Dual-core Structure Research Articles

A novel molecularly imprinted solid phase based on SiO2-Ag2O double-nucleation doped with graphene oxide for extraction and determination of flavonoids from Acanthaceae ebracteatus via HPLC-MS/MS

(Objectives) A novel method was developed for extracting and determining flavonoids from marine mangrove medicinal plants. This approach utilizes surface molecular imprinting to increase selectivity. Graphene oxide doped with a SiO2–Ag2O dual core structure served as a scaffold for synthesizing multilayer surface-imprinted polymers. The surface of the SiO2-Ag2O@GO composite was modified through self-polymerization. (Methods) Acacetin molecularly imprinted polymers (AMIPs) were created via surface-initiated precipitation polymerization with acacetin as the template. These AMIPs were synthesized and characterized via ultraviolet (UV) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Recycling experiments demonstrated the stability of the AMIPs. Analysis of the adsorption mechanism via the Langmuir and Freundlich models indicated that the Langmuir model was more suitable for predicting AMIPs. (Results) Scatchard plots showing two different binding sites of AMIPs for acacetin adsorption at various concentrations. The class selectivity of AMIPs for flavonoids was found in Acanthaceae ebracteatus. Compared with other analogs, competitive binding experiments revealed that the polymer had greater selectivity for acacetin. After AMIP solid-phase extraction (AMISPE), the linearity, LOD, LOQ, intraday and interday variabilities, recovery, and repeatability of AMIPs combined with HPLC–MS/MS were validated, confirming the method’s selectivity, precision, accuracy, and reproducibility. The contents of acacetin, apigenin, kaempferol, luteolin, quercetin, and genistein in Acanthaceae ebracteatus were determined. (Conclusions) These results indicate that AMISPE coupled with HPLC–MS/MS is a new, simple, and practical method for extracting, purifying, and enriching flavonoids from complex samples, such as those of herbs and other natural marine plants.

Chirally-coupled-ring fibers for arbitrary-order orbital angular momentum mode generation and detection

A novel chirally-coupled-ring fiber (CCRF) is proposed for efficiently generating and detecting arbitrary-order orbital angular momentum (OAM) modes in ring-core fibers (RCFs). The CCRF comprises inner and outer cores, N angularly uniformly distributed dielectric rods, and a cladding layer. These rods, twisted along the fiber axis between the cores, introduce angular geometry perturbations to manipulate the core modes. Through meticulous theoretical modeling and systematic analysis grounded in coupled-mode theory, we reveal CCRF eigenmodes carrying spin-entangled OAM, elucidate the mode coupling and power transfer in CCRFs, and present the CCRF design principle. Utilizing the full-vector beam propagation method, we carry out a proof-of-principle experimental system to demonstrate the capability of CCRFs in OAM mode manipulation and their feasibility and superiority in system-level applications. Additionally, we generate OAM modes across a wide range of topological charges from ℓ = −8 to ℓ = 8 using CCRFs, with conversion efficiencies from 92.10% to 99.63% and mode purities from 90.28% to 99.48%. Attributed to a coaxial dual-core structure with core-separated geometry perturbations, CCRFs enable flexible manipulation of arbitrary-order OAM modes without altering core geometry parameters, effectively solving design flexibility and compatibility problems in conventional single-core fiber devices. The proposed CCRF holds great promise for fiber-based OAM applications, especially for RCF-based OAM multiplexing communications.

Mediation and Convergent Sociality: Toward a Theory of Social Dialogue

The article investigates the mechanisms shaping a new quality of social development in contemporary Russia amidst growing societal challenges. Four key mechanisms are explored: mediation, social dialogue, polysubjectivity, and convergence. These are analyzed for their role in fostering novel forms of social integration and development. The mechanisms serve as tools for studying and shaping the current interplay between tradition and innovation, cultural stasis and social dynamics across various sociocultural contexts and transitional processes. The paper draws upon works presented at the All-Russian Scientific Conference “Individualization and Collectivism in Contemporary Russian Society,” offering an original interpretation that synthesizes and structures these studies. Notable contributions include V.A. Lektorsky’s concept of “the supra-individual as social universality,” which advances our understanding of socio-individual meaning formation and transcends the individual-society dichotomy. A.A. Auzan’s analysis of the dual-core structure of Russian culture aptly captures the unique challenges of social development in Russia. O.V. Aksenova’s examination of the contradictory nature of social action subjects in an increasingly technologized society illuminates the complexities of balancing freedom with necessity, and uniformity with diversity in social action. V.M. Rozin’s approach is considered for its potential to facilitate mediational social dialogue in Russian society. The author argues that neither the individualistic nor the collectivist cores of Russian culture can independently drive effective modernization. Instead, the concept of convergence is proposed as a means to transcend the extremes of ego-individualism and totalitarian collectivism. Three primary directions for implementing convergent strategies are identified: synthesizing individual and social aspects in social action and dialogue, optimizing center-periphery interactions in governance, and developing public-private partnership models as a form of economic convergence. The study emphasizes the need for new forms of social integration and concludes that Russia’s sustainable social development requires an integrative socio-individual model, combining elements of individual freedom and collective solidarity.

Synthesis, structure and electrochemical properties of Co-MOF containing pyridine polycarboxylic acid

Metal-organic frameworks (MOFs) have been widely used in filed of electrochemistry. Compared with traditional inorganic porous materials, the polyvalent pyridinecarboxylic acid ligands have many advantages which contains more active sites, flexible coordination mode, adjustable structure. Therefore, it becomes good choice for constructing MOFs materials with excellent performance. In this paper, a novel MOF was synthesized by pyridine polycarboxylic acid ligand and CoCl2·6H2O using solvothermal method. The physicochemical properties were characterized by FT-IR, powder diffraction and thermogravimetry. Single crystal X-ray diffraction reveal that MOF-1 crystallizes in monoclinic system with P21/C space group. The central Co2+ ions have a dual core structure with 5 and 6 coordination, respectively. The carboxyl groups show two kinds of coordination modes μ2: η1: η1 and μ2: η1: η2, and the pyridine N atoms also coordinate to form a three-dimensional network structure. Electrochemical experiments show that MOF-1 has a lower overpotential (339.4 mV) and Tafel slope (65.3 mV·dec−1) with higher ECSA and better OER kinetics. A large number of exposed active sites indicate that the MOF has higher potential as catalyst for oxygen evolution reaction.

Subsurface eddies east of the Philippines: Geographic characteristics, vertical structures, volume and thermohaline transport

Energetic subsurface eddies (SSEs) play a significant role in regulating the subthermocline circulation east of the Philippines. However, due to the paucity of targeted observations, they remain largely unexplored. By analyzing the outputs from an eddy-resolving ocean general circulation model (OGCM), this study investigated the statistics of SSEs east of the Philippines, including their geographic characteristics, vertical structures, and eddy-induced transport. During the period of 2009–2019, approximately 1927 and 1176 SSEs were detected to be anticyclonic and cyclonic, respectively, indicating the predominance of subsurface anticyclonic eddies (SSAE). The hotspot area of SSEs is in the latitude band of 6° N–15° N off the Philippine coast, especially around 10° N and 14° N–15° N prevailing abundant SSEs. Most SSEs originate at ∼138° E furthest with a mean lifespan of 55 days and a westward translation speed of 6 cm/s. The composite SSAE exhibits a typical subsurface-intensified feature with a velocity core at ∼520 m, while the subsurface cyclonic eddy (SSCE) has a relatively shallow core at ∼420 m and exhibits considerable strength near the surface with a rotating speed is around 5 cm/s. Temperature anomalies induced by SSEs show a dual-core structure associated with lens-like isopycnal undulations, and salinity anomalies are characterized by an alternating positive and negative signal owing to the complexity of the water masses. SSEs-induced meridional volume transport mainly occurs off the Philippine coast, where the northward transport is approximately 0.3 Sv and the southward transport is approximately 0.5 Sv. The zonal volume transport of SSEs is 1–2 Sv per latitude and mainly occurs in the North Equatorial Current (NEC) region. SSEs-induced stirring heat/salt transport is 1–2 orders larger than the trapping component and is mainly concentrated near the Mindanao coast. The meridional stirring heat transport is equatorward, which is up to 2.7 × 107 W/m, and the salt transport is northward with a magnitude of ∼100 kg·m−1·s−1 between 200 m and 2000 m. At the 8°N section, the mean salt transport associated with SSEs is about 24% of that induced by the Mindanao Undercurrent (MUC).

Highly Responsive, Miniaturized Methane Telemetry Sensor Based on Open-Path TDLAS

This paper proposes the design of a highly responsive, compact, non-contact methane telemetry sensor, employing the open-path tunable diode laser absorption spectroscopy (OP-TDLAS) technology. The sensor uses the dual-core structure of FPGA and ARM to achieve high-speed methane telemetry at 100 KHz repeated modulation frequency for the first time with a non-cooperate target, and a higher gas responsive time of 1.8 ms was achieved than previously reported. Moreover, the optical system (L × W × H: 68.8 × 52 × 62.7 mm) and the electronic system (L × W: 70 × 50 mm) make the sensor more compact. Methane gas samples of varying integral concentrations were examined at a distance of 20 m. The amplitude of the absorption peaks was subjected to a linear fit with the standard concentration values, resulting in a robust linear correlation coefficient (R2 = 0.998). Notably, despite the compact form factor of the methane sensor, it demonstrated commendable stability in gas concentration detection, offering a minimum detection limit of 43.14 ppm·m. Consequently, this highly responsive and compact methane sensor, with its open-path feature, is apt for integration into a variety of applications requiring such attributes. These include handheld telemetry devices, Unmanned Aerial Vehicle (UAV) gas detection systems, vehicle mounted gas detection, and laser gas radar.

A High-Efficiency Deep Blue Emitter for OLEDs with a New Dual-Core Structure Incorporating ETL Characteristics.

In this study, we introduced the weak electron-accepting oxazole derivative 4,5-diphenyl-2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)oxazole (TPO) into both anthracene and pyrene moieties of a dual core structure. Ultimately, we developed 2-(4-(6-(anthracen-9-yl)pyren-1-yl)phenyl)-4,5-diphenyloxazole (AP-TPO) as the substitution on the second core, pyrene, and 4,5-diphenyl-2-(4-(10-(pyren-1-yl)anthracen-9-yl)phenyl)oxazole (TPO-AP) as the substitution on the first core, anthracene. Both materials exhibited maximum photoluminescence wavelengths at 433 and 443 nm in solution and emitted deep blue light with high photoluminescence quantum yields of 82% and 88%, respectively. When used as the emitting layer in non-doped devices, TPO-AP outperformed AP-TPO, achieving a current efficiency of 5.49 cd/A and an external quantum efficiency of 4.26% in electroluminescence. These materials introduce a new category of deep blue emitters in the organic light-emitting diodes field, combining characteristics related to the electron transport layer.

An approach to urban system spatial planning in Chengdu Chongqing economic circle using geospatial big data

Evidence suggests city grouping is an important way to implement urbanization in China. However, the Chengdu-Chongqing Economic Circle (CCEC) is a typical dual-core structure, and the development level of each city is different. If we do not focus on the key directions for urban development, it will not be conducive to the new-type urbanization process. Therefore, we use spatial analysis techniques and geographic big data sets to construct an approach for urban system layout optimization from a global perspective. It mainly includes urban extended trend analysis based on night light, multi-modal traffic network analysis, and spatial economic density analysis using Open Street Map (OSM) and Point of Interest (POI) data. The research results show the following interesting findings. Firstly, the historical relationship of cities has a significant impact on city grouping, and efficient transportation connections and prosperous enterprise distribution are key conditions for urban grouping during the acceleration period of urbanization. Secondly, the development of urban grouping should break through administrative restrictions and achieve a moderate separation of administrative divisions and economic divisions. It is beneficial to the rapid growth of the city group and the improvement of the internal structure. Thirdly, the urban group of Southern Sichuan and Western Chongqing (SSWC) is the region with the most potential for growth in CCEC. The urban expansion index (UEI) of the Yibin-Luzhou area is 2.16, and the spatial economic density has increased by 130/km2 in the past decade. Providing flexible development authority and focus on the construction of the Yibin-Luzhou Urban Belt along the Yangtze River is an important way to integrate southern Sichuan. Moreover, we found the UEI has a good universality and it can be used for studying urban expansion trends and city relationships in rapidly developing regions, especially in metropolitan areas or urban agglomeration.

Fin core dimensionality and corner effect in dual core gate-all-around FinFET

This article proposes investigation of low power performance of a fin field-effect transistor (FinFET) with surrounding gates through a calibrated technology computer-aided design (TCAD) framework. The proposed silicon body FinFET has a dual core structure in its source and drain regions, which offers opportunities for tuning its performance in terms on current, off current, threshold voltage and sub-threshold swing. Through variation of height and width of inner and outer cores, different electrical parameters are reported. To assess the impact of corner effect on device performance, gate edge suppression is introduced from all four sides, and their effects are reported for two cases: one, with equal suppressions, and the other, with suppressions in a 2:1 ratio. The percentage of occupancy of the inner core with respect to the overall volume of the source/drain decides the electrical parameters for different cases of core dimensions. For a 35 % reduction in the channel length, the overall low power performance of the device improves.

Urban growth and shrinkage with Chinese characteristics: Evidence from Shandong Province, China

Whilst China experiences long-term rapid urbanization, urban shrinkage, as a new normal, has become a common phenomenon in urban development along with growth. In this study, we innovatively established a full-quadrant urban growth-shrinkage model from the dimensions of population, economy, and space. We identified the spatiotemporal evolution and influencing factors of city growth and shrinkage at the county scale based on multi-source data, hot spot analysis, and stepwise regression, and explored the differences and trends among administrative units with Chinese characteristics in Shandong, China, a province that attaches great importance to the high-quality development of county economy but has large internal differences. The results are as follows. (1) Counties with population- and economy-related shrinkage in Shandong Province gradually increased and tended to intensify. In 2020, it presented a pattern of urban growth along the river and the sea area and significant shrinkage in the rest of the region. Meanwhile, the urban growth in the spatial dimension was more obvious, and the hotspot areas in population and economy presented a dual-core structure (Ji'nan and Qingdao). Spatially, the development along the Yellow River and southern Shandong grew slowly. (2) The growth and shrinkage and their evolution trends of municipal districts, counties, and county-level cities were significantly unique; that is, while the county-level units in the total factor growth tended to decrease, all dimensions of their shrinkage and growth tended to be unique. (3) The influencing factors of urban growth and shrinkage were roughly the same. A good social foundation, sound economic development conditions, and strong innovative vitality could promote urban growth, but their impact on different county-level units in different dimensions varied significantly.

A 4–5.2 GHz PLL with 74.8 fs RMS jitter in 28 nm for RF Sampling Transceiver application

AbstractThis paper presents a novel ultra low jitter phase‐locked loop (PLL) circuit architecture for RF Sampling Transceiver. The programmable frequency divider with duty cycle expansion and the new phase frequency detector and charge pump circuit are used to solve the problem of voltage domain conversion of narrow pulses in the traditional high‐performance charge pump PLL structure. The traditional structure degrades charge pump linearity and noise, thus deteriorating overall jitter performance. Furthermore, voltage‐controlled oscillator uses the dual core structure and the second harmonic suppression technology, combined with the proposed new switching capacitor structure, and achieves −139.3 dBc/Hz phase noise at the 1 MHz frequency offset of the 5.2 GHz carrier under the open loop state. The PLL implemented in a standard Taiwan Semiconductor Manufacturing Company 28 nm process occupies a core area of 0.4 mm2 and generates a frequency ranging from 4 to 5.2 GHz using 50 MHz oscillator input, the power consumption is 40 mW. It achieves 74.8 fs root‐mean‐square jitter integrated from 10 KHz to 30 MHz. When the PLL output is divided by 2, the output phase noise at 1 MHz frequency offset is −125.75 dBc/Hz, and the PLL FoM is −246.

Inverse Design of Broadband Dispersion Compensation Fiber Based on Deep Learning and Differential Evolution Algorithm

A Ge-doped dual-core dispersion compensation photonic crystal fiber (DC-DCPCF) is proposed. The small diameters of two layers’ air holes make DC-DCPCF form a dual-core structure, which is conducive to broadband dispersion compensation. Low Ge-doped silica as the only background material reduces the preparation difficulty and cost. It is inversely designed by using artificial neural network (ANN) combined with differential evolution algorithm (DE) to obtain target dispersion compensation. ANN replaces the finite element method to accomplish fast forward prediction of DC-DCPCF properties. DE solves the single solution problem of single or cascade network that makes it flexible and reproducible. The results demonstrate that the designed DC-DCPCF can not only compensate 45 and 25 times its length of Corning single-mode fiber 28 (SMF28) in S+C+L+U bands and E+S+C+L+U bands respectively, but also accurately compensate the residual dispersion with effective dispersion compensation being only +0.005∼+0.842ps/(nm·km) and −0.03∼+1.31ps/(nm·km), respectively. In addition, the kappa values of DCP-PCF are well matched with SMF28 in the broadband wavelength range. It takes only about 10 seconds to complete the inverse design of the target DC-DCPCF. It provides a design method for custom DC-DCPCF and an efficient inverse design solution for photonic automation in fiber optical communication systems.

Investigating the Synergistic Evolution Mechanism of Multi-Scale Cities: A Case Study of Three Urban Agglomerations in Eastern China

Urban growth has evolved from cities to metropolitan areas and urban agglomerations, exhibiting a multi-scale pattern. Urban scaling law can reflect the nonlinear relationship between urban indicators and population size, which is very important for urban planning through analyzing the evolution of urban system characteristics. However, existing studies mainly focused on scalar law within countries, neglecting the multi-scale synergistic evolution of complex urban systems. The purpose of this study is to investigate the scalar relationship between urban indicators and population size at multiple scales from the perspective of individual cities, metropolitan areas, and urban agglomerations, using data from 45 cities in three urban agglomerations in eastern China. Based on the urban scaling law, local spatial autocorrelation model is used to analyze and explore the collaborative evolution of multiple scales. Results show that from the perspective of time evolution, the three urban agglomerations exhibit greater scaling effects than metropolitan areas, with a scaling exponent (β) greater than 1 for urban indicators including economy, land, infrastructure, ecological pressure, and innovation. From the perspective of spatial differences, the spatial development gap between the metropolitan area scale and the urban agglomeration scale is relatively small compared with the city scale. In addition, the Beijing–Tianjin–Hebei urban agglomeration (BTH) mainly displays the synergistic development of the dual-core structure of Beijing and Tianjin. The Yangtze River Delta (YRD) exhibits significant disparities between its cities, resulting in a low degree of overall synergy. In contrast, the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) leads in terms of synergistic evolution. This study is crucial to help understand the development of urban systems at different scales and to support regional planning and the achievement of coordinated development.

Design of a photonic crystal fiber polarization beam splitter with simple structure and ultra-wide bandwidth

A novel polarization beam splitter (PBS) based on dual-core photonic crystal fiber (DC-PCF) is proposed in this work. The proposed DC-PCF PBS contains two kinds of lattices and three kinds of air holes to form the asymmetrical elliptic dual-core structure. By using the full-vector finite element method, the propagation characteristics of the proposed DC-PCF PBS are investigated. The simulation results show that the bandwidth of the proposed DC-PCF PBS can reach to 340 nm, which covers the S + C + L + U communication bands, the shortest splitting length is 1.97 mm, and the maximum extinction ratio appears near wavelength 1550 nm. Moreover, the insertion loss of the proposed DC-PCF PBS is very low. It is believed that the proposed DC-PCF PBS has important applications in the field of all-optical communication and network.

Spatiotemporal mechanism of urban heat island effects on human health—Evidence from Tianjin city of China

The increasingly intensifying global warming and urban heat island (UHIs) are seriously damaging the physical and mental health of urban residents. However, the spatiotemporal evolution of how high temperatures affect human health in megacities remains unclear. Therefore, in this study, with Tianjin during 2006–2020 as an example, and based on data from meteorological stations, Landsat remote sensing images, and point of interest big data, this study applied hot- and cold-spot statistics and remote sensing retrieval in numerical modeling and established an appraisal system to assess how and to what extent UHIs affect resident health. The results showed that the overall influence of UHIs on respiratory and cardiovascular diseases and mental health increased to 373 km2 in area and two levels in intensity; the influence was mainly concentrated in the downtown area, with a rising influence level. Owing to the dual-core structure of the city, the influence was distributed along the main traffic lines in Binhai New District, having a strong influence in the area mainly concentrated in the southeastern part. Many cold spots clustered in the central urban area to cool the thermal environment: the cooled area was 6.5 times larger than the area of intense cooling influence. Our study provides a method for identifying health risks in urban spaces, lays a theoretical foundation to improve the planning of urban green space systems, and offers some decision-making guidance for the planning of healthy cities.

Spatial Differentiation Effect of Rural Logistics in Urban Agglomerations in China Based on the Fuzzy Neural Network

Rural logistics is particularly important for the sustainable development of Chinese urban agglomeration, which features the coexistence of urban circles and vast countryside. However, the existing literature generally focuses on urban logistics while ignoring rural logistics. Taking the Chengdu-Chongqing agglomeration as an example, this study constructed a rural logistics index system and proposed a new dynamic assessment model for rural logistics development using a fuzzy neural network, Moran index, and Kernel density estimation. The results are as follows: the development of rural logistics has been enhanced, and gaps among cities have gradually narrowed over the past decade. In particular, the spatial distribution of rural logistics showcases a dual-core structure in the Chengdu-Chongqing agglomeration, which is different from the unipolar structure manifested in other urban agglomerations. Because of administrative barriers, the impact from the dual-core cities is very different: Chengdu has a significant spillover effect on its surrounding cities, which is not the case for Chongqing. The findings are of great significance for local governments to provide decision-making support for the sustainable development of urban agglomerations.

Numerical studying of broadband tunable dispersion compensation based on photonic crystal fiber

We propose a broadband tunable negative dispersion photonic crystal fiber (BT-ND-PCF) for dispersion compensation over the S + C + L wavelength bands. BT-ND-PCF is a dual-core structure in which air holes are arranged with a hexagonal lattice and temperature-sensitive liquid is infiltrated into the air holes of the fourth layer. The performance of BT-ND-PCF is numerically analyzed by the finite element method with an anisotropic perfect matching layer. The results show that BT-ND-PCF has a broadband negative dispersion coefficient of −1533.2 to −2836.4 ps / km / nm over the S + C + L wavelength bands, a dispersion coefficient of −2268.9 ps / km / nm at 1550 nm, and a kappa value of 287.9 nm at 1550 nm, which matches with Corning single-mode fiber 28 (SMF). The residual dispersion (RD) after compensating for the dispersion of 1 km SMF is in the range of −0.22 to +0.16 ps / nm. In addition, the dispersion coefficient is changed by 0.679 ps/km/nm per 1°C by controlling the temperature, which is conducive to the accurate compensation of RD. Due to its unique optical properties, BT-ND-PCF can be used in broadband dispersion compensation for dense wavelength division multiplexing optical fiber communication systems.

Temporal Variation of Summer Hypoxia off Changjiang Estuary During 1997–2014 and Its Association With ENSO

Temporal variation of summer hypoxia, along a repeated hydrographic section from the Changjiang River mouth to Cheju Island, is investigated using cruise data during 1997–2014. The climatological mean of dissolved oxygen (DO) presents a “dual-core structure” below the oxycline, associated with two hypoxic centers near the river mouth and offshore of the Changjiang Bank, respectively. The DO value is highly variable from year to year, with dramatic interannual variation but an insignificant linear trend during 1997–2014. Composite analysis indicates that the interannual variation of DO and associated hypoxia events are strongly affected by the El Niño–Southern Oscillation (ENSO) cycle. In the El Niño decaying summer, large river discharge and relatively strong stratification, combined with calm climatic and hydrographic conditions, enhance DO depletion off the Changjiang Estuary. It is likely that El Niño is not a prerequisite for hypoxia occurrences. However, El Niño did enhance bottom hypoxia probability off the Changjiang Estuary during 1997–2014.

From World Factory to Global City-Region: The Dynamics of Manufacturing in the Pearl River Delta and Its Spatial Pattern in the 21st Century

Since the 21st century, the PRD has gradually been transforming from a world factory to a global city-region. Based on the manufacturing and urban economic data, this paper uses the upgrade (UPG) index of industrial structure, comparative advantage and economies of scale to evaluate the development level of manufacturing in the PRD from 2000 to 2019. Through geographically and temporally weighted regression (GTWR), this paper measures the impact of four types of components (R & D, service economy, production capability and foreign investment) on the development of manufacturing in different periods. The results show the disharmony between the scale, structure and quality of the manufacturing in different cities. The impact on the manufacturing from R & D has spatiotemporal differences; the impact of foreign investment on the west coast cities of PRD is stronger than that of the east coast cities with varied impact mechanisms. The impact of the service economy is strong in sub-core cities. The impact of production capability has a transmission effect from core cities to the sub-core cities, indicating the manufacturing subdivision of function within the region. By 2019, The PRD has gradually transformed into a dual-core structure and the two cores have differentiated development paths.

Research on Construction Land Use Benefit and the Coupling Coordination Relationship Based on a Three-Dimensional Frame Model—A Case Study in the Lanzhou-Xining Urban Agglomeration

Coordinating the social, economic, and eco-environmental benefits of construction land use has become the key to the high-quality development of Lanzhou-Xining urban agglomerations (LXUA). Therefore, based on the coupling coordination connotation and interaction mechanism of construction land use benefit (CLUB), we measured the CLUB level and the coupling coordination degree (CCD) between its principal elements in LXUA from 2005 to 2018. Results showed that: (1) The construction land development intensity (CLDI) in the LXUA is generally low, and spatially presents a dual-core structure with Lanzhou and Xining urban areas as the core. (2) The comprehensive construction land use benefit has increased over time, but the overall level is not high. The spatial differentiation is obvious, and the core cities (Lanzhou and Xining) are significantly higher than other cities. (3) The regional differences in the subsystem benefit of construction land use are obvious. The social benefit and economic benefit showed a “convex” shape distribution pattern of “high in the middle and low in the east and west wings”, and regional differences of economic benefit vary greatly. The eco-environmental benefit was relatively high, showed a “concave” shape evolution in the east–west direction. (4) In addition, the CCD of the CLUB were still at a medium–low level. The higher the administrative level of the city, the better the economic foundation, and the higher or better the CCD of the social, economic, and eco-environmental benefits. (5) The CCD is inseparable from the influence of the three benefits of construction land use. Therefore, different regions should form their own targeted development paths to promote the coordinated and orderly development of LXUA.