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With the advancement of the concept of smart cities, research on urban and rural planning is also developing rapidly. How to make the spatial relationship description model in the context of smart cities more in line with the actual situation of urban development is still a problem to be solved. This article focuses on the spatial relationship description model and algorithm of urban and rural planning results in the context of smart cities, studies the impact of urban industrial structure under the action of the spatial relationship description model, and evaluates the impact of policy as well as the impact of smart city construction on urban green innovation efficiency. Its dynamic effects and urban heterogeneity are expanded and analyzed. The research results show that compared with the traditional ordinary least squares (OLS) technology, geographically weighted regression (GWR) has significantly improved the solution results of the model, the R value is reduced by 0.3–0.4, the residual sum of squares value is significantly reduced, and the Akaike information criterion value is significantly improved. For the same training samples and test data, compared with the OLS technology, the mean-squared error reduction rate of the prediction results obtained by the GWR technology basically reached more than 50%, especially in Experiment 4; it reached 57.9%, which shows a very obvious advantage in prediction accuracy. Smart city policies have a significant role in promoting green innovation efficiency in pilot areas, and over time, innovation efficiency has increased year by year, and the policy effects are particularly prominent in the eastern coastal areas with a good development foundation. Therefore, the construction of smart cities is based on the characteristics of the region, and it is necessary to seek a sustainable development path based on the conditions of the region.

In people with cancer, certain chemotherapy drugs can have hiccups as a side effect, seriously affecting the quality of life. According to the Traditional Chinese Medicine theory, the chemotherapy-induced hiccup is associated with Zangfu, blood stasis and syndrome of Zhuodu and Huoxie. This paper summarized the etiology, pathogenesis and nursing countermeasures of chemotherapy-induced hiccup, investigate the key issues in Traditional Chinese Medicine therapy by syndrome differentiation, and provided reference for precision treatment and care of patients with chemotherapy-induced hiccup. (化疗相关性呃逆是肿瘤患者治疗过程中常见的并发症, 严重影响患者生活质量。中医认为化疗相关性呃逆与肿瘤疾病、化疗药物以及脏腑、淤血、浊毒、火邪均有关。本研究对中医中关于呃逆的病因机制以及治疗和护理方法进行总结, 探讨中医治疗呃逆的辨证要点, 旨在为化疗相关性呃逆的精准化治疗和护理提供参考。)

Healthy water balance is the foundation of promoting the coordination between water and land. Also, it is the premise of high-quality development of territory space. The integrated protection and efficient utilization of territory space is the fundamental way to construct healthy water balance and ensure national water security. However, in China the tempo-spatial mismatch between water and other productivity elements is extremely prominent. Meanwhile, in space planning and its development practice, the principle of water resources sustainability is not well implemented. Facing the demand of ecological civilization and territory space planning, the goal of achieving healthy water balance and high-quality development of territory space is proposed. Then, the overall strategy for coordinated development of water balance and territorial space is constructed, which is based on the principle of integrated protection and utilization of Mountain-River-Forest-Farmland-Lake-Grassland, as well as the cooperative management of land and water space. There are four key points to implement this strategy. Firstly, thresholds of healthy water balance should be clarified to optimize the objectives of territory space planning. Secondly, infrastructures layout and construction should be reinforced to promote water resources allocation in time-space. Thirdly, we need to intensify comprehensive ecological protection and restoration of territorial space. Finally, intensive, coordinated and balanced development of territorial space is highly necessary. Meanwhile, we need to realize intensive and efficient utilization of natural resources including water, land and so on.Furthermore, proposals on harmony evolution between water balance and territorial space are put forward from several aspects.They are mainly concerned with the comprehensive monitoring and evaluation of water balance state, the promotion of water and land compatibility, the rational delineation of ecology, production and living space, the practical artificial greening of territorial space and so on.

Objective To explore the method of measuring root volume with cone-beam computed tomography (CBCT) three-dimensional reconstruction technology, and to study root length and root volume of upper and lower central incisors in patients with skeletal Class Ⅲ malocclusion treated by surgical orthodontic treatment. Methods Twenty patients with skeletal Class Ⅲ malocclusion undergoing surgical orthodontic treatment were selected. CBCT data at three time points, before decompensation treatment (T0), after decompensation treatment (before orthognathic surgery, T1), and the end of post-operative orthodontic treatment (T2) were collected. Three-dimensional reconstruction technology was used to measure the root length and root volume of the upper and lower central incisors (including total root volume, cervical root and apical root), calculate the percentage of reduction volume, and measure the distance of tooth movement after orthodontic treatment. Data were statistically analyzed by SPSS 20.0 software. Least significant difference (LSD) method was used for pair comparison between the groups subject to normal distribution, and non-parametric test was used for comparison between the groups not subject to normal distribution. The differences of root length and root volume of upper and lower incisors were compared, and the characteristics of root absorption were analyzed. Results Root length and root volume of the upper and lower central incisors were reduced during the surgical orthodontic treatment (P < 0.05) in cases. Both the root volume of cervical root and apical root were significantly reduced (P < 0.05), the reduction of apical root was more significant. The percentage of root volume reduction of the upper central incisor was (30.51±23.23)%, and lower central incisor (23.24±11.96)%. Compared with the upper central incisor, the root volume reduction amount and percentage of the lower central incisor were smaller, and apical root volume reduction of the upper central incisor was greater than that of the lower central incisor, which was statistically significant (P < 0.05). During pre-surgical orthodontic treatment, maxillary central incisor palatal moving was in a controlled tipping manner, and the mandibular central incisor tipped labially. Conclusion In patients with skeletal Class Ⅲ malocclusion, root length and total root volume of upper and lower central incisors decreased during surgical orthodontic treatment. Root volume measurement indicated that the cervical root also had root resorption. The difference in root resorption of the upper and lower central incisors might be related to the distance and direction of teeth movement. CBCT three-dimensional reconstruction will compensate for the limitation of root length measurement in evaluating root resorption.

BACKGROUND Rare earth resources are essential for a wide range of advanced technologies, which have received considerable attention in the world. Bayan Obo is the largest rare earth mine in the world. The study on the distribution characteristics of rare earth elements (REEs) and heavy metal elements in the environmental media such as soil and plants in the Bayan Obo mining area can provide basic data for the investigation of the environmental status of the mining area and provide reference for its environmental restoration. OBJECTIVES To investigate the distribution characteristics of REEs and heavy metal elements in various environmental media at different areas in the Bayan Obo mine. METHODS Nine plant samples, six soil samples, one rock sample and one cow manure sample were collected from the Bayan Obo rare earth mine and surrounding areas. The contents of 15 rare earth elements and 8 heavy metal elements of these samples were determined by ICP-MS, which were used to study the behavior of elements and the variation rules in space. RESULTS The results showed that the distribution patterns of REEs in rocks, soil, plants, and cow manure samples were similar: obvious enrichment of light-REEs and depletion of high-REEs. The richest rare earth element in soil and plant was Ce, reaching 49.95% and 48.55%, respectively. The spatial variation law of the total content of rare earth element in Limonium bicolor (Bag.) Kuntze was consistent with the mineralization change of the three ore bodies: the main ore>the east ore>Dongjielegele ore. This indicated that the rare earth content of this plant was basically controlled by the minerality of the ore body, and it was more accurate to indicate the enrichment degree of rare earth in the growth environment. In addition, there was accumulation of Zn (465-778mg/kg), Cd (1.35-2.23mg/kg), Pb (181-431mg/kg) in the soil of the mining area. Some points of Cd and Pb were beyond the risk control value. CONCLUSIONS The ore, soil, and plant samples in Bayan Obo all show the characteristics of Ce enrichment. Moreover, the rare earth content of plants is highly correlated with the ore body where it grows. The REE content characteristics among the three media show obvious inheritance and consistency. Special attention should be paid to the mining and agricultural activities in the main mining area in Bayan Obo because of the accumulation of Zn, Cd, and Pb in these mining areas.

BACKGROUND Hydrogen and oxygen isotopes can be used to identify water sources and trace water cycles and have been used in hydrogeochemistry since the 1950s. Studies have been carried out on stable isotopes of atmospheric precipitation, rivers and lakes in Xinjiang.However, the research on hydrogen and oxygen isotopes of waters in Altay is scarce, except for atmospheric precipitation. Researchers found that the rainfall in the Altai Mountains during the warm season (April-October) increased significantly from 1959 to 2014. Due to this background of climate condition changes, it is meaningful to study the hydrogen and oxygen isotope compositions of various types of water bodies in the Altay region, at the southern foot of the Altai Mountains. OBJECTIVES To obtain the basic data of hydrogen and oxygen isotopic composition of water in Altay and reveal their spatial distribution characteristics. METHODS Hydrogen and oxygen isotope compositions of river water, lake water, spring water, snow water, and water from a mine pit in the Altay region of Xinjiang were determined by liquid water laser isotope analyzer (LGR DT100, America). The dissolved oxygen (DO), TDS, T, and pH of the water samples were measured using the German WTW3430 multi-parameter water quality analyzer. The concentrations of Na+, K+, Ca2+, and Mg2+ were analyzed by inductively coupled plasma-optical emission spectrometry (PE8300, PerkinElmer, USA). The concentrations of HCO3- and CO32- were determined by alkali titration method. Cl- and SO42- concentrations were analyzed by ion chromatography method. RESULTS The results showed that the ranges of δ18O and δD of the waters in the Altay area were from -15.4‰ to -5‰ and from -121‰ to -49‰, respectively. The hydrogen and oxygen isotope content of various types of water in the Altay region were significantly different. The δ18O and δD values of river waters varied from -15.4‰ to -11.5‰ and from -114‰ to -100‰, respectively, and the deuterium excess parameter varied from -12.4‰ to 12.4‰. The δ18O and δD of Ulungur Lake were much higher than those of surface rivers, with an average value of -5.95‰ and -78.5‰, respectively. The deuterium excess parameter of Ulungur Lake was much lower than those of surface rivers, with an average value of -30.9‰. The δ18O value (-14.9‰ and -11.8‰) of groundwater was similar to that of surface rivers, but δD (-114‰ and -121‰) was slightly higher than that of surface rivers, indicating that groundwater was supplied by surface rivers but may be affected by water-rock reactions. The δ18O and δD values of snow water and the water from a mine pit were -11.8‰ and -90‰, -11.6‰ and -106‰, respectively. The fitting lines for hydrogen and oxygen isotopes of the Irtysh River and Ulungur River were δD=1.7297δ18O-83.879 and δD=1.986δ18O-76.5, respectively. Surface rivers were remarkably different from the global and Urumqi atmospheric precipitation lines, indicating that apart from atmospheric precipitation, surface rivers were also recharged by glacier meltwater, and underwent evaporation and isotope fractionation during the water cycle.Due to the temperature and latitude effect of hydrogen and oxygen isotopes, the δD and δ18O showed significant positive correlation relationships with T, TDS, and the molar concentration of major ions such as Na+, K+, Ca2+, Cl-, and SO42-, also showing a significant negative correlation with the latitude of the sampling sites and DO (P < 0.05, n=32). CONCLUSIONS The hydrogen and oxygen isotope composition characteristics obtained in this study provide basic data for the stable isotope research of various types of water bodies in the Altay area.The precipitation in Altay has increased significantly in recent decades. Due to this background, it is indeed necessary to continue to conduct long-term and in-depth systematic research on the composition of hydrogen and oxygen isotopes in Altay's atmospheric precipitation and other types of water bodies.

BACKGROUND The Jiulong area in western Sichuan is an important rare metal production area in China, which has a large resource potential. As an ecological protection barrier on the upper reaches of the Yangtze River, the ecological environment of this area is fragile. Facing the huge opportunities of mining development and under the current situation of 'environmental protection first', it is urgent to investigate the environmental background of this area to support the development of national energy strategy. OBJECTIVES To evaluate the ecological risk of heavy metals in soils from the Jiulong Li-Be mining area. METHODS A total of 352 soil samples were collected. The concentration of 7 heavy metals (Cd, As, Pb, Cr, Cu, Ni, Zn) in soil was analyzed by NexION 300x inductively coupled plasma-mass spectrometer (ICP-MS). The comprehensive assessment methods including geoaccumulation index, pollution load index, potential ecological risk index, and health risk model, combined with GIS spatial analysis were used to study the spatial distribution characteristics and ecological risk of heavy metals in the soil. RESULTS The average concentration of all 7 heavy metals in the soil in Jiulong did not exceed the Chinese national standard. There was no soil heavy metals pollution in the studied area. Compared with the soil background value of Sichuan Province, the average concentrations of As and Pb were lower than the background; the concentrations of Cd, Cr, Cu, Ni, and Zn were higher than the background, which were 2.44, 1.04, 1.15, 1.28, and 1.17 times the background values, respectively. The spatial distribution characteristics of these elements except As were affected by biotite granite in the study area. The high concentration center of Pb and the low concentration center of Cr, Cu, Ni and Zn had an obvious correspondence with the spatial position of the rock mass. Except for the weak accumulation indicated by Cd Igeo, there was no accumulation of other heavy metals. Similarly, there was no potential ecological risk in the study area, except for the slight potential ecological risk of Cd. Spatially, the distribution of Cd single element potential ecological risk index was related to the rock mass, and the area without potential ecological risk corresponded to the location of the biotite granite rock mass. Heavy metals in the soil can enter the human body through direct contact with hands, mouth, and skin, and through inhalation. The hand-to-mouth approach is the most important way to generate health risks among all 3 approaches. Except hand-to-mouth approach of Cr, which has an acceptable and normal natural carcinogenic risk, there is no carcinogenic risk for other metals. CONCLUSIONS At present, there is no pollution of heavy metals in the soil in the studied area. The potential risk of heavy metals is low, and there are no non-carcinogenic and carcinogenic risks. However, due to the cumulative effect of heavy metals in the soil, close attention must be paid to changes in the concentration of heavy metals in the soil in the future mining development process, to prevent the risk caused by heavy metals pollution.

BACKGROUND The 'Strategic Emerging Industry Mineral Investigation' project actively advocates the application of new theories and methods of green investigation in the exploration and development of large-scale resource bases. Green investigation is one of the main content of the comprehensive investigation and evaluation work of large-scale lithium and beryllium resource bases in western Sichuan. OBJECTIVES To summarize the development history and current situation of the hydrochemical prospecting method, and the main problems of the hydrochemical prospecting method in mineral exploration and environmental investigation are put forward. To preliminarily elucidate the lithium prospect area which should be further investigated in details, by using hydrochemical prospecting method in the humid and semi-humid alpine mountainous area of Jiulong, West Sichuan. METHODS The temperature, pH value, electrical conductivity, dissolved oxygen and total dissolved solids (TDS) of surface water were measured by field multi-parameter tester. The content of trace elements such as Li, B, Rb, Sr, Ni, W and Sc were determined by inductively coupled plasma-mass spectrometry (ICP-MS). RESULTS The content of lithium, boron, strontium and nickel in the water body of the study area was significantly higher than the background value. Among the 60 samples, more than 17% of the samples had content of trace elements in excess of the abnormal lower limit (7.76μg/L). The lithium content of the water body flowing through the southeast corner of the Wulaxi rock mass (Shitougou) reached the maximum value of 20.1μg/L, which was 4.5 times the background value of the water body lithium content in the study area and 2.6 times the abnormal lower limit. These anomalies were closely related to mineralization, and its obvious change law can be used as a hydrochemical lithium search prospecting sign. The southeastern part of the Wulaxi pluton and the surrounding water body of the Lomo Pluton had an obvious relationship with mineralization, which can be used as a prospective area for the next detailed investigation. CONCLUSIONS Under the current conditions of continuous improvement of the strategic position of environmental protection, continuous increase of green exploration efforts, and equal emphasis on resource investigation and environmental protection, hydrochemical methods have important guiding significance for early prospecting deployment. The research results provide a reference for solving practical problems such as prospecting deployment and environmental protection bottlenecks in the ecologically fragile areas of the Western Sichuan Plateau.

Complete avulsion of teeth are one of the most serious traumatic dental injuries. The preferred treatment is tooth replantation. When teeth usually cannot be treated in time, the periodontal membrane on the root surface becomes necrotic , and the success rate of replantation is greatly reduced. How to use seed cells, growth factors and scaffold materials to promote periodontal tissue regeneration, improve periodontal membrane healing of replanted teeth, and achieve successful replantation of completely dislocated teeth is an urgent problem. Periodontal ligament stem cells (PDLSCs) express stem cell markers, have the potential to undergo multicellular differentiation and have important application value in periodontal tissue regeneration and repair. Fibroblast growth factor-2 (FGF-2), basic fibroblast growth factor (bFGF), lysobisphosphatidic acids (LPA) and other related regulatory factors promote periodontal tissue regeneration. Seed cells combined with scaffold materials can promote periodontal tissue regeneration and repair periodontal tissue defects. At present, studies have shown that PDLSCs and other seed cells have the potential for periodontal tissue regeneration and have been widely studied in experimental animal models of periodontitis and bone defects. However, there are few reports on the application of replanted teeth after complete avulsion, and its mechanism is not clear. In this paper, the research progress of periodontal tissue regeneration after total dislocation replantation is reviewed. We expect to apply periodontal tissue regeneration research to the replantation of fully dislocated teeth to achieve periodontal membrane healing of fully dislocated replanted teeth to provide a theoretical basis for future clinical work.

BACKGROUND When inductively coupled plasma-mass spectrometry (ICP-MS) is used to determine the rare earth elements (REE) in the barite-associated light rare earth ores, Ba and light rare earth elements La, Ce, Pr, Nd, Sm, cause severe mass spectral overlap interference to the medium and heavy rare earths. Therefore, under the condition that complete digestion of oress, if the appropriate pretreatment method can be selected to achieve effective separation of the target elements from the matrix, it will be beneficial to reduce mass spectrum interferences. OBJECTIVES To reduce the mass spectrum interferences by establishing a simple and effective pretreatment method for separation of rare earth elements from barium and other coexisting elements in barite-associated rare earth ores. METHODS The barite-associated rare earth ores samples were fused with sodium peroxide and sodium carbonate. After dissolution of the fusion cake, the target REE and the undesired barium were precipitated in triethanolamine solution, but some matrix elements like Si, Fe, Mg, and Al in samples, and most fusion agents, were separated by filtration. The target REE were secondly precipitated in ammonium hydroxide after dissolution of the precipitates by acid, so that Ba, Sr and Ca could be separated from REE. The separation exceeds 96%, so the mass spectrum interferences caused by barium polyatomic ions were effectively reduced. In addition, the interference correction coefficients by measuring the interference concentration at m/z 138-175 of the high concentration lighter rare earths standard single element solution were adopted to account for the oxide and hydroxide overlap problem for the determination of middle and heavier rare earth elements. RESULTS The validity of the method was evaluated by analyses of rare earth ores certified reference materials and the results were in good agreement with certified values (|RE| < 10%). For the actual sample analysis of the barite-associated rare earth ores, the relative standard deviations (n=12) were from 0.5% to 4.6%, which proved that the method can be used to analyze rare earth elements in high-Ba ores. CONCLUSIONS The results demonstrate that this method is both practical and effective for rare earth elements analysis in barite-associated rare earth ores.

BACKGROUND Under the background of coordinated development of resources, environment and economy, the development of green mining has become a national strategic focus and has been widely recognized. Environmental investigation and evaluation is one of the main content in investigation and assessment of large lithium metallic mineral bases in Sichuan Province, which will play an important role in solving the bottleneck problems, such as prospecting deployment and environmental protection in the ecologically fragile district of the Western Sichuan Plateau. OBJECTIVES To put forward the green investigation method and to establish an index system of environmental evaluation and demonstration of typical mining areas. METHODS Green investigation and environmental assessment were combined, an indicator framework in four levels was constructed, and the status quo and change information of the ecological environment through 3S technology were extracted. Based on three years of surface water, soil and other multi-environmental media field survey and analysis data, a mature evaluation method has been optimized, and a large-scale lithium resource base environment evaluation model based on support vector machine was established by using a more compatible and scalable Python language programming. RESULTS Using this model, the current status of large-scale bases was divided into four categories:environmentally poor areas, general environmental areas, better environmental areas, and good environmental areas. The overall accuracy rate was 97.77%. CONCLUSIONS The set of a targeted evaluation index system established and reported on in this paper effectively evaluates the environmental status of large-scale lithium resource bases in Western Sichuan, and realizes the visual level of 'pixel-level' environmental status of large-scale lithium resource bases through technological innovation. The method objectively reflects the development and environmental impacts of the Jiajika mining area and surrounding resources, and to a certain extent, can assist in regulating the management and decision-making of the development and utilization of large-scale mineral resources.

BACKGROUND With the increasing consumption of lithium resources in recent years, the boom of lithium exploration and development has grown worldwide. At present, three main types of lithium deposits have been explored and utilized in the world:brine-type, pegmatite-type and sedimentary-type. Among them, sedimentary-type lithium deposits have important geological significance and economic value due to their huge reserves. OBJECTIVES To understand the distribution and status of exploration and development for domestic and foreign sedimentary-type lithium deposits, and provide experience for the exploration of sedimentary-lithium deposits in China. METHODS The cores of borehole ZK001 and borehole ZK601 in the Huangjinkou area in Eastern Sichuan Province were continuously sampled and 196 samples were taken. Those samples were used to study lithium enrichment characteristics and depositional environment. Element content of samples was determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). RESULTS Sedimentary-type lithium deposits were mainly distributed in North America, but a few were distributed in South America and Europe. The ore was mainly composed of clay minerals. The study of cores from Huangjinkou area revealed that lithium was mainly enriched in the anhydrite of the Jialingjiang Formation and the carbonate rocks of the Leikoupo Formation, with a maximum content of 103.25μg/g. CONCLUSIONS The enrichment of lithium in the two strata may be due to the dual effects of depositional environment changes and provenance changes, but the specific provenance and occurrence of lithium were still unclear and need further investigation. The discovery of high-lithium strata provide important clues for the exploration of sedimentary-type lithium deposits in the Sichuan Basin, and provide scientific basis for further study on the source, migration, enrichment and occurrence of lithium.

Objective To provide reference for further perfection and revision of standards relevant to limb injury by comparing the evaluation results of different disability standards of long bone fracture. Methods Thirty cases were selected from the long bone fracture cases accepted by our institution in 2018. These cases include 5 cases of shoulder, elbow, wrist, hip, knee, ankle joints, respectively, to investigate the degree of loss of function of joints after long bone fracture. Disability evaluation was made according to Classification of the Impairment Related To Injury （hereinafter referred to as Classification）, Assessment for Body Impairment of the injured in road traffic accidents （now repealed, hereinafter referred to as original Road Standard） and Identifying Work Ability-Gradation of Disability Caused by Work-related Injuries and Occupational Diseases （hereinafter referred to as Work Standard）. The disability evaluation results of every domestic standard were compared with the joint damage rate of Guides to the Evaluation of Permanent Impairment （hereinafter referred to as GEPI）. Results The functional loss rate of joints （except ankle） was 26%-48%，and the ankle functional loss rate was 51%-64%. The mean value of GEPI joint impairment rate of the joints was 13%-22%, with the fluctuation range less than 10%. The rate of level 10 disability was 100% according to the Classification. The rate of level 10 disability was 27%, the rate of level 9 disability was 6% and 67% were not disabled according to the original Road Standard. The rate of level 10 disability was 10% according to the Work Standard and 90% had a disability above level 10 （47% were classified as level 7 disability）. Conclusion The people with limb joint dysfunction in this study had evaluation results with a smaller fluctuation range and better consistency according to the Classification and GEPI. The evaluation results according to the original Road Standard and the Work Standard has a less consistency. The Classification is more similar to GEPI and is more reasonable.

Trisomy 13 (Patau syndrome) is the third most common autosomal trisomy with a prevalence between 1 in 10,000 - 20,000 live births. Robertsonian translocations represent the largest number of chromosomal aberrations in human population with an incidence of 1.23 in 1000 live birth and translocation 13;14 is one of the most frequent Robertsonian translocations (approximately 75%). We sampled umbilical vein blood from a 27-yr-old woman whose ultrasonography findings revealed congenital heart defects, single ventricle, polycystic kidney, median cleft lip and palate and holoprosencephaly at gestational age of 23+6 weeks for karyotype and sequencing during intra-amniotic cavity injection of acrinol for labor induction. Next-generation sequencing indicated 47,XN,+13 and karyotype was identified as 46,XN,+13,rob (13;14). An unexpected problem becomes more and more obvious in human cytogenetics – it seems to become difficult to decide how and when to use the “molecular cytogenetics” or “traditional karyotype analysis”. Molecular cytogenetics, such as next-generation sequencing and array-based comparative genomic hybridization (array-CGH), can detect microdeletions and micro-duplications, but it cannot detect balanced translocations. For this case, we cannot find balanced translocations by Molecular cytogenetics. The purpose of this case is that molecular cytogenetics cannot replace the traditional karyotype analysis, but can serve as a useful complement for G-banding to be used in the clinical cytogenetic diagnosis.

Because coal and rock in tunnelling roadway has phenomenon of sharp hardness change, so it's difficult to change swing speed of cutting arm of roadheader timely and effectively by manual control, then it will affect life of cutting head pick and cutting motor seriously. To solve the problem, the paper proposed an automatic control method of swing speed of cutting arm based on PID by analyzing relationship between swing speed v of cutting arm, cutting motor current I and hardness of coal and rock f, namely takes the difference of cutting motor rated current I0 and actual current I as input variable to control current I1 controlling valve port opening of electron-hydraulic proportional valve through linear combination of proportion unit, integration unit and differentiation unit, so as to control swing speed of cutting arm. The paper also proposed 5% control precision standard according to coal industry standard MT/T971-2005. The control method achieves aims of replacing artificial manipulation, protecting cutting head pick and cutting motor and makes cutting motor always work with full-load and constant power. Key words:

The paper analyzed function requirements of electrical control system of roadheader, put forward a design scheme of a novel electrical control system for boom-type roadheader which takes Power Panel and PCC as controllers, and introduced software and hardware designs of the novel control system and its implementation method in details. The novel electrical control system takes PCC as lower computer and Power Panel as upper computer, and has functions of automatic forming of mine laneway section, constant power auto-traction and speed regulation of cutting arm, auto-detection of body position, directional excavation and full-function remote control, which realizes computer control of laneway automatic cutting and directional excavation system and lays a foundation for automatization and intellgence of boom-type roadheader. The actual running result showed that the system has perfect control effect.