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Reverse osmosis (RO) is widely used in wastewater reclamation to alleviate the increasingly global water shortage. However, it has an inconvenient defect of biofouling. Some disinfection processes have been reported to select certain undesirable disinfection-residual bacteria (DRB), leading to severe long-term biofouling potential. To provide constructive guidance on biofouling prevention in RO systems, this study performed a 32-day experiment to parallelly compared the biofouling characteristics of RO membranes of DRB after five mature water disinfection methods (NaClO, NH2Cl, ClO2, UV, and O3) and two recently developed water disinfection methods (K2FeO4 and flow-through electrode system). As a result, the DRB biofilm of K2FeO4 and O3 caused a slight normalised flux drop (22.4 ± 2.4% and 23.9 ± 1.7%) of RO membrane compared to the control group (non-disinfected, ~27% normalised flux drop). FES, UV, NaClO and ClO2 caused aggravated membrane flux drop (29.1 ± 0.3%, 33.3 ± 7.8%, 34.6 ± 6.4%, and 35.5 ± 4.0%, respectively). The biofouling behaviour showed no relationship with bacterial concentration or metabolic activity (p > 0.05). The thickness and compactness of the biofilms and the organics/bacterial number ratio in the biofilm, helped explain the difference in the fouling degree between each group. Moreover, microbial community analysis showed that the relative abundance of typical highly EPS-secretory and biofouling-related genera, such as Pseudomonas, Sphingomonas, Acinetobacter, Methylobacterium, Sphingobium, and Ralstonia, were the main reasons for the high EPS secreting ability of the total bacteria, resulting in aggravation of biofouling degree (p 2 effectively prevented pathogen reproduction in the DRB biofilm.

Objectives We aimed to construct an induction system for polyploid giant cancer cells (PGCCs), as well as to investigate PGCC features and clinical significance. Methods A laryngeal neoplasm‐PGCC induction system was constructed using paclitaxel liposomes (PTX). We used western blots to compare expression of epithelial‐mesenchymal transition‐related proteins, stem cell interrelated proteins, and cyclin‐associated proteins. We then measured PGCC count in tissue samples of patients with laryngeal neoplasms and analyzed its relationship with prognosis. Statistical significance was determined using t‐tests. Results PTX successfully induced PGCCs. Western blotting showed that CyclinB1, CDC25C, CDK1, E‐cadherin, and EIF‐4A expression decreased in PGCCs compared with normal cancer cells, whereas vimentin and CD133 expression increased. Number of PGCCs in laryngeal cancer tissues and overall survival time were inversely correlated (P

Biofouling is a critical defect of the reverse osmosis (RO) system. It has been reported that disinfection processes tend to select certain undesirable disinfection-residual bacteria (DRB), leading to severe long-term biofouling potential. To provide constructive guidance on biofouling prevention in RO systems, this study evaluated the biofouling characteristics of RO membranes of DRB after the application of five mature disinfection methods (NaClO, NH2Cl, ClO2, UV, and O3) and two novel disinfection methods (K2FeO4 and flow-through electrode system (FES)). After a 32-day biofilm cultivation on the RO membranes, the DRB biofilm of K2FeO4 and O3 caused a slight normalised flux drop (22.4 ± 2.4% and 23.9 ± 1.7%, respectively) of RO membrane compared with the control group (non-disinfected, ~ 27% normalised flux drop). Moreover, the biofouling degree of the NH2Cl-DRB biofilm was similar to that of the control group. The remaining disinfection types aggravated membrane biofouling. The biofouling behaviour of DRB showed no relationship with bacterial concentration or activity. The thickness and density of the biofilms as well as the organics/bacterial number ratio in the DRB biofilm, helped explain the difference in the fouling degree between each group. Moreover, microbial community analysis showed that the relative abundance of typical highly secretory and biofouling-related genera, such as Pseudomonas, Sphingomonas, Acinetobacter, Methylobacterium, Sphingobium, and Ralstonia, were the main reasons for the difference in biofouling degree. All types of disinfection effectively prevented pathogen reproduction in the DRB biofilm. However, the relative abundance of (opportunistic) pathogens increased significantly after NaClO and ClO2 disinfection.

Adsorption and coagulation were commonly used to alleviate reverse osmosis (RO) membrane fouling caused by dissolved organic matters (DOM), but the effects of changed composition and structure of DOM in dyeing wastewater after adsorption and coagulation on RO membrane fouling have seldom been studied. This study aimed at resolving the mechanism how the RO membrane fouling during dyeing wastewater treatment was alleviated by using adsorption and coagulation. The dyeing wastewater caused serious RO membrane fouling. Pretreatment with granular activated carbon (GAC), polyferric sulfate (PFS) and polyaluminum chloride (PACl) were conducted. It was shown that GAC could remove most of the DOM (95%) and preferred to adsorb protein, hydrophobic neutrals and fluorescent compounds. Both coagulants of PFS and PACl preferred to remove polysaccharides (the removal rate was 9-19% higher than that of DOM), high-MW compounds and these compounds with high fouling potential. Afterwards, the RO membrane fouling potential of the dyeing wastewater was tested. The GAC and PFS performed well to alleviate fouling. After GAC treatment, the decline rate of RO flux was similar to that of raw wastewater after 6-fold dilution. With pretreatment by PFS or PACl, the fouling potential of dyeing wastewater was much lower than that of raw wastewater after diluted to the same DOM content. Changes in polysaccharides content in the DOM had more effects on RO membrane fouling than that of proteins after these pretreatment. Although the DOM changed significantly after pretreatment, the fouling type was still intermediate blocking.

Chlorine disinfection is often used as a pretreatment technology to control biofouling of reverse osmosis (RO) membranes. However, previous studies showed that biofouling of the RO system was aggravated after chlorine disinfection. Chlorine-resistant bacteria (CRB) were presumed to be closely related to the aggravation of fouling caused by chlorine disinfection. In order to analyze the membrane fouling mechanisms of CRB, 5 CRB strains were isolated from the surface of fouled RO membranes for wastewater reclamation, and 3 reference bacterial strains, Sphingopyxis soli BM1-1, Pseudomonas aeruginosa PAO1 and Escherichia coli CGMCC1.3373, were selected for comparative study. The chlorine resistance, membrane fouling potential, secretion and adhesion characteristics of these strains were evaluated. Among these isolated strains, 3 strains showed much higher chlorine resistance than PAO1 under the condition of 0.5, 2, 5 mg/L-Cl

Fouling of RO membranes has long been a complex but inevitable problem in wastewater reclamation. In this study, a modified intermediate blocking model with two parameters was applied to describe the flux change of RO membranes treating various water samples, including municipal secondary effluent, treated industrial wastewater, surface water, and groundwater. The model was validated by 55 sets of data reported by 13 articles, and the results were promising, with 90% of the determination coefficient (R

The epidemic of COVID-19 has aroused people's particular attention to biosafety. A growing number of disinfection products have been consumed during this period. However, the flaw of disinfection has not received enough attention, especially in water treatment processes. While cutting down the quantity of microorganisms, disinfection processes exert a considerable selection effect on bacteria and thus reshape the microbial community structure to a great extent, causing the problem of disinfection-residual-bacteria (DRB). These systematic and profound changes could lead to the shift in regrowth potential, biofouling potential, as well as antibiotic resistance level and might cause a series of potential risks. In this review, we collected and summarized the data from the literature in recent 10 years about the microbial community structure shifting of natural water or wastewater in full-scale treatment plants caused by disinfection. Based on these data, typical DRB with the most reporting frequency after disinfection by chlorine-containing disinfectants, ozone disinfection, and ultraviolet disinfection were identified and summarized, which were the bacteria with a relative abundance of over 5% in the residual bacteria community and the bacteria with an increasing rate of relative abundance over 100% after disinfection. Furthermore, the phylogenic relationship and potential risks of these typical DRB were also analyzed. Twelve out of fifteen typical DRB genera contain pathogenic strains, and many were reported of great secretion ability. Pseudomonas and Acinetobacter possess multiple disinfection resistance and could be considered as model bacteria in future studies of disinfection. We also discussed the growth, secretion, and antibiotic resistance characteristics of DRB, as well as possible control strategies. The DRB phenomenon is not limited to water treatment but also exists in the air and solid disinfection processes, which need more attention and more profound research, especially in the period of COVID-19., Graphical Abstract Image, graphical abstract

Isoliquiritigenin (2’,4’,4-trihydroxychalcone, ISL) is one of the most important chalcone compounds which is mainly derived from licorice root and many other plants. It exhibits a remarkable range of potent biological and pharmacological activities such as antioxidative, antitumor, antiaging, anti-inflammatory, anti-diabetic activities, etc. Numerous research teams have demonstrated that ISL posseses the ability to carry out antigrowth and proliferation in various cancer cells in vitro and in vivo. Meanwhile, the underlying mechanisms of ISL that inhibit cancer cell proliferation have not been well explored. However, the poor bioavailability and low water-soluble limit its clinical application. This review aims at providing a comprehensive overview of the pharmacology antitumor activity of ISL and its mechanisms in different malignancy especially in breast cancer cell line and summarize developments of formulation utilized to overcome the barrier between its delivery characteristics and application in clinics over the past 20 years.

Extracellular polymeric substances (EPS) were the main cause of membrane biofouling in advanced treatment of wastewater. Disinfection was usually used to reduce microbial concentration in the feed water and prevent biofouling. However, the disinfection residual bacteria (DRB) could regrow to produce EPS, and there was still a paucity of information on EPS productivity and properties from DRB and their further interaction with membranes. In this study, three commonly-used disinfection methods (free chlorine, chloramine and ozone disinfection) were used to investigate their effects on microbial EPS production and the further effects on membrane fouling. It was found all the disinfection treatment increased the relative abundance of typical bacterial genus with high EPS production ability, and thus significantly enhanced EPS volumetric productivity (by 26%–82%). The molecular weight and fluorescence intensity of EPS produced by DRB also increased. The fouling potential of these EPS on ultrafiltration (UF) membranes and reverse osmosis (RO) membranes was then tested. EPS of DRB showed significantly higher fouling potential. Compared with the control group, the time for transmembrane pressure (TMP) increased to 3 bar decreased by 43%–49% in the constant-flow UF system in the disinfection groups. As for the constant-pressure RO systems, the final flux decreased by 33%–41% in the disinfection groups compared with the control group. The thickness of foulants on UF and RO membranes in the disinfection groups was all higher than that in the control group. The extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory further showed that the EPS of DRB had significantly higher interaction energy with membranes than that in the control group. Therefore, caution should be exercised when oxidizing disinfection was used as pre-treatment for membrane filtration in the wastewater reclamation process.

Soluble microbial products (SMP) are one of the main causes of reverse osmosis (RO) membrane fouling in wastewater reclamation, and coagulation and adsorption are commonly used to prevent such fouling. However, the mechanism by which typical coagulants and adsorbents affect the RO membrane fouling caused by SMP remains unclear. In this study, two bacterial strains isolated from fouled RO membranes in a full-scale wastewater reclamation plant were used to produce SMP. Both bacterial strains were found to generate high SMP yield (0.23–0.25 g/g), which caused severe RO membrane fouling. Coagulation by polyaluminum chloride (PACl) and ferric chloride (FeCl3) and adsorption by granular activated carbon (GAC) were applied as pretreatment methods to alleviate the membrane fouling caused by SMP. Compared with PACl, FeCl3 performed better in removing SMP, decreasing fluorescence intensity, and reducing molecular weight (MW). GAC preferentially adsorbed protein and humic substances in SMP and unselectively and efficiently removed fluorescent compounds; however, it could only remove a limited amount of the high-MW compound. The RO membrane fouling potential of treated SMP was investigated, and FeCl3 and GAC were found to effectively alleviate the fouling. In addition to a decrease in the dissolved organic carbon content of SMP, a decrease in specific fluorescence intensity, MW, and polysaccharide content caused by coagulation or adsorption could result in lower RO membrane fouling.

Membrane fouling is a prominent problem that hinders the stable and efficient operation of the reverse osmosis (RO) system for wastewater reclamation. Previous studies showed that chlorine disinfection, which was commonly used in industrial RO systems as pretreatment, could lead to significant change in microbial community structure and resulted in serious biofouling. In order to prevent biofouling during wastewater reclamation, the effect of ultraviolet (UV) disinfection on RO membrane fouling was investigated and the mechanism was also revealed in this study. With the disinfection pretreatment by UV of 20, 40 and 80 mJ/cm2, the bacteria in the feed water were inactivated significantly with a log reduction of 1.11, 2.55 and 3.61-log, respectively. However, RO membrane fouling aggravated with higher UV dosage. Especially, in the group with the UV dosage of 80 mJ/cm2, the normalized RO membrane flux decreased by 15% compared with the control group after 19-day operation. The morphology of the fouled RO membranes indicated serious biofouling in all groups. The analysis on the microbial amount of the foulants showed that the heterotrophic plate counts (HPC) and ATP content on the fouled RO membranes with and without UV disinfection were at the same level. However, the total organic carbon content of the foulants with the UV dosage of 40 and 80 mJ/cm2 was significantly higher than the control group, with higher content of proteins and polysaccharides as indicated by EEM and FTIR spectrum. Microbial community structure analysis showed that some typical UV-resistant bacteria were selected and remained on the RO membrane after disinfection with high UV dosage, including. These residual bacteria after disinfection with high UV dosage showed higher extracellular polymeric substances (EPS) secretion compared with those without UV disinfection, and thus aggravated RO membrane fouling. Thicker EPS could decrease the transmission of UV rays, and thus bacteria with higher EPS secretion might be selected after UV disinfection.

The methyl polypropylene was prepared bsaed on toluene as solvent, cuprous bromide (CuBr) / copper bromide (CuBr2)/tris (2-dimethylaminoethyl) amine (Me6TREN) as catalyst, azo dimethoxyisoquinolin heptanenitrile (V-70) as radical additive, 2-bromoisobutyrate (EtBiB) as initiator. The polymerization reaction was initiated by using the ultimate atomic radical polymerization (UATRPSM), whose chain reaction was manifested in linear first-order kinetics. In this study, the conversion of monomers, polymer dispersion coefficient and the relative molecular weight with monomer conversion rate changes were studied by gas chromatography (GC) and gel permeation chromatography (GPC). The results show that the final monomer conversion was 87%; with increasing monomer conversion, polymer dispersion coefficient (PDI) decreases and reaches the optimum value 1.19, while the relative molecular weight of the linear growth, and prove the reaction was precise control.

Simulative training should include network simulation in information age, and network simulation needs to meet the real-time requirements. For the real-time implementation of Tactical Internet (TI) simulation, the paper proposed a "water-wave type" topology updating method for simulation, which solved the real-time problem of tactical radio network topology updating simulation. Secondly, the paper proposed a data packet transmission method based on characteristic information, which solved the large data problem of TI simulation, and then the real-time of simulation was improved. Finally, the paper proposed a transmission success-rate calculating method based on prediction, which solved the real-time simulation problem of transmission. The practical application proved that the paper’s methods had good effect.

Appraising is an important work of Tactical Internet (TI) simulative training. As a new type of network, the appraising of TI training needs to be solved by new method. Therefore, the paper set up a new index system firstly, laid the foundation for the appraising of Tactical Internet simulative training. Secondly, the paper used a Petri net method, which solved the acquisition problem for those indexes that are dynamic changed and not easy to be directly calculated. Thirdly, the paper used a BP neural network method, which solved the calculation of index weights. Finally, based on the method of satisfaction degree, the paper set up an appraising model which realized the appraising of trainees’ training level。The paper’s work has been applied in practice and achieved good results.

The traditional Tactical Internet (TI) simulative training didnt consider the terrain environment and maneuver simulation, so its fidelity was low. The paper aimed to resolve it. Firstly, the paper gave the modeling process of TI terrain environment, and put forward the corresponding ways to some parts of the modeling process. Secondly, the paper gave the optimization steps of TI terrain model, it improved the simulation running efficiency; and then the paper utilized the large area database management technique to solve dynamic loading and rendering problem of large terrain model. Lastly, the paper gave the maneuver simulation way to the communication vehicles of TI, it solved the problems of maneuver collision and precise maneuvering along the road. The paper presented the realization results in each part, and it proved the effectiveness of the given ways.

Objective To evaluate levels of lead (Pb) and cadmium (Cd) in the breast milk in the second postpartum month, to investigate the relationship between Pb/Cd levels in breast milk and some sociodemographic parameters, and to explore whether these levels affect the infants' physical status or the mothers' psychological status (postpartum depression). Methods A cross-sectional study was conducted between November 2009 and December 2010. Altogether 170 healthy mothers were enrolled from Nanjing Maternity and Child Health Care Hospital. The inclusion criteria were: voluntary to participate in this study, healthy, with no chronic disease, breastfeeding in the second postpartum month, living in a suburban but not non-industrial area of Nanjing, and not occupationally exposed to toxic metals. All the mothers completed a questionnaire and were evaluated based on the Edinburgh Postpartum Depression Scale (EPDS) to identify the risk of postpartum depression. Pb and Cd levels in breast milk were determined by inductively coupled plasma mass spectroscopy. The infants of these mothers were examined for their z scores of weight for age, length for age, head circumference for age, and body mass index for age. Results The median breast milk levels of Pb and Cd were 40.6 μg/L and 0.67 μg/L, respectively. In 164 (96.5%) of the 170 samples, Pb levels were higher than the limit reported by the World Health Organization (> 5 μg/L). Breast milk Cd level was > 1 μg/L in 54 (31.8%) mothers. The mothers with a history of anemia had a higher breast milk Pb level than those without a history of anemia (41.1 μg/L vs. 37.9 μg/L, P = 0.050). The median breast milk Cd level in those who were active and passive smokers during pregnancy was significantly higher than that in non-smokers (0.88 μg/L vs. 0.00 μg/L, P = 0.025). The breast milk Cd level in the mothers not taking iron and vitamin supplements for 2 months postpartum was higher than in those taking the supplements (iron supplement: 0.74 μg/L vs. 0.00 μg/L, P = 0.025; vitamin supplement: 0.78 μg/L vs. 0.00 μg/L, P = 0.005). Breast milk Cd level at the second postpartum month was negatively correlated with the z scores of head circumference (r = − 0.248, P = 0.042) and weight for age at birth (r = − 0.241, P = 0.024) in girls. No correlation was found between the breast milk Pb/Cd levels and the EPDS scores. Conclusion Considering the high levels of Pb and Cd in breast milk in this study, breast milk monitoring programs are necessary.

Design mode of product form is constructed combining Kansei Engineering (KE) with Ergonomics. KE is used as main technique to transform consumers' feelings and images of shape, size, material, operability of product into design form futures. The main factors and problems of Kansei experiment and Kansei analysis are also identified.Ergonomics acts as the assisting technique for meeting physiological criteria of consumer group. An implement of a product form design was conducted, and then the feasibility of proposed design mode based on KE is discussed which provides related products’ reference to designers.

The design criteria, operational frequency, operational order and compatibility are proposed and analyzed for nuclear power plant main control room. A layout optimization mathematic model is created based on these rules. Objective function of the mathematic model is developed, in which the distance of hands’ moving is added in order to measure the workload of operators. An example of 12 components on panel is implemented by particle swarm optimization.

Panel layout in control room of nuclear power plant requires satisfying layout principles and requirement for multiple operational conditions. Traditional panel layout methods are difficult to integrate these principles; the layout scheme heavily depends on designers’ individual judgments and experience. So the randomness of layout scheme is hard to overcome. Particle swarm optimization is a global efficient solution to complex optimization problems with multi-constraints. First, the operational efficiency is selected as optimization object. Second, objective function is constructed according to the evaluating indexes which include operation frequency, sequence and importance of components. Third, Particle swarm algorithm was used to optimize the layout scheme. A case study of layout optimization design is conducted to illustrate the proposed method.

The time-dependent barrier passage of a Brownian particle diffusing in the fractional damping environment is studied by using the reactive flux method. Characteristic quantities such as the rate constant and stationary transmission coefficient are computed for a thimbleful of insight into the barrier escaping dynamics. Results show that the barrier recrossing of the fractional damping reactive system is obviously weakened. And the nonmonotonic varying of the stationary transmission coefficient reveals a close dependence of the escaping process on the fractional damping properties. The time-dependent barrier passage of one-dimensional fractional damping reactive process is found very similar to the two-dimensional non-Ohmic case.

The southeastern Tibetan Plateau has the highest timberlines in the world and climate change affects this area to a considerable extent. Quantification of vegetation biomass in the forests at the timberline is essential for understanding carbon balance, forest structure and functional changes in the forests at timberlines. We describe biomass and its constituent components of a smith fir timberline forest occurring at an elevation of 4320 m on the Sergyemla Mountain in the southeastern Tibetan Plateau. The results show that, in the tree layer, the average diameter at breast height (DBH) was 35.6 cm, the density 251 trees per hectare with a total biomass of 309.9 t·ha−1. Of the total biomass, the trunks accounted for 70.49%, branches for 9.09%, leaves for 5.57% and roots for 14.85%. The total biomass in the shrub layer was 77.9 t·ha−1 of which the biomass of trunks, branches, leaves and roots accounted for 42.8, 14.9, 4.6 and 15.6 t·ha−1, respectively. The total biomass in the herb layer was 3.0 t·ha−1. The total vegetation biomass in the smith fir timberline forest was 390.9 t·ha−1, to which the tree layer contributed the most (79.3%), followed by shrubs (19.9%) and herbs (0.8%). We estimate that the smith fir forest stand at the timberline had a higher total biomass than other fir or spruce forest stands in the surrounding area.

A novel method for layout has been proposed for control panel. Six layout principles of ergonomics are taken into consideration to reduce the influences of indeterminate factors caused by the subjective judgments of designers. Optimization method and function is constructed to optimize the layout result based on genetic algorithm. And a computer-aided layout system is developed based on UG/OPEN API to realize automatic layout by computer. A detailed example of control panel layout of a thermal power plant is provided. The result shows that the efficiency and quality of layout are improved by this method.

We have previously reported that Kv1.3 channel is expressed in Daudi cells. However, the present study demonstrates that Daudi cell cycle progression is not affected by margatoxin, a Kv1.3 channel blocker, but can be suppressed by tetraethylammonium (TEA) and 1-[(2-chlorophenyl) diphenylmethyl]-1H-pyrazole (TRAM-34), a selective blocker of intermediate-conductance Ca(2+)-activated K(+) (IK) channels. Our patch-clamp data indicate that Daudi cells express an IK channel because it has a unit conductance of about 30 pS, is voltage-independent, and can be activated by submicromolar Ca(2+) and blocked by TRAM-34. Fetal bovine serum (FBS) elevated intracellular Ca(2+) concentration ([Ca(2+)](i)) and activated this IK channel. Conversely, Rituximab, a human-mouse chimeric monoclonal antibody of CD20, significantly decreased [Ca(2+)](i) and inhibited the channel. Furthermore, both FBS-induced IK channel expression and cell cycle progression were attenuated by the treatment with LY-294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor. These data together suggest that a growth factor(s) in FBS triggers cell cycle progression by elevating both IK channel activity via CD20 and IK channel expression on the cell surface via PI3K. Thus, elevated IK channel activity and expression may account, in part, for Daudi cell malignant growth and proliferation.

As for communication network simulation, embedding real network into simulation loop can bring lots of advantage. However, there are some problems waiting to be addressed. Targeting the application of communication network training, this paper firstly put forward a simulation structure of “Real-Network-in-the-Loop”, which can connect the real communication network with the simulated communication network and implement the data packet interaction between two. Secondly, this paper designed the internal structure of IP/HLA Converter, which can complete the conversion between the IP-format data packet and HLA-format data packet. Finally, this paper put forward some ways for realization of key techniques such as IP packet intercepting, raw IP packet sending and etc. With above schemes, paper solved the simulation issue of “Real-Network-in-the-Loop” fully.

TiN/Ti/NiSi/Si multilayer system is of great technological importance for complementary metal-oxide-semiconductor (CMOS) device fabrication. Interfacial reactions in this multilayer system play a critical role in determining the contact resistance and affect silicon consumption, a key issue in shallow junction structures. In this report, interfacial reactions in TiN/Ti/NiSi/Si multilayer systems, with a focus on Ti/NiSi interface, were characterized using X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and four-point probe measurements. Impact of thermal treatment temperatures was investigated.

The third-harmonic coefficient ${\mathit{B}}_{0}$ in a Au-film percolation system deposited on \ensuremath{\alpha}-${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ fracture surfaces by dc magnetron sputtering method is studied. The critical current ${\mathit{I}}_{\mathit{c}}$, coefficient ${\mathit{B}}_{0}$, and the relation between ${\mathit{I}}_{\mathit{c}}$ and ${\mathit{B}}_{0}$ are measured as functions of the zero-power sheet resistance ${\mathit{R}}_{0}$. The power-law behaviors ${\mathit{I}}_{\mathit{c}}$\ensuremath{\propto}${\mathit{R}}_{0}^{\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\alpha}}}$ and ${\mathit{I}}_{\mathit{c}}$\ensuremath{\propto}${\mathit{B}}_{0}^{\mathrm{\ensuremath{-}}\mathit{x}}$ are observed in the system and the exponents \ensuremath{\alpha} and x are found to be 0.51\ifmmode\pm\else\textpm\fi{}0.05 and 0.24\ifmmode\pm\else\textpm\fi{}0.08, respectively, which are different from those of other percolation systems and predictions of present theories applied to two-dimensional systems. The physical interpretation of the results and the universality discussion are also presented.

A wedge-shaped Pt-film percolation system was prepared by the magnetron sputtering method. A new nonlinear I-Vbehavior was found and can be well explained by the location-dependent hopping effect. Power-law behavior, σ(ω) α ωx and ϵ(ω) α ω−y, is observed near the percolation threshold. The exponents x and y are found to be 0.87±0.04 and 0.08±0.03, respectively, in agreement with the general scaling relation x + y = 1.

The temperature dependence of the conductance and the nonlinear electrical response of a Pt-film percolation system, deposited on fracture surfaces of \ensuremath{\alpha}-${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ ceramics, have been measured over three decades of sheet resistance. We find that in the temperature interval of T=77--300 K, the resistance temperature coefficient \ensuremath{\beta}=(1/R)dR/dT is not a constant, which is different from that for flat films. A dc I-V characteristic which strongly depends on the thickness of the film is found and it can be interpreted as a competition among the local Joule heating, hopping, and tunneling effects. The third-harmonic measurement suggests that the critical exponent comes from 1/f noise, which obeys the power-law dependences ${\mathit{S}}_{\mathit{R}}$\ensuremath{\propto}(p-${\mathit{p}}_{\mathit{c}}$${)}^{\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\kappa}}}$, R\ensuremath{\propto}(p-${\mathit{p}}_{\mathit{c}}$${)}^{\mathrm{\ensuremath{-}}\mathit{t}}$, and then ${\mathit{S}}_{\mathit{R}}$\ensuremath{\propto}${\mathit{R}}^{\mathit{w}}$ with w=\ensuremath{\kappa}/t, where ${\mathit{S}}_{\mathit{R}}$ is the mean square of resistance fluctuations, p the surface coverage fraction, and ${\mathit{p}}_{\mathit{c}}$ its percolation critical value. We find that w=0.45\ifmmode\pm\else\textpm\fi{}0.06, which is lower than the flat-film exponent. This result indicates that the tunneling and hopping effects in the fractal samples are much stronger than that of flat films.

The crystallinity, surface morphology, and I‐V characteristics of the Ag thin films deposited on fractal substrates by rf magnetron sputtering have been investigated. The poor crystallinity, fractal surface morphology, and abnormal nonlinear I‐V behavior of the thin films have been observed. The crystallinity of the films deposited on the fractal substrates is improved by increasing the substrate temperature and the thickness of the thin films. The nonlinear I‐V characteristics are influenced by the thickness of the thin films, substrate temperature, and measuring environment.

Although railway has played a great role in transportation in China, there has been no any study on air pollutants emissions of locomotives until now. Based on the annual statistical data collected by the Chinese Railway Statistic Center, using the emission factor method derived from fuel consumption, the air pollutants emissions of locomotives during 1975-2007 were calculated, and their emission intensities and dynamic characteristics were analyzed. The results show that the emissions of soot, SO2, CO and CnHm from steam and diesel locomotives in china decreased from 3510.6 thousand, 399.7 thousand, 846.0 thousand and 845.3 thousand ton in 1975 to 78.7 thousand, 11.4 thousand, 36.7 thousand and 26.4 thousand ton in 2007, indicating a decrease of 107.0 thousand, 12.1 thousand, 25.3 thousand and 25.6 thousand ton per year, respectively. However, the emissions of NO,showed an increase trend from 34.8 thousand ton in 1975 to 98.3 thousand ton in 2007 with an increase rate of 2.0 thousand ton per year. The emission intensities of soot, SO2, CO and CnHm decreased significantly from 686.2, 78.1, 165.4 and 165.2 g/(hundred converted ton-km) in 1975 to 5.4, 0.8, 2.5 and 1.8 g/(hundred converted ton-km) in 2007, respectively. The emission intensity of NOx fluctuated in the range of 5.0-8.0 g/(hundred converted ton-km). Air pollutants emissions of locomotives accounted for very little of the total emissions in China, and the emission intensities decreased persistently. It shows that railway transportation is a perfect way of saving energy and reducing emission in the sector of transportation.

To explore the inhibitory effect of KAI1 gene on breast cancer cell growth in vitro.Highly metastatic human breast cancer cell line MDA-MB-231 was transfected with pCMV-KAI1 or mock transfected plasmid pCMV with lipofectamine. Western blot was used to determine the expression of target protein of KAI1. The proliferative ability of cells was tested by MTT assay and colony-forming test. The cell cycle pattern was assayed by flow cytometry. The metastatic ability was investigated by cell adhesion and invasion assays.A stable cell clone transfected with KAI1 gene was obtained and over-expression of KAI1 protein was observed. There was a significant decline in cell proliferative ability of pCMV-KAI1 transfected MDA-MB-231 cells in comparison with the mock-transfected ones and non-transfected ones, revealed by MTT assay and colony-forming test (P0.05). The ability of adherence and invasion of pCMV-KAI1 transfected cells was significantly reduced in comparison with the other two groups (P0.05). Also, flow cytometry analysis revealed that in KAI1 transfected cell group the number of cells in G0/G1 phase increased markedly from 36.78% +/- 0.61% to 64.00% +/- 7.56%, while the number of cells in G2/M phase decreased from 17.88% +/- 0.76% to 7.63% +/- 0.60%, comparing with the non-transfected ones.KAI1 gene suppresses the invasive ability of human breast cancer cells in vitro and may inhibit the proliferative ability by changing the cell cycle pattern.

A new type of inhomogeneous system was constructed by depositing Ag thin films on fractal surfaces. The I-V characteristics of such samples exhibit a non-linear effect in air and a voltage breakdown effect in vacuum. Based on the special structure geometry of the samples, these unusual phenomena can be explained by the random tunnelling junction model under different environment.