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Zircon U-Pb geochronology, geochemistry and Hf isotope analysis of supracrustal rocks in the Anshan-Benxi area in the northeastern part of the North China Craton can help constrain their petrogenesis and tectonic background, providing evidence for a further investigation of the late Neoarchaean tectonic environment in the Anshan-Benxi area. The primary rock types observed among the supracrustal rocks in the Anshan-Benxi area comprise amphibolite, metamorphic rhyolite, metamorphic sandstone, chlorite schist, actinolite schist, among others. SHRIMP zircon U-Pb dating indicates that magmatic zircons from the amphibolite (GCN-1) formed at 2553 ± 18Ma. Similarly, LA-ICP-MS zircon U-Pb dating reveals that magmatic zircons from the metamorphic rhyolite (G2304-1) were formed at 2457 ± 35Ma. The peak age of the metamorphic sandstone is determined to be approximately 2500Ma, suggesting that the supracrustal rocks in the Anshan-Benxi area originated in the late Neoarchaean. The protoliths of sericite quartz schist and metamorphic rhyolite are identified as rhyolitic volcanic rocks, displaying a right-leaning distribution pattern of rare earth elements (REEs). On the other hand, actinolite schist, chlorite schist and amphibolite are classified as basaltic volcanic rocks, exhibiting a flat REE pattern with a weak negative Eu anomaly. The εHf(t) value of metamorphic rhyolite ranges between -1.19 and -1.47, with a two- stage depleted mantle model age of tDM2(Ma) = 2922–3132 Ma. The protolith magma of sericite quartz schist and metamorphic rhyolite originates from partial melting of 3.0Ga basaltic crust, while the source of actinolite schist, chlorite schist and amphibolite are mainly derived from the mantle. In summary, the findings suggest that plate already existed in the late Neoarchaean or earlier, with magmatism in the Anshan-Benxi area likely occurring within an arc tectonic environment linked to plate subduction.
We study the melting process of a solid under microgravity, driven solely by lateral vibrations that are perpendicular to the applied temperature gradient due to the absence of gravity-induced convection. Using direct numerical simulations with the phase-field method, we examine two-dimensional vibration-induced melting in a square cavity over four orders of magnitude of vibrational Rayleigh numbers, $10^5\le Ra_{{vib}}\le 10^9$. Our results show that as melting progresses, the flow structure transitions from a periodic-circulation regime with diffusion-dominated heat transfer to a columnar regime with vibroconvection. The mean height of the liquid–solid interface follows a power-law dependency with time, $\bar {\xi } \sim \tilde t^{1/(2-2\alpha )}$, where $\alpha = 0$ in the periodic-circulation regime and $\alpha = 1/2$ in the columnar regime. We further observe that within the columnar regime, the morphological evolution of the liquid–solid interface is influenced by the interaction of columnar thermal plumes in the central regions and the peripheral flow near the sidewalls. Specifically, we offer a comprehensive analysis of the plume merging behaviour, which is governed by the aspect ratio ($\bar {\xi }$) of the liquid layer and the intensity of vibration, quantified by the effective vibrational Rayleigh number $Ra_{vib}^{eff}$. We identify the relationship between the number of columnar plumes $K_m$ and $Ra_{vib}^{eff}$, finding that $K_m \sim \bar {\xi }^{-1} (Ra_{vib}^{eff})^{\gamma }$ with the fitting scaling exponent $\gamma = 0.150 \pm 0.025$. We subsequently quantify the characteristics of the interface roughness amplitude evolution in microgravity vibroconvection. Our results indicate that the roughness amplitude exhibits a power-law dependence on the mean height of the liquid layer. Drawing from the Stefan boundary condition, we theoretically deduce this dependence under the assumption of a non-uniform heat flux distribution at the interface, where the theory is corroborated by our numerical simulations.
Linear instability analysis of a viscous swirling liquid jet surrounded by ambient gas is carried out by considering the significant influence of axial shear effect. The jet azimuthal flow is assumed as a Rankine vortex, and the non-uniform velocity distribution in the jet axial direction is approximated by parabolic and error functions. The enhancement of jet rotation is found to promote the predominant mode with larger azimuthal wavenumbers, and the mode transition is decided by the competition between centrifugal force and axial shear stress. Subsequently, the influence of the axial shear effect is examined through changing the degree of shear stress and the thickness of the gas velocity boundary layer. It is found that an increase of jet average velocity or surface velocity in the axial direction leads to the predominant mode transition to smaller azimuthal wavenumbers, due to the combined effects of shear stress and gas pressure perturbation. A larger velocity difference between ambient gas and liquid jet also promotes the predominant modes with smaller azimuthal wavenumbers, and the physical mechanism is attributed to gas pressure perturbation. Phase diagrams of different azimuthal modes are given and compared with the study of Kubitschek & Weidman (J. Fluid Mech., vol. 572, 2007, pp. 261–286), where a static swirling column without axial shear stress was considered. The strengthened axial shear effect is found to delay the transition of predominant modes with the increase of angular velocity. Experimental studies considering the swirling jets with different axial velocities are further carried out, which validate the theoretical findings. Different instability mechanisms and their transition rules are also identified through energy budget analysis. This study is expected to give scientific guidance on understanding the instability mechanisms of the swirling jets that widely exist in natural phenomena and engineering applications.
Rising income and wealth inequality across the developed world has prompted a renewed focus on the mechanisms driving inequality. This paper contributes to the existing literature by studying the impact from life-cycle savings, intergenerational transfers, and fertility differences between the rich and the poor on the wealth distribution. We find that bequests increase the level of wealth inequality and that fertility differences between the rich and the poor amplify this relationship. The counterfactual exercises show that the interaction between bequests and differential fertility is quantitatively important for understanding wealth inequality in the United States.
Decimetre-scale carbonaceous macrofossils from the Mesoproterozoic Gaoyuzhuang Formation in the Yanshan Range are known as the current oldest unambiguous evidence of macroscopic multicellular eukaryotes. Here, we reported a new SIMS zircon age of 1588.8 ± 6.5 Ma from a volcanic tuff in the Qianxi County of Hebei Province, about 11 m above the macrofossil’s horizon. This new age provides a direct age constraint on the macroscopic eukaryotic fossils from the Gaoyuzhuang Formation. It indicates that macroscopic life with the moderate diversity and certain morphological complexity had already evolved at the beginning of the Mesoproterozoic, and implies a possibility of discovering macroscopic eukaryotes in earlier rocks. This study also calls for a stratigraphic framework to integrate biological and environmental studies in different regions for a better understanding of the evolution of multicellular organisms and environmental change during this important period.
We report the unified constitutive law of vibroconvective turbulence in microgravity, i.e. $Nu \sim a^{-1} Re_{os}^\beta$ where the Nusselt number $Nu$ measures the global heat transport, $a$ is the dimensionless vibration amplitude, $Re_{os}$ is the oscillational Reynolds number and $\beta$ is the universal exponent. We find that the dynamics of boundary layers plays an essential role in vibroconvective heat transport and the $Nu$-scaling exponent $\beta$ is determined by the competition between the thermal boundary layer (TBL) and vibration-induced oscillating boundary layer (OBL). Then a physical model is proposed to explain the change of scaling exponent from $\beta =2$ in the TBL-dominant regime to $\beta = 4/3$ in the OBL-dominant regime. Our finding elucidates the emergence of universal constitutive laws in vibroconvective turbulence, and opens up a new avenue for generating a controllable effective heat transport under microgravity or even microfluidic environment in which the gravity effect is nearly absent.
To investigate the influence of inertia and slip on the instability of a liquid film on a fibre, a theoretical framework based on the axisymmetric Navier–Stokes equations is proposed via linear instability analysis. The model reveals that slip significantly enhances perturbation growth in viscous film flows, whereas it exerts minimal influence on flows dominated by inertia. Moreover, under no-slip boundary conditions, the dominant instability mode of thin films remains unaltered by inertia, closely aligning with predictions from a no-slip lubrication model. Conversely, when slip is introduced, the dominant wavenumber experiences a noticeable reduction as inertia decreases. This trend is captured by an introduced lubrication model with giant slip. Direct numerical simulations of the Navier–Stokes equations are then performed to further confirm the theoretical findings at the linear stage. For the nonlinear dynamics, no-slip simulations show complex vortical structures within films, driven by fluid inertia near surfaces. Additionally, in scenarios with weak inertia, a reduction in the volume of satellite droplets is observed due to slip, following a power-law relationship.
The surface modification of Zeolite 4A using cetyl trimethyl ammonium bromide (CTAB) as a modifier via an ultrasonic method was carried out and the surface physicochemical properties measured. Response surface methodology (RSM) was developed with CTAB concentration, handling time, and handling temperature as variables, to help predict the performance of the modified zeolite under particular conditions. The influence of organic-modified surface treatment and of the amount of modified zeolite on the water-absorption capability of starch-g-poly (acrylic acid) hydrogel composites was also assessed. The results showed that the channels and skeleton structure of zeolite 4A were unchanged after organic modification by CTAB and the surface modification was effective. The results suggest that organic-modified zeolite 4A has improved the water-absorption capability.
The latest clinical practice guidelines for non-small cell lung cancer (NSCLC) published by the National Comprehensive Cancer Network in 2022 recommend that patients with NSCLC (>1 and ≤2 cm) should be diagnosed as T1b. Segmentectomy and lobectomy are equally effective in treating patients with NSCLC no bigger than 2 cm, and especially for tumors no bigger than 1 cm. However, the effectiveness of these treatments for NSCLC tumors between 1 and 2 cm is unknown. We conducted a systemic review and meta- analysis to assess the efficacy of these two surgical treatments in patients with T1b stage NSCLC.
Methods
We searched for randomized controlled trials (RCTs) and cohort studies investigating the efficacy of lobectomy and segmentectomy for patients with T1b stage NSCLC. Study quality was assessed with the Cochrane Quality in Prognosis Studies tool. We used random effects models to analyze overall survival (OS) and lung cancer-specific survival (LCSS), expressed as hazard ratios (HR) and 95% confidence intervals (CIs). The effect of covariates was assessed using subgroup analysis. All procedures were performed according to the PRISMA guidelines.
Results
We identified ten cohort studies that matched our selection criteria, with general low risk of quality, including a total of 37,691 patients. No publication bias was found. Compared to lobectomy, segmentectomy had lower OS (HR 1.31, 95% CI: 1.16, 1.47; p=0.026) and LCSS (HR 1.21, 95% CI: 1.03, 1.42, p=0.015) before Cox regression. After multivariable Cox regression, adjusted by age, sex, histological type, and lymph node section, segmentectomy had similar OS (HR 1.17, 95% CI: 1.00, 1.37; p=0.2) and LCSS (HR 1.10, 95% CI: 0.89, 1.36; p=0.8).
Conclusions
Segmentectomy can be used to treat patients with T1b stage NSCLC. Patients who undergo segmentectomy have survival outcomes that are the same as those of patients who received lobectomy. This evidence-based observation provides a reference for surgical choice in the treatment of patients with T1b stage NSCLC, which should be further confirmed through RCTs.
In this paper, we propose a numerical model to simulate gas–liquid–solid interaction problems, coupling the lattice Boltzmann method and discrete element method (LBM–DEM). A cascaded LBM is used to simulate the liquid–gas flow field using a pseudopotential interaction model for describing the liquid–gas multiphase behaviour. A classical DEM resorting to fictitious overlaps between the particles is used to simulate the multiple-solid-particle system. A multiphase fluid–solid two-way coupling algorithm between LBM and DEM is constructed. The model is validated by four benchmarks: (i) single disc sedimentation, (ii) single floating particle on a liquid–gas interface, (iii) sinking of a horizontal cylinder and (iv) self-assembly of three particles on a liquid–gas interface. Our simulations agree well with the numerical results reported in the literature. Our proposed model is further applied to simulate droplet impact on deformable granular porous media at pore scale. The dynamic droplet spreading process, the deformation of the porous media (composed of up to 1277 solid particles) as well as the invasion of the liquid into the pores are well captured, within a wide range of impact Weber number. The droplet spreading dynamics on particles is analysed based on the energy budget, which reveals mechanisms at play, showing the evolution of particle energy, surface energy and viscous dissipation energy. A scaling relation based on the impact Weber number is proposed to describe the maximum spreading ratio.
Retropharyngeal lymphadenectomy is challenging. This study investigated a minimally invasive approach to salvage retropharyngeal lymphadenectomy in patients with nasopharyngeal carcinoma.
Methods
An anatomical study of four fresh cadaveric heads was conducted to demonstrate the relevant details of retropharyngeal lymphadenectomy using the endoscopic transoral medial pterygomandibular fold approach. Six patients with nasopharyngeal cancer with retropharyngeal lymph node recurrence, who underwent retropharyngeal lymphadenectomy with the endoscopic transoral medial pterygomandibular fold technique at the Eye and ENT Hospital of Fudan University from July to December 2021, were included in this study.
Results
The anatomical study demonstrated that the endoscopic transoral medial pterygomandibular fold approach offers a short path and minimally invasive approach to the retropharyngeal space. The surgical procedure was well tolerated by all patients, with no significant post-operative complications.
Conclusion
The endoscopic transoral medial pterygomandibular fold approach is safe and efficient for retropharyngeal lymphadenectomy.
This study investigates the effect of vibration on the flow structure transitions in thermal vibrational convection (TVC) systems, which occur when a fluid layer with a temperature gradient is excited by vibration. Direct numerical simulation (DNS) of TVC in a two-dimensional enclosed square box is performed over a range of dimensionless vibration amplitudes $0.001 \le a \le 0.3$ and angular frequencies $10^{2} \le \omega \le 10^{7}$, with a fixed Prandtl number of 4.38. The flow visualisation shows the transition behaviour of flow structure upon the varying frequency, characterising three distinct regimes, which are the periodic-circulation regime, columnar regime and columnar-broken regime. Different statistical properties are distinguished from the temperature and velocity fluctuations at the boundary layer and mid-height. Upon transition into the columnar regime, columnar thermal coherent structures are formed, in contrast to the periodic oscillating circulation. These columns are contributed by the merging of thermal plumes near the boundary layer, and the resultant thermal updrafts remain at almost fixed lateral position, leading to a decrease in fluctuations. We further find that the critical point of this transition can be described nicely by the vibrational Rayleigh number ${{Ra}}_{vib}$. As the frequency continues to increase, entering the so-called columnar-broken regime, the columnar structures are broken, and eventually the flow state becomes a large-scale circulation (LSC), characterised by a sudden increase in fluctuations. Finally, a phase diagram is constructed to summarise the flow structure transition over a wide range of vibration amplitude and frequency parameters.
Seed coat colour in adzuki bean is an important quality trait and closely associated with anthocyanin metabolism pathways. To further understand the inheritance of seed coat colour pattern, the inheritance between multiple seed coat colours and ivory seed were analysed using F1:2, F2:3 and F3:4 populations derived from five bi-parental crosses. The differences between ivory and red mottle on ivory are controlled by a single recessive R locus and RI locus, respectively. Green, light brown and golden are all dominant to red and governed by two loci. The B (brown) locus shows dominant epistasis over T locus. The R (red) locus was recessive epistasis to B (black), T (light brown), G (golden), GR (green) and RI (red mottle on ivory) loci. The new insight into the strong recessive epistasis of the R locus will be important for gene mapping and cloning, candidate gene functional validation and quality improvement in adzuki bean.
Improving existing products plays a vital role in enhancing customer satisfaction and coping with changes in the market. Analyzing user experience (UX) to find the deficiencies of existing products and establishing improved schemes is the key to UX-driven product improvement, especially at the conceptual design stage. Although some tools used in conceptual design, such as requirements analysis and knowledge reasoning, have advanced recently, they lack targeted goals and sufficient efficiency in identifying insufficient product attributes and improving existing functions and structures. The challenge lies in considering the influence imposed on design activities by the original product features (including attributes, functions, and structure). In this study, a knowledge-enabled approach and framework that integrates the conceptual design process, online reviews for UX, and knowledge is proposed to support product improvement. Specifically, a decision-making algorithm based on UX analysis is proposed to identify to-be-improved product attributes. Then, through optimizing the previous knowledge application model from knowledge requirement transformation, knowledge modeling, and knowledge reasoning, a smart knowledge reasoning model is established to push knowledge for functional solving of the to-be-improved attributes. A knowledge configuration method is used to modify product features to generate an improved scheme. To demonstrate the feasibility of the proposed approach, a case study of improving an agricultural sprayer is conducted. Through discussion, this study can help to regulate design activities for product improvement, enhance data and knowledge application, and promote divergent thinking during scheme modification.
We develop a simple two-sector neoclassical growth model in which the upstream sector produces intermediate goods, and the downstream sector produces final goods with outputs from the upstream. While the downstream sector features perfect competition, firms in the upstream sector engage in Cournot competition and charge a markup. We show that the deregulation and the introduction of competition in the upstream goods sector not only increases the productivity in the sector but also has a substantial spillover effect on the productivity of the downstream sector and factor prices. We calibrate the model to the Chinese economy and use the calibrated model to quantitatively evaluate the extent to which the deregulation in the upstream market in China from 1998 to 2006 can account for the rapid economic growth and the high and rising returns to capital in China over the same period. Our quantitative experiments show that the deregulation in the upstream sector can account for a significant share of economic growth in China during the study period. In addition, our model delivers implications that are consistent with several other relevant observations in China during the same period.
We report that vertical vibration with small amplitude and high frequency can tame convective heat transport in Rayleigh–Bénard convection in a turbulent regime. When vertical vibration is applied, a dynamically averaged ‘anti-gravity’ results that stabilizes the thermal boundary layer and inhibits the eruption of thermal plumes. This eventually leads to the attenuation of the intensity of large-scale mean flow and a significant suppression of turbulent heat transport. Accounting for both the thermally led buoyancy and the vibration-induced anti-gravitational effects, we propose an effective Rayleigh number that helps to extend the Grossmann–Lohse theory to thermal vibrational turbulence. The prediction of the reduction on both the Nusselt and Reynolds numbers obtained by the extended model is found to agree well with the numerical data. In addition, vibrational influences on the mean flow structure and the temporal evolution of Nusselt and Reynolds numbers are investigated. The non-uniform characteristic of vibration-induced ‘anti-gravity’ is discussed. The present findings provide a powerful basis for studying thermal vibrational turbulence and put forward a novel strategy for actively controlling thermal turbulence.
In the treatment of infertile patients with non-obstructive azoospermia (NOA) caused by the deletion of the azoospermia factor c region (AZFc) on the Y chromosome, synchronous and asynchronous surgical strategies are discussed. Clinical data from NOA patients with the AZFc deletion who underwent micro-TESE were analyzed retrospectively. The sperm retrieval rate (SRR) and sperm utilization rate of synchronous and asynchronous operation groups were followed up and compared. The fertilization rate, high-quality embryo rate, clinical pregnancy rate, abortion rate, and cumulative live birth rate of ICSI in patients with successful sperm retrieval were compared between the two groups. The two groups had sperm utilization rates of 98.9% (93/94) and 50.0% (14/28), respectively. The asynchronous group’s sperm consumption rates were much lower than those of the synchronous operation group. Fertilization rate, high-quality embryo rate, clinical pregnancy rate of fresh transfer cycle, abortion rate, and cumulative live birth rate of patients in the synchronous operation group with fresh sperm, and the asynchronous operation group with thawed sperm, respectively, were 30.6% vs 33.8%, 33.8% vs 40.7%, 40.0% vs 12.5%, 30.4% vs 7.1%. Between the two groups, there was no significant difference. This suggests that individuals with NOA caused by the AZFc deletion have a high possibility of successfully acquiring sperm using micro-TESE and ICSI to conceive their own offspring. Synchronous micro-TESE is recommended to improve sperm utilization rate and the cumulative live birth rate.
In this paper, we report that reversals of the large-scale circulation in two-dimensional Rayleigh–Bénard (RB) convection can be suppressed by imposing sinusoidally distributed heating to the bottom plate. We examine how the frequency of flow reversals depends on the dimensionless wavenumber $k$ of the spatial temperature modulation with various modulation amplitude $A$. For sufficiently large $k$, the flow reversal frequency is close to that in the standard RB convection under uniform heating. However, when $k$ decreases, the frequency of flow reversal gradually becomes lower and can even be largely reduced. Furthermore, we examine the growth of the corner roll and the global flow structure based on Fourier mode decomposition, and reveal that the size of the corner roll diminishes as the wavenumber decreases. The reason is that the regions occupied by the cold phase can absorb heat from the hot plumes and thus lower their temperature, which reduces the corner roll's kinetic energy input provided by the buoyancy force, and weakens the feeding process of the corner rolls. This results in the locking of the corner roll into a smaller region near the corner, making it harder for a reversal to occur. Using the concept of horizontal convection caused by non-uniform heating, we find a relevant parameter $k/A$ to describe briefly how the reversal frequency depends on wavenumber and modulation amplitude. The present work provides a new way to control the flow reversals in RB convection through modifying temperature boundary conditions.
In this paper, we introduce the notion of planar two-center Stark–Zeeman systems and define four
$J^{+}$
-like invariants for their periodic orbits. The construction is based on a previous construction for a planar one-center Stark–Zeeman system in [K. Cieliebak, U. Frauenfelder and O. van Koert. Periodic orbits in the restricted three-body problem and Arnold’s
$J^+$
-invariant. Regul. Chaotic Dyn.22(4) (2017), 408–434] as well as Levi-Civita and Birkhoff regularizations. We analyze the relationship among these invariants and show that they are largely independent, based on a new construction called interior connected sum.
The gut microbiota plays an important role in animals’ survival in their local environments. The intertidal rocky shore is a key interface of oceanic, atmospheric and terrestrial environments, and the transmission modes of microbes between an intertidal host and the environment are complex and largely ignored. In the present study, we characterized the gut microbiota of the intertidal snail Nerita yoldii, which is experiencing a northward range shift under the combined impacts of climate change and anthropogenic seascape transformation, and also determined the nearby environmental microbiota on the rock and in the seawater at five locations along the snail's distribution range in China. The gut microbial communities were significantly different from the environmental microbial communities, and the dominant phyla were Tenericutes, Cyanobacteria and Bacteroidetes, and Proteobacteria in the gut, rock and seawater microbial communities, respectively. At the genus level, Mycoplasma, with a relative abundance of 48.0 ± 10.2%, was the dominant genus in the gut microbial community, however, the relative abundances of this genus on the rock and in the water were low. These results imply that the gut microbial community of the intertidal snail N. yoldii is relatively independent from the environmental microbial community, and the dominant genus Mycoplasma in the gut, that is rare in the environment, can potentially assist the snail living in the harsh intertidal environment, especially at its northernmost distribution range edge.