Western Zhou Dynasty (ca. 1046–771 BC) was established soon after conquering the Shang Dynasty (ca. 1600–1046 BC) and brought about the earliest enfeoffment system in Chinese history. Yan was one of the vassal states of the same clan as Zhou. According to historical records, the capital of Yan state was located near Yan mountain, which is now known as the Liulihe site in the Fangshan District, Beijing. This study carries out the high-precision dating of two newly discovered Western Zhou Dynasty noble tombs at the Liulihe site. The man in tomb M1902 participated in the groundbreaking ceremony of Yan’s capital according to inscriptions on the bronze vessel found in this tomb. Samples of different materials, especially different parts of human skeletons from the tombs, were selected to form a sample series in chronological order. Wiggle-matching models were established in OxCal program based on the growth and development time of different teeth and bones of human skeletons. More accurate ages were acquired for the death of the individuals. The results indicate that the most probable distribution range of the death date of the individual in M1902 is about 1045–1010 BC. The radiocarbon dates of M1902 give important chronological information about the founding of Yan state, and they are very close to those of the year in which King Wu of Zhou conquered the Shang Dynasty.

A high-energy pulsed vacuum ultraviolet (VUV) solid-state laser at 177 nm with high peak power by the sixth harmonic of a neodymium-doped yttrium aluminum garnet (Nd:YAG) amplifier in a KBe2BO3F2 prism-coupled device was demonstrated. The ultraviolet (UV) pump laser is a 352 ps pulsed, spatial top-hat super-Gaussian beam at 355 nm. A high energy of a 7.12 mJ VUV laser at 177 nm is obtained with a pulse width of 255 ps, indicating a peak power of 28 MW, and the conversion efficiency is 9.42% from 355 to 177 nm. The measured results fitted well with the theoretical prediction. It is the highest pulse energy and highest peak power ever reported in the VUV range for any solid-state lasers. The high-energy, high-peak-power, and high-spatial-uniformity VUV laser is of great interest for ultra-fine machining and particle-size measurements using UV in-line Fraunhofer holography diagnostics.

This article investigates the internationalization process of incubating, parenting, and eventually spinning-off overseas entrepreneurial ventures originating from emerging markets. In a comparative case study of Chinese high-tech firms, we leveraged multiple sources of data to reveal (1) how the exploitation of parent firms’ technological and platform resources enables them to initiate, support, and eventually profit from the international growth of foreign ventures that autonomously engage in the exploration of product and market innovations, and (2) how ambidextrous synergy was created through the continuous exchange, combination, and reconfiguration of knowledge and resources between parent firms and foreign ventures. These findings extend our understanding of how Chinese high-tech firms manage the learning process in overseas venturing. We draw implications of these findings for research and practice.

Ridge B is one of the least studied areas in Antarctica but has been considered to be a potential location for the oldest ice on Earth. Among important parameters for calculating where very old ice may exist, geothermal heat flux (GHF) is critical but poorly understood. Here, GHF is determined by quantifying the transitions between dry and wet basal conditions using a radioglaciological method applied to airborne radio-echo sounding data. GHF is then constrained by a thermodynamic model matched to the transitions. The results show that GHF in Ridge B varies locally and ranges from 48.5 to 65.1 mW m−2, with an average value of 58.0 mW m−2, which is consistent with the current known GHF constrained by subglacial lakes and derived from Vostok ice core temperature measurements. Our work highlights the value of considering local GHF when locating the oldest ice in this potential region or other regions.

Large-scale Ulva prolifera green tides have successively occurred for 16 years (2007–2022) in the Yellow Sea (YS), and the different life stages of U. prolifera play critical roles in regulating the occurrence and development of green tides. U. prolifera and microalgae have a similar niche in seawater, but their potential interactions are not yet clearly understood. In this study, we investigated the competition relationship between two microalgae and U. prolifera at five different development stages in controlled laboratory experiments. The results showed that one microalgae Alexandrium tamarense, can only inhibit U. prolifera gametes at the first settlement stage. Inversely, the germinated U. prolifera begin to show negative effects on microalgae in multiple ways at the subsequent four stages, and the growth inhibition rates among these stages ranged from 19 to 100%. The complex interactions may influence the formation of green tides. Meanwhile, the potential ecological consequences on phytoplankton, even the decreased occurrence of microalgal blooms in the YS need to be further evaluated.

The phase summation effect in sum-frequency mixing process is utilized to avoid a nonlinearity obstacle in the power scaling of single-frequency visible or ultraviolet lasers. Two single-frequency fundamental lasers are spectrally broadened by phase modulation to suppress stimulated Brillouin scattering in fiber amplifier and achieve higher power. After sum-frequency mixing in a nonlinear optical crystal, the upconverted laser returns to single frequency due to phase summation, when the phase modulations on two fundamental lasers have a similar amplitude but opposite sign. The method was experimentally proved in a Raman fiber amplifier-based laser system, which generated a power-scalable sideband-free single-frequency 590 nm laser. The proposal manifests the importance of phase operation in wave-mixing processes for precision laser technology.

We present a high-energy, hundred-picosecond (ps) pulsed mid-ultraviolet solid-state laser at 266 nm by a direct second harmonic generation (SHG) in a barium borate (BaB2O4, BBO) nonlinear crystal. The green pump source is a 710 mJ, 330 ps pulsed laser at a wavelength of 532 nm with a repetition rate of 1 Hz. Under a green pump energy of 710 mJ, a maximum output energy of 253.3 mJ at 266 nm is achieved with 250 ps pulse duration resulting in a peak power of more than 1 GW, corresponding to an SHG conversion efficiency of 35.7% from 532 to 266 nm. The experimental data were well consistent with the theoretical prediction. To the best of our knowledge, this laser exhibits both the highest output energy and highest peak power ever achieved in a hundred-ps/ps regime at 266 nm for BBO-SHG.

High-power continuous-wave single-frequency Er-doped fiber amplifiers at 1560 nm by in-band and core pumping of a 1480 nm Raman fiber laser are investigated in detail. Both co- and counter-pumping configurations are studied experimentally. Up to 59.1 W output and 90% efficiency were obtained in the fundamental mode and linear polarization in the co-pumped case, while less power and efficiency were achieved in the counter-pumped setup for additional loss. The amplifier performs indistinguishably in terms of laser linewidth and relative intensity noise in the frequency range up to 10 MHz for both configurations. However, the spectral pedestal is raised in co-pumping, caused by cross-phase modulation between the pump and signal laser, which is observed and analyzed for the first time. Nevertheless, the spectral pedestal is 34.9 dB below the peak, which has a negligible effect for most applications.

Ahsan, Sinha, and Srinivasan (2020) studied the motives of knowledge-intensive Indian firms’ international expansion based on resource-based considerations and the locational advantages offered by host countries. They identified firm characteristics associated with strategic asset-seeking, opportunity-seeking, and market-seeking motives. In this replication study, we examine Ahsan et al.'s (2020) model in the Chinese context. Based on our improved empirical model, our findings reveal some similarities but more importantly some key differences in the antecedents of internationalization motives between Indian and Chinese firms. Drawing on insights from prior studies, we propose that these differences can be attributed to differences in absorptive capacity, international expansion scales and patterns, ownership type, and the home institutional contexts in which Indian and Chinese firms operate. Overall, this replication study demonstrates the importance of contextualizing international business research.

The attitude control error of the robot end-effector directly affects the manufacturing accuracy. The study aims to develop a real-time measurement method of the industrial robot end-effector attitude in the field environment for improving the control accuracy of robot attitude.

In this paper, an attitude measurement method of robot end-effector based on the inertial technology was proposed. First, an inertial measurement system was designed, and the measurement parameters and installation errors were calibrated. Then the inertia measurement principle of robot end-effector attitude was explored, and the robot end-effector attitude measurement was realized with the fourth-order Runge−Kutta algorithm. In addition, the influence of the data processing algorithm and sampling frequency on the attitude accuracy was analyzed. Finally, a test platform was built to experimentally explore the proposed inertial measurement method.

The inertial measured data were compared with the data obtained with the laser tracker. The measurement accuracy of the inertial measurement method reached 0.15°, which met the accuracy requirements of real-time measurements of robot end-effector attitude in the manufacturing field.

The method proposed in this paper is convenient and can realize the real-time attitude measurement of industrial robot. The measurement results can compensate the attitude control error of the robot end-effector and improve the attitude control accuracy of the robot.

Understanding the size of oil droplets released from a jet in crossflow is crucial for estimating the trajectory of hydrocarbons and the rates of oil biodegradation/dissolution in the water column. We present experimental results of an oil jet with a jet-to-crossflow velocity ratio of 9.3. The oil was released from a vertical pipe 25 mm in diameter with a Reynolds number of 25 000. We measured the size of oil droplets near the top and bottom boundaries of the plume using shadowgraph cameras and we also filmed the whole plume. In parallel, we developed a multifluid large eddy simulation model to simulate the plume and coupled it with our VDROP population balance model to compute the local droplet size. We accounted for the slip velocity of oil droplets in the momentum equation and in the volume fraction equation of oil through the local, mass-weighted average droplet rise velocity. The top and bottom boundaries of the plume were captured well in the simulation. Larger droplets shaped the upper boundary of the plume, and the mean droplet size increased with elevation across the plume, most likely due to the individual rise velocity of droplets. At the same elevation across the plume, the droplet size was smaller at the centre axis as compared with the side boundaries of the plume due to the formation of the counter-rotating vortex pair, which induced upward velocity at the centre axis and downward velocity near the sides of the plume.

This study examines the international performance of emerging economy multinational enterprises (EMNEs) from a strategic configuration perspective. We propose that the strategic patterns of EMNEs that deliver growth and/or profitability are characterized by different configurations of environment, strategy, and managerial resource factors. Therefore, identifying and assessing strategic configurations is key to understanding EMNEs’ international performance. Employing fuzzy-set qualitative comparative analysis, we analyze a multi-sourced dataset of Chinese firms’ outward investment and identify multiple equifinal strategic configurations that are associated with superior international performance in terms of sales growth and/or profitability. These findings inform the development of a taxonomy of EMNEs’ strategic configurations corresponding with three performance groups, namely profitable growth, profitable niche, and poor performers.

The present study evaluated whether fat mass assessment using the triceps skinfold (TSF) thickness provides additional prognostic value to the Global Leadership Initiative on Malnutrition (GLIM) framework in patients with lung cancer (LC). We performed an observational cohort study including 2672 LC patients in China. Comprehensive demographic, disease and nutritional characteristics were collected. Malnutrition was retrospectively defined using the GLIM criteria, and optimal stratification was used to determine the best thresholds for the TSF. The associations of malnutrition and TSF categories with survival were estimated independently and jointly by calculating multivariable-adjusted hazard ratios (HR). Malnutrition was identified in 808 (30·2 %) patients, and the best TSF thresholds were 9·5 mm in men and 12 mm in women. Accordingly, 496 (18·6 %) patients were identified as having a low TSF. Patients with concurrent malnutrition and a low TSF had a 54 % (HR = 1·54, 95 % CI = 1·25, 1·88) greater death hazard compared with well-nourished individuals, which was also greater compared with malnourished patients with a normal TSF (HR = 1·23, 95 % CI = 1·06, 1·43) or malnourished patients without TSF assessment (HR = 1·31, 95 % CI = 1·14, 1·50). These associations were concentrated among those patients with adequate muscle mass (as indicated by the calf circumference). Additional fat mass assessment using the TSF enhances the prognostic value of the GLIM criteria. Using the population-derived thresholds for the TSF may provide significant prognostic value when used in combination with the GLIM criteria to guide strategies to optimise the long-term outcomes in patients with LC.