We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Soil organic matter (SOM) and its fractions play an important role in maintaining or improving soil quality and soil fertility. Therefore, the effects of a 34-year long-term fertilizer regime on six functional SOM fractions under a double-cropping rice paddy field of southern China were studied in the current paper. The field experiment included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM) and without fertilizer input as control (CK). The results showed that coarse unprotected particulate organic matter (cPOM), biochemically, physically–biochemically and chemically protected silt-sized fractions (NH-dSilt, NH-μSilt and H-dSilt) were the main carbon (C) storage fractions under long-term fertilization conditions, accounting for 16.7–26.5, 31.1–35.6, 16.2–17.3 and 7.5–8.2% of the total soil organic carbon (SOC) content in paddy soil, respectively. Compared with control, OM treatment increased the SOC content in the cPOM, fine unprotected POM fraction, pure physically protected fraction and physico-chemically protected fractions by 58.9, 106.7, 117.6 and 28.3%, respectively. The largest proportion of SOC to total SOC in the different fractions was biochemically protected, followed by chemically and unprotected, and physically protected were the smallest. These results suggested that a physical protection mechanism plays an important role in stabilizing C of paddy soil. In summary, the results showed that higher functional SOM fractions and physical protection mechanism play an important role in SOM cycling in terms of C sequestration under the double-cropping rice paddy field.
This paper presents a compact multilayer substrate integrated waveguide (SIW) bandpass filter with wide stopband. The square SIW cavity resonators in multilayer substrates are horizontally and vertically coupled with magnetic coupling. By properly designing the coupling structure, the couplings between the higher-order resonant modes can be suppressed. Compared with the conventional single-layer SIW filters, the proposed multilayer SIW filter also exhibits a compact size. To verify the design concept, a double-layered SIW filter is fabricated and measured. The measured results agree well with the simulations. The measured results show that the upper stopband of the filter is extended to 2.73 times of the center frequency 8.02 GHz.
Changes in soil bulk density (BD), soil organic carbon (SOC) content, SOC stocks and soil labile organic C fractions (mineralizable C (Cmin), microbial biomass C (MBC), dissolved organic C (DOC), particulate organic C (POC), light fraction organic C (LFOC) and permanganate oxidizable C (KMnO4-C)) were explored over 3 years in a double-cropping rice system of southern China. Five organic and inorganic nitrogen (N) inputs were used: (1) 100% from chemical fertilizer (M0), (2) 30% from organic manure, 70% from chemical fertilizer (M30), (3) 50% from organic manure, 50% from chemical fertilizer (M50), (4) 100% from organic manure (M100) and (5) without N fertilizer input, as control (CK). All organic manure treatments decreased BD significantly in the 0–20 cm soil layer compared with CK. The SOC content and stocks with organic manure were significantly higher than in M0 or CK; also, the cumulative amount of SOC stocks in M30 and M50 increased at the plough layer, compared with CK. The non-labile C content increased significantly and the percentage of labile C were significantly higher with organic manure application than in M0 or CK. The soil carbon management index (CMI) also increased significantly under the application of organic manure. Therefore, application of organic manure can increase the pool of stable C in surface layers, and increase content and percentage of labile C. Based on soil carbon storage and CMI, the combined application of 30 or 50% N of organic manure with chemical fertilizer improves carbon cycling services and soil quality in southern China paddy soil.
We herein report an experimental study to explore the effects of impact inertia, film thickness and viscosity on the dynamics of shape deformation of a drop impacting a liquid film. We have identified that the spreading dynamics shows a weak dependence on impact inertia, but strongly depends on the film thickness. For a thick film, the liquid surface deforms and absorbs part of the impact energy, and hence inhibits spreading of the drop. For a thin film, the drop motion is restricted by the bottom solid substrate, promoting spreading. The periodicity of the capillary controlled shape oscillation, on the other hand, is found to be independent of impact inertia and film thickness. The damping of the shape oscillation shows strong dependence on the film thickness, in that the oscillation decays faster for smaller film thicknesses, due to the enhanced viscous loss.
Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.
Several studies analysed the associations between dietary carbohydrate intake, glycaemic index (GI) and glycaemic load (GL) and digestive system cancers; however, the results remain controversial. This study was to perform a meta-analysis evaluating the quantitative and dose–response associations between carbohydrate intake, GI and GL, and risk of digestive system cancers. We searched medical and biological databases up to June 2018 and identified twenty-six cohort studies and eighteen case–control studies. Meta-analytic fixed or random effects models were applied to process data. We also performed dose–response analysis, meta-regression and subgroup analyses. We found that high levels of GI were significantly associated with the risk of digestive system cancers at the highest compared with the lowest categories from cohort studies (summary relative risk (RR)=1·10, 95 % CI 1·05, 1·15). Similar effects were observed from case–control studies of the comparison between the extreme categories, but the difference did not reach statistical significance (summary OR=1·28, 95 % CI 0·97, 1·69). We also observed significant dose–response association between GI and digestive system cancers, with every 10-unit increase in GI (summary RR=1·003; 95 % CI 1·000, 1·012 for cohort studies; summary OR=1·09; 95 % CI 1·06, 1·11 for case–control studies). In addition, both cohort studies and case–control studies indicated that neither dietary carbohydrate intake nor GL bore any statistical relationship to digestive system cancers from the results of the highest compared with the lowest categories analyses and dose–response analyses. The results suggest a moderate association between high-GI diets and the risk of digestive system cancers.
A series of metal oxides (MnFeOx, MnCrOx, MnTiOx, and MnFeTiOx) supported on attapulgite (ATP) were synthesized by coprecipitation for the low-temperature selective catalytic reduction (SCR) of NOx with NH3. Then, they were subjected to appropriate characterizations for their properties (XRD, TEM, BET, XPS, etc.). The catalytic activity of MnFeTiOx/ATP catalyst was over 95% NOx conversion within a wide temperature window between of 175 and 300 °C, and 88% N2 selectivity. Moreover, MnFeTiOx/ATP presented excellent potassium resistance relative to the traditional V–W–Ti catalyst, and its denitration performance was significantly improved. The NOx conversion rate could be restored to nearly 90% at 210 °C after removing potassium via washing of K–MnFeTiOx/ATP. In addition, the MnFeTiOx/ATP showed better SO2 resistance and stability than the traditional V–W–Ti catalyst. Therefore, the MnFeTiOx/ATP catalyst has been proved to have broad prospects in NH3-SCR.
Study of the residues of organochlorine pesticides (OCPs) can assist with the assessment of the contamination level, distribution, sources, transportation and trends in these selected OCPs. We investigated the concentration levels of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethane (DDT), chlordane, which is currently used, and the never-used aldrin and dieldrin in the Ningbo region – a heavily industrialised and urbanised area in East China. OCPs were found in all soil samples and were predominantly composed of HCHs, DDT and its metabolites. The concentration of DDTs in the soil ranged from 2.2 to 566.6ngg–1, with a mean value of 55.6±94.8ngg–1, while the concentration of HCHs ranged from 2.7 to 28.2ngg–1, with an average of 4.6±2.9ngg–1. Aldrin, dieldrin, endrin and heptachlor were detected at much lower concentrations. The wide distribution of these never-used OCPs indicates that they have been input via long-range atmospheric processes. The results from analysis suggest that HCHs and DDTs were mainly derived from use in historical times.
A necessary and sufficient condition for a continuous function $g$ to be almost periodic on time scales is the existence of an almost periodic function $f$ on $\mathbb{R}$ such that $f$ is an extension of $g$. Our aim is to study this question for pseudo almost periodic functions. We prove the necessity of the condition for pseudo almost periodic functions. An example is given to show that the sufficiency of the condition does not hold for pseudo almost periodic functions. Nevertheless, the sufficiency is valid for uniformly continuous pseudo almost periodic functions. As applications, we give some results on the connection between the pseudo almost periodic (or almost periodic) solutions of dynamic equations on time scales and of the corresponding differential equations.
C3N4/Bi2WO6 heterojunction photocatalysts were successfully synthesized using consecutive hydrothermal and calcination processes. These photocatalysts were characterized using x-ray diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet-visible diffuse reflectance spectroscopy, x-ray photoelectron spectroscopy, and photoluminescence measurements. The results of these measurements indicated that the Bi2WO6 nanoparticles were approximately 30–50 nm and uniformly distributed on the surface of C3N4 lamellar structures. The 20% C3N4/Bi2WO6 displayed enhanced visible-light absorption from 432 nm to 468 nm. Photocatalytic tests also revealed that the 20% C3N4/Bi2WO6 photocatalyst exhibited significantly enhanced photocatalytic activity compared to that of pure C3N4 and Bi2WO6 under irradiation by visible light (λ > 420 nm). Furthermore, the excellent photocatalytic efficiency of the 20% C3N4/Bi2WO6 photocatalyst was determined to be related to the formation of C3N4/Bi2WO6 heterojunctions, and their presence was found to be generally beneficial for the separation of photogenerated electron–hole pairs.
In this paper, the hole carrier mobility of organic semiconductor N,N′-diphenyl-N,N′bis(1,1′-biphenyl)-4,4′-diamine (NPD) was researched by negative differential susceptance spectra (−ΔB = −w(C − Cgeo) ~ f). Under the condition of space charge limited current (SCLC), through solving the drift current equation and Poisson equation and simulating the spectra −ΔB = −w(C − Cgeo) ~ f, the relationship between the peak of −ΔB = −w(C − Cgeo) ~ f spectra (1/ƒp = τp) and the transfer time of carrier (τdc) could be achieved to be τdc = k × τp. So the hole-only device of ITO/NPD/Ag was fabricated to determine the capacitance spectra, and through which its −ΔB = −w(C − Cgeo) ~ f could be plotted. According to the relationship of τdc = k × τp, where k was determined to be 0.56, the transfer time and further the carrier mobility could be obtained. The carrier mobility depended on the electric field according to Poole-Frenkel model was further investigated in this report.
In this paper, carrier dynamics in N,N′-diphenyl-N,N′bis(1,1′-biphenyl)-4,4′-diamine (NPB) was studied using impedance spectroscopy (IS) and particle swarm optimization algorithm (PSO). We applied PSO to fit the frequency dependence of impedance spectroscopy of NPB, and achieved the charge-carrier transit time and the dispersive parameters of NPB, and then obtained carrier mobility. The impacts of the dispersive degree on the impedance had been analyzed. Though PSO, the three unknown parameters, charge-carrier transit time τdc and dispersive degree M, α in the admittance model were achieved simultaneously. The results verified the reliability of this method. Furthermore, we have presented the advantages of PSO compared with the traditional nonlinear least squares algorithm. In our limited knowledge, this paper begins the work to study materials in the deep level of algorithm
Ultrashort electron bunch trains can be used for plasma wake field acceleration (PWFA) to overcome the limit of transformer ratio of a single electron bunch, or high-power terahertz (Thz) radiation production by various radiation mechanisms. Basic facility for high-power THz radiation development based on ultrashort electron beam has been set up at accelerator lab of TUB. Using birefringent crystal serials, ultraviolet (UV) pulse shaping for photocathode radio frequency gun to produce THz-repetition-rate pulse train was realized. Driven by such pulses, ultrashort electron bunch train with picosecond (ps) spacing was obtained for THz production. Measurement of the stacked UV pulse trains was done by difference frequency generation (DFG), and the measured group velocity mismatch of α-BBO crystal at 266.7-nm wavelength was 0.8 ps/mm. This method may also be applied to form ramped electron bunch trains for PWFA.
Nitric oxide (NO) plays an important role in the dopaminergic and serotonergic system as the second messenger of the NMDA receptor and has possible roles in neurotransmission, neurosecretion, synaptic plasticity, and tissue injury in many neurological disorders, including schizophrenia. There is also genetic evidence to support the human NOS1 (neuronal nitric oxide synthase 1) gene as a promising candidate gene associated with schizophrenia. In this paper we conducted a case-control association study involving 1705 Chinese subjects and 12 genetic markers [11 single nucleotide polymorphisms (SNPs) and 1 microsatellite] mainly in the 5' flank region of the gene by direct sequencing and capillary electrophoresis. We identified SNP rs3782206 and several haplotypes derived from it as being significantly associated with schizophrenia and, specifically, in a paranoid subgroup. Our results strongly support a previous hypothesis that NOS1 contributes to the genetic risk of schizophrenia and suggest that further research on more NOS1 variants and its regular elements are warranted.
Amblyopia is usually considered to be a deficit in spatial vision. But
there is evidence that amblyopes may also suffer specific deficits in
motion sensitivity as opposed to losses that can be explained by the known
deficits in spatial vision. We measured sensitivity to visual motion in
random dot displays for strabismic and anisometropic amblyopic monkeys. We
used a wide range of spatial and temporal offsets and compared the
performance of the fellow and amblyopic eye for each monkey. The amblyopes
were severely impaired at detecting motion at fine spatial and long
temporal offsets, corresponding to fine spatial scale and slow speeds.
This impairment was also evident for the untreated fellow eyes of
strabismic but not anisometropic amblyopes. Motion sensitivity functions
for amblyopic eyes were shifted toward large spatial scales for amblyopic
compared to fellow eyes, to a degree that was correlated with the shift in
scale of the spatial contrast sensitivity function. Amblyopic losses in
motion sensitivity, however, were not correlated with losses in spatial
contrast sensitivity. This, combined with the specific impairment for
detecting long temporal offsets, reveals a deficit in spatiotemporal
integration in amblyopia which cannot be explained by the lower spatial
resolution of amblyopic vision.
InN nanowires were synthesized and characterized using a variety of techniques. A two-zone chemical vapor deposition technique was used to operate the vapor generation and the nanowire growth at differential temperatures, leading to high-quality single-crystalline nanowires and growth rates as high as 4–10 μm/h. Precise diameter control was achieved by using monodispersed gold clusters as the catalyst. Photoluminescence and Raman studies have been carried out for the InN nanowires at room temperature. Devices consisting of single nanowires have been fabricated to explore their electronic transport properties. The temperature dependence of the conductance revealed thermal emission as the dominating transport mechanism.