by the types, opening degrees and the relative locations of the window as well. Natural ventilation by reasonable window opening can enhance the air quality if the outside air is not polluted. It should be noticed that optimized width and relative location of the window opening exist if economy is to be considered.

The paint spraying waste gas contains a large amount of paint mist, volatile organic compounds (VOCs) and other hazardous materials, which seriously affects human health and atmospheric environment. Paint mist cannot be separated from paint spraying waste gas effectively by the existing dry filtration methods because of the filter blocking. A new separation process and a novel coupling device with high separation efficiency have been developed. A numerical model was established to optimize the structure and operation parameters of the baffle interceptor by hydrodynamics method which verified by the coupling device experiment. From the simulating results, when plate spacing was 20 mm, folding angle was 90° and airflow velocity was up to 8 m/s, the separation efficiency of paint mist with the diameter of 15 μm was 84.7% and the pressure drop of the baffle interceptor was 220.2 Pa. Experiment was conducted under the above-optimized conditions, and the results showed that the pressure drop of the baffle interceptor was 303.33 Pa, and the paint mist separation efficiencies of the baffle interceptor and the interception-filtration coupling device were 78.34% and 96.38%, respectively.

The performance of pollutant removals, activated sludge characteristics, and microbial communities of two biofilm membrane bioreactors coupled with pre-anoxic tanks (BF-AO-MBRs) (one using fiber bundle bio-carriers (FB-MBR) and the other using suspended bio-carriers (MB-MBR)) were compared at the salinity between zero and 60 g/L. At all salinities, three bioreactors showed good COD average removal efficiencies (>94.1%), and FB-MBR showed the best TN removal efficiency (90.4% at 30 g/L salinity). Moreover, FB-MBR had the faster process start-up time and better salt shock resistance. At high salinities (30–60 g/L), more extracellular polymeric substances were produced by the BF-AO-MBRs to avoid the penetration of salt and protect the bacterial community. Because of the different attachment patterns of biofilms, the microbial community structure in the FB-MBR exposed to 30 g/L salinity had higher nitrite-oxidizing/ammonia-oxidizing bacteria ratio (6.44) with more abundance of denitrifiers, which contribute to higher TN removal efficiency and lower nitrite accumulation.

Hesperidin, a kind of citrus bioflavonoid distributed in foods including grapefruits, oranges and lemons, has many pharmacological activities. This study was aimed to evaluate the anti-depressant-like effect of hesperidin on chronic unpredictable mild stress (CUMS)-induced mice. Depressive-like behavior was detected by the sucrose preference test (SPT), tail suspension test (TST) and forced swimming test (FST). A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay was performed to assess the cell viability of corticosterone-induced PC12 cells. The serum, hippocampal and cell supernatant concentrations of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α were determined using enzyme-linked immunosorbent assay (ELISA) commercial kits. Furthermore, the protein expression levels of high-mobility group box 1 protein (HMGB1), receptor for advanced glycation end-products (RAGE)/NF-κB and brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase B (TrkB) pathway in the hippocampus and corticosterone-induced PC12 cells were detected by Western blot. Our results showed that hesperidin (100, 200 mg/kg) significantly relieved depressive-like behaviors, including decreased sucrose consumption in sucrose preference test (SPT), immobility in the forced swimming test (FST), tail suspension test, and locomotor activity in the open field test (OFT). Hesperidin reduced inflammatory cytokine levels by attenuating the HMGB1/RAGE/NF-κB signaling pathway and BDNF/TrkB pathway both in vivo and in vitro. In conclusion, hesperidin possessed efficient neuroprotective effects on depression, which was associated with neuroinflammation mediated by the HMGB1/RAGE/NF-κB and BDNF/TrkB pathways.

Lycium ruthenicum has been used as ethnic medicine and nutraceutical food. Existing studies of L. ruthenicum can be classifies into three areas: (1) those in which molecular biology methods were used to study its origin, genetic variation and relationships with other species; (2) those in which phytochemical methods were used to extract, isolate, and identify compounds; and (3) those in which pharmacological methods were used to study active compounds. The purpose of this paper is to provide an overview of L. ruthenicum studies. This review will provide a useful bibliography for further investigations and applications of L. ruthenicum in medicines and foods.

Scutellaria baicalensis is a common and important medicinal plant in China, facing with reducing sharply in wild resources. To meet the needs in Chinese herbwouls medicine market and clinical application, S. baicalensis has been widely cultivated in Ningxia, Hebei, Shanxi, and Gansu et al. HPLC finger-print and near-infrared were studied in the research to evaluate quality difference of S. baicalensis in four districts. The results showed that the similarity of HPLC finger-print of 12 cultivated S. baicalensis and reference crude herb is more than 0.961, and the other is more than 0.983. On the other hand, paired sample t-test indicated there has no significant difference between the common peaks' area of 12 cultivated S. baicalensis and reference crude herb. It was verified that 12 cultivated S. baicalensis has highly consistency with reference crude herb. On the basis of chromatographic finger-print and near-infrared spectrum, the study applied paired sample t-test to verify analysis results, which could avoid erroneous judgment induced by indefinite threshold values in the similarity of chromatographic finger-print and provide reliable basis for the analysis results. Meanwhile, it also provides a new idea for improving the quality control method of Chinese medicinal materials by comparative study about two comprehensive detection means.

The distribution information of Glycyrrhiza uralensis was collected by interview investigation and field survey, and 46 related environmental factors were collected, some kinds of functional chemical constituents of G.uralensis were analyzed. Integrated climate, topography and other related ecological factors, the habitat suitability study was conducted based on Arc geographic information system(ArcGIS),and maximum entropy model. The AUC of ROC curve was both above 0.95, indicating that the predictive results with the maximum model were highly precise. The results showed that 5 major ecological factors have obvious influence on ecology suitability distributions of G. uralensis, including July average temperature, soil sub category, Dec precipitation, vegetation types and standard deviation of seasonal variation in temperature, et al. It is suitable for the living habits of the G. uralensis, adequate light, low rainfall, summer heat and large temperature difference between day and night, which is suitable for distribution in the northern temperate plains and mountains. In addition, the ecological suitability regionalization based on the chemical constituents of G.uralensis also provides a new suitable distribution area other than the traditional distribution area, which provides a scientific basis for the reasonable introduction of G.uralensis.

The present study was designed to investigate the protective effect of Sophoraflavanone G (SG) on streptozotocin (STZ)-induced diabetic rats. The rats were intraperitoneally injected with STZ (35mg/kg). 7days later, the rats were intragastrically administered with Metformin (MET, 150mg/kg), SG (20mg/kg) or SG (40mg/kg) once daily for consecutive 30 days. The animals were anaesthetized, the blood and liver samples were also collected for further assay. SG significantly decreased the serum levels of glucose, insulin, aspartate transaminase (AST), alanine aminotransferase (ALT). In addition, SG increased superoxide dismutase (SOD) activity and inhibited malondialdehyde (MDA) content in serum. SG also ameliorated the histopathological condition. Furthermore, SG attenuated the expressions of thioredoxin (Trx), thioredoxin-interacting protein (Txnip) and the phosphorylations of inhibitory kappa B kinase (IKK)α, IKKβ, nuclear factor-κB inhibitory proteins (IκB)α, nuclear factor κB (NF-κB). These findings demonstrated that SG showed beneficial effects on STZ-induced diabetic rats.

The distribution information of Lycii Fructus was collected by interview investigation and field survey, and 46 related environmental factors were collected, some kinds of functional chemical constituents the of Lycii Fructus were analyzed. Integrated climate, topography and other related ecological factors, the habitat suitability study was conducted based on Arc geographic information system(ArcGIS),and maximum entropy model. The AUC of ROC curve was both above 0.95, indicating that the predictive results with the maximum model were highly precise. The results showed that 5 major ecological factors had obvious influence on ecology suitability distributions of Lycii Fructus, including soil pH, soil subclass, vegetation type and in August the average temperature et al. It is suitable for the living habits of the Lycii Fructus, dry, cool weather, more hardy, drought-resistant, alkali soil, which is suitable for distribution in the northern temperate plains. In addition, the ecological suitability regionalization based on the chemical constituents of Lycii Fructus also provides a new suitable distribution area other than the traditional distribution area, which provides a scientific basis for the reasonable introduction of Lycii Fructus.

Crocetin ester (CE) is the active ingredient of Crocus sativus L. stigmas and Gardenia jasminoides Ellis fruit. The main purpose of the present study was to investigate the protective effect of CE on isoproterenol (ISO)-induced acute myocardial ischemia (AMI) through Rho/ROCK/NF-κB pathway and explore its underlying mechanism. Administration of CE (25 and 50 mg/kg) could significantly reduce the serum contents of pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6). In addition, pretreatment with CE attenuated the contents of creatine kinase (CK), malondialdehyde (MDA) and the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD) in serum. Treatment with CE also improved the histopathological alteration and decreased the ST elevation. Furthermore, CE could ameliorate the cardiac expressions of Cu, Zn-superoxide dismutase (SOD1), MDA5, Rho, ROCK, p-IκB and p-NF-κBp65 in ISO-induced rats. It was assumed that CE might be a new therapeutic candidate for the treatment of AMI possibly through the inhibition of Rho/ROCK/NF-κB pathway.

Methyl 3-deoxy-3-(diphenylphosphino)-4,6-O-benzylidene-α-D-altropyranoside (1) and methyl 2-deoxy-2-(diphenylphosphino)-4,6-O-benzylidene-α-D-altropyranoside (2) were prepared from methyl 2,3-anhydro-4,6-O-benzylidene-O-D-mannopyranoside and methyl 2,3-anhydro-4,6-O-benzylidene-α-D-allopyranoside, respectively, via regioselective and stereospecific ring-opening reactions in high yields. Compounds 1 and 2 were oxidized to give the corresponding phosphine oxides (S and 4).

In this paper, based upon Fanger's thermal comfort concept, several concepts, which utilize computing results obtained from the large eddy simulation (LES), are put forward, such as thermal comfort index based on time-averaged parameters, instantaneous thermal index, time-averaged thermal comfort index and time-averaged thermal comfort index along walking routes. Also their discrepancies and calculation methods are discussed in the paper. Apart from these, we have calculated PD value as an example, whose results indicate that the distributions of four indices are obviously different. Therefore, it is suggested to distinguish different cases and select correspondingly thermal comfort evaluation indices while considering the question of thermal comfort.

Ardisia plant species have been used in traditional medicines, and their bioactive constituents of 13,28-epoxy triterpenoid saponins have excellent biological activities for new drug development. In this study, a fast and simple method based on ultrafast liquid chromatography coupled to electrospray ionization mass spectrometry (UFLC-MS) was developed to simultaneously identify and quantitatively analyze triterpenoid saponins in Ardisia crenata extracts. In total, 22 triterpenoid saponins, including two new compounds, were identified from A. crenata. The method exhibited good linearity, precision and recovery for the quantitative analysis of eight marker saponins. A relative quantitative method was also developed using one major saponin (ardisiacrispin B) as the standard to break through the choke-point of the lack of standards in phytochemical analysis. The method was successfully applied to quantitatively analyze saponins in commercially available plant samples. This study describes the first systematic analysis of 13,28-epoxy-oleanane-type triterpenoid saponins in the genus Ardisia using LC-ESI-MS. The results can provide the chemical support for further biological studies, phytochemotaxonomical studies and quality control of triterpenoid saponins in medicinal plants of the genus Ardisia.

The polymerization kinetics of acrylamide was investigated in the system of cetyltrimethyltetrammonium bromide-water micelles. The maximal polymerization rate was found at the second critical micelle concentration. A square-root dependence of the polymerization rates, R p , on the initiator concentrations was obtained. Polymerization in microemulsions was also investigated to establish a connection between the structures of microemulsions and polymerization reaction rate. The microemulsions consisted of cetyltrimethylammonium bromide, n-butanol, n-octane and water. Their structures were determined by conductivity measurements. Our results showed that maximal polymerization rates occurred at two transition points from water in oil (W/O) to bicontinuous (BC) and from bicontinuous (BC) to oil in water (O/W). At the same time, we also found that the polyacrylamide molecular weights depended on the structures of microemulsions.

The paper presents the design, fabrication and test of a 118GHz sub-harmonic mixer based on Schottky Diode. The co-simulation between HFSS and ADS was applied to the modeling of the mixer. After test, much analysis and adjusting was made on the mixer, and, consideration of the technics, the design was modified. The final test result indicates that the single side band(SSB) conversion loss of the mixer is lower than 9.3dB within 103GHz to 132GHz, and the best conversion loss is 3.6dB.

The load-carrying capacity, friction reduction and antiwear properties of two benzotriazole derivatives containing the R 2 NC(=S)S- group, added in liquid paraffin under boundary lubrication conditions were evaluated using a Seta-Shell Four-ball lubrication machine and an optimal SRV tester. Their anticorrosive and antioxidative properties, and thermal stabilities were also examined. The results when compared with those of zinc butyloctyldithiophosphate (ZDDP) show that the two novel compounds possess an excellent load-carrying capacity similar to ZDDP and better antiwear and antioxidative properties than ZDDP. Besides that, they have good anticorrosive properties and high thermal stabilities. The rubbed surfaces were investigated using X-ray photoelectron spectroscopy, Auger electron spectroscopy and electron probe microanalysis analytical tools. The extreme-pressure, antiwear and antioxidative mechanisms were discussed.

The ion implantation of N + B (3.1 × 10 17 N ions cm -2 at 90 keV followed by 3.2 × 10 17 B ions cm -2 at 90 keV) into GCrl15 bearing steel was carried out. The phase structure and the distribution and binding energy of elements in the implanted layer were investigated using X-ray diffraction, Auger electron spectroscopy and X-ray photoelectron spectroscopy. The dry sliding friction and wear behaviour of the implanted layer and GCr15 bearing steel substrate was also examined in detail using a friction and wear machine. It is found that a surface layer with a lower friction coefficient and a higher wear resistance than the substrate was obtained by implanting N + B into GCr15 bearing steel. Because of dispersion strengthening of the hexagonal BN phase and e-Fe 2 N-Fe 3 N phase and solid solution strengthening of B atoms, the surface hardness of the implanted layer is increased. As a result of the increased hardness and the existence of a graphite-like carbon film on the surface of the implanted layer, the antiadhesive and antiabrasive properties of the implanted layer were considerably enhanced. the friction coefficient was reduced from 0.60 to 0.20 and the wear resistance was also greatly improved.

This paper presents a low-power high-precision switched-opamp(SO)-based delta—sigma (ΔΣ) analog-to-digital converter (ADC). The proposed SO design allows circuit operation at sub-1 V supply voltage, only needs to work in half of a clock cycle, and thus is suitable for low power applications. In addition, an opamp-sharing technique is applied to save on hardware overheads. Due to the use of a dual cycle shift data weighted averaging (DCS-DWA) technique, mismatch errors caused in the feedback DAC have been eliminated without introducing signal-dependent tones. The proposed ADC has been implemented in a standard 0.18 μm process and measured to have a 92.2 dB peak SNDR and 94.1 dB dynamic range with 25 kHz signal bandwidth. The power consumption is 58 μW for the modulator at 0.9 V supply voltage and 96 μW for the decimation filter, which translate to the figure-of-merit (FOM) of 35.4 fJ/step for the solo modulator, and 94 fJ/step for the whole system.

Alumina-supported molybdenum carbide and its modifier with small amounts of nickel were evaluated and characterized. The evaluation results showed that a nickel-doped carbide catalyst exhibited a much higher conversion of methane and selectivity to CO and H2for the partial oxidation of methane (POM) to syngas. Also, the addition of a small amount of nickel resulted in significant improvement of catalysis stability. Characterization by temperature programmed surface reaction (TPSR) indicated that the addition of nickel promoted the carburization of molybdenum oxide. Especially under the conditions of the POM to syngas, this promotion resulted in more active phases being held. The nickel doped catalyst had small particles, larger specific area and greater ability to resist sintering. All these improved the catalytic stability. The other characterizations by XRD, XPS, SEM as well as BET surface area measurement also confirmed these promotions of nickel. In addition, the doped nickel made possible the increase of the intrinsic activity of catalytic centers over molybdenum carbide catalyst.

After decades of development, great progress has been made in capillary number theory and it has important but often incorrect application in EOR. Investigation into progress on capillary number theory and some misuse of capillary number theory helps to make better use of it. Latest progress concerning with capillary number theory and its application in chemical EOR is reviewed by studying the experiments data and checking its model hypothesis. Classic Capillary Desaturation Curves (CDC) are summarized and new CDC is introduced. Typical classical CDC showed larger capillary number lead to lower residual oil saturation and when capillary number increased to a certain critical value(first critical value), the residual oil saturation could drop to a minimum value even zero. CDC shapes were different in water-wet and oil-wet media. Recovery can be improved by increasing flooding rate, though invalid and impractical, displacement phase viscosity or/and reducing oil/water interfacial tension, which are actually adopted by chemical flooding. Guided by this theory and also first critical capillary number value requirement, it lead to the pursuit of low interfacial tension to largest extent and the requirement of ultra-low interfacial tension (10-3mN/m) in surfactant screening. However, experiments data showed that residual oil saturation was not always decreasing as capillary number increased. After capillary number increased to a certain value (second critical value), the residual oil saturation may increase or decrease as capillary number increase. What was more, the final residual oil saturation was quite more than zero and this CDC was regarded as the new CDC. Experiments in heavy oil laboratory tests showed that smaller injection rate lead to higher recovery which seemed contrary to capillary theory.