小农经济现代化的社会主义道路

学界从均等分配角度揭示了家庭承包经营制后农业发展的'社会主义'性质及其制度合理性,本文尝试从农业生产角度揭示1980年以来中国社会主义道路实践,探究小农经济现代化问题。家庭承包经营制改革后的小农经济采取双层经营体制,集体经济以集体统一经营的方式存在。在不同生产力阶段,集体经济分别以资金整合、地权整合和土地集中的方式,促进小农经济现代化。从集体经济扩大农业经营单位,克服小农经济局限性的角度,中国在资本主义式私人大农场农业、社会主义式集体大农场农业、资本主义式小农家庭农业之外,探索出具有中国特色的第四种农业现代化道路,即社会主义式小农家庭农业。

Slags containing transition metal(chromium and vanadium)oxides——Conversion from ticking bombs to valuable resources:Collaborative studies between KTH and USTB

As the steel industry expands worldwide,slag dumps with transition metals(especially chromium and vanadium)are becoming more common,posing a serious environmental threat.Understanding the properties of slags containing transition metal oxides,as well as how to use the slags to recover and recycle metal values,is critical.Toward this end,the University of Science and Technology Beijing(USTB)and Royal Institute of Technology(KTH)have been collaborating on slags containing transition metals for decades.The research was carried out from a fundamental viewpoint to get a better understanding of the structure of these slags and their properties,as well as industrial practices.The research focused on the three“R”s,viz.retention,recovery,and recycling.The present paper attempts to highlight some of the important achievements in these joint studies.

An attention-based cascade R-CNN model for sternum fracture detection in X-ray images

Fracture is one of the most common and unexpected traumas.If not treated in time,it may cause serious consequences such as joint stiffness,traumatic arthritis,and nerve injury.Using computer vision technology to detect fractures can reduce the workload and misdiagnosis of fractures and also improve the fracture detection speed.However,there are still some problems in sternum fracture detection,such as the low detection rate of small and occult fractures.In this work,the authors have constructed a dataset with 1227 labelled X-ray images for sternum fracture detection.The authors designed a fully automatic fracture detection model based on a deep convolution neural network(CNN).The authors used cascade R-CNN,attention mechanism,and atrous convolution to optimise the detection of small fractures in a large X-ray image with big local variations.The authors compared the detection results of YOLOv5 model,cascade R-CNN and other state-of-the-art models.The authors found that the convolution neural network based on cascade and attention mechanism models has a better detection effect and arrives at an mAP of 0.71,which is much better than using the YOLOv5 model(mAP=0.44)and cascade R-CNN(mAP=0.55).

Lithium Storage Property of Graphite/AlCuFe Quasicrystal Composites

Quasicrystals have long-range quasi-periodic translational ordering and non-crystallographic rotational symmetry.Al-Cu-Fe quasicrystals have great potential for lithium storage because of their high Al content and a large number of defects in the structure.In our previous study(J.Alloys Compd.805(2019)942)we showed that Al-Cu-Fe quasicrystals have good initial capacity whereas its cycle stability is poor.In the present study,graphite/AlCuFe is prepared by the mechanical alloying method.The results show that graphite/AlCuFe quasicrystal composites are successfully synthesized by planetary ball milling at 550 rpm for 80 h.The quasicrystal particle size decreases and the amorphous graphite forms onion-like carbon(OLC)when the two phases mix evenly.OLC forms on the surface of the Al-Cu-Fe quasicrystalline powder.Charge and discharge tests show that graphite/AlCuFe quasicrystal composites have high-stability capacity of 480 mAh/g after 20 cycles,which is larger than the sum of capacities of graphite and Al-Cu-Fe quasicrystals.

肿瘤转移的几种理论模型及其意义(英文)

Cancer metastasis is the most important factor causing patients death. Cancer diseases will be controllable if metastasis does not happen. Concerning the mechanism of cancer metastasis, there are still many points to be clarified. Currently, the mechanism of cancer metastasis has been explained from several aspects of its biological behaviors. Here we briefly summarized some newly-developed metastasis models to provide a global glance at this topic.

Bioinformatic exploration of MTAl-regulated gene networks in colon cancer

Metastasis-associated gene 1 （MTA1） controls a series of biological processes in tumor progression. Tumor progression is a complex process regulated by a gene network. The global cancer gene regulatory network must be analyzed to determine the position of MTA1 in the molecular network and its cooperative genes by further exploring the biological functions of this gene. We used TCGA data sets and GeneCards database to screen MTA1- related genes. GO and KEGG pathway analyses were conducted with DAVID and gene network analysis via STRING and Cytoscape. Results showed that in the development of colon cancer, MTA1 is linked to certain signal pathways, such as Wnt/Notch/nucleotide excision repair pathways. The findings also suggested that MTA1 demonstrates the closest relationship in a coregulation process with the key molecules AKT1, EP300, CREBBP, SMARCA4, RHOA, and CAD. These results lead MTAI exploration to an in-depth investigation in different directions, such as Wnt, Notch, and DNA repair.

Analyzing close relations between target artifacts for improving IR-based requirement traceability recovery

Requirement traceability is an important and costly task that creates trace links from requirements to different software artifacts.These trace links can help engineers reduce the time and complexity of software maintenance.The information retrieval(IR)technique has been widely used in requirement traceability.It uses the textual similarity between software artifacts to create links.However,if two artifacts do not share or share only a small number of words,the performance of the IR can be very poor.Some methods have been developed to enhance the IR by considering relations between target artifacts,but they have been limited to code rather than to other types of target artifacts.To overcome this limitation,we propose an automatic method that combines the IR method with the close relations between target artifacts.Specifically,we leverage close relations between target artifacts rather than just text matching from requirements to target artifacts.Moreover,the method is not limited to the type of target artifacts when considering the relations between target artifacts.We conduct experiments on five public datasets and take account of trace links between requirements and different types of software artifacts.Results show that under the same recall,the precisions on the five datasets improve by 40%,8%,20%,4%,and6%,respectively,compared with the baseline method.The precision on the five datasets improves by an average of15.6%,showing that our method outperforms the baseline method when working under the same conditions.

A Novel Criterion of Mixing Time in Gas-Stirred Ladle Systems

A novel criterion of mixing time in gas-stirred ladle systems was proposed in this paper. The essential difference between the previous criterion and the present one is that the former is based on the concentration itself while the latter is based on the variation rate of the concentration, which reflects the mixing efficiency directly. Experiment was carried out in an acrylic glass vessel with bottom blowing, and the tracer concentration was monitored by electrical conductivity probes. The mixing time obtained through the new criterion is approximately 20% less than that obtained through the 95% criterion, and the deviations of mixing times calculated from the new criterion are smaller than that from the previous one under the same conditions.