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In order to support economic and social development and high-quality development of water conservancy, it is crucial to scientifically judge the spatial equilibrium state of regional water resources. Therefore, the Lorentz curve matching water resources with population and GDP was constructed, and the population and GDP were weighted. The comprehensive Gini coefficient of each element after matching regional water resources was calculated to judge the spatial equilibrium state. Subtractive set pair potential was used to identify vulnerable regions affecting the spatial equilibrium of regional water resources. A comprehensive evaluation model of spatial equilibrium of regional water resources based on the Gini coefficient and subtractive set pair potential was established and applied to Chongqing. The findings demonstrate that the water resources in Chongqing are generally in an unbalanced spatial state from 2015 to 2022, particularly in the central city, western regions, and eastern new cities of Chongqing. Concurrently, the subtractive set pair potential in these three regions, manifested as partial reverse potential or reverse potential, designates them as vulnerable regions that impact the spatial equilibrium state of water resources in Chongqing. In the future, it is necessary to take control measures to improve the equilibrium state in these regions. The evaluation model can provide a reference for the high-quality development of regional water conservancy and optimal allocation of water resources.

Background: Older patients with cancer have a higher risk for malnutrition and impaired quality of life (QoL). The present study aimed to investigate the relationship between malnutrition diagnosed according to the Global Leadership Initiative Malnutrition (GLIM) criteria and QoL across various tumor types, and to evaluate the combined prognostic value of malnutrition and QoL in predicting survival among older patients with cancer. Methods: This multicenter, observational cohort study included 5310 older patients with cancer and 2184 with malnutrition (moderate stage, n = 1023; severe stage, n = 1161). An empirical cumulative distribution curve was performed to illustrate the correlation between malnutrition and QoL. The primary objective was to investigate the association between malnutrition and QoL using logistic regression analysis. Survival analyses were performed to assess the combined prognostic value of malnutrition and QoL. Results: The median age of the patients (66.9% male, 33.1% female) was 70 years (interquartile range [IQR] 67–74 years) years. The median QoL score was highest in patients without malnutrition (91.88 [IQR 84.44–97.44]), followed by those with moderate (86.15 [IQR 76.18–93.85) and severe (82.31 [IQR 69.87–91.11]) malnutrition. Logistics regression revealed that the risk for developing impaired QoL increased 1.98 (95% confidence interval [CI] 1.64–2.38; P < 0.001) and 2.33 (95% CI 1.93–2.81; P < 0.001) times in patients with moderate and severe malnutrition, respectively. Kaplan–Meier curves showed that QoL in combination with GLIM criteria demonstrated a significant discriminative performance for survival and served as an independent prognostic factor among older patients with cancer, especially for lung and gastric cancers. Conclusions: Malnutrition diagnosed according to the GLIM criteria was a predictor of impaired QoL. Additionally, the combination of QoL and malnutrition demonstrated utility for predicting survival outcomes in older patients with cancer.

In large object radiation imaging system, the interaction between medium and high energy (MeV) X/γ-ray and matter is dominated by Compton scattering, which produces a large number of the scattered particles. And the influence of the scattered particles on the radiographic images has always been a tough problem that plagues the developers. And the rear collimator is commonly used to reduce the influence of the scattered particles and improve the quality of the radiographic images. At present, the relevant research mainly analyzes the distribution of the scattered particles in the detector array, but there is a lack of research on the distribution of the scattered particles on the surface of the inspected object. Based on the Monte-Carlo simulation model of the 60Co large object radiation imaging system, a common medium-density substance (iron plate) was selected as the inspected object, and the number distribution and energy distribution of the scattered particles were analyzed in detail when γ-ray penetrates iron plates from different positions and with different thicknesses. Also, the diffusion effect of the scattered particles and the shielding effect of the rear collimator on the scattered particles were analyzed. There are some results drawn in this paper. In the horizontal direction, the diffusion effect of the scattered particles caused by multiple Compton scattering is limited, and most of the scattered particles come from the area covered by the initial γ-ray beam on the object. About 90% of the scattered particles have a horizontal distribution range of 40-70 mm on the surface of the object, which will limit the shielding effect of the rear collimator. When the distance S between the iron plate (with the thickness of 100 mm) and the detector array is reduced to the limit of 500 mm for safe driving, there is approximately 39.74% of the scattered particles shielded by the rear collimator (Fe) with the collimation ratio of 20∶1 and the best thickness of 5 mm, while the ideal rear collimator absorbing all incident particles can shield about 63.21% of the scattered particles. When the distance S increases to 1 750 mm or more, the scattering effect of the rear collimator will be severe and cause an increase in the number of the scattered particles instead of performing its function of shielding the scattered particles, and a wider rear collimator may cause more serious scattering interference. Therefore, in the large object radiation imaging system, the scattering effect of the rear collimator cannot be ignored, and its shielding effect on the scattered particles is also limited.

Ti-6Al-4V(TC4) titanium alloy is a kind of α+β type two-phase titanium alloy widely used. However, due to the microscopic defects in additive manufacturing titanium alloy, its mechanical properties are lower than the forging level, and post-treatment is usually required. Therefore, it is necessary to further study the additive manufacturing process and post-treatment of TC4 titanium alloy. In this paper, the microstructure and comprehensive properties of titanium alloy were analyzed by the changes of common process parameters such as energy input power and scanning strategy in the additive manufacturing process, and the influence of other process parameters such as protective gas type, substrate thickness, powder size and other factors in the additive manufacturing process was introduced. The influence of common heat treatment methods after additive manufacturing on its microstructure and mechanical properties was also comprehensively analyzed, and the influence of new post-heat treatment methods, such as vacuum heat treatment and cyclic heat treatment, as well as the influence of multiple post-treatment and comprehensive use of heat treatment were summarized. Generally speaking that the reasonable selection of additive manufacturing process parameters and the application of post-heat treatment method are the basis for obtaining titanium alloy components with excellent performance. The comprehensive use of various heat treatment methods or other post-treatment methods and heat treatment are the effective ways to further improve the performance of titanium alloy components in additive manufacturing. To establish a uniform selection standard for additive manufacturing process parameters and post-processing process is the key to the future development of additive manufacturing.

Abstract Background Chronic kidney disease (CKD) is an important global public health issue. In China, CKD affects a large number of patients and causes a huge economic burden. This study provided a new way to predict the number of patients with CKD and estimate its economic burden in China based on the autoregressive integrated moving average (ARIMA) model. Methods Data of the number of patients with CKD in China from 2000 to 2019 were obtained from the Global Burden of Disease. The ARIMA model was used to fit and predict the number of patients with CKD. The direct and indirect economic burden of CKD were estimated by the bottom-up approach and the human capital approach respectively. Results The results of coefficient of determination (0.99), mean absolute percentage error (0.26%), mean absolute error (343,193.8) and root mean squared error (628,230.3) showed that the ARIMA (1,1,1) model fitted well. Akaike information criterion (543.13) and Bayesian information criterion (546.69) indicated the ARIMA (1,1,1) model was reliable when analyzing our data. The result of relative error of prediction (0.23%) also suggested that the model predicted well. The number of patients with CKD in 2020 to 2025 was predicted to be about 153 million, 155 million, 157 million, 160 million, 163 million and 165 million respectively, accounting for more than 10% of the Chinese population. The total economic burden of CKD from 2019 to 2025 was estimated to be $179 billion, $182 billion, $185 billion, $188 billion, $191 billion, $194 billion and $198 billion respectively. Conclusion The number of patients with CKD and the economic burden of CKD will continue to rise in China. The number of patients with CKD in China would increase by 2.6 million (1.6%) per year on average from 2020 to 2025. Meanwhile, the total economic burden of CKD in China would increase by an average of $3.1 billion per year. The ARIMA model is applicable to predict the number of patients with CKD. This study provides a new perspective for more comprehensive understanding of the future risk of CKD.

Metal foam composite is a kind of lightweight composite with low density, high strength, high shielding performance, high damping performance and other characteristics. It has a wide range of application prospects in aerospace, drilling trap floats, artificial bone and other fields, which has attracted people's attention. In this paper, based on the research of the existing literature, the fabrication methods of metal foam composites were introduced, the effect of microstructure on the properties of metal foam composites was analyzed, the progress of mechanical properties, damping properties, shielding properties and heat insulation and their mechanisms of metal foam composites and their applications in relevant fields were reviewed, which provides a theoretical basis for the development of metal foam composites in the future, and the new fabrication technology, modeling research, sandwich structure of metal foam composites and the fabrication of high performance foam hollow sphere composite were also prospected.

The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far. The Pulang porphyry copper deposit (also referred to as the Pulang deposit) in this area has proven copper reserves of 5.11×106 t. This deposit has been exploited on a large scale using advanced mining methods, exhibiting substantial economic benefit. Based on many research results of previous researchers and the authors’ team, this study proposed the following key insights. (1) The Geza island arc was once regarded as an immature island arc with only andesites and quartz diorite porphyrites occurring. This understanding was overturned in this study. Acidic endmember components such as quartz monzonite porphyries and quartz monzonite porphyries have been identified in the Geza island arc, and the mineralization is mainly related to the magmatism of quartz monzonite porphyries. (2) Complete porphyry orebodies and large vein orebodies have developed in the Pulang deposit. Main orebody KT1 occurs in the transition area between the potassium silicate alteration zone of quartz monzonite porphyries and the sericite-quartz alteration zone. Most of them have developed in the potassium silicate alteration zone. The main orebody occurs as large lenses at the top of the hanging wall of rock bodies, with an engineering-controlled length of 1920 m and thickness of 32.5‒630.29 m (average: 187.07 m). It has a copper grade of 0.21%‒1.56% (average: 0.42%) and proven copper resources of 5.11×106 t, which are associated with 113 t of gold, 1459 t of silver, and 170×103 t of molybdenum. (3) Many studies on diagenetic and metallogenic chronology, isotopes, and fluid inclusions have been carried out for the Pulang deposit, including K-Ar/Ar-Ar dating of monominerals (e.g., potassium feldspars, biotites, and amphiboles), zircon U-Pb dating, and molybdenite Re-Os dating. The results show that the porphyries in the Pulang deposit are composite plutons and can be classified into pre-mineralization quartz diorite porphyrites, quartz monzonite porphyries formed during the mineralization, and post-mineralization granite porphyries, which were formed at 223±3.7 Ma, 218±4 Ma, and 207±3.9 Ma, respectively. The metallogenic age of the Pulang deposit is 213‒216 Ma. (4) The petrogeochemical characteristics show that the Pulang deposit has the characteristics of volcanic arc granites. The calculation results of trace element contents in zircons show that quartz monzonite porphyries and granite porphyries have higher oxygen fugacity. The isotopic tracing results show that the diagenetic and metallogenic materials were derived from mixed crust- and mantle-derived magmas.©2022 China Geology Editorial Office.

With the rapid development of modern high technology and continuous improvement of production technology, stringent requirements have been imposed on modern barrel weapons in terms of precision, range, power, and mobility. This needs a substantial improvement and optimization of the detection equipment used to test the performance of barrel weapons. In the present work, an optimization method based on a light screen with a reflection for effectively and economically detecting bullets from barreled weapons within a large detection area is proposed. First, the detection principle of this system is described in detail. Next, the mathematical model of system detection performance is established. Then, the system is simulated, and the simulation results show the ability to realize the effective detection of a small projectile with a diameter of 5.8 mm through an area of 10 m × 10 m. The detection performance at different coordinates of the detection area is symmetrically distributed about the diagonal. Besides, the detection performance is improved with an increase in the bullet diameter and the laser power, respectively. Finally, an equal-scale reduction system with a detection area of 4 m × 4 m is constructed to perform a live ammunition shooting experiment. The distribution and variation of detection performance obtained experimentally are consistent with the simulation. Consequently, the proposed optimization method can meet the requirements concerning high detection performance, large detection area, and low cost.

The study status on the joining of titanium alloy/steel dissimilar joint technology was summarized and reviewed, the microstructure characteristics of titanium alloy/steel direct joining and interlayer joining interface were analyzed.The formation and evolution process of titanium alloy/steel joint interface products with different interlayers (copper, copper-based alloy and others) were emphatically described, and the mechanical properties of titanium alloy/steel with different interlayers and preparation processes were also summarized.Finally, the methods and design ideas that can be adopted for the preparation of good titanium alloy/steel joints were summarized, and it was pointed out that the future development of this field can be combined with simulation in addition to using traditional methods to further the existing research, so as to achieve deeper understanding and experimental prediction.

The safe realization of on-orbit capture remains a challenging task because of uncontrolled service objects, big impact forces, post-impact control, and so on. In this study, based on the relationships between the kinematics and forces established by impedance control, a force constraint function is developed to reduce the contact force during the collision process of capture. Additionally, to realize flexible contact and improve motion performance during the capture process, a control method combining impedance and a sliding mode is designed to make the end-effector exhibit mass-spring-damping behavior after contact with the target, decreasing movement overshoot and stabilization time. Finally, numerical simulations are carried out in a scenario where a planar two-link space robot is utilized to capture a non-cooperative target, and the effectiveness of the proposed method is demonstrated.

To recognize the state trend of regional water resources carrying capacity and its key influence indicators,this paper adopts the game theory to determine the combined weight of the evaluation indicators.The five-variable gravitation subtraction set pair potential is introduced to judge the trend and identify the key indicators.The dynamic evaluation method of regional water resources carrying capacity based on the game theory and the five-variable gravitation subtraction set pair potential is established and applied to Guangdong Province.The results show that the water resources carrying capacity of Guangdong Province is generally good and developing well from 2013 to 2019.It fluctuates downward in 2014 and 2017.The five-variable gravitation subtraction set pair potential identifies the key indicators,including the water resources per unit area,the proportion of environmental protection investment in GDP,urbanization rate,and the industrial water consumption per ten thousand yuan output.The evaluation method of regional water resources carrying capacity based on five-variable gravitation subtraction set pair potential is easy to conduct and is readable,which can provide a new method for dynamic evaluation of water resources carrying capacity.

The surface evolution of vermicular cast iron in a high frequent cyclic plasma and facial cooling airflow was studied to understand the behavior and mechanism in different cooling conditions under a unique thermal shock environment. Results indicated that both the mass and linear loss presented titled inverted V-shaped relationships with the flux of the cooling airflow, while the change in roughness decreased continuously. As the cooling airflow rose, the eroded zone was reduced, the iron oxides lessened, and fluctuation of the surface temperature weakened. In combination with the thermodynamic calculations and thermal analysis, it was confirmed that the oxidation and mechanical erosion had contrary tendencies with the rising flux in the facial cooling airflow. The transformation of the dominant factor from oxidation to peeling off by thermal stress and scouring resulted in the evolution of mass and thickness. The surface oxides dominated the change in the roughness.

Low-expansion alloys are of great importance and can be used for the development of new aerospace materials. Herein, we report diverse rare earth quasicrystal alloys fabricated by the vacuum suction casting process. The effects of the addition of cerium (Ce) on the microstructure, thermal expansion properties and microhardness of the Al-Cu-Fe alloy were systematically investigated. This study discovered the tiny Al-Cu-Fe-Ce microstructure. A uniform distribution could be achieved after Ce addition amount is elevated. At the Ce addition amount of 1 at%, the lowest alloy thermal expansion coefficient was obtained. The alloy exhibited the maximum microhardness under these conditions. The microhardness of alloys containing 1 at% of Ce was approximately 2.4 times higher than the microhardness exhibited by alloys devoid of Ce additives. The coefficient of thermal expansion decreases by approximately 20%. The use of the suction casting process and the addition of an appropriate amount of Ce can potentially help design and develop Al-Cu-Fe-Ce alloys.

In order to know the carrying capacity of regional water resources and provide reference for regional water resources allocation,this paper selects evaluation indexes from three subsystems of water resources carrying capacity (i.e.,carrying ability system,carrying pressure system and regulation ability system),calculates the subjective weights of evaluation indexes by correcting analytic hierarchy process based on accelerating genetic algorithm (AGA-CAHP),the objective weights of evaluation indexes by projection pursuit based on accelerating genetic algorithm (AGA-PP) and the combined weights of evaluation indexes by the principle of minimum relative information entropy,obtains the connection number of regional water resources carrying capacity by improved set pair analysis based on grey correlation analysis,and then establishes a set pair analysis evaluation model for regional water resources carrying capacity based on entropy principles,combined weights and grey correlation analysis,and finally applies the model in Anhui Province.The results show that the water resources carrying capacity of Anhui Province was in the critical overload from 2005 to 2015,while that was gradually increasing from 2012 to 2015,with the southern region stronger than the northern region.The evaluation results accorded with the actual situation.Therefore,the model can fully integrate the subjective experience information and objective information in the evaluation process,with reasonable results.It has great application value in the comprehensive evaluation of regional resources and environmental carrying capacity.

The XBT automatic launch and measurement system can automatically launch probes in severe sea conditions, and the motor control unit is the control core of the launch mechanism. The unit consists of a power management module, communication and motor control interface module, main control chip and etc, the stepping motor, servo motor and DC motor in the launch system can be controlled in real time. After putting forward the design scheme of hardware and software, the various faults found in the test for motor control unit are analyzed from mechanism. The test result after improved shows that the motor control unit can respond to the control commands of the host computer in real time, ensuring the stable motion of each motor, and the automatic launch and measurement system has the characteristics of good practicability, high efficiency and automation.

In this paper, the performance of A1515 centrifugal pump was studied on a high parameters and precision large general test platform in combination with the Huang-jin-xia hydro-junction in Hanjiang-to-Weihe River valley water diversion project. The efficiency characteristics and cavitation performance of the pump were tested and measured respectively. All measured parameters were collected and recorded through the acquisition system. The experimental results show that the optimal efficiency and weighted average efficiency of the pump is 92.46% and 92.18%, and the design point efficiency is 92.39%, all of which meet the design requirements. After conversion to the prototype pump, the efficiency value at each working point is higher than the guaranteed value. The pump hump margin is 3.03%, which is greater than 2% of the required value and meets the requirements. In the whole normal operating range, the cavitation performance of the model pump meets the design and test requirements. The comprehensive error of model test is less than ±0.2%. The research results provide reference for the design of large centrifugal pump.

The evolution of the microstructure and the variation in the thermal expansion properties of the Al _63 Cu _25 Fe _12 alloy by the addition of different amounts of cerium (Ce) are investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). Herein, a new series of quasicrystal alloys containing Ce are prepared. Results revealed that the Al _63 Cu _25 Fe _12 alloy contains icosahedral quasicrystal phase ( I -phase), λ − Al _13 Fe _4 phase, β − Al _0.5 Fe _0.5 phase and Al _2 Cu _3 phase. The addition of Ce is confirmed to lead to grain refinement, formation of the Al _13 Ce _2 Cu _13 phase, disappearance of the λ − Al _13 Fe _4 phase. Furthermore, the area fraction of the I -phase in the alloy is confirmed to reach the maximum value, and the linear expansion coefficient of the alloy is the lowest due to the addition of Ce of up to 1 at%. The addition of Ce can reduce the linear expansion coefficient of the Al _63 Cu _25 Fe _12 alloy by ∼20%. The contribution of Ce will render better prospects for the application of Al-Cu-Fe-Ce materials.

Two-dimensional FE models of CGI with different pearlite contents for thermal conductivity analysis were established according to the real metallographic images obtained by Pro/E and ANSYS. Meanwhile, thermal conductivity of CGI with different pearlite contents was tested through the laser flash method. It is indicated that the thermal conductivity of CGI declines with the increase of pearlite. When pearlite is increased from 10% to 80%, the experimental values decline from 46.63 W/m·K to 36.86 W/m·K, reducing by 21%. However, this declining tendency becomes gentle and slight when pearlite is more than 40%. In addition, the calculation results with the consideration of interfacial contact thermal conductance (ICTC) and pearlite are much close to experimental values; especially when pearlite is 80%, the difference between them is only about 2%. It can be concluded that the FE models are convenient and reasonable to analyze thermal conductivity of CGI.

Considering that the orthogonality of STBC in frequency-selective fading will be destroyed by the multiple path interference（MPI）,an iterative interference cancellation based maximum likelihood sequence estimation（MLSE） decoding scheme was proposed for STBC in frequency-selective fading.Meanwhile,the maximum ratio combining（MRC） method was introduced to improve the proposed scheme,and decrease the computational complexity further.These schemes could effectively make up for the decoding deficiency of conventional STBC in frequency-selective fad-ing.They canceled not only the MPI from even terms corresponding to the orthogonality undestroyed by fading,but also the MPI from odd terms corresponding to the orthogonality destroyed by fading;they has superior performance.More-over,they have lower decoding complexity when compared with direct MLSE decoding of the long sequence signal.Thus they implement good decoding performance with low complexity.