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Planar gated blood pool (GBP-P) radionuclide imaging is a valuable non-invasive technique for assessing left ventricular ejection fraction (LVEF). Serial cardiac imaging can be performed to monitor the potential decline in LVEF among patients undergoing cardiotoxic chemotherapy. Consequently, accurate LVEF determination becomes paramount. While commercial software programs have enhanced the LVEF values' reproducibility, concerns remain regarding their accuracy. This study aimed to generate a database of GBP-P studies with known LVEF values using Monte Carlo simulations and to assess LVEF values' accuracy using four commercial software programs.We utilised anthropomorphic 4D-XCAT models to generate 64 clinically realistic GBP-P studies with Monte Carlo simulations. Four commercial software programs (Alfanuclear, Siemens, General Electric Xeleris, and Mediso Tera-Tomo) were used to process these simulated studies. The accuracy and reproducibility of the LVEF values determined with these software programs and the intra- and inter-observer reproducibility of the LVEF values were assessed.Our study revealed a strong correlation between LVEF values calculated by the software programs and the true LVEF values derived from the 4D-XCAT models. However, all the software programs slightly underestimated LVEF at lower LVEF values. Intra- and inter-observer reliability for LVEF measurements was excellent.Accurate LVEF assessment is crucial for determining the patient's cardiac function before initiating and during chemotherapy treatment. The observed underestimation, particularly at lower LVEF values, emphasises the need for the accurate and reproducible determination of these values to avoid excluding suitable candidates for chemotherapy. The software programs' excellent intra- and inter-observer reliability highlights their potential to reduce subjectivity when using the semi-automatic processing option.This study confirms the accuracy and reliability of these commercial software programs in determining LVEF values from simulated GBP-P studies. Future research should investigate strategies to mitigate the underestimation biases and extend findings to diverse patient populations.Gated blood pool studies, left ventricular ejection fraction, Monte Carlo simulations, 4D-XCAT models.

A 3D scene graph is a compact and explicit representation in scene analysis. In today’s 3D scene graph prediction methods, the feature encoding method of nodes and edges is relatively simple, which essentially hinders the network from fully learning 3D point cloud features. In this paper, we propose a 3D scene graph task framework that fully expresses node and edge features, trying to meet the requirements of fully utilizing point cloud features to achieve high-precision prediction. Experimental results show that with the help of the new representation method, the prediction performance of 3D scene graphs has been significantly improved.

We present the development and evaluation of MOM6-COBALT-NWA12 version 1.0, a 1/12∘ model of ocean dynamics and biogeochemistry in the northwest Atlantic Ocean. This model is built using the new regional capabilities in the MOM6 ocean model and is coupled with the Carbon, Ocean Biogeochemistry and Lower Trophics (COBALT) biogeochemical model and Sea Ice Simulator version-2 (SIS2) sea ice model. Our goal was to develop a model to provide information to support living-marine-resource applications across management time horizons from seasons to decades. To do this, we struck a balance between a broad, coastwide domain to simulate basin-scale variability and capture cross-boundary issues expected under climate change; a high enough spatial resolution to accurately simulate features like the Gulf Stream separation and advection of water masses through finer-scale coastal features; and the computational economy required to run the long simulations of multiple ensemble members that are needed to quantify prediction uncertainties and produce actionable information. We assess whether MOM6-COBALT-NWA12 is capable of supporting the intended applications by evaluating the model with three categories of metrics: basin-wide indicators of the model's performance, indicators of coastal ecosystem variability and the regional ocean features that drive it, and model run times and computational efficiency. Overall, both the basin-wide and the regional ecosystem-relevant indicators are simulated well by the model. Where notable model biases and errors are present in both types of indicator, they are mainly consistent with the challenges of accurately simulating the Gulf Stream separation, path, and variability: for example, the coastal ocean and shelf north of Cape Hatteras are too warm and salty and have minor biogeochemical biases. During model development, we identified a few model parameters that exerted a notable influence on the model solution, including the horizontal viscosity, mixed-layer restratification, and tidal self-attraction and loading, which we discuss briefly. The computational performance of the model is adequate to support running numerous long simulations, even with the inclusion of coupled biogeochemistry with 40 additional tracers. Overall, these results show that this first version of a regional MOM6 model for the northwest Atlantic Ocean is capable of efficiently and accurately simulating historical basin-wide and regional mean conditions and variability, laying the groundwork for future studies to analyze this variability in detail, develop and improve parameterizations and model components to better capture local ocean features, and develop predictions and projections of future conditions to support living-marine-resource applications across timescales.

Owing to the substantial traffic emissions in urban areas, especially near road areas, the concentrations of pollutants, such as ozone (O3) and its precursors, have a large difference compared to regional averages, and their distributions cannot be captured accurately by traditional single-scale air quality models. In this study, a new version of a regional urban–street network model (an Integrated Air Quality Modeling System coupling regional urban–street: IAQMS-street v2.0) is presented. An upscaling module is implemented in IAQMS-street v2.0 to calculate the impact of mass transfer to regional scale from street network. The influence of pollutants in the street network is considered in the concentration calculation on the regional scale, which is not considered in a previous version (IAQMS-street v1.0). In this study, the simulated results in Beijing during August 2021, using IAQMS-street v2.0, IAQMS-street v1.0, and the regional model (Nested Air Quality Prediction Modeling System, NAQPMS), are compared. On-road traffic emissions in Beijing, as the key model input data, were established using intelligent image-recognition technology and real-time traffic big data from navigation applications. The simulated results showed that the O3 and nitrogen oxide (NOx) concentrations in Beijing were reproduced by using IAQMS-street v2.0 on both the regional scale and street scale. The prediction fractions within a factor of 2 (FAC2s) between simulations and observations of NO and NO2 increased from 0.11 and 0.34 in NAQPMS to 0.78 and 1.00 in IAQMS-street v2.0, respectively. The normalized mean biases (NMBs) of NO and NO2 decreased from 2.67 and 1.33 to −0.25 and 0.08. In the coupled model, the concentration of NOx at the street scale is higher than that at the regional scale, and the simulated distribution of pollutants on a regional scale was improved in IAQMS-street v2.0 when compared with that in IAQMS-street v1.0. We further used IAQMS-street v2.0 to quantify the contribution of local on-road traffic emissions to the O3 and NOx emissions and analyze the effect of traffic regulation policies in Beijing. Results showed that heavy-duty trucks are the major source of on-road traffic emissions of NOx. The relative contributions of local traffic emissions to NO2, NO, and O3 concentrations were 53.41 %, 57.45 %, and 8.49 %, respectively. We found that traffic regulation policies in Beijing largely decreased the concentrations of NOx and hydrocarbons (HC); however, the O3 concentration near the road increased due to the decrease consumption of O3 by NO. To decrease the O3 concentration in urban areas, controlling the local emissions of HC and NOx from other sources requires consideration.

High-resolution temperature reconstructions in the previous millennium are limited in Northeast Asia, but they are important for assessing regional climate dynamics. Here, we present, for the first time, a 202-year reliable reconstruction of April temperature changes before the millennium volcanic eruption in 946 CE using tree rings of carbonized logs buried in the tephra in Changbai Mountain, Northeast Asia. The reconstructed temperature changes were consistent with previous reconstructions in China and the Northern Hemisphere. The influences of large-scale oscillations (e.g. El Niño–Southern Oscillation, ENSO) on temperature variability were not significantly different between the periods of 745–946 CE preceding the eruption and 1883–2012. However, compared to the palaeotemperature of the previous millennium, the temperature changes were more complex with stronger temperature fluctuations, more frequent temperature abruption, and a weaker periodicity of temperature variance during the last 130 years. These recent changes correspond to long-term anthropogenic influences on regional climate.

Background: There has been a rapid increase in the number of human adenovirus type 7 (HAdV-7) and invasive pulmonary fungal infections (IPFIs) co-infection. Methods: In this study, we included patients with confirmed HAdV-7 infection during the period from 2018 to 2019 to explore clinical characteristics of severe HAdV-7 pneumonia combined with IPFIs. Results: Among the 143 patients, 35 cases were co-infected with IPFIs. Others were assigned to the control group (n Z 108). Patients wereprone to be complicated with respiratory failure, heart failure and hemophagocytic syndromein IPFIs group. Thirty-one species of fungi were detected in the IPFIs group, among whichAspergillus was the most common species. Compared to control group, patients had lowerlevels of WBC, CD3þ T lymphocyte counts and CD19þ B lymphocyte counts in IPFIs group. Conclusion: Aspergillus is the most common species in IPFIs combined with severe HAdV-7 pneumonia. For children with severe HAdV-7 pneumonia who are younger, have a long course of disease, and have been admitted to the ICU, we should predict the occurrence of IPFIs when there is multi-system dysfunction and the reduction of CD3+ T lymphocyte counts and CD19+ B lymphocyte counts in course of their disease.

In this work, model-predictive control (MPC) was combined for the first time with singular perturbation theory, and an original plasma kinetic control method based on extremely simple data-driven models and a two-time-scale MPC algorithm has been developed. A comprehensive review is presented in this paper. Slow and fast semi-empirical models are identified from data, by considering the fast kinetic plasma dynamics as a singular perturbation of a quasi-static equilibrium, which itself is governed, on the slow time scale, by the flux diffusion equation. This control technique takes advantage of the large ratio between the time scales involved in magnetic and kinetic plasma transport. It is applied here to the simultaneous control of the safety factor profile, q (𝑥), and of several kinetic variables, such as the poloidal beta parameter, β _p , and the internal inductance parameter, l _i , on the EAST tokamak. In the experiments, the available control actuators were lower hybrid current drive (LHCD) and co-current neutral beam injection (NBI) from different sources. Ion cyclotron resonant heating (ICRH) and electron cyclotron resonant heating (ECRH) are used as additional actuators in control simulations. In the controller design, an observer provides, in real time, an estimate of the system states and of the mismatch between measured and predicted outputs, which ensures robustness to model errors and offset-free control. Based on the observer information, the controller predicts the behavior of the system over a given time horizon and computes the optimal actuation by solving a quadratic programming optimization problem that takes the actuator constraints into account. A number of control applications are described in the paper, either in nonlinear simulations with EAST-like parameters or in real experiments on EAST. The simulations were performed with a fast plasma simulator (METIS) using either two control actuators (LHCD and ICRH) in a low density scenario, or up to four actuators at higher density: LHCD, ECRH, and two NBI systems driven in a on/off pulse-width-modulation (PWM) mode, with different injection angles. The control models are identified with the prediction-error method, using datasets obtained from open loop simulations in which the actuators are modulated with pseudo-random binary sequences. The simulations with two actuators show that various q (𝑥) profiles and β _p waveforms can be tracked without offset, within times that are consistent with the resistive and thermal diffusion time scales, respectively. In simulations with four actuators, simultaneous tracking of time-dependent targets is shown for q (𝑥) at two normalized radii, 𝑥 = 0 and 𝑥 = 0.4, and for β _p . Due to the inherent mismatch between the optimal NBI power request and the delivered PWM power, the kinetic controller performs with reduced accuracy compared with simulations that do not use the NBI/PWM actuators. The first experimental tests using this new control algorithm were performed on EAST when the only available actuator was the LHCD system at 4.6 GHz. The algorithm was thus used in its simplest single-input-single-output version to track time-dependent targets for the central safety factor, q _0 , or for β _p . In the closed loop control experiments, the q _0 targets were tracked in about one second, consistently with the plasma resistive time constant. Excellent tracking of a piecewise linear β _p target waveform was also achieved. When the NBI system became controllable in real time by the EAST plasma control system, new experiments were dedicated to multiple-input-multiple-output MPC control with three actuators: LHCD and two NBI actuators using the PWM algorithm. Given that the minimum time allowed between NBI on/off switching was 0.1 s, i.e. larger than the characteristic time of the fast plasma dynamics, a reduced version of the MPC controller based only on the slow model was used. Various controller configurations were tested during a single experimental session, with up to three controlled variables chosen among q _0 = q ( 𝑥 = 0), q _1 = q ( 𝑥 = 0.5), β _p and l _i . The main difficulty encountered during this session was the unavailability of the full baseline ICRH and ECRH powers that were used in the reference scenario, and from which the plasma model was identified. This often led to the saturation of one or several actuators, which prevented some targets selected in advance from being accessible. Nevertheless, in cases that were free from actuator saturation, q _0 and q _1 targets were successfully reached, in a time that is consistent with the resistive diffusion time of the model and with small oscillations that are characteristic of the PWM operation of the neutral beams. During the simultaneous control of q _0 and β _p , the ICRH power was too low and, in addition, the plasma density was much larger than the reference one. The q _0 targets were not accessible in this high-density/low-power case, but β _p control was successful. Finally, the simultaneous control of q _0 and l _i was satisfactory and, during the simultaneous control of, q _0 , β _p and l _i , the tracking of β _p and l _i was satisfactory but q _0 was too large due to the lack of ICRH power and to NBI saturation. In conclusion, the extensive nonlinear simulations described in this paper have demonstrated the relevance of combining MPC, data-driven models and singular perturbation methods for plasma kinetic control. This technique was also assessed experimentally on EAST, although some tests were perturbed by undesired parameter changes with respect to the reference scenario.

To investigate the characteristics and changes in the sources of carbonaceous aerosols in northern Chinese cities after the implementation of the Action Plan for Air Pollution Prevention and Control in 2013, we collected PM2.5 samples from three representative inland cities, i.e., Beijing (BJ), Xi'an (XA), and Linfen (LF), from January 2018 to April 2019. Elemental carbon (EC), organic carbon (OC), levoglucosan, stable carbon isotope, and radiocarbon were measured in PM2.5 to quantify the sources of carbonaceous aerosol, combined with Latin hypercube sampling. The best estimate of source apportionment showed that the emissions from liquid fossil fuels contributed 29.3±12.7 %, 24.9±18.0 %, and 20.9±12.3 % of the total carbon (TC) in BJ, XA, and LF, respectively, whereas coal combustion contributed 15.5±8.8 %, 20.9±18.0 %, and 42.9±19.4 %, respectively. Non-fossil sources accounted for 55±11 %, 54±10 %, and 36±14 % of the TC in BJ, XA, and LF, respectively. In XA, 44.8±26.8 % of non-fossil sources were attributed to biomass burning. The highest contributors to OC in LF and XA were fossil sources (74.2±9.6 % and 43.2±10.8 %, respectively), whereas those in BJ were non-fossil sources (66.8±13.9 %). The main contributors to EC were fossil sources, accounting for 91.4±7.5 %, 66.8±23.8 %, and 88.4±10.8 % in BJ, XA, and LF, respectively. The decline (6 %–16 %) in fossil source contributions in BJ since the implementation of the Action Plan indicates the effectiveness of air quality management. We suggest that specific measures targeted at coal combustion, biomass burning, and vehicle emissions in different cities should be strengthened in the future.

Many efforts have been devoted to quantifying the impact of intercontinental transport on global air quality by using global chemical transport models with horizontal resolutions of hundreds of kilometers in recent decades. In this study, a global online air quality source–receptor model (GNAQPMS-SM) is designed to effectively compute the contributions of various regions to ambient pollutant concentrations. The newly developed model is able to quantify source–receptor (S-R) relationships in one simulation without introducing errors by nonlinear chemistry. We calculate the surface and planetary boundary layer (PBL) S-R relationships in 19 regions over the whole globe for ozone (O3), black carbon (BC), and non-sea-salt sulfate (nss-sulfate) by conducting a high-resolution (0.5&deg &times 0.5&deg) simulation for the year 2018. The model exhibits a realistic capacity in reproducing the spatial distributions and seasonal variations of tropospheric O3, carbon monoxide, and aerosols at global and regional scales – Europe (EUR), North America (NAM), and East Asia (EA). The correlation coefficient (R) and normalized mean bias (NMB) for seasonal O3 at global background and urban–rural sites ranged from 0.49 to 0.87 and −2 % to 14.97 %, respectively. For aerosols, the R and NMB in EUR, NAM, and EA mostly exceed 0.6 and are within ±15 %. These statistical parameters based on this global simulation can match those of regional models in key regions. The simulated tropospheric nitrogen dioxide and aerosol optical depths are generally in agreement with satellite observations. The model overestimates ozone concentrations in the upper troposphere and stratosphere in the tropics, midlatitude, and polar regions of the Southern Hemisphere due to the use of a simplified stratospheric ozone scheme and/or biases in estimated stratosphere–troposphere exchange dynamics. We find that surface O3 can travel a long distance and contributes a non-negligible fraction to downwind regions. Non-local source transport explains approximately 35 %–60 % of surface O3 in EA, South Asia (SAS), EUR, and NAM. The O3 exported from EUR can also be transported across the Arctic Ocean to the North Pacific and contributes nearly 5 %–7.5 % to the North Pacific. BC is directly linked to local emissions, and each BC source region mainly contributes to itself and surrounding regions. For nss-sulfate, contributions of long-range transport account for 15 %–30 % within the PBL in EA, SAS, EUR, and NAM. Our estimated international transport of BC and nss-sulfate is lower than that from the Hemispheric Transport of Air Pollution (HTAP) assessment report in 2010, but most surface O3 results are within the range. This difference may be related to the different simulation years, emission inventories, vertical and horizontal resolutions, and S-R revealing methods. Additional emission sensitivity simulation shows a negative O3 response in receptor region EA in January from EA. The difference between two methods in estimated S-R relationships of nss-sulfate and O3 are mainly due to ignoring the nonlinearity of pollutants during chemical processes. The S-R relationship of aerosols within EA subcontinent is also assessed. The model that we developed creates a link between the scientific community and policymakers. Finally, the results are discussed in the context of future model development and analysis opportunities.

The influence of sub-grid particle formation (SGPF) in point source plumes on aerosol particles over eastern China was firstly illustrated by implementing an SGPF scheme into a global–regional nested chemical transport model with an aerosol microphysics module. The key parameter in the scheme was optimized based on the observations in eastern China. With the parameterization of SGPF, the spatial heterogeneity and diurnal variation in particle formation processes in sub-grid scale were well resolved. The SGPF scheme can significantly improve the model performance in simulating aerosol components and new particle formation processes at typical sites influenced by point sources. The comparison with observations at Beijing, Wuhan and Nanjing showed that the normal mean bias (NMB) of sulfate and ammonium could be reduced by 23 %–27 % and 12 %–14 %, respectively. When wind fields are well reproduced, the correlation of sulfate between simulation and observation can be increased by 0.13 in Nanjing. Considering the diurnal cycle of new particle formation, the SGPF scheme can greatly reduce the overestimation of particle number concentration in nucleation and Aitken mode at night caused by fixed-fraction parameterization of SGPF. On the regional scale, downwind areas of point source experienced an increase in sulfate concentration of 25 %–50 %. The results of this study indicate the significant effects of SGPF on aerosol particles over areas with the point source and the necessity of a reasonable representation of SGPF processes in chemical transport models.

Aerosol microphysical processes are essential for the next generation of global and regional climate and air quality models to determine particle size distribution. The contribution of organic aerosols (OAs) to particle formation, mass, and number concentration is one of the major uncertainties in current models. A new global–regional nested aerosol model was developed to simulate detailed microphysical processes. The model combines an advanced particle microphysics (APM) module and a volatility basis set (VBS) OA module to calculate the kinetic condensation of low-volatility organic compounds and equilibrium partitioning of semi-volatile organic compounds in a 3-D framework using global–regional nested domain. In addition to the condensation of sulfuric acid, the equilibrium partitioning of nitrate and ammonium, and the coagulation process of particles, the microphysical processes of the OAs are realistically represented in our new model. The model uses high-resolution size bins to calculate the size distribution of new particles formed through nucleation and subsequent growth. The multi-scale nesting enables the model to perform high-resolution simulations of the particle formation processes in the urban atmosphere in the background of regional and global environments. By using the nested domains, the model reasonably reproduced the OA components obtained from the analysis of aerosol mass spectrometry measurements through positive matrix factorization and the particle number size distribution in the megacity of Beijing during a period of approximately a month. Anthropogenic organic species accounted for 67 % of the OAs of secondary particles formed by nucleation and subsequent growth, which is considerably larger than that of biogenic OAs. On the global scale, the model well predicted the particle number concentration in various environments. The microphysical module combined with the VBS simulated the universal distribution of organic components among the different aerosol populations. The model results strongly suggest the importance of anthropogenic organic species in aerosol particle formation and growth at polluted urban sites and over the whole globe.

Vertical distributions of dicarboxylic acids, oxoacids, α-dicarbonyls and other organic tracer compounds in fine aerosols (PM2.5) were investigated at three heights (8, 120 and 260 m) based on a 325 m meteorological tower in urban Beijing in the summer of 2015. Results showed that the concentrations of oxalic acid (C2), the predominant diacid, were more abundant at 120 m (210±154 ng m−3) and 260 m (220±140 ng m−3) than those at the ground surface (160±90 ng m−3). Concentrations of phthalic acid (Ph) decreased with the increase in height, indicating that local vehicular exhausts were the main contributor. Positive correlations were noteworthy for C2 ∕ total diacids with mass ratios of C2 to main oxoacids (Pyr and ωC2) and α-dicarbonyls (Gly and MeGly) in polluted days (0.42≤r2≤0.65), especially at the ground level. In clean days, the ratios of carbon content in oxalic acid to water-soluble organic carbon (C2−C ∕ WSOC) showed larger values at 120 and 260 m than those at the ground surface. However, in polluted days, the C2−C ∕ WSOC ratio mainly reached its maximum at ground level. These phenomena may indicate the enhanced contribution of aqueous-phase oxidation to oxalic acid in polluted days. Combined with the influence of wind field, total diacids, oxoacids and α-dicarbonyls decreased by 22 %–58 % under the control on anthropogenic activities during the 2015 Victory Parade period. Furthermore, the positive matrix factorisation (PMF) results showed that the secondary formation routes (secondary sulfate formation and secondary nitrate formation) were the dominant contributors (37 %–44 %) to organic acids, followed by biomass burning (25 %–30 %) and motor vehicles (18 %–24 %). In this study, the organic acids at ground level were largely associated with local traffic emissions, while the long-range atmospheric transport followed by photochemical ageing contributed more to diacids and related compounds in the urban boundary layer than the ground surface in Beijing.

Solid state beam steering devices are key elements in low cost, robust, and three-dimensional imaging systems. Here, we present a silicon photonic beam steering device based upon an 8 × 8 grating coupler focal plane array approach fed by a thermo-optic Mach–Zehnder switching tree. In this device, transmission of light from the grating couplers is made through the backside of the chip using topside mirrors allowing for both high-efficiency out-coupling and direct flip-chip integration of drive electronics, providing a path to scale to denser focal plane arrays with large numbers of points in the future. A −13.8 dB fiber-to-fiber transmission was achieved in our preliminary test around 1523 nm for the beam steering chip.

This study introduces an effective channel selection method for hyperspectral infrared sounders. The method is illustrated for the Atmospheric InfraRed Sounder (AIRS) instrument. The results are as follows. (1) Using the improved channel selection (ICS), the atmospheric retrievable index is more stable, with the value reaching 0.54. The coverage of the weighting functions is more evenly distributed over height with this method. (2) Statistical inversion comparison experiments show that the accuracy of the retrieval temperature, using the improved channel selection method in this paper, is consistent with that of 1D-Var channel selection. In the stratosphere and mesosphere especially, from 10 to 0.02 hPa, the accuracy of the retrieval temperature of our improved channel selection method is improved by about 1 K. The accuracy of the retrieval temperature of ICS is also improved at lower heights. (3) Statistical inversion comparison experiments for four different regions illustrate latitudinal and seasonal variations and better performance of ICS compared to the numerical weather prediction (NWP) channel selection (NCS) and primary channel selection (PCS) methods. The ICS method shows potential for future applications.

Regional transport and heterogeneous reactions have been shown to play crucial roles in haze formation over a megacity cluster centered on Beijing. In this study, the updated Nested Air Quality Prediction Model System (NAQPMS) and the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model were employed to investigate the evolution of aerosols – in terms of the number concentration, size distribution, and degree of aging – in Beijing during six haze episodes between 15 November and 15 December 2016, as part of the Air Pollution and Human Health–Beijing (APHH-Beijing) winter campaign of 2016. The model exhibited reasonable performance not only with respect to mass concentrations of PM2.5 and its components in Beijing but also regarding the number concentration, size distribution, and degree of aging. We revealed that regional transport played a non-negligible role in haze episodes, with contributions of 14 %–31 % to the surface PM2.5 mass concentration. The contribution of regional transport to secondary inorganic aerosols was larger than that to primary aerosols (30 %–63 % and 3 %–12 %, respectively). The chemical transformation of SO2 along the transport pathway from source regions to Beijing was the major source of SO42-. We also found that sulfate formed outside Beijing from SO2 emitted in Beijing; this sulfate was then blown back to Beijing and considerably influenced haze formation. Along the transport pathway, aerosols underwent aging, which altered the mass ratio of the coating of black carbon to black carbon (RBC) and the size distribution of number concentrations. During the episodes, the geometric mean diameter (GMD) increased from less than 100 nm at the initial site to approximately 120 nm at the final site (Beijing), and the RBC increased from 2–4 to 4–8. During haze episodes with high humidity, the average contributions of gas and aqueous chemistry, heterogeneous chemistry, and primary emission to sulfate were comparable. However, their relative contributions varied with pollution levels. Primary emissions had the greatest impact under light to moderate pollution levels, whereas heterogeneous chemistry had a stronger effect under high pollution levels.

In this study, a full description and comprehensive evaluation of a global–regional nested model, the Aerosol and Atmospheric Chemistry Model of the Institute of Atmospheric Physics (IAP-AACM), is presented for the first time. Not only are the global budgets and distribution explored, but comparisons of the nested simulation over China against multiple datasets are investigated, which benefit from access to Chinese air quality monitoring data from 2013 to the present and the “Model Inter-Comparison Study for Asia” project. The model results and analysis can help reduce uncertainties and aid with understanding model diversity with respect to assessing global and regional aerosol effects on climate and human health, especially over East Asia and areas affected by East Asia. For the global simulation, the 1-year simulation for 2014 shows that the IAP-AACM is within the range of other models. Overall, it reasonably reproduced spatial distributions and seasonal variations of trace gases and aerosols in both surface concentrations and column burdens (mostly within a factor of 2). The model captured spatial variation for carbon monoxide well with a slight underestimation over ocean, which implicates the uncertainty of the ocean source. The simulation also matched the seasonal cycle of ozone well except for the continents in the Northern Hemisphere, which was partly due to the lack of stratospheric–tropospheric exchange. For aerosols, the simulation of fine-mode particulate matter (PM2.5) matched observations well. The simulation of primary aerosols (normalized mean biases, NMBs, are within ±0.64) is better than that of secondary aerosols (NMB values are greater than 1.0 in some regions). For the nested regional simulation, the IAP-AACM shows the superiority of higher-resolution simulation using the nested domain over East Asia. The model reproduced variation of sulfur dioxide (SO2), nitrogen dioxide (NO2), and PM2.5 accurately in typical cities, with correlation coefficients (R) above 0.5 and NMBs within ±0.5. Compared with the global simulation, the nested simulation exhibits an improved ability to capture the high temporal and spatial variability over China. In particular, the R values for SO2, NO2 and PM2.5 are increased by ∼0.15, ∼0.2, and ∼0.25 respectively in the nested grid. Based on the evaluation and analysis, future model improvements are suggested.

Beijing has suffered from heavy local emissions as well as regional transport of air pollutants, resulting in severe atmospheric fine-particle (PM2.5) pollution. This study developed a combined method to investigate source types of PM2.5 and its source regions during winter 2016 in Beijing, which include the receptor model (positive matrix factorization, PMF), footprint and an air quality model. The PMF model was performed with high-time-resolution measurements of trace elements, water soluble ions, organic carbon and elemental carbon using online instruments during the wintertime campaign of the Air Pollution and Human Health in a Chinese Megacity – Beijing (APHH-Beijing) program in 2016. Source types and their contributions estimated by PMF model using online measurements were linked with source regions identified by the footprint model, and the regional transport contribution was estimated by an air quality model (the Nested Air Quality Prediction Model System, NAQPMS) to analyze the specific sources and source regions during haze episodes. Our results show that secondary and biomass-burning sources were dominated by regional transport, while the coal combustion source increased with local contribution, suggesting that strict control strategies for local coal combustion in Beijing and a reduction of biomass-burning and gaseous precursor emissions in surrounding areas were essential to improve air quality in Beijing. The combination of PMF with footprint results revealed that secondary sources were mainly associated with southern footprints (53 %). The northern footprint was characterized by a high dust source contribution (11 %), while industrial sources increased with the eastern footprint (10 %). The results demonstrated the power of combining receptor model-based source apportionment with other models in understanding the formation of haze episodes and identifying specific sources from different source regions affecting air quality in Beijing.

First-order reversal curve (FORC) diagram, which visualizes the variation of magnetic interaction on a field plane, has been applied to nanocrystalline Ce-Fe-B melt-spinning ribbons. The FORC diagram exhibits different vertical spread along the Hu axis when the applied field is parallel or perpendicular to the ribbon surface. The discrepancy of vertical spread corresponds to different intergranular interactions, which can also be verified by Henkel plot, another method to identify the interactions. The larger vertical spread on the Hu axis along the perpendicular direction is ascribed to the dominance of magnetostatic interaction, while the smaller one along the parallel direction indicates the existence of stronger exchange coupling interaction. The remanence enhancement effect along the parallel direction further confirms the existence of exchange coupling. These indicate that a FORC diagram is a powerful evaluation method for distinguishing different magnetic interactions in permanent magnets. Moreover, Lorentz transmission electron microscopy was used to analyze the magnetic domain structure of nanocrystalline Ce-Fe-B melt-spinning ribbons.

In the 2015 winter month of December, northern China witnessed the most severe air pollution phenomena since the 2013 winter haze events occurred. This triggered the first-ever red alert in the air pollution control history of Beijing, with an instantaneous fine particulate matter (PM2. 5) concentration over 1 mg m−3. Air quality observations reveal large temporal–spatial variations in PM2. 5 concentrations over the Beijing–Tianjin–Hebei (Jing-Jin-Ji) area between 2014 and 2015. Compared to 2014, the PM2. 5 concentrations over the area decreased significantly in all months except November and December of 2015, with an increase of 36 % in December. Analysis shows that the PM2. 5 concentrations are significantly correlated with the local meteorological parameters in the Jing-Jin-Ji area such as the stable conditions, relative humidity (RH), and wind field. A comparison of two month simulations (December 2014 and 2015) with the same emission data was performed to explore and quantify the meteorological impacts on the PM2. 5 over the Jing-Jin-Ji area. Observation and modeling results show that the worsening meteorological conditions are the main reasons behind this unusual increase of air pollutant concentrations and that the emission control measures taken during this period of time have contributed to mitigate the air pollution ( ∼ 9 %) in the region. This work provides a scientific insight into the emission control measures vs. the meteorology impacts for the period.

Surface complexation modeling (SCM) has emerged as a powerful tool for simulating heavy metal adsorption processes on the surface of soil solid components under different geochemical conditions. The component additivity (CA) approach is one of the strategies that have been widely used in multicomponent systems. In this study, potentiometric titration, isothermal adsorption, zeta potential measurement, and extended X-ray absorption fine-structure (EXAFS) spectra analysis were conducted to investigate Cd adsorption on 2 : 1 clay mineral montmorillonite, on Gram-positive bacteria Bacillus subtilis, and their mineral–organic composite. We developed constant capacitance models of Cd adsorption on montmorillonite, bacterial cells, and mineral–organic composite. The adsorption behavior of Cd on the surface of the composite was well explained by CA-SCM. Some deviations were observed from the model simulations at pH 2Cd, SOCd+, R-COOCd+, and R-POCd+ were the predominant species on the composite surface over the pH range of 3 to 8. The distribution ratio of the adsorbed Cd between montmorillonite and bacterial fractions in the composite as predicted by CA-SCM closely coincided with the estimated value of EXAFS at pH 6. The model could be useful for the prediction of heavy metal distribution at the interface of multicomponents and their risk evaluation in soils and associated environments.

The mid-subtropical forest area in southwest China was affected by anthropogenic mercury (Hg) emissions over the past 3 decades. We quantified mercury dynamics on the forest field and measured fluxes and pools of Hg in litterfall, throughfall, stream water and forest soil in an evergreen broadleaved forest field in southwestern China. Total Hg (THg) input by the throughfall and litterfall was assessed at 32.2 and 42.9 µg m−2 yr−1, respectively, which was remarkably higher than those observed from other forest fields in the background of North America and Europe. Hg fluxes across the soil–air interface (18.6 mg m−2 yr−1) and runoff and/or stream flow (7.2 µg m−2 yr−1) were regarded as the dominant ways for THg export from the forest field. The forest field hosts an enormous amount of atmospheric Hg, and its reserves is estimated to be 25 341 µg m2. The ratio of output to input Hg fluxes (0.34) is higher compared with other study sites. The higher output / input ratio may represent an important ecological risk for the downstream aquatic ecosystems, even if the forest field could be an effective sink of Hg.

Additive manufacturing based on liquid resin curing is one of the most promising methods to construct delicate structures. However, precision and speed are limited by the vertical adhesion of in situ cured resin at the curing interface. To overcome the unavoidable adhesion and to develop a general curing interface, we propose a slippery surface taking inspiration of the peristome surface of the pitcher plant. Such surface shows ultra-low adhesive energy at the curing interface due to the inhibition of the direct contact between the cured resin and the solid surface, which also increases the refilling speed of liquid resin. This ultra-low adhesive energy interface is effective for continuous 3D printing and provides insights into the physical mechanisms in reducing vertical solid-solid interfacial adhesion.

Nucleation is an important source of atmospheric aerosols which have significant climatic and health implications. Despite intensive theoretical and field studies over the past decades, the dominant nucleation mechanism in the lower troposphere remains to be mysterious. Several recent laboratory studies on atmospheric nucleation may shed light on this important problem. However, the most interesting finding from those studies was based on the derived H2SO4 concentration whose accuracy has not yet been evaluated by any other means. Moreover, the threshold H2SO4 concentration needed to reach the same degree of nucleation reported by two separate nucleation studies varies by about one order of magnitude. In this study, we apply a recently updated kinetic nucleation model to study the nucleation phenomena observed in those recent experiments. We show that the H2SO4 concentration can be estimated with a higher level of accuracy with the kinetic model by constraining the simulated particle size distributions with observed ones. We find that the required H2SO4 concentrations to achieve the best agreement between modeling and measurements are a factor of ~2 to 4 higher than reported in those experiments. More importantly, by comparing the derived thermodynamic properties associated with the nucleation process, we conclude that different unknown species may participate in the two separate nucleation experimental studies, which may explain the large difference in the reported threshold H2SO4 concentration. Although the unknown species involved has yet to be identified, the derived values of thermodynamic properties can serve as a valuable guideline for the search of their chemical identities using advanced quantum-chemical approaches.

The concern of adverse health impacts from exposure to vehicle-emitted nanoparticles has been escalating over the past few years. In order to meet more stringent EPA emission standards for particle mass emissions, advanced exhaust after-treatment systems such as continuously regenerating diesel particle filters (CRDPFs) have to be employed on vehicles and fuel with ultra-low sulfur is to be used. Although CRDPFs were found to be effective in reducing particle mass emissions, they were revealed to increase the potential of volatile nanoparticle formation. Significant nanoparticle concentrations have also been detected for vehicles running on ultra-low sulfur fuel but without CRDPFs. The main focus of this paper is the formation and evolution of nanoparticles in an exhaust plume under ultra-low sulfur conditions. Such a study is necessary to project future nanoparticle emissions as fuel compositions and after-treatment systems change. We have carried out a comprehensive quantitative assessment of the effects of enhanced sulfur conversion efficiency, sulfur storage/release, and presence of non-volatile cores on nanoparticle formation using a detailed composition resolved aerosol microphysical model with a recently improved H2SO4-H2O homogeneous nucleation (BHN) module. Two well-controlled case studies show good agreement between model predictions and measurements in terms of particle size distribution and temperature dependence of particle formation rate, which leads us to conclude that BHN is the main source of nanoparticles for vehicles equipped with CRDPFs. We found that the employment of CRDPFs may lead to the higher number concentration of nanoparticles (but smaller size) in the exhaust of vehicles running on ultra-low sulfur fuel compared to those emitted from vehicles running on high sulfur fuel. We have also shown that the sulfate storage and release effect can lead to significant enhancement in nanoparticle production under favorable conditions. For vehicles running on ultra-low sulfur fuel but without CRDPFs, the BHN is negligible; however, the condensation of low volatile organic compounds on nanometer-sized non-volatile cores may explain the observed nucleation mode particles.

Distance and experience/endurance: liminal spaces and survival in Ingrid Winterbach’s Niggie (Cousin) In this article aspects of Ingrid Winterbach’s novel, “Niggie” (“Cousin”), which is set against the backdrop of the last months of the Anglo-Boer War (1899-1902) are analysed. The geographical (spatial) and psychological isolation of the characters and the influence of the historical situation on the psyche of the characters are discussed. Special attention is paid to the relation of the characters to nature. The main characters seem to find themselves in a series of liminal situations. The war experiences force them to accept the inevitable, but also to find ways and means to transcend personal and collective trauma. Though they do change irrevocably and have to exploit their own creativity and psychological resources to the utmost, they do survive and eventually continue their lives under more normal circumstances. The novel explores the experience of trauma and the possibility and quality of survival, but the sensitive analysis of the human aspects of the specific historical circumstances has a wider resonance – so that the novel can be regarded as a historical novel about the future.

In this article the argument is put forward that although the criterial force in narrative texts is the fact that these texts are intrinsically narrative, there is a range of extra-narrative components which should also be taken into consideration in processes of interpretation. The article explores the cultural dimension of a short story in Setswana and illustrates how cultural knowledge is essential to reach a more comprehensive understanding of the text.

Length–weight relations were estimated for 14 endemic fish species of the upper Yangze River, namely Sinogastromyzon szechuanensis Fang, 1930; Jinshaia sinensis (Sauvage et Dabry de Thiersant, 1874); Megalobrama pellegrini (Tchang, 1930); Coreius guichenoti (Sauvage et Dabry de Thiersant, 1874); Rhinogobio cylindricus Günther, 1888; Rhinogobio ventralis (Sauvage et Dabry de Thiersant, 1874); Procypris rabaudi (Tchang, 1930); Ancherythroculter kurematsui (Kimura, 1934); Ancherythroculter nigrocauda Yih et Wu, 1964; Acrossocheilus monticola (Günther, 1888); Leptobotia elongata (Bleeker, 1870); Hemiculterella sauvagei Warpachowski, 1888; Hemiculter tchangi Fang, 1942; and Xenophysogobio boulengeri (Tchang, 1929). The a values obtained ranged from 0.006 to 0.023, and b values ranged from 2.955 to 3.377. The t-test results indicated the first seven species grew isometrically and the other 7 species grew allometrically.

Footprints in the sand – a re-evaluation of C.M. van den Heever’s oeuvre C.M. van den Heever was a prominent Afrikaans writer in the period between 1930 and 1950. Since the 1960s the general opinion held by literary scholars has been that his work has become dated thematically as well as stylistically. In an essay, written in 1947, Van den Heever states and explains his poetical stance on some key issues such as the sources of his writing, the schism between romanticism and realism in his life and work, the importance of a vision of life in his work. The essay also contains some valuable indications of the philosophical influences on Van den Heever as a person and as a writer. In this article Van den Heever’s own views are compared to the views held by critics. The article indicates that Van den Heever consciously addressed exactly those problems that critics regard as shortcomings in his oeuvre. The article concludes that rereading older works of literature opens up new perspectives on the past and on older literary texts. Older literature also adds to the present because knowledge of the past contributes to an understanding of the present. In the final instance the statement is made that literature constitutes a link between past and present, and older literature lives on through rereadings by committed readers.

Karolina Ferreira (1993) by Lettie Viljoen and Vincent van Gogh’s 'The Night Café' (1888): A spatial-coherent reading Building on the text-linguistic definition of coherence as an intra-, inter-, and extratextual unity the underlying relations in Karolina Ferreira by Lettie Viljoen are explored. Vincent van Gogh’s “The Night Café” is a hidden spatial-visual intertext which can serve as a centre of contemplation regarding the coherence of Karolina Ferreira and that of Viljoen’s oeuvre. Van Gogh’s description of this work in his letters is echoed in Viljoen’s depiction of the billiard room, a space betwixt and between. “The Night Café” resonates intra-, inter-, and metatextually and unlocks the circular or spheric-spatial coherence of Karolina Ferreira, which can be visualized as a (Buddhist) mandala. At the core of this mandala is the billiard table: the meditative object and centre of control with respect to the narrative space (textual space) and the narrated, intertextual, and metatextual spatial dimensions of Karolina Ferreira. Metatextually Karolina Ferreira disrupts the conventional temporality of narrative texts in favour of the suppressed narrative category of space.

Textness: The degree of creativity of a text as marker of the boundaries between language disciplines In this article it is proposed that the traditional distinction between linguistics and literature poses more questions than it gives answers. In view of the modern academic context of focus areas and research programmes the focus should rather be on the similarities between the subdisciplines of language than on the differences. The growth of creative writing as science and the development of the discipline of language usage as applied in South Africa force us to look afresh at language-related subjects. Text is postulated as the binding factor between the study of linguistics, literature, creative writing and language usage. But text has to be defined in terms of the degree of creativity, thus indicating text as the binding factor of a given text, and creativity as the differentiating factor.

Die skrywer van die jeugboek is in verreweg die meeste gevalle ’n volwassene, terwyl die verteller soms grootmens, soms jongmens is, en die veronderstelde leser per definisie altyd ’n jeugdige. In wese dus ’n paradoks, ’n teelaarde vir ’n kommunikasiegaping. Hoe oorleef die skrywer dié paradoks?

Characters for young readers In discussions on the nature of children and youth literature, various aspects occur repeatedly. The presumption that these aspects are also factors that exert a meaningful influence on the characters in the genre is largely confirmed by research. Based on developmental characteristics, 11-14 year-olds are identifiable as a group with a unique profile. From this it follows that a relationship between the reader profile en genre conventions can be indicated and that it can be applied specifically to character as an element of the narrative. Characteristic genres and genre conventions establish a framework of expectations within the reader, which co-determines the selection, creation and portrayal of characters. The social cognitive development of the young reader appears to be of special importance in character portrayal. Reader identification with characters largely contributes to reader involvement and to the pleasure a young reader derives from the reading of stories. As a result of the educational situatedness of the young reader, ideology plays an important role in literature for the young. Successful characters have always been regarded as important in ensuring the success of a story. Through selection and the equipping of characters, and by means of portrayal, the writer can work towards this aim.

The endless thread This article discusses the volume of short stories, Boereoorlogstories, which was compiled and edited by Jeanette Ferreira. The stories are all about the Anglo-Boer War (1899-1902) and though some of the stories simply retell history from the point of view of specific individuals, some of the stories are indeed fine examples of postmodernist fiction. In the best stories in the volume the narrators engage with history in a number of ways: by indicating the fallacies of historiography, by contrasting little narratives with the master narrative of official historical documents, by emphasizing the textuality of history and the necessity of retelling the past. Personalized history and personalized interpretations of historical facts and historical documents are used in attempting to find or create new identities. The use of historiographical metafiction enables these narrators to interact with a present which is so complex and still so near that it can only be approached indirectly through stories.

Intertextuality as symbiosis: two namesakes and an erudite angel This article focuses on the relations among the variety of texts which are referred to in the story "Dr. Diedericks leer om te lag" by T.T. Cloete. The apparently explicit allusions become much more complex when analysed closely. Cloete's story becomes a postmodernist discourse in which precursors, sources and "other voices” are creatively “misread”. In the process of transforming an older text, Van Melle's story "Oom Diederik leer om te huil" gains a new lease on life, but the boundaries of literature are also challenged by incorporating philosophical writings and popular medical books into the story. A metaphysical layer surfaces in the interpretation of the story as the directions of the erudite angelic figure to the sick man are analysed. The analysis and interpretation of the intertextual web created by Cloete’s story are used to illustrate the symbiotic nature of the relations among texts.

Events such as strikes by nurses presently focus the attention on human rights in health care. During the four year training of the student nurse leading to registration the tutor should facilitate the development of respect for rights and responsibilities of people. The purpose of this study was to determine the extent to which respect for rights and responsibilities of people are facilitated with the student nurse, as well as to set guidelines for facilitating respect for rights and responsibilities in nursing education practice.

Truthful lying in T.T. Cloete’s short stories In this article an attempt is made to characterize the short stories of T.T. Cloete in Die waarheid gelieg. The theory of focalization is examined briefly and a definition of focalization which emphasizes the epistemological aspects ofperspective and formulation is used to examine the stories. The stories are compared to stories of Kafka and Borges indicating the resemblances, especially the fascination with the unexpected and weird contradictions in reality, as well as the differences. An intratextual reading of the stories and poems by the same author is undertaken in an attempt to formulate the epistemic position of the focalization in the texts. The article concludes that the Christian worldview as well as a poetics of nomenliterature of the abstract author can be deduced from the stories on account of the assumption that epistemic stances are reflected in the narrative representation and can be communicated to readers by means of propositional attitudes.

T.T. Cloete: prospector of the planet earth In this article the publication of this special issue of Literator is motivated by giving an introduction to the work of T.T. Cloete as teacher of literature, as critic and as poet. The contributions in the journal are then discussed and similarities and differences in the articles are indicated. The idea is put forward that an intertextual web, echoing the intertextual relations in the poetry and prose, is formed by the various views in the articles. The article concludes with an extended bibliography of studies on the work of T.T. Cloete.

In this article the Orange River variety of modern Afrikaans is investigated in terms of Van Coetsems types of language interference: borrowing and imposition. It is argued that the initial contact between Dutch and Khoi resulted in the imposition of Khoi forms on seventeenth-century Dutch. These two forms of interference can still be traced in modern Orange River Afrikaans. A modern variety of a language can thus be studied in order to shed some light on the history of that language.

The American linguist, William Labov, distinguished six elements underlying a well-structured oral narrative. These elements are, in the course of this article, developed into a paradigm which can he used in the writing of a children's story. Against the background of the sociolinguistics of Labov’s analysis the elements are further placed within Mary Louise Pratt's narratological approach. The elements are then applied to children's literature. Published and unpublished children's stories are analysed with reference to the elements indicated by Labov. On the basis of the analysis the elements are developed into a paradigm in the Creative Writing sense of the term.

This study was conducted to assess the occurrence of fractures in solid-organ transplant recipients. Methods. Medical record review and surveys were performed. Patients received less than 6 months of glucocorticoids. Results. Of 351 transplant patients, 175 patients provided fracture information, with 48 (27.4%) having fractured since transplant (2–6 years). Transplants included 19 kidney/liver (50% male), 47 kidney/pancreas (53% male), 92 liver (65% male), and 17 pancreas transplants (41% male). Age at transplant was 50.8±10.3 years. Fractures were equally seen across both genders and transplant types. Calcium supplementation (n=94) and bisphosphonate therapy (n=52) were observed, and an association with a lower risk of fractures was noted for bisphosphonate users (OR=0.45 95% C.I. 0.24, 0.85). Fracture location included 8 (16.7%) foot, 12 (25.0%) vertebral, 3 (6.3%) hand, 2 (4.2%) humerus, 5 (10.4%) wrist, 10 (20.8%) fractures at other sites, and 7 (14.6%) multiple fractures. The estimated relative risk of fracture was nearly seventeen-times higher in male liver transplant recipients ages 45–64 years compared with the general male population, and comparable to fracture rates on conventional immunosuppressant regimens. Conclusion. We identify a high frequency of fractures in transplant recipients despite limited glucocorticoid use.

Creative writing has been taught as a subject at the tertiatiory level in the USA for many years. In this article the issue of creative writing as subject for a South African degree is discussed. The matter at issue is not whether creative writing has the potential to be a university subject, but rather what such a subject should include. Thus the content of creative writing as university subject and how it should be taught are addressed. The conclusion that is reached is that the main issue at stake is the balance to be struck among literary theory, writing theory and writing practice. Starting in the near future the Potchefstroom University for CHE will be offering a course in creative writing as a degree credit. The subject-matter, possible organization and integration, as well as its specific niche are considered.

Om oor ’n onderwerp soos die taalgebruik by die bediening van die Woord van God te gesels is moeiliker as wat dit by die eerste ja-sê gelyk het. Moeiliker nog as jy so voortvarend is om voor te gee dat jy iets van godsdiensuitsending weet. Aan die ander kant; ek het gemeen dit gaan tog maar net oor kommunikasie, en oor die feit dat taal die duidelikste en die voor die hand liggendste manier van kommunikasie is. Dit is egter as ’n mens jou gedagtes oor die onderwerp wil begin orden dat jy agterkom in watter wildernis jy jou bevind. Jy loop in die eerste plek die gevaar dat jy aardse uitsprake kan maak in aardse woorde oor ’n saak wat juis hoër as die aarde lê; jy loop die verdere gevaar dat jy as onopgeleide vir die teologies opgeleides wil kom sê hoe hulle iets moet kommunikeer wat veel, veel meer is as ’n blote stuk vakinhoud. Dus moet jy jouself die reg, en die wete, aanmatig dat jy weet hoe om dit wat jy self maar net op die geloof af hoop, aan ander te verduidelik. Dit gaan daarom nie net om kom­ munikasie nie, dit gaan juis om die soort kommunikasie wat groter is as woorde, dit gaan om die oopmaak van die diepste binnekant van ons menswees hier op aarde. En dan uiteindelik om hierdie oopmaak oor ’n medium waar die gehoor onweetbaar groot en divers is.

Without trying to distinguish between the subject Afrikaans and the language Afrikaans, and without denying the metaphoric meaning of a statement like ‘Afrikaans is oppressive’, this article investigates the position of Afrikaans among the other ten main languages of South Africa. The idea that Afrikaans is a mere minority language in South Africa is repudiated. Statistical figures indicate that Afrikaans is the language with the largest number of speakers and the third largest mother longue in South Africa. The question as to why Afrikaans is regarded as a minority language - even by its own users - is also touched upon. In this article it is argued that the political system of apartheid has split the language community into two parts and that therefore this community has never been a unity. The future role of Afrikaans in a democratic South Africa will also be determined by the users of Afrikaans, given that the Afrikaans language community could be consolidated. This article argues that the lack of unity within the Afrikaans speech community is mainly the reason for the belief that Afrikaans is, in a statistical sense, a minority language. I f the Afrikaans speech community can be consolidated, Afrikaans will be able to take its natural place among the other ten languages of South Africa. Such a consolidation, however, has to be brought about by those who form this community.

In this article a course in narratology, in which the emphasis falls on films based on specific novels, is discussed. The article is mainly informative, giving details about the principles on which the course is based, explaining the way in which the course was developed and outlining the contents of the course. In the last part of the article three examples of the approach which is followed are given and the bibliography can be seen as a basic reading list for such a course. The article is an empirical report which puts forward a possible way in which the study of films on an advanced level can be approached.

Chromosome numbers of 46 specimens of grasses, involving 24 taxa from South Africa and Australia, have been determined during the present study. For the first time chromosome numbers are given for Eragrostis sarmentosa (Thunb.) Trin. (n = 20). Panicum aequinerve Nees (n = 18), Digitaria argyrograpta (Nees) Stapf (n = 9) and D. maitlandii Stapf & C.E. Hubb. (n = 9). Additional polyploid levels are described for Diplachne fusca (L.) Beauv. ex Roem. & Schult. (n = 10) and Digitaria diagonalis (Nees) Stapf var. diagonalis (n = 9). B-chromosomes were observed in several different specimens. The presence of B-chromosomes often results in abnormal chromosomal behaviour during meiosis.

This article pays tribute to Elisabeth Eybers who was not only the first woman to publish a volume of poetry in Afrikaans, but who has also received numerous awards for her poetry over the years. She has recently been awarded the P.C. Hooftprijs, the most prestigious literary award in the Netherlands. The relevance of her work is indicated by a discussion of her unique position in the Afrikaans and Dutch literary worlds, and by proposing a new reading of a well-known poem to illustrate the point of view that good poetry can always be reread in relevant ways.

A new heavy-ion linac within a continuous-wave (CW) 4-rod radio-frequency quadrupole (RFQ) was designed and constructed as the injector for the separated-sector cyclotron (SSC) at the Heavy Ion Research Facility at Lanzhou (HIRFL). In this paper, we present the development of and the beam commissioning results for the 53.667 MHz CW RFQ. In the beam dynamics design, the transverse phase advance at zero current, σ_{0⊥}, is maintained at a relatively high level compared with the longitudinal phase advance (σ_{0∥}) to avoid parametric resonance. A quasi-equipartitioning design strategy was applied to control the emittance growth and beam loss. The installation error of the electrodes was checked using a FARO 3D measurement arm during the manufacturing procedure. This method represents a new approach to measuring the position shifts of electrodes in a laboratory environment and provides information regarding the manufacturing quality. The experimental results of rf measurements exhibited general agreement with the simulation results obtained using CST code. During on-line beam testing of the RFQ, two kinds of ion beams (^{40}Ar^{8+} and ^{16}O^{5+}) were transported and accelerated to 142.8 keV/u, respectively. These results demonstrate that the SSC-Linac has made a significant progress. And the design scheme and technology experiences developed in this work can be applied to other future CW RFQs.

In this article the concept of the sociocode, as described and used by Fokkema (1984), is used to describe the characteristic way of representation in modernist texts. Representation in literature is explained as the result of a specific set of perceptions which are individually as well culturally determined. From the discussion of the sociocode of Modernism, the conclusion is made that modernist texts do not represent; these texts are presentations, they are primarily concerned with their own ontology. In conclusion the similarities between Modernism as a literary movement in Western Europe and the work of the Sestigers in Afrikaans are indicated. It is suggested that these similarities should be investigated in more detail.